Renamed libs

Cleaner and more flexible.

14 files changed, 0 insertions, 9378 deletions

diff --git a/libgui/Makefile b/libgui/Makefile
deleted file mode 100644
index 166a3c0..0000000
--- a/libgui/Makefile
+++ /dev/null
@@ -1,25 +0,0 @@
-# MIT License, Copyright (c) 2020 Marvin Borner
-
-COBJS = psf.o \
-	bmp.o \
-	png.o \
-	gfx.o \
-	gui.o \
-	msg.o
-CC = ccache ../cross/opt/bin/i686-elf-gcc
-LD = ccache ../cross/opt/bin/i686-elf-ld
-AR = ccache ../cross/opt/bin/i686-elf-ar
-
-CFLAGS = $(CFLAGS_DEFAULT) -Iinc/ -I../libc/inc/ -fPIE -Duserspace
-
-all: libgui
-
-%.o: %.c
-	@$(CC) -c $(CFLAGS) $< -o $@
-
-libgui: $(COBJS)
-	@mkdir -p ../build/
-	@$(AR) rcs ../build/libgui.a $+
-
-clean:
-	@find . -name "*.o" -type f -delete
diff --git a/libgui/bmp.c b/libgui/bmp.c
deleted file mode 100644
index c8795e8..0000000
--- a/libgui/bmp.c
+++ /dev/null
@@ -1,29 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-
-#include <bmp.h>
-#include <def.h>
-#include <mem.h>
-#include <print.h>
-#include <sys.h>
-
-struct bmp *bmp_load(const char *path)
-{
-	void *buf = sread(path);
-	if (!buf)
-		return NULL;
-
-	struct bmp_header *h = buf;
-	if (h->signature[0] != 'B' || h->signature[1] != 'M')
-		return NULL;
-
-	// TODO: Support padding with odd widths
-	struct bmp_info *info = (struct bmp_info *)((u32)buf + sizeof(*h));
-	struct bmp *bmp = malloc(sizeof(*bmp));
-	bmp->size.x = info->width;
-	bmp->size.y = info->height;
-	bmp->data = (u8 *)((u32)buf + h->offset);
-	bmp->bpp = info->bpp;
-	bmp->pitch = bmp->size.x * (bmp->bpp >> 3);
-
-	return bmp;
-}
diff --git a/libgui/gfx.c b/libgui/gfx.c
deleted file mode 100644
index ff5bf69..0000000
--- a/libgui/gfx.c
+++ /dev/null
@@ -1,267 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-// Some GFX functions
-// TODO: Better support for bpp < 32
-// TODO: Use efficient redrawing
-
-#include <assert.h>
-#include <bmp.h>
-#include <gfx.h>
-#include <mem.h>
-#include <msg.h>
-#include <png.h>
-#include <psf.h>
-#include <str.h>
-#include <sys.h>
-#include <vesa.h>
-
-// TODO: Move to some global config file
-#define FONT_COUNT 6
-#define FONT_8_PATH "/font/spleen-5x8.psfu"
-#define FONT_12_PATH "/font/spleen-6x12.psfu"
-#define FONT_16_PATH "/font/spleen-8x16.psfu"
-#define FONT_24_PATH "/font/spleen-12x24.psfu"
-#define FONT_32_PATH "/font/spleen-16x32.psfu"
-#define FONT_64_PATH "/font/spleen-32x64.psfu"
-
-struct font *fonts[FONT_COUNT] = { 0 };
-
-static void load_font(enum font_type font_type)
-{
-	if (fonts[font_type])
-		return;
-
-	const char *path = NULL;
-
-	switch (font_type) {
-	case FONT_8:
-		path = FONT_8_PATH;
-		break;
-	case FONT_12:
-		path = FONT_12_PATH;
-		break;
-	case FONT_16:
-		path = FONT_16_PATH;
-		break;
-	case FONT_24:
-		path = FONT_24_PATH;
-		break;
-	case FONT_32:
-		path = FONT_32_PATH;
-		break;
-	case FONT_64:
-		path = FONT_64_PATH;
-		break;
-	default:
-		return;
-	}
-
-	fonts[font_type] = psf_parse(sread(path));
-	assert(fonts[font_type]);
-}
-
-static void write_char(struct context *ctx, vec2 pos, struct font *font, u32 c, char ch)
-{
-	int bypp = ctx->bpp >> 3;
-
-	char *draw = (char *)&ctx->fb[pos.x * bypp + pos.y * ctx->pitch];
-
-	u32 stride = font->char_size / font->size.y;
-	for (u32 cy = 0; cy < font->size.y; cy++) {
-		for (u32 cx = 0; cx < font->size.x; cx++) {
-			u8 bits = font->chars[ch * font->char_size + cy * stride + cx / 8];
-			u8 bit = bits >> (7 - cx % 8) & 1;
-			if (bit) {
-				draw[bypp * cx] = GET_BLUE(c);
-				draw[bypp * cx + 1] = GET_GREEN(c);
-				draw[bypp * cx + 2] = GET_RED(c);
-				draw[bypp * cx + 3] = GET_ALPHA(c);
-			}
-		}
-		draw += ctx->pitch;
-	}
-}
-
-static void draw_rectangle(struct context *ctx, vec2 pos1, vec2 pos2, u32 c)
-{
-	int bypp = ctx->bpp >> 3;
-	u8 *draw = &ctx->fb[pos1.x * bypp + pos1.y * ctx->pitch];
-	for (u32 i = 0; i < pos2.y - pos1.y; i++) {
-		for (u32 j = 0; j < pos2.x - pos1.x; j++) {
-			draw[bypp * j] = GET_BLUE(c);
-			draw[bypp * j + 1] = GET_GREEN(c);
-			draw[bypp * j + 2] = GET_RED(c);
-			draw[bypp * j + 3] = GET_ALPHA(c);
-		}
-		draw += ctx->pitch;
-	}
-}
-
-struct context *gfx_new_ctx(struct context *ctx)
-{
-	/* struct message msg = { 0 }; */
-	assert(0);
-	/* assert(msg_send(pidof(WM_PATH), GFX_NEW_CONTEXT, ctx) > 0); */
-	/* assert(msg_receive(&msg) > 0); */
-	/* memcpy(ctx, msg.data, sizeof(*ctx)); */
-	return ctx;
-}
-
-// On-demand font loading
-struct font *gfx_resolve_font(enum font_type font_type)
-{
-	if (!fonts[font_type])
-		load_font(font_type);
-	return fonts[font_type];
-}
-
-void gfx_write_char(struct context *ctx, vec2 pos, enum font_type font_type, u32 c, char ch)
-{
-	struct font *font = gfx_resolve_font(font_type);
-	write_char(ctx, pos, font, c, ch);
-}
-
-void gfx_write(struct context *ctx, vec2 pos, enum font_type font_type, u32 c, const char *text)
-{
-	struct font *font = gfx_resolve_font(font_type);
-	u32 cnt = 0;
-	for (u32 i = 0; i < strlen(text); i++) {
-		// TODO: Should this be here?
-		if (text[i] == '\r') {
-			cnt = 0;
-		} else if (text[i] == '\n') {
-			cnt = 0;
-			pos.y += font->size.y;
-		} else if (text[i] == '\t') {
-			cnt += 4;
-		} else {
-			// TODO: Overflow on single line input
-			if ((cnt + 1) * font->size.x > ctx->size.x) {
-				cnt = 0;
-				pos.y += font->size.y;
-			}
-			write_char(ctx, vec2(pos.x + cnt * font->size.x, pos.y), font, c, text[i]);
-			cnt++;
-		}
-	}
-}
-
-void gfx_load_image(struct context *ctx, vec2 pos, const char *path)
-{
-	// TODO: Support x, y
-	// TODO: Detect image type
-	struct bmp bmp = { 0 };
-
-	u32 error = png_decode32_file(&bmp.data, &bmp.size.x, &bmp.size.y, path);
-	if (error)
-		err(1, "error %u: %s\n", error, png_error_text(error));
-
-	assert(bmp.size.x + pos.x <= ctx->size.x);
-	assert(bmp.size.y + pos.y <= ctx->size.y);
-
-	bmp.bpp = 32;
-	bmp.pitch = bmp.size.x * (bmp.bpp >> 3);
-
-	// TODO: Fix reversed png in decoder
-	int bypp = bmp.bpp >> 3;
-	// u8 *srcfb = &bmp->data[bypp + (bmp->size.y - 1) * bmp->pitch];
-	u8 *srcfb = bmp.data;
-	u8 *destfb = &ctx->fb[bypp];
-	for (u32 cy = 0; cy < bmp.size.y; cy++) {
-		memcpy(destfb, srcfb, bmp.pitch);
-		// srcfb -= bmp->pitch;
-		srcfb += bmp.pitch;
-		destfb += ctx->pitch;
-	}
-}
-
-void gfx_load_wallpaper(struct context *ctx, const char *path)
-{
-	gfx_load_image(ctx, vec2(0, 0), path);
-}
-
-void gfx_copy(struct context *dest, struct context *src, vec2 pos, vec2 size)
-{
-	int bypp = dest->bpp >> 3;
-	u8 *srcfb = &src->fb[pos.x * bypp + pos.y * src->pitch];
-	u8 *destfb = &dest->fb[pos.x * bypp + pos.y * dest->pitch];
-	for (u32 cy = 0; cy < size.y; cy++) {
-		memcpy(destfb, srcfb, size.x * bypp);
-		srcfb += src->pitch;
-		destfb += dest->pitch;
-	}
-}
-
-// TODO: Support alpha values other than 0x0 and 0xff (blending)
-// TODO: Optimize!
-void gfx_ctx_on_ctx(struct context *dest, struct context *src, vec2 pos)
-{
-	if (src->size.x == dest->size.x && src->size.y == dest->size.y) {
-		memcpy(dest->fb, src->fb, dest->pitch * dest->size.y);
-		return;
-	}
-
-	if (src->size.x > dest->size.x || src->size.y > dest->size.y)
-		return;
-
-	// TODO: Negative x and y
-	int bypp = dest->bpp >> 3;
-	u8 *srcfb = src->fb;
-	u8 *destfb = &dest->fb[pos.x * bypp + pos.y * dest->pitch];
-	for (u32 cy = 0; cy < src->size.y && cy + pos.y < dest->size.y; cy++) {
-		int diff = 0;
-		for (u32 cx = 0; cx < src->size.x && cx + pos.x < dest->size.x; cx++) {
-			if (srcfb[bypp - 1])
-				memcpy(destfb, srcfb, bypp);
-
-			srcfb += bypp;
-			destfb += bypp;
-			diff += bypp;
-		}
-		srcfb += src->pitch - diff;
-		destfb += dest->pitch - diff;
-	}
-}
-
-void gfx_draw_rectangle(struct context *ctx, vec2 pos1, vec2 pos2, u32 c)
-{
-	draw_rectangle(ctx, pos1, pos2, c);
-}
-
-void gfx_fill(struct context *ctx, u32 c)
-{
-	draw_rectangle(ctx, vec2(0, 0), vec2(ctx->size.x, ctx->size.y), c);
-}
-
-void gfx_border(struct context *ctx, u32 c, u32 width)
-{
-	if (width <= 0)
-		return;
-
-	int bypp = ctx->bpp >> 3;
-	u8 *draw = ctx->fb;
-	for (u32 i = 0; i < ctx->size.y; i++) {
-		for (u32 j = 0; j < ctx->size.x; j++) {
-			if (j <= width - 1 || i <= width - 1 ||
-			    j - ctx->size.x + width + 1 <= width ||
-			    i - ctx->size.y + width <= width) {
-				draw[bypp * j + 0] = GET_BLUE(c);
-				draw[bypp * j + 1] = GET_GREEN(c);
-				draw[bypp * j + 2] = GET_RED(c);
-				draw[bypp * j + 3] = GET_ALPHA(c);
-			}
-		}
-		draw += ctx->pitch;
-	}
-}
-
-int gfx_font_height(enum font_type font_type)
-{
-	struct font *font = gfx_resolve_font(font_type);
-	return font->size.y;
-}
-
-int gfx_font_width(enum font_type font_type)
-{
-	struct font *font = gfx_resolve_font(font_type);
-	return font->size.x;
-}
diff --git a/libgui/gui.c b/libgui/gui.c
deleted file mode 100644
index 87ea4c9..0000000
--- a/libgui/gui.c
+++ /dev/null
@@ -1,153 +0,0 @@
-// MIT License, Copyright (c) 2021 Marvin Borner
-
-#include <assert.h>
-#include <def.h>
-#include <errno.h>
-#include <gui.h>
-#include <list.h>
-#include <msg.h>
-#include <print.h>
-
-#define WM_PATH "/bin/wm"
-
-struct gui_window {
-	u32 id;
-	struct context ctx;
-};
-
-struct list *windows = NULL;
-
-static struct gui_window *win_by_id(u32 id)
-{
-	assert(windows);
-	struct node *iterator = windows->head;
-	while (iterator) {
-		struct gui_window *win = iterator->data;
-		if (win->id == id)
-			return iterator->data;
-		iterator = iterator->next;
-	}
-	return NULL;
-}
-
-/**
- * GFX wrappers
- */
-
-static res fill(u32 id, u32 c)
-{
-	struct gui_window *win = win_by_id(id);
-	if (!win)
-		return -ENOENT;
-	gfx_fill(&win->ctx, c);
-	return EOK;
-}
-
-/**
- * Program interface
- */
-
-res gui_new_window(void)
-{
-	if (!windows)
-		windows = list_new();
-
-	struct gui_window *win = zalloc(sizeof(*win));
-
-	struct message_new_window msg = { .header.state = MSG_NEED_ANSWER };
-	if (msg_send(pidof(WM_PATH), GUI_NEW_WINDOW, &msg, sizeof(msg)) > 0 &&
-	    msg_receive(&msg, sizeof(msg)) > 0 &&
-	    msg.header.type == (GUI_NEW_WINDOW | MSG_SUCCESS)) {
-		win->id = msg.id;
-		win->ctx = msg.ctx;
-		u32 size;
-		res ret = shaccess(msg.shid, (u32 *)&win->ctx.fb, &size);
-		if (ret < 0 || !win->ctx.fb)
-			return MIN(ret, -EFAULT);
-		list_add(windows, win);
-		assert(fill(win->id, COLOR_BLACK) == EOK);
-		gui_redraw_window(win->id);
-		return win->id;
-	}
-	return -EINVAL;
-}
-
-res gui_redraw_window(u32 id)
-{
-	struct message_redraw_window msg = { .id = id, .header.state = MSG_NEED_ANSWER };
-	if (msg_send(pidof(WM_PATH), GUI_REDRAW_WINDOW, &msg, sizeof(msg)) > 0 &&
-	    msg_receive(&msg, sizeof(msg)) > 0 &&
-	    msg.header.type == (GUI_REDRAW_WINDOW | MSG_SUCCESS))
-		return id;
-	return -EINVAL;
-}
-
-/**
- * Message handling
- */
-
-static res handle_error(const char *op, res code)
-{
-	log("GUI error at '%s': %s (%d)\n", op, strerror(code), code);
-	return code;
-}
-
-static res handle_ping(struct message_ping *msg)
-{
-	if (msg->ping != MSG_PING_SEND)
-		return handle_error("ping", EINVAL);
-
-	msg->header.type |= MSG_SUCCESS;
-	msg->ping = MSG_PING_RECV;
-	msg_send(msg->header.src, GUI_PING, &msg, sizeof(msg));
-
-	return errno;
-}
-
-static res handle_mouse(struct message_mouse *msg)
-{
-	if (msg->header.state == MSG_NEED_ANSWER)
-		msg_send(msg->header.src, msg->header.type | MSG_SUCCESS, msg, sizeof(*msg));
-
-	return errno;
-}
-
-static void handle_exit(void)
-{
-	if (!windows)
-		return;
-
-	struct node *iterator = windows->head;
-	while (iterator) {
-		struct gui_window *win = iterator->data;
-		struct message_destroy_window msg = { .id = win->id };
-		msg_send(pidof(WM_PATH), GUI_DESTROY_WINDOW, &msg, sizeof(msg));
-		iterator = iterator->next;
-	}
-
-	list_destroy(windows);
-}
-
-/**
- * Main loop
- */
-
-void gui_loop(void)
-{
-	atexit(handle_exit);
-
-	void *msg = zalloc(4096);
-	while (msg_receive(msg, 4096)) {
-		struct message_header *head = msg;
-		switch (head->type) {
-		case GUI_PING:
-			handle_ping(msg);
-			break;
-		case GUI_MOUSE:
-			handle_mouse(msg);
-			break;
-		default:
-			handle_error("loop", EINVAL);
-		}
-	}
-}
diff --git a/libgui/inc/bmp.h b/libgui/inc/bmp.h
deleted file mode 100644
index ff8360b..0000000
--- a/libgui/inc/bmp.h
+++ /dev/null
@@ -1,39 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-
-#ifndef BMP_H
-#define BMP_H
-
-#include <def.h>
-#include <vec.h>
-
-struct bmp_header {
-	u8 signature[2];
-	u32 size;
-	u32 reserved;
-	u32 offset;
-} __attribute__((packed));
-
-struct bmp_info {
-	u32 size;
-	u32 width;
-	u32 height;
-	u16 planes;
-	u16 bpp;
-	u32 compression;
-	u32 compressed_size;
-	u32 x_pixel_meter;
-	u32 y_pixel_meter;
-	u32 colors;
-	u32 important_colors;
-};
-
-struct bmp {
-	vec2 size;
-	u8 *data;
-	u32 bpp;
-	u32 pitch;
-};
-
-struct bmp *bmp_load(const char *path);
-
-#endif
diff --git a/libgui/inc/gfx.h b/libgui/inc/gfx.h
deleted file mode 100644
index f3555a4..0000000
--- a/libgui/inc/gfx.h
+++ /dev/null
@@ -1,88 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-// Some GFX functions
-
-#ifndef GFX_H
-#define GFX_H
-
-#include <def.h>
-#include <sys.h>
-#include <vec.h>
-#include <vesa.h>
-
-#define WM_PATH "/bin/wm"
-
-#define GET_ALPHA(color) ((color >> 24) & 0x000000FF)
-#define GET_RED(color) ((color >> 16) & 0x000000FF)
-#define GET_GREEN(color) ((color >> 8) & 0x000000FF)
-#define GET_BLUE(color) ((color >> 0) & 0X000000FF)
-
-#define COLOR_TRANSPARENT 0x00000000
-#define COLOR_INVISIBLE 0x00000000
-#define COLOR_BLACK 0xff0f0f0f
-#define COLOR_RED 0xfff07f7f
-#define COLOR_GREEN 0xff7ff088
-#define COLOR_YELLOW 0xffeef07f
-#define COLOR_BLUE 0xff7facf0
-#define COLOR_MAGENTA 0xffd67ff0
-#define COLOR_CYAN 0xff7fe7f0
-#define COLOR_WHITE 0xffe9e9e9
-#define COLOR_BRIGHT_BLACK 0xff928374
-#define COLOR_BRIGHT_RED 0xffed9a9a
-#define COLOR_BRIGHT_GREEN 0xff9ef0a5
-#define COLOR_BRIGHT_YELLOW 0xffe7e897
-#define COLOR_BRIGHT_BLUE 0xff98b9eb
-#define COLOR_BRIGHT_MAGENTA 0xffd196e3
-#define COLOR_BRIGHT_CYAN 0xff94dae0
-#define COLOR_BRIGHT_WHITE 0xffe3e3e3
-#define COLOR_FG COLOR_WHITE
-#define COLOR_BG COLOR_BLACK
-
-#define WF_DEFAULT (0 << 0)
-#define WF_NO_FOCUS (1 << 0)
-#define WF_NO_DRAG (1 << 1)
-#define WF_NO_RESIZE (1 << 2)
-#define WF_NO_FB (1 << 3)
-#define WF_NO_WINDOW (1 << 4)
-/* #define WF_RELATIVE (1 << 4) */
-
-enum font_type { FONT_8, FONT_12, FONT_16, FONT_24, FONT_32, FONT_64 };
-
-// Generalized font struct
-struct font {
-	char *chars;
-	vec2 size;
-	int char_size;
-};
-
-struct context {
-	vec2 size;
-	u8 *fb;
-	u32 bpp;
-	u32 pitch;
-	u32 bytes;
-};
-
-struct context *gfx_new_ctx(struct context *ctx);
-struct font *gfx_resolve_font(enum font_type font_type);
-void gfx_write_char(struct context *ctx, vec2 pos, enum font_type font_type, u32 c, char ch);
-void gfx_write(struct context *ctx, vec2 pos, enum font_type font_type, u32 c, const char *text);
-void gfx_load_image(struct context *ctx, vec2 pos, const char *path);
-void gfx_load_wallpaper(struct context *ctx, const char *path);
-void gfx_copy(struct context *dest, struct context *src, vec2 pos, vec2 size);
-void gfx_ctx_on_ctx(struct context *dest, struct context *src, vec2 pos);
-void gfx_draw_rectangle(struct context *ctx, vec2 pos1, vec2 pos2, u32 c);
-void gfx_fill(struct context *ctx, u32 c);
-void gfx_border(struct context *ctx, u32 c, u32 width);
-
-int gfx_font_height(enum font_type);
-int gfx_font_width(enum font_type);
-
-/**
- * Wrappers
- */
-
-/* #define gfx_redraw()                                                                               \ */
-/* 	(msg_send(pidof(WM_PATH), GFX_REDRAW, NULL)) // TODO: Partial redraw (optimization) */
-/* #define gfx_redraw_focused() (msg_send(pidof(WM_PATH), GFX_REDRAW_FOCUSED, NULL)) */
-
-#endif
diff --git a/libgui/inc/gui.h b/libgui/inc/gui.h
deleted file mode 100644
index a3f74f8..0000000
--- a/libgui/inc/gui.h
+++ /dev/null
@@ -1,13 +0,0 @@
-// MIT License, Copyright (c) 2021 Marvin Borner
-
-#ifndef GUI_H
-#define GUI_H
-
-#include <def.h>
-#include <errno.h>
-
-res gui_new_window(void);
-res gui_redraw_window(u32 id);
-void gui_loop(void);
-
-#endif
diff --git a/libgui/inc/msg.h b/libgui/inc/msg.h
deleted file mode 100644
index 0e85d5a..0000000
--- a/libgui/inc/msg.h
+++ /dev/null
@@ -1,71 +0,0 @@
-// MIT License, Copyright (c) 2021 Marvin Borner
-
-#ifndef MSG_H
-#define MSG_H
-
-#include <def.h>
-#include <gfx.h>
-
-#define MSG_PING_SEND 0x07734
-#define MSG_PING_RECV 0x7474
-
-#define MSG_MAGIC 0x42042069
-#define MSG_SUCCESS (1 << 29)
-#define MSG_FAILURE (1 << 30)
-
-enum message_state {
-	MSG_GO_ON,
-	MSG_NEED_ANSWER,
-};
-
-struct message_header {
-	u32 magic;
-	u32 src;
-	u32 type;
-	enum message_state state;
-};
-
-struct message_ping {
-	struct message_header header;
-	u32 ping;
-};
-
-struct message_new_window {
-	struct message_header header;
-	u32 id;
-	u32 shid;
-	struct context ctx;
-};
-
-struct message_redraw_window {
-	struct message_header header;
-	u32 id;
-};
-
-struct message_destroy_window {
-	struct message_header header;
-	u32 id;
-};
-
-struct message_mouse {
-	struct message_header header;
-	vec2 pos;
-	struct {
-		u8 click : 1;
-	} bits;
-};
-
-enum message_type {
-	GUI_PING,
-	GUI_NEW_WINDOW,
-	GUI_REDRAW_WINDOW,
-	GUI_DESTROY_WINDOW,
-
-	GUI_MOUSE,
-	GUI_KEYBOARD,
-};
-
-res msg_send(u32 pid, enum message_type type, void *data, u32 size);
-res msg_receive(void *buf, u32 size);
-
-#endif
diff --git a/libgui/inc/png.h b/libgui/inc/png.h
deleted file mode 100644
index dba0947..0000000
--- a/libgui/inc/png.h
+++ /dev/null
@@ -1,1036 +0,0 @@
-/*
-LodePNG version 20201017
-
-Copyright (c) 2005-2020 Lode Vandevenne
-Copyright (c) 2021 Marvin Borner
-
-This software is provided 'as-is', without any express or implied
-warranty. In no event will the authors be held liable for any damages
-arising from the use of this software.
-
-Permission is granted to anyone to use this software for any purpose,
-including commercial applications, and to alter it and redistribute it
-freely, subject to the following restrictions:
-
-    1. The origin of this software must not be misrepresented; you must not
-    claim that you wrote the original software. If you use this software
-    in a product, an acknowledgment in the product documentation would be
-    appreciated but is not required.
-
-    2. Altered source versions must be plainly marked as such, and must not be
-    misrepresented as being the original software.
-
-    3. This notice may not be removed or altered from any source
-    distribution.
-*/
-
-#ifndef PNG_H
-#define PNG_H
-
-/* For now! TODO: Use PNG encoding */
-#define PNG_NO_COMPILE_ENCODER
-
-#include <def.h>
-extern const char *PNG_VERSION_STRING;
-
-/*
-The following #defines are used to create code sections. They can be disabled
-to disable code sections, which can give faster compile time and smaller binary.
-The "NO_COMPILE" defines are designed to be used to pass as defines to the
-compiler command to disable them without modifying this header, e.g.
--DPNG_NO_COMPILE_ZLIB for gcc.
-In addition to those below, you can also define PNG_NO_COMPILE_CRC to
-allow implementing a custom png_crc32.
-*/
-/*deflate & zlib. If disabled, you must specify alternative zlib functions in
-the custom_zlib field of the compress and decompress settings*/
-#ifndef PNG_NO_COMPILE_ZLIB
-#define PNG_COMPILE_ZLIB
-#endif
-
-/*png encoder and png decoder*/
-#ifndef PNG_NO_COMPILE_PNG
-#define PNG_COMPILE_PNG
-#endif
-
-/*deflate&zlib decoder and png decoder*/
-#ifndef PNG_NO_COMPILE_DECODER
-#define PNG_COMPILE_DECODER
-#endif
-
-/*deflate&zlib encoder and png encoder*/
-#ifndef PNG_NO_COMPILE_ENCODER
-#define PNG_COMPILE_ENCODER
-#endif
-
-/*the optional built in harddisk file loading and saving functions*/
-#ifndef PNG_NO_COMPILE_DISK
-#define PNG_COMPILE_DISK
-#endif
-
-/*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/
-#ifndef PNG_NO_COMPILE_ANCILLARY_CHUNKS
-#define PNG_COMPILE_ANCILLARY_CHUNKS
-#endif
-
-/*ability to convert error numerical codes to English text string*/
-#ifndef PNG_NO_COMPILE_ERROR_TEXT
-#define PNG_COMPILE_ERROR_TEXT
-#endif
-
-/*Compile the default allocators (C's free, malloc and realloc). If you disable this,
-you can define the functions png_free, png_malloc and png_realloc in your
-source files with custom allocators.*/
-#ifndef PNG_NO_COMPILE_ALLOCATORS
-#define PNG_COMPILE_ALLOCATORS
-#endif
-
-/*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/
-#ifdef __cplusplus
-#ifndef PNG_NO_COMPILE_CPP
-#define PNG_COMPILE_CPP
-#endif
-#endif
-
-#ifdef PNG_COMPILE_CPP
-#include <string>
-#include <vector>
-#endif /*PNG_COMPILE_CPP*/
-
-#ifdef PNG_COMPILE_PNG
-/*The PNG color types (also used for raw image).*/
-typedef enum pngColorType {
-	LCT_GREY = 0, /*grayscale: 1,2,4,8,16 bit*/
-	LCT_RGB = 2, /*RGB: 8,16 bit*/
-	LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/
-	LCT_GREY_ALPHA = 4, /*grayscale with alpha: 8,16 bit*/
-	LCT_RGBA = 6, /*RGB with alpha: 8,16 bit*/
-	/*LCT_MAX_OCTET_VALUE lets the compiler allow this enum to represent any invalid
-  byte value from 0 to 255 that could be present in an invalid PNG file header. Do
-  not use, compare with or set the name LCT_MAX_OCTET_VALUE, instead either use
-  the valid color type names above, or numeric values like 1 or 7 when checking for
-  particular disallowed color type byte values, or cast to integer to print it.*/
-	LCT_MAX_OCTET_VALUE = 255
-} pngColorType;
-
-#ifdef PNG_COMPILE_DECODER
-/*
-Converts PNG data in memory to raw pixel data.
-out: Output parameter. Pointer to buffer that will contain the raw pixel data.
-     After decoding, its size is w * h * (bytes per pixel) bytes larger than
-     initially. Bytes per pixel depends on colortype and bitdepth.
-     Must be freed after usage with free(*out).
-     Note: for 16-bit per channel colors, uses big endian format like PNG does.
-w: Output parameter. Pointer to width of pixel data.
-h: Output parameter. Pointer to height of pixel data.
-in: Memory buffer with the PNG file.
-insize: size of the in buffer.
-colortype: the desired color type for the raw output image. See explanation on PNG color types.
-bitdepth: the desired bit depth for the raw output image. See explanation on PNG color types.
-Return value: png error code (0 means no error).
-*/
-u32 png_decode_memory(u8 **out, u32 *w, u32 *h, const u8 *in, u32 insize, pngColorType colortype,
-		      u32 bitdepth);
-
-/*Same as png_decode_memory, but always decodes to 32-bit RGBA raw image*/
-u32 png_decode32(u8 **out, u32 *w, u32 *h, const u8 *in, u32 insize);
-
-/*Same as png_decode_memory, but always decodes to 24-bit RGB raw image*/
-u32 png_decode24(u8 **out, u32 *w, u32 *h, const u8 *in, u32 insize);
-
-#ifdef PNG_COMPILE_DISK
-/*
-Load PNG from disk, from file with given name.
-Same as the other decode functions, but instead takes a filename as input.
-*/
-u32 png_decode_file(u8 **out, u32 *w, u32 *h, const char *filename, pngColorType colortype,
-		    u32 bitdepth);
-
-/*Same as png_decode_file, but always decodes to 32-bit RGBA raw image.*/
-u32 png_decode32_file(u8 **out, u32 *w, u32 *h, const char *filename);
-
-/*Same as png_decode_file, but always decodes to 24-bit RGB raw image.*/
-u32 png_decode24_file(u8 **out, u32 *w, u32 *h, const char *filename);
-#endif /*PNG_COMPILE_DISK*/
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_ENCODER
-/*
-Converts raw pixel data into a PNG image in memory. The colortype and bitdepth
-  of the output PNG image cannot be chosen, they are automatically determined
-  by the colortype, bitdepth and content of the input pixel data.
-  Note: for 16-bit per channel colors, needs big endian format like PNG does.
-out: Output parameter. Pointer to buffer that will contain the PNG image data.
-     Must be freed after usage with free(*out).
-outsize: Output parameter. Pointer to the size in bytes of the out buffer.
-image: The raw pixel data to encode. The size of this buffer should be
-       w * h * (bytes per pixel), bytes per pixel depends on colortype and bitdepth.
-w: width of the raw pixel data in pixels.
-h: height of the raw pixel data in pixels.
-colortype: the color type of the raw input image. See explanation on PNG color types.
-bitdepth: the bit depth of the raw input image. See explanation on PNG color types.
-Return value: png error code (0 means no error).
-*/
-u32 png_encode_memory(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h, pngColorType colortype,
-		      u32 bitdepth);
-
-/*Same as png_encode_memory, but always encodes from 32-bit RGBA raw image.*/
-u32 png_encode32(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h);
-
-/*Same as png_encode_memory, but always encodes from 24-bit RGB raw image.*/
-u32 png_encode24(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h);
-
-#ifdef PNG_COMPILE_DISK
-/*
-Converts raw pixel data into a PNG file on disk.
-Same as the other encode functions, but instead takes a filename as output.
-NOTE: This overwrites existing files without warning!
-*/
-u32 png_encode_file(const char *filename, const u8 *image, u32 w, u32 h, pngColorType colortype,
-		    u32 bitdepth);
-
-/*Same as png_encode_file, but always encodes from 32-bit RGBA raw image.*/
-u32 png_encode32_file(const char *filename, const u8 *image, u32 w, u32 h);
-
-/*Same as png_encode_file, but always encodes from 24-bit RGB raw image.*/
-u32 png_encode24_file(const char *filename, const u8 *image, u32 w, u32 h);
-#endif /*PNG_COMPILE_DISK*/
-#endif /*PNG_COMPILE_ENCODER*/
-
-#ifdef PNG_COMPILE_CPP
-namespace png
-{
-#ifdef PNG_COMPILE_DECODER
-/*Same as png_decode_memory, but decodes to an std::vector. The colortype
-is the format to output the pixels to. Default is RGBA 8-bit per channel.*/
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, const u8 *in, u32 insize,
-	   pngColorType colortype = LCT_RGBA, u32 bitdepth = 8);
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, const std::vector<u8> &in,
-	   pngColorType colortype = LCT_RGBA, u32 bitdepth = 8);
-#ifdef PNG_COMPILE_DISK
-/*
-Converts PNG file from disk to raw pixel data in memory.
-Same as the other decode functions, but instead takes a filename as input.
-*/
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, const std::string &filename,
-	   pngColorType colortype = LCT_RGBA, u32 bitdepth = 8);
-#endif /* PNG_COMPILE_DISK */
-#endif /* PNG_COMPILE_DECODER */
-
-#ifdef PNG_COMPILE_ENCODER
-/*Same as png_encode_memory, but encodes to an std::vector. colortype
-is that of the raw input data. The output PNG color type will be auto chosen.*/
-u32 encode(std::vector<u8> &out, const u8 *in, u32 w, u32 h, pngColorType colortype = LCT_RGBA,
-	   u32 bitdepth = 8);
-u32 encode(std::vector<u8> &out, const std::vector<u8> &in, u32 w, u32 h,
-	   pngColorType colortype = LCT_RGBA, u32 bitdepth = 8);
-#ifdef PNG_COMPILE_DISK
-/*
-Converts 32-bit RGBA raw pixel data into a PNG file on disk.
-Same as the other encode functions, but instead takes a filename as output.
-NOTE: This overwrites existing files without warning!
-*/
-u32 encode(const std::string &filename, const u8 *in, u32 w, u32 h,
-	   pngColorType colortype = LCT_RGBA, u32 bitdepth = 8);
-u32 encode(const std::string &filename, const std::vector<u8> &in, u32 w, u32 h,
-	   pngColorType colortype = LCT_RGBA, u32 bitdepth = 8);
-#endif /* PNG_COMPILE_DISK */
-#endif /* PNG_COMPILE_ENCODER */
-} /* namespace png */
-#endif /*PNG_COMPILE_CPP*/
-#endif /*PNG_COMPILE_PNG*/
-
-#ifdef PNG_COMPILE_ERROR_TEXT
-/*Returns an English description of the numerical error code.*/
-const char *png_error_text(u32 code);
-#endif /*PNG_COMPILE_ERROR_TEXT*/
-
-#ifdef PNG_COMPILE_DECODER
-/*Settings for zlib decompression*/
-typedef struct pngDecompressSettings pngDecompressSettings;
-struct pngDecompressSettings {
-	/* Check pngDecoderSettings for more ignorable errors such as ignore_crc */
-	u32 ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
-	u32 ignore_nlen; /*ignore complement of len checksum in uncompressed blocks*/
-
-	/*Maximum decompressed size, beyond this the decoder may (and is encouraged to) stop decoding,
-  return an error, output a data size > max_output_size and all the data up to that point. This is
-  not hard limit nor a guarantee, but can prevent excessive memory usage. This setting is
-  ignored by the PNG decoder, but is used by the deflate/zlib decoder and can be used by custom ones.
-  Set to 0 to impose no limit (the default).*/
-	u32 max_output_size;
-
-	/*use custom zlib decoder instead of built in one (default: null).
-  Should return 0 if success, any non-0 if error (numeric value not exposed).*/
-	u32 (*custom_zlib)(u8 **, u32 *, const u8 *, u32, const pngDecompressSettings *);
-	/*use custom deflate decoder instead of built in one (default: null)
-  if custom_zlib is not null, custom_inflate is ignored (the zlib format uses deflate).
-  Should return 0 if success, any non-0 if error (numeric value not exposed).*/
-	u32 (*custom_inflate)(u8 **, u32 *, const u8 *, u32, const pngDecompressSettings *);
-
-	const void *custom_context; /*optional custom settings for custom functions*/
-};
-
-extern const pngDecompressSettings png_default_decompress_settings;
-void png_decompress_settings_init(pngDecompressSettings *settings);
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_ENCODER
-/*
-Settings for zlib compression. Tweaking these settings tweaks the balance
-between speed and compression ratio.
-*/
-typedef struct pngCompressSettings pngCompressSettings;
-struct pngCompressSettings /*deflate = compress*/ {
-	/*LZ77 related settings*/
-	u32 btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/
-	u32 use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/
-	u32 windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Default value: 2048.*/
-	u32 minmatch; /*minimum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/
-	u32 nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/
-	u32 lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/
-
-	/*use custom zlib encoder instead of built in one (default: null)*/
-	u32 (*custom_zlib)(u8 **, u32 *, const u8 *, u32, const pngCompressSettings *);
-	/*use custom deflate encoder instead of built in one (default: null)
-  if custom_zlib is used, custom_deflate is ignored since only the built in
-  zlib function will call custom_deflate*/
-	u32 (*custom_deflate)(u8 **, u32 *, const u8 *, u32, const pngCompressSettings *);
-
-	const void *custom_context; /*optional custom settings for custom functions*/
-};
-
-extern const pngCompressSettings png_default_compress_settings;
-void png_compress_settings_init(pngCompressSettings *settings);
-#endif /*PNG_COMPILE_ENCODER*/
-
-#ifdef PNG_COMPILE_PNG
-/*
-Color mode of an image. Contains all information required to decode the pixel
-bits to RGBA colors. This information is the same as used in the PNG file
-format, and is used both for PNG and raw image data in png.
-*/
-typedef struct pngColorMode {
-	/*header (IHDR)*/
-	pngColorType
-		colortype; /*color type, see PNG standard or documentation further in this header file*/
-	u32 bitdepth; /*bits per sample, see PNG standard or documentation further in this header file*/
-
-	/*
-  palette (PLTE and tRNS)
-
-  Dynamically allocated with the colors of the palette, including alpha.
-  This field may not be allocated directly, use png_color_mode_init first,
-  then png_palette_add per color to correctly initialize it (to ensure size
-  of exactly 1024 bytes).
-
-  The alpha channels must be set as well, set them to 255 for opaque images.
-
-  When decoding, by default you can ignore this palette, since png already
-  fills the palette colors in the pixels of the raw RGBA output.
-
-  The palette is only supported for color type 3.
-  */
-	u8 *palette; /*palette in RGBARGBA... order. Must be either 0, or when allocated must have 1024 bytes*/
-	u32 palettesize; /*palette size in number of colors (amount of used bytes is 4 * palettesize)*/
-
-	/*
-  transparent color key (tRNS)
-
-  This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit.
-  For grayscale PNGs, r, g and b will all 3 be set to the same.
-
-  When decoding, by default you can ignore this information, since png sets
-  pixels with this key to transparent already in the raw RGBA output.
-
-  The color key is only supported for color types 0 and 2.
-  */
-	u32 key_defined; /*is a transparent color key given? 0 = false, 1 = true*/
-	u32 key_r; /*red/grayscale component of color key*/
-	u32 key_g; /*green component of color key*/
-	u32 key_b; /*blue component of color key*/
-} pngColorMode;
-
-/*init, cleanup and copy functions to use with this struct*/
-void png_color_mode_init(pngColorMode *info);
-void png_color_mode_cleanup(pngColorMode *info);
-/*return value is error code (0 means no error)*/
-u32 png_color_mode_copy(pngColorMode *dest, const pngColorMode *source);
-/* Makes a temporary pngColorMode that does not need cleanup (no palette) */
-pngColorMode png_color_mode_make(pngColorType colortype, u32 bitdepth);
-
-void png_palette_clear(pngColorMode *info);
-/*add 1 color to the palette*/
-u32 png_palette_add(pngColorMode *info, u8 r, u8 g, u8 b, u8 a);
-
-/*get the total amount of bits per pixel, based on colortype and bitdepth in the struct*/
-u32 png_get_bpp(const pngColorMode *info);
-/*get the amount of color channels used, based on colortype in the struct.
-If a palette is used, it counts as 1 channel.*/
-u32 png_get_channels(const pngColorMode *info);
-/*is it a grayscale type? (only colortype 0 or 4)*/
-u32 png_is_greyscale_type(const pngColorMode *info);
-/*has it got an alpha channel? (only colortype 2 or 6)*/
-u32 png_is_alpha_type(const pngColorMode *info);
-/*has it got a palette? (only colortype 3)*/
-u32 png_is_palette_type(const pngColorMode *info);
-/*only returns true if there is a palette and there is a value in the palette with alpha < 255.
-Loops through the palette to check this.*/
-u32 png_has_palette_alpha(const pngColorMode *info);
-/*
-Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image.
-Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels).
-Returns false if the image can only have opaque pixels.
-In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values,
-or if "key_defined" is true.
-*/
-u32 png_can_have_alpha(const pngColorMode *info);
-/*Returns the byte size of a raw image buffer with given width, height and color mode*/
-u32 png_get_raw_size(u32 w, u32 h, const pngColorMode *color);
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-/*The information of a Time chunk in PNG.*/
-typedef struct pngTime {
-	u32 year; /*2 bytes used (0-65535)*/
-	u32 month; /*1-12*/
-	u32 day; /*1-31*/
-	u32 hour; /*0-23*/
-	u32 minute; /*0-59*/
-	u32 second; /*0-60 (to allow for leap seconds)*/
-} pngTime;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-/*Information about the PNG image, except pixels, width and height.*/
-typedef struct pngInfo {
-	/*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/
-	u32 compression_method; /*compression method of the original file. Always 0.*/
-	u32 filter_method; /*filter method of the original file*/
-	u32 interlace_method; /*interlace method of the original file: 0=none, 1=Adam7*/
-	pngColorMode color; /*color type and bits, palette and transparency of the PNG file*/
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	/*
-  Suggested background color chunk (bKGD)
-
-  This uses the same color mode and bit depth as the PNG (except no alpha channel),
-  with values truncated to the bit depth in the u32 integer.
-
-  For grayscale and palette PNGs, the value is stored in background_r. The values
-  in background_g and background_b are then unused.
-
-  So when decoding, you may get these in a different color mode than the one you requested
-  for the raw pixels.
-
-  When encoding with auto_convert, you must use the color model defined in info_png.color for
-  these values. The encoder normally ignores info_png.color when auto_convert is on, but will
-  use it to interpret these values (and convert copies of them to its chosen color model).
-
-  When encoding, avoid setting this to an expensive color, such as a non-gray value
-  when the image is gray, or the compression will be worse since it will be forced to
-  write the PNG with a more expensive color mode (when auto_convert is on).
-
-  The decoder does not use this background color to edit the color of pixels. This is a
-  completely optional metadata feature.
-  */
-	u32 background_defined; /*is a suggested background color given?*/
-	u32 background_r; /*red/gray/palette component of suggested background color*/
-	u32 background_g; /*green component of suggested background color*/
-	u32 background_b; /*blue component of suggested background color*/
-
-	/*
-  Non-international text chunks (tEXt and zTXt)
-
-  The char** arrays each contain num strings. The actual messages are in
-  text_strings, while text_keys are keywords that give a short description what
-  the actual text represents, e.g. Title, Author, Description, or anything else.
-
-  All the string fields below including strings, keys, names and language tags are null terminated.
-  The PNG specification uses null characters for the keys, names and tags, and forbids null
-  characters to appear in the main text which is why we can use null termination everywhere here.
-
-  A keyword is minimum 1 character and maximum 79 characters long (plus the
-  additional null terminator). It's discouraged to use a single line length
-  longer than 79 characters for texts.
-
-  Don't allocate these text buffers yourself. Use the init/cleanup functions
-  correctly and use png_add_text and png_clear_text.
-
-  Standard text chunk keywords and strings are encoded using Latin-1.
-  */
-	u32 text_num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/
-	char **text_keys; /*the keyword of a text chunk (e.g. "Comment")*/
-	char **text_strings; /*the actual text*/
-
-	/*
-  International text chunks (iTXt)
-  Similar to the non-international text chunks, but with additional strings
-  "langtags" and "transkeys", and the following text encodings are used:
-  keys: Latin-1, langtags: ASCII, transkeys and strings: UTF-8.
-  keys must be 1-79 characters (plus the additional null terminator), the other
-  strings are any length.
-  */
-	u32 itext_num; /*the amount of international texts in this PNG*/
-	char **itext_keys; /*the English keyword of the text chunk (e.g. "Comment")*/
-	char **itext_langtags; /*language tag for this text's language, ISO/IEC 646 string, e.g. ISO 639 language tag*/
-	char **itext_transkeys; /*keyword translated to the international language - UTF-8 string*/
-	char **itext_strings; /*the actual international text - UTF-8 string*/
-
-	/*time chunk (tIME)*/
-	u32 time_defined; /*set to 1 to make the encoder generate a tIME chunk*/
-	pngTime time;
-
-	/*phys chunk (pHYs)*/
-	u32 phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/
-	u32 phys_x; /*pixels per unit in x direction*/
-	u32 phys_y; /*pixels per unit in y direction*/
-	u32 phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/
-
-	/*
-  Color profile related chunks: gAMA, cHRM, sRGB, iCPP
-
-  png does not apply any color conversions on pixels in the encoder or decoder and does not interpret these color
-  profile values. It merely passes on the information. If you wish to use color profiles and convert colors, please
-  use these values with a color management library.
-
-  See the PNG, ICC and sRGB specifications for more information about the meaning of these values.
-  */
-
-	/* gAMA chunk: optional, overridden by sRGB or iCCP if those are present. */
-	u32 gama_defined; /* Whether a gAMA chunk is present (0 = not present, 1 = present). */
-	u32 gama_gamma; /* Gamma exponent times 100000 */
-
-	/* cHRM chunk: optional, overridden by sRGB or iCCP if those are present. */
-	u32 chrm_defined; /* Whether a cHRM chunk is present (0 = not present, 1 = present). */
-	u32 chrm_white_x; /* White Point x times 100000 */
-	u32 chrm_white_y; /* White Point y times 100000 */
-	u32 chrm_red_x; /* Red x times 100000 */
-	u32 chrm_red_y; /* Red y times 100000 */
-	u32 chrm_green_x; /* Green x times 100000 */
-	u32 chrm_green_y; /* Green y times 100000 */
-	u32 chrm_blue_x; /* Blue x times 100000 */
-	u32 chrm_blue_y; /* Blue y times 100000 */
-
-	/*
-  sRGB chunk: optional. May not appear at the same time as iCCP.
-  If gAMA is also present gAMA must contain value 45455.
-  If cHRM is also present cHRM must contain respectively 31270,32900,64000,33000,30000,60000,15000,6000.
-  */
-	u32 srgb_defined; /* Whether an sRGB chunk is present (0 = not present, 1 = present). */
-	u32 srgb_intent; /* Rendering intent: 0=perceptual, 1=rel. colorimetric, 2=saturation, 3=abs. colorimetric */
-
-	/*
-  iCCP chunk: optional. May not appear at the same time as sRGB.
-
-  png does not parse or use the ICC profile (except its color space header field for an edge case), a
-  separate library to handle the ICC data (not included in png) format is needed to use it for color
-  management and conversions.
-
-  For encoding, if iCCP is present, gAMA and cHRM are recommended to be added as well with values that match the ICC
-  profile as closely as possible, if you wish to do this you should provide the correct values for gAMA and cHRM and
-  enable their '_defined' flags since png will not automatically compute them from the ICC profile.
-
-  For encoding, the ICC profile is required by the PNG specification to be an "RGB" profile for non-gray
-  PNG color types and a "GRAY" profile for gray PNG color types. If you disable auto_convert, you must ensure
-  the ICC profile type matches your requested color type, else the encoder gives an error. If auto_convert is
-  enabled (the default), and the ICC profile is not a good match for the pixel data, this will result in an encoder
-  error if the pixel data has non-gray pixels for a GRAY profile, or a silent less-optimal compression of the pixel
-  data if the pixels could be encoded as grayscale but the ICC profile is RGB.
-
-  To avoid this do not set an ICC profile in the image unless there is a good reason for it, and when doing so
-  make sure you compute it carefully to avoid the above problems.
-  */
-	u32 iccp_defined; /* Whether an iCCP chunk is present (0 = not present, 1 = present). */
-	char *iccp_name; /* Null terminated string with profile name, 1-79 bytes */
-	/*
-  The ICC profile in iccp_profile_size bytes.
-  Don't allocate this buffer yourself. Use the init/cleanup functions
-  correctly and use png_set_icc and png_clear_icc.
-  */
-	u8 *iccp_profile;
-	u32 iccp_profile_size; /* The size of iccp_profile in bytes */
-
-	/* End of color profile related chunks */
-
-	/*
-  unknown chunks: chunks not known by png, passed on byte for byte.
-
-  There are 3 buffers, one for each position in the PNG where unknown chunks can appear.
-  Each buffer contains all unknown chunks for that position consecutively.
-  The 3 positions are:
-  0: between IHDR and PLTE, 1: between PLTE and IDAT, 2: between IDAT and IEND.
-
-  For encoding, do not store critical chunks or known chunks that are enabled with a "_defined" flag
-  above in here, since the encoder will blindly follow this and could then encode an invalid PNG file
-  (such as one with two IHDR chunks or the disallowed combination of sRGB with iCCP). But do use
-  this if you wish to store an ancillary chunk that is not supported by png (such as sPLT or hIST),
-  or any non-standard PNG chunk.
-
-  Do not allocate or traverse this data yourself. Use the chunk traversing functions declared
-  later, such as png_chunk_next and png_chunk_append, to read/write this struct.
-  */
-	u8 *unknown_chunks_data[3];
-	u32 unknown_chunks_size[3]; /*size in bytes of the unknown chunks, given for protection*/
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-} pngInfo;
-
-/*init, cleanup and copy functions to use with this struct*/
-void png_info_init(pngInfo *info);
-void png_info_cleanup(pngInfo *info);
-/*return value is error code (0 means no error)*/
-u32 png_info_copy(pngInfo *dest, const pngInfo *source);
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-u32 png_add_text(pngInfo *info, const char *key, const char *str); /*push back both texts at once*/
-void png_clear_text(pngInfo *info); /*use this to clear the texts again after you filled them in*/
-
-u32 png_add_itext(pngInfo *info, const char *key, const char *langtag, const char *transkey,
-		  const char *str); /*push back the 4 texts of 1 chunk at once*/
-void png_clear_itext(pngInfo *info); /*use this to clear the itexts again after you filled them in*/
-
-/*replaces if exists*/
-u32 png_set_icc(pngInfo *info, const char *name, const u8 *profile, u32 profile_size);
-void png_clear_icc(pngInfo *info); /*use this to clear the texts again after you filled them in*/
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-/*
-Converts raw buffer from one color type to another color type, based on
-pngColorMode structs to describe the input and output color type.
-See the reference manual at the end of this header file to see which color conversions are supported.
-return value = png error code (0 if all went ok, an error if the conversion isn't supported)
-The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
-of the output color type (png_get_bpp).
-For < 8 bpp images, there should not be padding bits at the end of scanlines.
-For 16-bit per channel colors, uses big endian format like PNG does.
-Return value is png error code
-*/
-u32 png_convert(u8 *out, const u8 *in, const pngColorMode *mode_out, const pngColorMode *mode_in,
-		u32 w, u32 h);
-
-#ifdef PNG_COMPILE_DECODER
-/*
-Settings for the decoder. This contains settings for the PNG and the Zlib
-decoder, but not the Info settings from the Info structs.
-*/
-typedef struct pngDecoderSettings {
-	pngDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/
-
-	/* Check pngDecompressSettings for more ignorable errors such as ignore_adler32 */
-	u32 ignore_crc; /*ignore CRC checksums*/
-	u32 ignore_critical; /*ignore unknown critical chunks*/
-	u32 ignore_end; /*ignore issues at end of file if possible (missing IEND chunk, too large chunk, ...)*/
-	/* TODO: make a system involving warnings with levels and a strict mode instead. Other potentially recoverable
-     errors: srgb rendering intent value, size of content of ancillary chunks, more than 79 characters for some
-     strings, placement/combination rules for ancillary chunks, crc of unknown chunks, allowed characters
-     in string keys, etc... */
-
-	u32 color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	u32 read_text_chunks; /*if false but remember_unknown_chunks is true, they're stored in the unknown chunks*/
-
-	/*store all bytes from unknown chunks in the pngInfo (off by default, useful for a png editor)*/
-	u32 remember_unknown_chunks;
-
-	/* maximum size for decompressed text chunks. If a text chunk's text is larger than this, an error is returned,
-  unless reading text chunks is disabled or this limit is set higher or disabled. Set to 0 to allow any size.
-  By default it is a value that prevents unreasonably large strings from hogging memory. */
-	u32 max_text_size;
-
-	/* maximum size for compressed ICC chunks. If the ICC profile is larger than this, an error will be returned. Set to
-  0 to allow any size. By default this is a value that prevents ICC profiles that would be much larger than any
-  legitimate profile could be to hog memory. */
-	u32 max_icc_size;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-} pngDecoderSettings;
-
-void png_decoder_settings_init(pngDecoderSettings *settings);
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_ENCODER
-/*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/
-typedef enum pngFilterStrategy {
-	/*every filter at zero*/
-	LFS_ZERO = 0,
-	/*every filter at 1, 2, 3 or 4 (paeth), unlike LFS_ZERO not a good choice, but for testing*/
-	LFS_ONE = 1,
-	LFS_TWO = 2,
-	LFS_THREE = 3,
-	LFS_FOUR = 4,
-	/*Use filter that gives minimum sum, as described in the official PNG filter heuristic.*/
-	LFS_MINSUM,
-	/*Use the filter type that gives smallest Shannon entropy for this scanline. Depending
-  on the image, this is better or worse than minsum.*/
-	LFS_ENTROPY,
-	/*
-  Brute-force-search PNG filters by compressing each filter for each scanline.
-  Experimental, very slow, and only rarely gives better compression than MINSUM.
-  */
-	LFS_BRUTE_FORCE,
-	/*use predefined_filters buffer: you specify the filter type for each scanline*/
-	LFS_PREDEFINED
-} pngFilterStrategy;
-
-/*Gives characteristics about the integer RGBA colors of the image (count, alpha channel usage, bit depth, ...),
-which helps decide which color model to use for encoding.
-Used internally by default if "auto_convert" is enabled. Public because it's useful for custom algorithms.*/
-typedef struct pngColorStats {
-	u32 colored; /*not grayscale*/
-	u32 key; /*image is not opaque and color key is possible instead of full alpha*/
-	u16 key_r; /*key values, always as 16-bit, in 8-bit case the byte is duplicated, e.g. 65535 means 255*/
-	u16 key_g;
-	u16 key_b;
-	u32 alpha; /*image is not opaque and alpha channel or alpha palette required*/
-	u32 numcolors; /*amount of colors, up to 257. Not valid if bits == 16 or allow_palette is disabled.*/
-	u8 palette[1024]; /*Remembers up to the first 256 RGBA colors, in no particular order, only valid when numcolors is valid*/
-	u32 bits; /*bits per channel (not for palette). 1,2 or 4 for grayscale only. 16 if 16-bit per channel required.*/
-	u32 numpixels;
-
-	/*user settings for computing/using the stats*/
-	u32 allow_palette; /*default 1. if 0, disallow choosing palette colortype in auto_choose_color, and don't count numcolors*/
-	u32 allow_greyscale; /*default 1. if 0, choose RGB or RGBA even if the image only has gray colors*/
-} pngColorStats;
-
-void png_color_stats_init(pngColorStats *stats);
-
-/*Get a pngColorStats of the image. The stats must already have been inited.
-Returns error code (e.g. alloc fail) or 0 if ok.*/
-u32 png_compute_color_stats(pngColorStats *stats, const u8 *image, u32 w, u32 h,
-			    const pngColorMode *mode_in);
-
-/*Settings for the encoder.*/
-typedef struct pngEncoderSettings {
-	pngCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
-
-	u32 auto_convert; /*automatically choose output PNG color type. Default: true*/
-
-	/*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than
-  8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to
-  completely follow the official PNG heuristic, filter_palette_zero must be true and
-  filter_strategy must be LFS_MINSUM*/
-	u32 filter_palette_zero;
-	/*Which filter strategy to use when not using zeroes due to filter_palette_zero.
-  Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: LFS_MINSUM*/
-	pngFilterStrategy filter_strategy;
-	/*used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with
-  the same length as the amount of scanlines in the image, and each value must <= 5. You
-  have to cleanup this buffer, png will never free it. Don't forget that filter_palette_zero
-  must be set to 0 to ensure this is also used on palette or low bitdepth images.*/
-	const u8 *predefined_filters;
-
-	/*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette).
-  If colortype is 3, PLTE is _always_ created.*/
-	u32 force_palette;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	/*add png identifier and version as a text chunk, for debugging*/
-	u32 add_id;
-	/*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/
-	u32 text_compression;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-} pngEncoderSettings;
-
-void png_encoder_settings_init(pngEncoderSettings *settings);
-#endif /*PNG_COMPILE_ENCODER*/
-
-#if defined(PNG_COMPILE_DECODER) || defined(PNG_COMPILE_ENCODER)
-/*The settings, state and information for extended encoding and decoding.*/
-typedef struct pngState {
-#ifdef PNG_COMPILE_DECODER
-	pngDecoderSettings decoder; /*the decoding settings*/
-#endif /*PNG_COMPILE_DECODER*/
-#ifdef PNG_COMPILE_ENCODER
-	pngEncoderSettings encoder; /*the encoding settings*/
-#endif /*PNG_COMPILE_ENCODER*/
-	pngColorMode
-		info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/
-	pngInfo info_png; /*info of the PNG image obtained after decoding*/
-	u32 error;
-} pngState;
-
-/*init, cleanup and copy functions to use with this struct*/
-void png_state_init(pngState *state);
-void png_state_cleanup(pngState *state);
-void png_state_copy(pngState *dest, const pngState *source);
-#endif /* defined(PNG_COMPILE_DECODER) || defined(PNG_COMPILE_ENCODER) */
-
-#ifdef PNG_COMPILE_DECODER
-/*
-Same as png_decode_memory, but uses a pngState to allow custom settings and
-getting much more information about the PNG image and color mode.
-*/
-u32 png_decode(u8 **out, u32 *w, u32 *h, pngState *state, const u8 *in, u32 insize);
-
-/*
-Read the PNG header, but not the actual data. This returns only the information
-that is in the IHDR chunk of the PNG, such as width, height and color type. The
-information is placed in the info_png field of the pngState.
-*/
-u32 png_inspect(u32 *w, u32 *h, pngState *state, const u8 *in, u32 insize);
-#endif /*PNG_COMPILE_DECODER*/
-
-/*
-Reads one metadata chunk (other than IHDR) of the PNG file and outputs what it
-read in the state. Returns error code on failure.
-Use png_inspect first with a new state, then e.g. png_chunk_find_const
-to find the desired chunk type, and if non null use png_inspect_chunk (with
-chunk_pointer - start_of_file as pos).
-Supports most metadata chunks from the PNG standard (gAMA, bKGD, tEXt, ...).
-Ignores unsupported, unknown, non-metadata or IHDR chunks (without error).
-Requirements: &in[pos] must point to start of a chunk, must use regular
-png_inspect first since format of most other chunks depends on IHDR, and if
-there is a PLTE chunk, that one must be inspected before tRNS or bKGD.
-*/
-u32 png_inspect_chunk(pngState *state, u32 pos, const u8 *in, u32 insize);
-
-#ifdef PNG_COMPILE_ENCODER
-/*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/
-u32 png_encode(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h, pngState *state);
-#endif /*PNG_COMPILE_ENCODER*/
-
-/*
-The png_chunk functions are normally not needed, except to traverse the
-unknown chunks stored in the pngInfo struct, or add new ones to it.
-It also allows traversing the chunks of an encoded PNG file yourself.
-
-The chunk pointer always points to the beginning of the chunk itself, that is
-the first byte of the 4 length bytes.
-
-In the PNG file format, chunks have the following format:
--4 bytes length: length of the data of the chunk in bytes (chunk itself is 12 bytes longer)
--4 bytes chunk type (ASCII a-z,A-Z only, see below)
--length bytes of data (may be 0 bytes if length was 0)
--4 bytes of CRC, computed on chunk name + data
-
-The first chunk starts at the 8th byte of the PNG file, the entire rest of the file
-exists out of concatenated chunks with the above format.
-
-PNG standard chunk ASCII naming conventions:
--First byte: uppercase = critical, lowercase = ancillary
--Second byte: uppercase = public, lowercase = private
--Third byte: must be uppercase
--Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
-*/
-
-/*
-Gets the length of the data of the chunk. Total chunk length has 12 bytes more.
-There must be at least 4 bytes to read from. If the result value is too large,
-it may be corrupt data.
-*/
-u32 png_chunk_length(const u8 *chunk);
-
-/*puts the 4-byte type in null terminated string*/
-void png_chunk_type(char type[5], const u8 *chunk);
-
-/*check if the type is the given type*/
-u8 png_chunk_type_equals(const u8 *chunk, const char *type);
-
-/*0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard)*/
-u8 png_chunk_ancillary(const u8 *chunk);
-
-/*0: public, 1: private (see PNG standard)*/
-u8 png_chunk_private(const u8 *chunk);
-
-/*0: the chunk is unsafe to copy, 1: the chunk is safe to copy (see PNG standard)*/
-u8 png_chunk_safetocopy(const u8 *chunk);
-
-/*get pointer to the data of the chunk, where the input points to the header of the chunk*/
-u8 *png_chunk_data(u8 *chunk);
-const u8 *png_chunk_data_const(const u8 *chunk);
-
-/*returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!)*/
-u32 png_chunk_check_crc(const u8 *chunk);
-
-/*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
-void png_chunk_generate_crc(u8 *chunk);
-
-/*
-Iterate to next chunks, allows iterating through all chunks of the PNG file.
-Input must be at the beginning of a chunk (result of a previous png_chunk_next call,
-or the 8th byte of a PNG file which always has the first chunk), or alternatively may
-point to the first byte of the PNG file (which is not a chunk but the magic header, the
-function will then skip over it and return the first real chunk).
-Will output pointer to the start of the next chunk, or at or beyond end of the file if there
-is no more chunk after this or possibly if the chunk is corrupt.
-Start this process at the 8th byte of the PNG file.
-In a non-corrupt PNG file, the last chunk should have name "IEND".
-*/
-u8 *png_chunk_next(u8 *chunk, u8 *end);
-const u8 *png_chunk_next_const(const u8 *chunk, const u8 *end);
-
-/*Finds the first chunk with the given type in the range [chunk, end), or returns NULL if not found.*/
-u8 *png_chunk_find(u8 *chunk, u8 *end, const char type[5]);
-const u8 *png_chunk_find_const(const u8 *chunk, const u8 *end, const char type[5]);
-
-/*
-Appends chunk to the data in out. The given chunk should already have its chunk header.
-The out variable and outsize are updated to reflect the new reallocated buffer.
-Returns error code (0 if it went ok)
-*/
-u32 png_chunk_append(u8 **out, u32 *outsize, const u8 *chunk);
-
-/*
-Appends new chunk to out. The chunk to append is given by giving its length, type
-and data separately. The type is a 4-letter string.
-The out variable and outsize are updated to reflect the new reallocated buffer.
-Returne error code (0 if it went ok)
-*/
-u32 png_chunk_create(u8 **out, u32 *outsize, u32 length, const char *type, const u8 *data);
-
-/*Calculate CRC32 of buffer*/
-u32 png_crc32(const u8 *buf, u32 len);
-#endif /*PNG_COMPILE_PNG*/
-
-#ifdef PNG_COMPILE_ZLIB
-/*
-This zlib part can be used independently to zlib compress and decompress a
-buffer. It cannot be used to create gzip files however, and it only supports the
-part of zlib that is required for PNG, it does not support dictionaries.
-*/
-
-#ifdef PNG_COMPILE_DECODER
-/*Inflate a buffer. Inflate is the decompression step of deflate. Out buffer must be freed after use.*/
-u32 png_inflate(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-		const pngDecompressSettings *settings);
-
-/*
-Decompresses Zlib data. Reallocates the out buffer and appends the data. The
-data must be according to the zlib specification.
-Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
-buffer and *outsize its size in bytes. out must be freed by user after usage.
-*/
-u32 png_zlib_decompress(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-			const pngDecompressSettings *settings);
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_ENCODER
-/*
-Compresses data with Zlib. Reallocates the out buffer and appends the data.
-Zlib adds a small header and trailer around the deflate data.
-The data is output in the format of the zlib specification.
-Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
-buffer and *outsize its size in bytes. out must be freed by user after usage.
-*/
-u32 png_zlib_compress(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-		      const pngCompressSettings *settings);
-
-/*
-Find length-limited Huffman code for given frequencies. This function is in the
-public interface only for tests, it's used internally by png_deflate.
-*/
-u32 png_huffman_code_lengths(u32 *lengths, const u32 *frequencies, u32 numcodes, u32 maxbitlen);
-
-/*Compress a buffer with deflate. See RFC 1951. Out buffer must be freed after use.*/
-u32 png_deflate(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-		const pngCompressSettings *settings);
-
-#endif /*PNG_COMPILE_ENCODER*/
-#endif /*PNG_COMPILE_ZLIB*/
-
-#ifdef PNG_COMPILE_DISK
-/*
-Load a file from disk into buffer. The function allocates the out buffer, and
-after usage you should free it.
-out: output parameter, contains pointer to loaded buffer.
-outsize: output parameter, size of the allocated out buffer
-filename: the path to the file to load
-return value: error code (0 means ok)
-*/
-u32 png_load_file(u8 **out, u32 *outsize, const char *filename);
-
-/*
-Save a file from buffer to disk. Warning, if it exists, this function overwrites
-the file without warning!
-buffer: the buffer to write
-buffersize: size of the buffer to write
-filename: the path to the file to save to
-return value: error code (0 means ok)
-*/
-u32 png_save_file(const u8 *buffer, u32 buffersize, const char *filename);
-#endif /*PNG_COMPILE_DISK*/
-
-#ifdef PNG_COMPILE_CPP
-/* The png C++ wrapper uses std::vectors instead of manually allocated memory buffers. */
-namespace png
-{
-#ifdef PNG_COMPILE_PNG
-class State : public pngState {
-    public:
-	State();
-	State(const State &other);
-	~State();
-	State &operator=(const State &other);
-};
-
-#ifdef PNG_COMPILE_DECODER
-/* Same as other png::decode, but using a State for more settings and information. */
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, State &state, const u8 *in, u32 insize);
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, State &state, const std::vector<u8> &in);
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_ENCODER
-/* Same as other png::encode, but using a State for more settings and information. */
-u32 encode(std::vector<u8> &out, const u8 *in, u32 w, u32 h, State &state);
-u32 encode(std::vector<u8> &out, const std::vector<u8> &in, u32 w, u32 h, State &state);
-#endif /*PNG_COMPILE_ENCODER*/
-
-#ifdef PNG_COMPILE_DISK
-/*
-Load a file from disk into an std::vector.
-return value: error code (0 means ok)
-*/
-u32 load_file(std::vector<u8> &buffer, const std::string &filename);
-
-/*
-Save the binary data in an std::vector to a file on disk. The file is overwritten
-without warning.
-*/
-u32 save_file(const std::vector<u8> &buffer, const std::string &filename);
-#endif /* PNG_COMPILE_DISK */
-#endif /* PNG_COMPILE_PNG */
-
-#ifdef PNG_COMPILE_ZLIB
-#ifdef PNG_COMPILE_DECODER
-/* Zlib-decompress an u8 buffer */
-u32 decompress(std::vector<u8> &out, const u8 *in, u32 insize,
-	       const pngDecompressSettings &settings = png_default_decompress_settings);
-
-/* Zlib-decompress an std::vector */
-u32 decompress(std::vector<u8> &out, const std::vector<u8> &in,
-	       const pngDecompressSettings &settings = png_default_decompress_settings);
-#endif /* PNG_COMPILE_DECODER */
-
-#ifdef PNG_COMPILE_ENCODER
-/* Zlib-compress an u8 buffer */
-u32 compress(std::vector<u8> &out, const u8 *in, u32 insize,
-	     const pngCompressSettings &settings = png_default_compress_settings);
-
-/* Zlib-compress an std::vector */
-u32 compress(std::vector<u8> &out, const std::vector<u8> &in,
-	     const pngCompressSettings &settings = png_default_compress_settings);
-#endif /* PNG_COMPILE_ENCODER */
-#endif /* PNG_COMPILE_ZLIB */
-} /* namespace png */
-#endif /*PNG_COMPILE_CPP*/
-
-/*
-TODO:
-[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often
-[.] check compatibility with various compilers  - done but needs to be redone for every newer version
-[X] converting color to 16-bit per channel types
-[X] support color profile chunk types (but never let them touch RGB values by default)
-[ ] support all public PNG chunk types (almost done except sBIT, sPLT and hIST)
-[ ] make sure encoder generates no chunks with size > (2^31)-1
-[ ] partial decoding (stream processing)
-[X] let the "isFullyOpaque" function check color keys and transparent palettes too
-[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl"
-[ ] allow treating some errors like warnings, when image is recoverable (e.g. 69, 57, 58)
-[ ] make warnings like: oob palette, checksum fail, data after iend, wrong/unknown crit chunk, no null terminator in text, ...
-[ ] error messages with line numbers (and version)
-[ ] errors in state instead of as return code?
-[ ] new errors/warnings like suspiciously big decompressed ztxt or iccp chunk
-[ ] let the C++ wrapper catch exceptions coming from the standard library and return png error codes
-[ ] allow user to provide custom color conversion functions, e.g. for premultiplied alpha, padding bits or not, ...
-[ ] allow user to give data (void*) to custom allocator
-[X] provide alternatives for C library functions not present on some platforms (memcpy, ...)
-*/
-
-#endif /*PNG_H inclusion guard*/
diff --git a/libgui/inc/psf.h b/libgui/inc/psf.h
deleted file mode 100644
index 63a3d1e..0000000
--- a/libgui/inc/psf.h
+++ /dev/null
@@ -1,48 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-// PSF parser
-
-#ifndef PSF_H
-#define PSF_H
-
-#include <def.h>
-
-/**
- * PSF version 1
- */
-
-#define PSF1_MAGIC_0 0x36
-#define PSF1_MAGIC_1 0x04
-#define PSF1_MODE_256 0
-#define PSF1_MODE_512 1
-#define PSF1_MODE_256_UNICODE 2
-#define PSF1_MODE_512_UNICODE 3
-
-struct psf1_header {
-	u8 magic[2];
-	u8 mode;
-	u8 char_size;
-};
-
-/**
- * PSF version 2
- */
-
-#define PSF2_MAGIC_0 0x72
-#define PSF2_MAGIC_1 0xb5
-#define PSF2_MAGIC_2 0x4a
-#define PSF2_MAGIC_3 0x86
-
-struct psf2_header {
-	u8 magic[4];
-	u32 version;
-	u32 size;
-	u32 flags;
-	u32 glyph_count;
-	u32 char_size;
-	u32 height;
-	u32 width;
-};
-
-struct font *psf_parse(char *data);
-
-#endif
diff --git a/libgui/inc/vesa.h b/libgui/inc/vesa.h
deleted file mode 100644
index 892bd89..0000000
--- a/libgui/inc/vesa.h
+++ /dev/null
@@ -1,46 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-
-#ifndef VBE_H
-#define VBE_H
-
-#include <def.h>
-
-struct vbe {
-	u16 attributes;
-	u8 window_a;
-	u8 window_b;
-	u16 granularity;
-	u16 window_size;
-	u16 segment_a;
-	u16 segment_b;
-	u32 win_func_ptr;
-	u16 pitch;
-	u16 width;
-	u16 height;
-	u8 w_char;
-	u8 y_char;
-	u8 planes;
-	u8 bpp;
-	u8 banks;
-	u8 memory_model;
-	u8 bank_size;
-	u8 image_pages;
-	u8 reserved0;
-
-	u8 red_mask;
-	u8 red_position;
-	u8 green_mask;
-	u8 green_position;
-	u8 blue_mask;
-	u8 blue_position;
-	u8 reserved_mask;
-	u8 reserved_position;
-	u8 direct_color_attributes;
-
-	u8 *fb;
-	u32 off_screen_mem_off;
-	u16 off_screen_mem_size;
-	u8 reserved1[206];
-};
-
-#endif
diff --git a/libgui/msg.c b/libgui/msg.c
deleted file mode 100644
index 5f4ae39..0000000
--- a/libgui/msg.c
+++ /dev/null
@@ -1,31 +0,0 @@
-// MIT License, Copyright (c) 2021 Marvin Borner
-
-#include <assert.h>
-#include <errno.h>
-#include <msg.h>
-#include <print.h>
-#include <sys.h>
-
-res msg_send(u32 pid, enum message_type type, void *data, u32 size)
-{
-	if (!data)
-		return -EFAULT;
-	assert((signed)pid != -1 && size >= sizeof(struct message_header));
-	char path[32] = { 0 };
-	sprintf(path, "/proc/%d/msg", pid);
-	struct message_header *header = data;
-	header->magic = MSG_MAGIC;
-	header->src = getpid();
-	header->type = type;
-	return write(path, data, 0, size);
-}
-
-res msg_receive(void *buf, u32 size)
-{
-	int ret = read("/proc/self/msg", buf, 0, size);
-	struct message_header *header = buf;
-	if (header->magic == MSG_MAGIC)
-		return ret;
-	else
-		return -1;
-}
diff --git a/libgui/png.c b/libgui/png.c
deleted file mode 100644
index 5f55a3e..0000000
--- a/libgui/png.c
+++ /dev/null
@@ -1,7472 +0,0 @@
-/*
-LodePNG version 20201017
-
-Copyright (c) 2005-2020 Lode Vandevenne
-Copyright (c) 2021 Marvin Borner
-
-This software is provided 'as-is', without any express or implied
-warranty. In no event will the authors be held liable for any damages
-arising from the use of this software.
-
-Permission is granted to anyone to use this software for any purpose,
-including commercial applications, and to alter it and redistribute it
-freely, subject to the following restrictions:
-
-    1. The origin of this software must not be misrepresented; you must not
-    claim that you wrote the original software. If you use this software
-    in a product, an acknowledgment in the product documentation would be
-    appreciated but is not required.
-
-    2. Altered source versions must be plainly marked as such, and must not be
-    misrepresented as being the original software.
-
-    3. This notice may not be removed or altered from any source
-    distribution.
-*/
-
-/*
-The manual and changelog are in the header file "png.h"
-Rename this file to png.cpp to use it for C++, or to png.c to use it for C.
-*/
-
-#include <def.h>
-#include <mem.h>
-#include <png.h>
-#include <sys.h>
-
-#if defined(_MSC_VER) &&                                                                           \
-	(_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/
-#pragma warning(                                                                                   \
-	disable : 4244) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/
-#pragma warning(                                                                                   \
-	disable : 4996) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/
-#endif /*_MSC_VER */
-
-const char *PNG_VERSION_STRING = "20201017";
-
-/*
-This source file is built up in the following large parts. The code sections
-with the "PNG_COMPILE_" #defines divide this up further in an intermixed way.
--Tools for C and common code for PNG and Zlib
--C Code for Zlib (huffman, deflate, ...)
--C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...)
--The C++ wrapper around all of the above
-*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // Tools for C, and common code for PNG and Zlib.                       // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*The malloc, realloc and free functions defined here with "png_" in front
-of the name, so that you can easily change them to others related to your
-platform if needed. Everything else in the code calls these. Pass
--DPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out
-#define PNG_COMPILE_ALLOCATORS in the header, to disable the ones here and
-define them in your own project's source files without needing to change
-png source code. Don't forget to remove "static" if you copypaste them
-from here.*/
-
-#ifdef PNG_COMPILE_ALLOCATORS
-static void *png_malloc(u32 size)
-{
-#ifdef PNG_MAX_ALLOC
-	if (size > PNG_MAX_ALLOC)
-		return 0;
-#endif
-	return malloc(size);
-}
-
-/* NOTE: when realloc returns NULL, it leaves the original memory untouched */
-static void *png_realloc(void *ptr, u32 new_size)
-{
-#ifdef PNG_MAX_ALLOC
-	if (new_size > PNG_MAX_ALLOC)
-		return 0;
-#endif
-	return realloc(ptr, new_size);
-}
-
-static void png_free(void *ptr)
-{
-	free(ptr);
-}
-#else /*PNG_COMPILE_ALLOCATORS*/
-/* TODO: support giving additional void* payload to the custom allocators */
-void *png_malloc(u32 size);
-void *png_realloc(void *ptr, u32 new_size);
-void png_free(void *ptr);
-#endif /*PNG_COMPILE_ALLOCATORS*/
-
-/* convince the compiler to inline a function, for use when this measurably improves performance */
-/* inline is not available in C90, but use it when supported by the compiler */
-#if (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) ||                                \
-	(defined(__cplusplus) && (__cplusplus >= 199711L))
-#define PNG_INLINE inline
-#else
-#define PNG_INLINE /* not available */
-#endif
-
-/* restrict is not available in C90, but use it when supported by the compiler */
-#if (defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))) ||             \
-	(defined(_MSC_VER) && (_MSC_VER >= 1400)) ||                                               \
-	(defined(__WATCOMC__) && (__WATCOMC__ >= 1250) && !defined(__cplusplus))
-#define PNG_RESTRICT __restrict
-#else
-#define PNG_RESTRICT /* not available */
-#endif
-
-/* Replacements for C library functions such as memcpy and strlen, to support platforms
-where a full C library is not available. The compiler can recognize them and compile
-to something as fast. */
-
-static void png_memcpy(void *PNG_RESTRICT dst, const void *PNG_RESTRICT src, u32 size)
-{
-	u32 i;
-	for (i = 0; i < size; i++)
-		((char *)dst)[i] = ((const char *)src)[i];
-}
-
-static void png_memset(void *PNG_RESTRICT dst, int value, u32 num)
-{
-	u32 i;
-	for (i = 0; i < num; i++)
-		((char *)dst)[i] = (char)value;
-}
-
-/* does not check memory out of bounds, do not use on untrusted data */
-static u32 png_strlen(const char *a)
-{
-	const char *orig = a;
-	/* avoid warning about unused function in case of disabled COMPILE... macros */
-	(void)(&png_strlen);
-	while (*a)
-		a++;
-	return (u32)(a - orig);
-}
-
-#define PNG_MAX(a, b) (((a) > (b)) ? (a) : (b))
-#define PNG_MIN(a, b) (((a) < (b)) ? (a) : (b))
-#define PNG_ABS(x) ((x) < 0 ? -(x) : (x))
-
-#if defined(PNG_COMPILE_PNG) || defined(PNG_COMPILE_DECODER)
-/* Safely check if adding two integers will overflow (no undefined
-behavior, compiler removing the code, etc...) and output result. */
-static int png_addofl(u32 a, u32 b, u32 *result)
-{
-	*result = a + b; /* u32 addition is well defined and safe in C90 */
-	return *result < a;
-}
-#endif /*defined(PNG_COMPILE_PNG) || defined(PNG_COMPILE_DECODER)*/
-
-#ifdef PNG_COMPILE_DECODER
-/* Safely check if multiplying two integers will overflow (no undefined
-behavior, compiler removing the code, etc...) and output result. */
-static int png_mulofl(u32 a, u32 b, u32 *result)
-{
-	*result = a * b; /* u32 multiplication is well defined and safe in C90 */
-	return (a != 0 && *result / a != b);
-}
-
-#ifdef PNG_COMPILE_ZLIB
-/* Safely check if a + b > c, even if overflow could happen. */
-static int png_gtofl(u32 a, u32 b, u32 c)
-{
-	u32 d;
-	if (png_addofl(a, b, &d))
-		return 1;
-	return d > c;
-}
-#endif /*PNG_COMPILE_ZLIB*/
-#endif /*PNG_COMPILE_DECODER*/
-
-/*
-Often in case of an error a value is assigned to a variable and then it breaks
-out of a loop (to go to the cleanup phase of a function). This macro does that.
-It makes the error handling code shorter and more readable.
-
-Example: if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83);
-*/
-#define CERROR_BREAK(errorvar, code)                                                               \
-	{                                                                                          \
-		errorvar = code;                                                                   \
-		break;                                                                             \
-	}
-
-/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
-#define ERROR_BREAK(code) CERROR_BREAK(error, code)
-
-/*Set error var to the error code, and return it.*/
-#define CERROR_RETURN_ERROR(errorvar, code)                                                        \
-	{                                                                                          \
-		errorvar = code;                                                                   \
-		return code;                                                                       \
-	}
-
-/*Try the code, if it returns error, also return the error.*/
-#define CERROR_TRY_RETURN(call)                                                                    \
-	{                                                                                          \
-		u32 error = call;                                                                  \
-		if (error)                                                                         \
-			return error;                                                              \
-	}
-
-/*Set error var to the error code, and return from the void function.*/
-#define CERROR_RETURN(errorvar, code)                                                              \
-	{                                                                                          \
-		errorvar = code;                                                                   \
-		return;                                                                            \
-	}
-
-/*
-About uivector, ucvector and string:
--All of them wrap dynamic arrays or text strings in a similar way.
--png was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
--The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
--They're not used in the interface, only internally in this file as static functions.
--As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
-*/
-
-#ifdef PNG_COMPILE_ZLIB
-#ifdef PNG_COMPILE_ENCODER
-/*dynamic vector of u32 ints*/
-typedef struct uivector {
-	u32 *data;
-	u32 size; /*size in number of u32 longs*/
-	u32 allocsize; /*allocated size in bytes*/
-} uivector;
-
-static void uivector_cleanup(void *p)
-{
-	((uivector *)p)->size = ((uivector *)p)->allocsize = 0;
-	png_free(((uivector *)p)->data);
-	((uivector *)p)->data = NULL;
-}
-
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static u32 uivector_resize(uivector *p, u32 size)
-{
-	u32 allocsize = size * sizeof(u32);
-	if (allocsize > p->allocsize) {
-		u32 newsize = allocsize + (p->allocsize >> 1u);
-		void *data = png_realloc(p->data, newsize);
-		if (data) {
-			p->allocsize = newsize;
-			p->data = (u32 *)data;
-		} else
-			return 0; /*error: not enough memory*/
-	}
-	p->size = size;
-	return 1; /*success*/
-}
-
-static void uivector_init(uivector *p)
-{
-	p->data = NULL;
-	p->size = p->allocsize = 0;
-}
-
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static u32 uivector_push_back(uivector *p, u32 c)
-{
-	if (!uivector_resize(p, p->size + 1))
-		return 0;
-	p->data[p->size - 1] = c;
-	return 1;
-}
-#endif /*PNG_COMPILE_ENCODER*/
-#endif /*PNG_COMPILE_ZLIB*/
-
-/* /////////////////////////////////////////////////////////////////////////// */
-
-/*dynamic vector of u8s*/
-typedef struct ucvector {
-	u8 *data;
-	u32 size; /*used size*/
-	u32 allocsize; /*allocated size*/
-} ucvector;
-
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static u32 ucvector_resize(ucvector *p, u32 size)
-{
-	if (size > p->allocsize) {
-		u32 newsize = size + (p->allocsize >> 1u);
-		void *data = png_realloc(p->data, newsize);
-		if (data) {
-			p->allocsize = newsize;
-			p->data = (u8 *)data;
-		} else
-			return 0; /*error: not enough memory*/
-	}
-	p->size = size;
-	return 1; /*success*/
-}
-
-static ucvector ucvector_init(u8 *buffer, u32 size)
-{
-	ucvector v;
-	v.data = buffer;
-	v.allocsize = v.size = size;
-	return v;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef PNG_COMPILE_PNG
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-
-/*free string pointer and set it to NULL*/
-static void string_cleanup(char **out)
-{
-	png_free(*out);
-	*out = NULL;
-}
-
-/*also appends null termination character*/
-static char *alloc_string_sized(const char *in, u32 insize)
-{
-	char *out = (char *)png_malloc(insize + 1);
-	if (out) {
-		png_memcpy(out, in, insize);
-		out[insize] = 0;
-	}
-	return out;
-}
-
-/* dynamically allocates a new string with a copy of the null terminated input text */
-static char *alloc_string(const char *in)
-{
-	return alloc_string_sized(in, png_strlen(in));
-}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-#endif /*PNG_COMPILE_PNG*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#if defined(PNG_COMPILE_DECODER) || defined(PNG_COMPILE_PNG)
-static u32 png_read32bitInt(const u8 *buffer)
-{
-	return (((u32)buffer[0] << 24u) | ((u32)buffer[1] << 16u) | ((u32)buffer[2] << 8u) |
-		(u32)buffer[3]);
-}
-#endif /*defined(PNG_COMPILE_DECODER) || defined(PNG_COMPILE_PNG)*/
-
-#if defined(PNG_COMPILE_PNG) || defined(PNG_COMPILE_ENCODER)
-/*buffer must have at least 4 allocated bytes available*/
-static void png_set32bitInt(u8 *buffer, u32 value)
-{
-	buffer[0] = (u8)((value >> 24) & 0xff);
-	buffer[1] = (u8)((value >> 16) & 0xff);
-	buffer[2] = (u8)((value >> 8) & 0xff);
-	buffer[3] = (u8)((value)&0xff);
-}
-#endif /*defined(PNG_COMPILE_PNG) || defined(PNG_COMPILE_ENCODER)*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / File IO                                                                / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef PNG_COMPILE_DISK
-
-/* returns negative value on error. This should be pure C compatible, so no fstat. */
-static long png_filesize(const char *filename)
-{
-	struct stat s = { 0 };
-	stat(filename, &s);
-	return s.size;
-}
-
-/* load file into buffer that already has the correct allocated size. Returns error code.*/
-static u32 png_buffer_file(u8 *out, u32 size, const char *filename)
-{
-	u32 readsize;
-	readsize = read(filename, out, 0, size);
-
-	if (readsize != size)
-		return 78;
-	return 0;
-}
-
-u32 png_load_file(u8 **out, u32 *outsize, const char *filename)
-{
-	long size = png_filesize(filename);
-	if (size < 0)
-		return 78;
-	*outsize = (u32)size;
-
-	*out = (u8 *)png_malloc((u32)size);
-	if (!(*out) && size > 0)
-		return 83; /*the above malloc failed*/
-
-	return png_buffer_file(*out, (u32)size, filename);
-}
-
-/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
-u32 png_save_file(const u8 *buffer, u32 buffersize, const char *filename)
-{
-	err(1, "Not implemented!\n");
-	if (write(filename, buffer, 0, buffersize) <= 0)
-		return 79;
-	return 0;
-}
-
-#endif /*PNG_COMPILE_DISK*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // End of common code and tools. Begin of Zlib related code.            // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef PNG_COMPILE_ZLIB
-#ifdef PNG_COMPILE_ENCODER
-
-typedef struct {
-	ucvector *data;
-	u8 bp; /*ok to overflow, indicates bit pos inside byte*/
-} pngBitWriter;
-
-static void pngBitWriter_init(pngBitWriter *writer, ucvector *data)
-{
-	writer->data = data;
-	writer->bp = 0;
-}
-
-/*TODO: this ignores potential out of memory errors*/
-#define WRITEBIT(writer, bit)                                                                      \
-	{                                                                                          \
-		/* append new byte */                                                              \
-		if (((writer->bp) & 7u) == 0) {                                                    \
-			if (!ucvector_resize(writer->data, writer->data->size + 1))                \
-				return;                                                            \
-			writer->data->data[writer->data->size - 1] = 0;                            \
-		}                                                                                  \
-		(writer->data->data[writer->data->size - 1]) |= (bit << ((writer->bp) & 7u));      \
-		++writer->bp;                                                                      \
-	}
-
-/* LSB of value is written first, and LSB of bytes is used first */
-static void writeBits(pngBitWriter *writer, u32 value, u32 nbits)
-{
-	if (nbits == 1) { /* compiler should statically compile this case if nbits == 1 */
-		WRITEBIT(writer, value);
-	} else {
-		/* TODO: increase output size only once here rather than in each WRITEBIT */
-		u32 i;
-		for (i = 0; i != nbits; ++i) {
-			WRITEBIT(writer, (u8)((value >> i) & 1));
-		}
-	}
-}
-
-/* This one is to use for adding huffman symbol, the value bits are written MSB first */
-static void writeBitsReversed(pngBitWriter *writer, u32 value, u32 nbits)
-{
-	u32 i;
-	for (i = 0; i != nbits; ++i) {
-		/* TODO: increase output size only once here rather than in each WRITEBIT */
-		WRITEBIT(writer, (u8)((value >> (nbits - 1u - i)) & 1u));
-	}
-}
-#endif /*PNG_COMPILE_ENCODER*/
-
-#ifdef PNG_COMPILE_DECODER
-
-typedef struct {
-	const u8 *data;
-	u32 size; /*size of data in bytes*/
-	u32 bitsize; /*size of data in bits, end of valid bp values, should be 8*size*/
-	u32 bp;
-	u32 buffer; /*buffer for reading bits. NOTE: 'u32' must support at least 32 bits*/
-} pngBitReader;
-
-/* data size argument is in bytes. Returns error if size too large causing overflow */
-static u32 pngBitReader_init(pngBitReader *reader, const u8 *data, u32 size)
-{
-	u32 temp;
-	reader->data = data;
-	reader->size = size;
-	/* size in bits, return error if overflow (if u32 is 32 bit this supports up to 500MB)  */
-	if (png_mulofl(size, 8u, &reader->bitsize))
-		return 105;
-	/*ensure incremented bp can be compared to bitsize without overflow even when it would be incremented 32 too much and
-  trying to ensure 32 more bits*/
-	if (png_addofl(reader->bitsize, 64u, &temp))
-		return 105;
-	reader->bp = 0;
-	reader->buffer = 0;
-	return 0; /*ok*/
-}
-
-/*
-ensureBits functions:
-Ensures the reader can at least read nbits bits in one or more readBits calls,
-safely even if not enough bits are available.
-Returns 1 if there are enough bits available, 0 if not.
-*/
-
-/*See ensureBits documentation above. This one ensures exactly 1 bit */
-/*static u32 ensureBits1(pngBitReader* reader) {
-  if(reader->bp >= reader->bitsize) return 0;
-  reader->buffer = (u32)reader->data[reader->bp >> 3u] >> (reader->bp & 7u);
-  return 1;
-}*/
-
-/*See ensureBits documentation above. This one ensures up to 9 bits */
-static u32 ensureBits9(pngBitReader *reader, u32 nbits)
-{
-	u32 start = reader->bp >> 3u;
-	u32 size = reader->size;
-	if (start + 1u < size) {
-		reader->buffer =
-			(u32)reader->data[start + 0] | ((u32)reader->data[start + 1] << 8u);
-		reader->buffer >>= (reader->bp & 7u);
-		return 1;
-	} else {
-		reader->buffer = 0;
-		if (start + 0u < size)
-			reader->buffer |= reader->data[start + 0];
-		reader->buffer >>= (reader->bp & 7u);
-		return reader->bp + nbits <= reader->bitsize;
-	}
-}
-
-/*See ensureBits documentation above. This one ensures up to 17 bits */
-static u32 ensureBits17(pngBitReader *reader, u32 nbits)
-{
-	u32 start = reader->bp >> 3u;
-	u32 size = reader->size;
-	if (start + 2u < size) {
-		reader->buffer = (u32)reader->data[start + 0] |
-				 ((u32)reader->data[start + 1] << 8u) |
-				 ((u32)reader->data[start + 2] << 16u);
-		reader->buffer >>= (reader->bp & 7u);
-		return 1;
-	} else {
-		reader->buffer = 0;
-		if (start + 0u < size)
-			reader->buffer |= reader->data[start + 0];
-		if (start + 1u < size)
-			reader->buffer |= ((u32)reader->data[start + 1] << 8u);
-		reader->buffer >>= (reader->bp & 7u);
-		return reader->bp + nbits <= reader->bitsize;
-	}
-}
-
-/*See ensureBits documentation above. This one ensures up to 25 bits */
-static PNG_INLINE u32 ensureBits25(pngBitReader *reader, u32 nbits)
-{
-	u32 start = reader->bp >> 3u;
-	u32 size = reader->size;
-	if (start + 3u < size) {
-		reader->buffer = (u32)reader->data[start + 0] |
-				 ((u32)reader->data[start + 1] << 8u) |
-				 ((u32)reader->data[start + 2] << 16u) |
-				 ((u32)reader->data[start + 3] << 24u);
-		reader->buffer >>= (reader->bp & 7u);
-		return 1;
-	} else {
-		reader->buffer = 0;
-		if (start + 0u < size)
-			reader->buffer |= reader->data[start + 0];
-		if (start + 1u < size)
-			reader->buffer |= ((u32)reader->data[start + 1] << 8u);
-		if (start + 2u < size)
-			reader->buffer |= ((u32)reader->data[start + 2] << 16u);
-		reader->buffer >>= (reader->bp & 7u);
-		return reader->bp + nbits <= reader->bitsize;
-	}
-}
-
-/*See ensureBits documentation above. This one ensures up to 32 bits */
-static PNG_INLINE u32 ensureBits32(pngBitReader *reader, u32 nbits)
-{
-	u32 start = reader->bp >> 3u;
-	u32 size = reader->size;
-	if (start + 4u < size) {
-		reader->buffer = (u32)reader->data[start + 0] |
-				 ((u32)reader->data[start + 1] << 8u) |
-				 ((u32)reader->data[start + 2] << 16u) |
-				 ((u32)reader->data[start + 3] << 24u);
-		reader->buffer >>= (reader->bp & 7u);
-		reader->buffer |=
-			(((u32)reader->data[start + 4] << 24u) << (8u - (reader->bp & 7u)));
-		return 1;
-	} else {
-		reader->buffer = 0;
-		if (start + 0u < size)
-			reader->buffer |= reader->data[start + 0];
-		if (start + 1u < size)
-			reader->buffer |= ((u32)reader->data[start + 1] << 8u);
-		if (start + 2u < size)
-			reader->buffer |= ((u32)reader->data[start + 2] << 16u);
-		if (start + 3u < size)
-			reader->buffer |= ((u32)reader->data[start + 3] << 24u);
-		reader->buffer >>= (reader->bp & 7u);
-		return reader->bp + nbits <= reader->bitsize;
-	}
-}
-
-/* Get bits without advancing the bit pointer. Must have enough bits available with ensureBits. Max nbits is 31. */
-static u32 peekBits(pngBitReader *reader, u32 nbits)
-{
-	/* The shift allows nbits to be only up to 31. */
-	return reader->buffer & ((1u << nbits) - 1u);
-}
-
-/* Must have enough bits available with ensureBits */
-static void advanceBits(pngBitReader *reader, u32 nbits)
-{
-	reader->buffer >>= nbits;
-	reader->bp += nbits;
-}
-
-/* Must have enough bits available with ensureBits */
-static u32 readBits(pngBitReader *reader, u32 nbits)
-{
-	u32 result = peekBits(reader, nbits);
-	advanceBits(reader, nbits);
-	return result;
-}
-
-/* Public for testing only. steps and result must have numsteps values. */
-/*static u32 png_test_bitreader(const u8 *data, u32 size, u32 numsteps, const u32 *steps, u32 *result)
-{
-	u32 i;
-	pngBitReader reader;
-	u32 error = pngBitReader_init(&reader, data, size);
-	if (error)
-		return 0;
-	for (i = 0; i < numsteps; i++) {
-		u32 step = steps[i];
-		u32 ok;
-		if (step > 25)
-			ok = ensureBits32(&reader, step);
-		else if (step > 17)
-			ok = ensureBits25(&reader, step);
-		else if (step > 9)
-			ok = ensureBits17(&reader, step);
-		else
-			ok = ensureBits9(&reader, step);
-		if (!ok)
-			return 0;
-		result[i] = readBits(&reader, step);
-	}
-	return 1;
-}*/
-#endif /*PNG_COMPILE_DECODER*/
-
-static u32 reverseBits(u32 bits, u32 num)
-{
-	/*TODO: implement faster lookup table based version when needed*/
-	u32 i, result = 0;
-	for (i = 0; i < num; i++)
-		result |= ((bits >> (num - i - 1u)) & 1u) << i;
-	return result;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Deflate - Huffman                                                      / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#define FIRST_LENGTH_CODE_INDEX 257
-#define LAST_LENGTH_CODE_INDEX 285
-/*256 literals, the end code, some length codes, and 2 unused codes*/
-#define NUM_DEFLATE_CODE_SYMBOLS 288
-/*the distance codes have their own symbols, 30 used, 2 unused*/
-#define NUM_DISTANCE_SYMBOLS 32
-/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
-#define NUM_CODE_LENGTH_CODES 19
-
-/*the base lengths represented by codes 257-285*/
-static const u32 LENGTHBASE[29] = { 3,	4,  5,	6,  7,	8,  9,	10, 11,	 13,  15,  17,	19,  23, 27,
-				    31, 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258 };
-
-/*the extra bits used by codes 257-285 (added to base length)*/
-static const u32 LENGTHEXTRA[29] = { 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2,
-				     2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0 };
-
-/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
-static const u32 DISTANCEBASE[30] = {
-	1,   2,	  3,   4,   5,	 7,    9,    13,   17,	 25,   33,   49,   65,	  97,	 129,
-	193, 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577
-};
-
-/*the extra bits of backwards distances (added to base)*/
-static const u32 DISTANCEEXTRA[30] = { 0, 0, 0, 0, 1, 1, 2, 2,	3,  3,	4,  4,	5,  5,	6,
-				       6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13 };
-
-/*the order in which "code length alphabet code lengths" are stored as specified by deflate, out of this the huffman
-tree of the dynamic huffman tree lengths is generated*/
-static const u32 CLCL_ORDER[NUM_CODE_LENGTH_CODES] = { 16, 17, 18, 0, 8,  7, 9,	 6, 10, 5,
-						       11, 4,  12, 3, 13, 2, 14, 1, 15 };
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*
-Huffman tree struct, containing multiple representations of the tree
-*/
-typedef struct HuffmanTree {
-	u32 *codes; /*the huffman codes (bit patterns representing the symbols)*/
-	u32 *lengths; /*the lengths of the huffman codes*/
-	u32 maxbitlen; /*maximum number of bits a single code can get*/
-	u32 numcodes; /*number of symbols in the alphabet = number of codes*/
-	/* for reading only */
-	u8 *table_len; /*length of symbol from lookup table, or max length if secondary lookup needed*/
-	u16 *table_value; /*value of symbol from lookup table, or pointer to secondary table if needed*/
-} HuffmanTree;
-
-static void HuffmanTree_init(HuffmanTree *tree)
-{
-	tree->codes = 0;
-	tree->lengths = 0;
-	tree->table_len = 0;
-	tree->table_value = 0;
-}
-
-static void HuffmanTree_cleanup(HuffmanTree *tree)
-{
-	png_free(tree->codes);
-	png_free(tree->lengths);
-	png_free(tree->table_len);
-	png_free(tree->table_value);
-}
-
-/* amount of bits for first huffman table lookup (aka root bits), see HuffmanTree_makeTable and huffmanDecodeSymbol.*/
-/* values 8u and 9u work the fastest */
-#define FIRSTBITS 9u
-
-/* a symbol value too big to represent any valid symbol, to indicate reading disallowed huffman bits combination,
-which is possible in case of only 0 or 1 present symbols. */
-#define INVALIDSYMBOL 65535u
-
-/* make table for huffman decoding */
-static u32 HuffmanTree_makeTable(HuffmanTree *tree)
-{
-	static const u32 headsize = 1u << FIRSTBITS; /*size of the first table*/
-	static const u32 mask = (1u << FIRSTBITS) /*headsize*/ - 1u;
-	u32 i, numpresent, pointer, size; /*total table size*/
-	u32 *maxlens = (u32 *)png_malloc(headsize * sizeof(u32));
-	if (!maxlens)
-		return 83; /*alloc fail*/
-
-	/* compute maxlens: max total bit length of symbols sharing prefix in the first table*/
-	png_memset(maxlens, 0, headsize * sizeof(*maxlens));
-	for (i = 0; i < tree->numcodes; i++) {
-		u32 symbol = tree->codes[i];
-		u32 l = tree->lengths[i];
-		u32 index;
-		if (l <= FIRSTBITS)
-			continue; /*symbols that fit in first table don't increase secondary table size*/
-		/*get the FIRSTBITS MSBs, the MSBs of the symbol are encoded first. See later comment about the reversing*/
-		index = reverseBits(symbol >> (l - FIRSTBITS), FIRSTBITS);
-		maxlens[index] = PNG_MAX(maxlens[index], l);
-	}
-	/* compute total table size: size of first table plus all secondary tables for symbols longer than FIRSTBITS */
-	size = headsize;
-	for (i = 0; i < headsize; ++i) {
-		u32 l = maxlens[i];
-		if (l > FIRSTBITS)
-			size += (1u << (l - FIRSTBITS));
-	}
-	tree->table_len = (u8 *)png_malloc(size * sizeof(*tree->table_len));
-	tree->table_value = (u16 *)png_malloc(size * sizeof(*tree->table_value));
-	if (!tree->table_len || !tree->table_value) {
-		png_free(maxlens);
-		/* freeing tree->table values is done at a higher scope */
-		return 83; /*alloc fail*/
-	}
-	/*initialize with an invalid length to indicate unused entries*/
-	for (i = 0; i < size; ++i)
-		tree->table_len[i] = 16;
-
-	/*fill in the first table for long symbols: max prefix size and pointer to secondary tables*/
-	pointer = headsize;
-	for (i = 0; i < headsize; ++i) {
-		u32 l = maxlens[i];
-		if (l <= FIRSTBITS)
-			continue;
-		tree->table_len[i] = l;
-		tree->table_value[i] = pointer;
-		pointer += (1u << (l - FIRSTBITS));
-	}
-	png_free(maxlens);
-
-	/*fill in the first table for short symbols, or secondary table for long symbols*/
-	numpresent = 0;
-	for (i = 0; i < tree->numcodes; ++i) {
-		u32 l = tree->lengths[i];
-		u32 symbol = tree->codes[i]; /*the huffman bit pattern. i itself is the value.*/
-		/*reverse bits, because the huffman bits are given in MSB first order but the bit reader reads LSB first*/
-		u32 reverse = reverseBits(symbol, l);
-		if (l == 0)
-			continue;
-		numpresent++;
-
-		if (l <= FIRSTBITS) {
-			/*short symbol, fully in first table, replicated num times if l < FIRSTBITS*/
-			u32 num = 1u << (FIRSTBITS - l);
-			u32 j;
-			for (j = 0; j < num; ++j) {
-				/*bit reader will read the l bits of symbol first, the remaining FIRSTBITS - l bits go to the MSB's*/
-				u32 index = reverse | (j << l);
-				if (tree->table_len[index] != 16)
-					return 55; /*invalid tree: long symbol shares prefix with short symbol*/
-				tree->table_len[index] = l;
-				tree->table_value[index] = i;
-			}
-		} else {
-			/*long symbol, shares prefix with other long symbols in first lookup table, needs second lookup*/
-			/*the FIRSTBITS MSBs of the symbol are the first table index*/
-			u32 index = reverse & mask;
-			u32 maxlen = tree->table_len[index];
-			/*log2 of secondary table length, should be >= l - FIRSTBITS*/
-			u32 tablelen = maxlen - FIRSTBITS;
-			u32 start = tree->table_value[index]; /*starting index in secondary table*/
-			u32 num =
-				1u
-				<< (tablelen -
-				    (l -
-				     FIRSTBITS)); /*amount of entries of this symbol in secondary table*/
-			u32 j;
-			if (maxlen < l)
-				return 55; /*invalid tree: long symbol shares prefix with short symbol*/
-			for (j = 0; j < num; ++j) {
-				u32 reverse2 = reverse >> FIRSTBITS; /* l - FIRSTBITS bits */
-				u32 index2 = start + (reverse2 | (j << (l - FIRSTBITS)));
-				tree->table_len[index2] = l;
-				tree->table_value[index2] = i;
-			}
-		}
-	}
-
-	if (numpresent < 2) {
-		/* In case of exactly 1 symbol, in theory the huffman symbol needs 0 bits,
-    but deflate uses 1 bit instead. In case of 0 symbols, no symbols can
-    appear at all, but such huffman tree could still exist (e.g. if distance
-    codes are never used). In both cases, not all symbols of the table will be
-    filled in. Fill them in with an invalid symbol value so returning them from
-    huffmanDecodeSymbol will cause error. */
-		for (i = 0; i < size; ++i) {
-			if (tree->table_len[i] == 16) {
-				/* As length, use a value smaller than FIRSTBITS for the head table,
-        and a value larger than FIRSTBITS for the secondary table, to ensure
-        valid behavior for advanceBits when reading this symbol. */
-				tree->table_len[i] = (i < headsize) ? 1 : (FIRSTBITS + 1);
-				tree->table_value[i] = INVALIDSYMBOL;
-			}
-		}
-	} else {
-		/* A good huffman tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
-    If that is not the case (due to too long length codes), the table will not
-    have been fully used, and this is an error (not all bit combinations can be
-    decoded): an oversubscribed huffman tree, indicated by error 55. */
-		for (i = 0; i < size; ++i) {
-			if (tree->table_len[i] == 16)
-				return 55;
-		}
-	}
-
-	return 0;
-}
-
-/*
-Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
-numcodes, lengths and maxbitlen must already be filled in correctly. return
-value is error.
-*/
-static u32 HuffmanTree_makeFromLengths2(HuffmanTree *tree)
-{
-	u32 *blcount;
-	u32 *nextcode;
-	u32 error = 0;
-	u32 bits, n;
-
-	tree->codes = (u32 *)png_malloc(tree->numcodes * sizeof(u32));
-	blcount = (u32 *)png_malloc((tree->maxbitlen + 1) * sizeof(u32));
-	nextcode = (u32 *)png_malloc((tree->maxbitlen + 1) * sizeof(u32));
-	if (!tree->codes || !blcount || !nextcode)
-		error = 83; /*alloc fail*/
-
-	if (!error) {
-		for (n = 0; n != tree->maxbitlen + 1; n++)
-			blcount[n] = nextcode[n] = 0;
-		/*step 1: count number of instances of each code length*/
-		for (bits = 0; bits != tree->numcodes; ++bits)
-			++blcount[tree->lengths[bits]];
-		/*step 2: generate the nextcode values*/
-		for (bits = 1; bits <= tree->maxbitlen; ++bits) {
-			nextcode[bits] = (nextcode[bits - 1] + blcount[bits - 1]) << 1u;
-		}
-		/*step 3: generate all the codes*/
-		for (n = 0; n != tree->numcodes; ++n) {
-			if (tree->lengths[n] != 0) {
-				tree->codes[n] = nextcode[tree->lengths[n]]++;
-				/*remove superfluous bits from the code*/
-				tree->codes[n] &= ((1u << tree->lengths[n]) - 1u);
-			}
-		}
-	}
-
-	png_free(blcount);
-	png_free(nextcode);
-
-	if (!error)
-		error = HuffmanTree_makeTable(tree);
-	return error;
-}
-
-/*
-given the code lengths (as stored in the PNG file), generate the tree as defined
-by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
-return value is error.
-*/
-static u32 HuffmanTree_makeFromLengths(HuffmanTree *tree, const u32 *bitlen, u32 numcodes,
-				       u32 maxbitlen)
-{
-	u32 i;
-	tree->lengths = (u32 *)png_malloc(numcodes * sizeof(u32));
-	if (!tree->lengths)
-		return 83; /*alloc fail*/
-	for (i = 0; i != numcodes; ++i)
-		tree->lengths[i] = bitlen[i];
-	tree->numcodes = (u32)numcodes; /*number of symbols*/
-	tree->maxbitlen = maxbitlen;
-	return HuffmanTree_makeFromLengths2(tree);
-}
-
-#ifdef PNG_COMPILE_ENCODER
-
-/*BPM: Boundary Package Merge, see "A Fast and Space-Economical Algorithm for Length-Limited Coding",
-Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/
-
-/*chain node for boundary package merge*/
-typedef struct BPMNode {
-	int weight; /*the sum of all weights in this chain*/
-	u32 index; /*index of this leaf node (called "count" in the paper)*/
-	struct BPMNode *tail; /*the next nodes in this chain (null if last)*/
-	int in_use;
-} BPMNode;
-
-/*lists of chains*/
-typedef struct BPMLists {
-	/*memory pool*/
-	u32 memsize;
-	BPMNode *memory;
-	u32 numfree;
-	u32 nextfree;
-	BPMNode **freelist;
-	/*two heads of lookahead chains per list*/
-	u32 listsize;
-	BPMNode **chains0;
-	BPMNode **chains1;
-} BPMLists;
-
-/*creates a new chain node with the given parameters, from the memory in the lists */
-static BPMNode *bpmnode_create(BPMLists *lists, int weight, u32 index, BPMNode *tail)
-{
-	u32 i;
-	BPMNode *result;
-
-	/*memory full, so garbage collect*/
-	if (lists->nextfree >= lists->numfree) {
-		/*mark only those that are in use*/
-		for (i = 0; i != lists->memsize; ++i)
-			lists->memory[i].in_use = 0;
-		for (i = 0; i != lists->listsize; ++i) {
-			BPMNode *node;
-			for (node = lists->chains0[i]; node != 0; node = node->tail)
-				node->in_use = 1;
-			for (node = lists->chains1[i]; node != 0; node = node->tail)
-				node->in_use = 1;
-		}
-		/*collect those that are free*/
-		lists->numfree = 0;
-		for (i = 0; i != lists->memsize; ++i) {
-			if (!lists->memory[i].in_use)
-				lists->freelist[lists->numfree++] = &lists->memory[i];
-		}
-		lists->nextfree = 0;
-	}
-
-	result = lists->freelist[lists->nextfree++];
-	result->weight = weight;
-	result->index = index;
-	result->tail = tail;
-	return result;
-}
-
-/*sort the leaves with stable mergesort*/
-static void bpmnode_sort(BPMNode *leaves, u32 num)
-{
-	BPMNode *mem = (BPMNode *)png_malloc(sizeof(*leaves) * num);
-	u32 width, counter = 0;
-	for (width = 1; width < num; width *= 2) {
-		BPMNode *a = (counter & 1) ? mem : leaves;
-		BPMNode *b = (counter & 1) ? leaves : mem;
-		u32 p;
-		for (p = 0; p < num; p += 2 * width) {
-			u32 q = (p + width > num) ? num : (p + width);
-			u32 r = (p + 2 * width > num) ? num : (p + 2 * width);
-			u32 i = p, j = q, k;
-			for (k = p; k < r; k++) {
-				if (i < q && (j >= r || a[i].weight <= a[j].weight))
-					b[k] = a[i++];
-				else
-					b[k] = a[j++];
-			}
-		}
-		counter++;
-	}
-	if (counter & 1)
-		png_memcpy(leaves, mem, sizeof(*leaves) * num);
-	png_free(mem);
-}
-
-/*Boundary Package Merge step, numpresent is the amount of leaves, and c is the current chain.*/
-static void boundaryPM(BPMLists *lists, BPMNode *leaves, u32 numpresent, int c, int num)
-{
-	u32 lastindex = lists->chains1[c]->index;
-
-	if (c == 0) {
-		if (lastindex >= numpresent)
-			return;
-		lists->chains0[c] = lists->chains1[c];
-		lists->chains1[c] =
-			bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, 0);
-	} else {
-		/*sum of the weights of the head nodes of the previous lookahead chains.*/
-		int sum = lists->chains0[c - 1]->weight + lists->chains1[c - 1]->weight;
-		lists->chains0[c] = lists->chains1[c];
-		if (lastindex < numpresent && sum > leaves[lastindex].weight) {
-			lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight,
-							   lastindex + 1, lists->chains1[c]->tail);
-			return;
-		}
-		lists->chains1[c] = bpmnode_create(lists, sum, lastindex, lists->chains1[c - 1]);
-		/*in the end we are only interested in the chain of the last list, so no
-    need to recurse if we're at the last one (this gives measurable speedup)*/
-		if (num + 1 < (int)(2 * numpresent - 2)) {
-			boundaryPM(lists, leaves, numpresent, c - 1, num);
-			boundaryPM(lists, leaves, numpresent, c - 1, num);
-		}
-	}
-}
-
-u32 png_huffman_code_lengths(u32 *lengths, const u32 *frequencies, u32 numcodes, u32 maxbitlen)
-{
-	u32 error = 0;
-	u32 i;
-	u32 numpresent = 0; /*number of symbols with non-zero frequency*/
-	BPMNode *leaves; /*the symbols, only those with > 0 frequency*/
-
-	if (numcodes == 0)
-		return 80; /*error: a tree of 0 symbols is not supposed to be made*/
-	if ((1u << maxbitlen) < (u32)numcodes)
-		return 80; /*error: represent all symbols*/
-
-	leaves = (BPMNode *)png_malloc(numcodes * sizeof(*leaves));
-	if (!leaves)
-		return 83; /*alloc fail*/
-
-	for (i = 0; i != numcodes; ++i) {
-		if (frequencies[i] > 0) {
-			leaves[numpresent].weight = (int)frequencies[i];
-			leaves[numpresent].index = i;
-			++numpresent;
-		}
-	}
-
-	png_memset(lengths, 0, numcodes * sizeof(*lengths));
-
-	/*ensure at least two present symbols. There should be at least one symbol
-  according to RFC 1951 section 3.2.7. Some decoders incorrectly require two. To
-  make these work as well ensure there are at least two symbols. The
-  Package-Merge code below also doesn't work correctly if there's only one
-  symbol, it'd give it the theoretical 0 bits but in practice zlib wants 1 bit*/
-	if (numpresent == 0) {
-		lengths[0] = lengths[1] =
-			1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/
-	} else if (numpresent == 1) {
-		lengths[leaves[0].index] = 1;
-		lengths[leaves[0].index == 0 ? 1 : 0] = 1;
-	} else {
-		BPMLists lists;
-		BPMNode *node;
-
-		bpmnode_sort(leaves, numpresent);
-
-		lists.listsize = maxbitlen;
-		lists.memsize = 2 * maxbitlen * (maxbitlen + 1);
-		lists.nextfree = 0;
-		lists.numfree = lists.memsize;
-		lists.memory = (BPMNode *)png_malloc(lists.memsize * sizeof(*lists.memory));
-		lists.freelist = (BPMNode **)png_malloc(lists.memsize * sizeof(BPMNode *));
-		lists.chains0 = (BPMNode **)png_malloc(lists.listsize * sizeof(BPMNode *));
-		lists.chains1 = (BPMNode **)png_malloc(lists.listsize * sizeof(BPMNode *));
-		if (!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1)
-			error = 83; /*alloc fail*/
-
-		if (!error) {
-			for (i = 0; i != lists.memsize; ++i)
-				lists.freelist[i] = &lists.memory[i];
-
-			bpmnode_create(&lists, leaves[0].weight, 1, 0);
-			bpmnode_create(&lists, leaves[1].weight, 2, 0);
-
-			for (i = 0; i != lists.listsize; ++i) {
-				lists.chains0[i] = &lists.memory[0];
-				lists.chains1[i] = &lists.memory[1];
-			}
-
-			/*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/
-			for (i = 2; i != 2 * numpresent - 2; ++i)
-				boundaryPM(&lists, leaves, numpresent, (int)maxbitlen - 1, (int)i);
-
-			for (node = lists.chains1[maxbitlen - 1]; node; node = node->tail) {
-				for (i = 0; i != node->index; ++i)
-					++lengths[leaves[i].index];
-			}
-		}
-
-		png_free(lists.memory);
-		png_free(lists.freelist);
-		png_free(lists.chains0);
-		png_free(lists.chains1);
-	}
-
-	png_free(leaves);
-	return error;
-}
-
-/*Create the Huffman tree given the symbol frequencies*/
-static u32 HuffmanTree_makeFromFrequencies(HuffmanTree *tree, const u32 *frequencies, u32 mincodes,
-					   u32 numcodes, u32 maxbitlen)
-{
-	u32 error = 0;
-	while (!frequencies[numcodes - 1] && numcodes > mincodes)
-		--numcodes; /*trim zeroes*/
-	tree->lengths = (u32 *)png_malloc(numcodes * sizeof(u32));
-	if (!tree->lengths)
-		return 83; /*alloc fail*/
-	tree->maxbitlen = maxbitlen;
-	tree->numcodes = (u32)numcodes; /*number of symbols*/
-
-	error = png_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen);
-	if (!error)
-		error = HuffmanTree_makeFromLengths2(tree);
-	return error;
-}
-#endif /*PNG_COMPILE_ENCODER*/
-
-/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
-static u32 generateFixedLitLenTree(HuffmanTree *tree)
-{
-	u32 i, error = 0;
-	u32 *bitlen = (u32 *)png_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(u32));
-	if (!bitlen)
-		return 83; /*alloc fail*/
-
-	/*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
-	for (i = 0; i <= 143; ++i)
-		bitlen[i] = 8;
-	for (i = 144; i <= 255; ++i)
-		bitlen[i] = 9;
-	for (i = 256; i <= 279; ++i)
-		bitlen[i] = 7;
-	for (i = 280; i <= 287; ++i)
-		bitlen[i] = 8;
-
-	error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15);
-
-	png_free(bitlen);
-	return error;
-}
-
-/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
-static u32 generateFixedDistanceTree(HuffmanTree *tree)
-{
-	u32 i, error = 0;
-	u32 *bitlen = (u32 *)png_malloc(NUM_DISTANCE_SYMBOLS * sizeof(u32));
-	if (!bitlen)
-		return 83; /*alloc fail*/
-
-	/*there are 32 distance codes, but 30-31 are unused*/
-	for (i = 0; i != NUM_DISTANCE_SYMBOLS; ++i)
-		bitlen[i] = 5;
-	error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15);
-
-	png_free(bitlen);
-	return error;
-}
-
-#ifdef PNG_COMPILE_DECODER
-
-/*
-returns the code. The bit reader must already have been ensured at least 15 bits
-*/
-static u32 huffmanDecodeSymbol(pngBitReader *reader, const HuffmanTree *codetree)
-{
-	u16 code = peekBits(reader, FIRSTBITS);
-	u16 l = codetree->table_len[code];
-	u16 value = codetree->table_value[code];
-	if (l <= FIRSTBITS) {
-		advanceBits(reader, l);
-		return value;
-	} else {
-		u32 index2;
-		advanceBits(reader, FIRSTBITS);
-		index2 = value + peekBits(reader, l - FIRSTBITS);
-		advanceBits(reader, codetree->table_len[index2] - FIRSTBITS);
-		return codetree->table_value[index2];
-	}
-}
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_DECODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Inflator (Decompressor)                                                / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*get the tree of a deflated block with fixed tree, as specified in the deflate specification
-Returns error code.*/
-static u32 getTreeInflateFixed(HuffmanTree *tree_ll, HuffmanTree *tree_d)
-{
-	u32 error = generateFixedLitLenTree(tree_ll);
-	if (error)
-		return error;
-	return generateFixedDistanceTree(tree_d);
-}
-
-/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
-static u32 getTreeInflateDynamic(HuffmanTree *tree_ll, HuffmanTree *tree_d, pngBitReader *reader)
-{
-	/*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
-	u32 error = 0;
-	u32 n, HLIT, HDIST, HCLEN, i;
-
-	/*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
-	u32 *bitlen_ll = 0; /*lit,len code lengths*/
-	u32 *bitlen_d = 0; /*dist code lengths*/
-	/*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
-	u32 *bitlen_cl = 0;
-	HuffmanTree
-		tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
-
-	if (!ensureBits17(reader, 14))
-		return 49; /*error: the bit pointer is or will go past the memory*/
-
-	/*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
-	HLIT = readBits(reader, 5) + 257;
-	/*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
-	HDIST = readBits(reader, 5) + 1;
-	/*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
-	HCLEN = readBits(reader, 4) + 4;
-
-	bitlen_cl = (u32 *)png_malloc(NUM_CODE_LENGTH_CODES * sizeof(u32));
-	if (!bitlen_cl)
-		return 83 /*alloc fail*/;
-
-	HuffmanTree_init(&tree_cl);
-
-	while (!error) {
-		/*read the code length codes out of 3 * (amount of code length codes) bits*/
-		if (png_gtofl(reader->bp, HCLEN * 3, reader->bitsize)) {
-			ERROR_BREAK(50); /*error: the bit pointer is or will go past the memory*/
-		}
-		for (i = 0; i != HCLEN; ++i) {
-			ensureBits9(reader, 3); /*out of bounds already checked above */
-			bitlen_cl[CLCL_ORDER[i]] = readBits(reader, 3);
-		}
-		for (i = HCLEN; i != NUM_CODE_LENGTH_CODES; ++i) {
-			bitlen_cl[CLCL_ORDER[i]] = 0;
-		}
-
-		error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7);
-		if (error)
-			break;
-
-		/*now we can use this tree to read the lengths for the tree that this function will return*/
-		bitlen_ll = (u32 *)png_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(u32));
-		bitlen_d = (u32 *)png_malloc(NUM_DISTANCE_SYMBOLS * sizeof(u32));
-		if (!bitlen_ll || !bitlen_d)
-			ERROR_BREAK(83 /*alloc fail*/);
-		png_memset(bitlen_ll, 0, NUM_DEFLATE_CODE_SYMBOLS * sizeof(*bitlen_ll));
-		png_memset(bitlen_d, 0, NUM_DISTANCE_SYMBOLS * sizeof(*bitlen_d));
-
-		/*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
-		i = 0;
-		while (i < HLIT + HDIST) {
-			u32 code;
-			ensureBits25(
-				reader,
-				22); /* up to 15 bits for huffman code, up to 7 extra bits below*/
-			code = huffmanDecodeSymbol(reader, &tree_cl);
-			if (code <= 15) /*a length code*/ {
-				if (i < HLIT)
-					bitlen_ll[i] = code;
-				else
-					bitlen_d[i - HLIT] = code;
-				++i;
-			} else if (code == 16) /*repeat previous*/ {
-				u32 replength =
-					3; /*read in the 2 bits that indicate repeat length (3-6)*/
-				u32 value; /*set value to the previous code*/
-
-				if (i == 0)
-					ERROR_BREAK(54); /*can't repeat previous if i is 0*/
-
-				replength += readBits(reader, 2);
-
-				if (i < HLIT + 1)
-					value = bitlen_ll[i - 1];
-				else
-					value = bitlen_d[i - HLIT - 1];
-				/*repeat this value in the next lengths*/
-				for (n = 0; n < replength; ++n) {
-					if (i >= HLIT + HDIST)
-						ERROR_BREAK(
-							13); /*error: i is larger than the amount of codes*/
-					if (i < HLIT)
-						bitlen_ll[i] = value;
-					else
-						bitlen_d[i - HLIT] = value;
-					++i;
-				}
-			} else if (code == 17) /*repeat "0" 3-10 times*/ {
-				u32 replength = 3; /*read in the bits that indicate repeat length*/
-				replength += readBits(reader, 3);
-
-				/*repeat this value in the next lengths*/
-				for (n = 0; n < replength; ++n) {
-					if (i >= HLIT + HDIST)
-						ERROR_BREAK(
-							14); /*error: i is larger than the amount of codes*/
-
-					if (i < HLIT)
-						bitlen_ll[i] = 0;
-					else
-						bitlen_d[i - HLIT] = 0;
-					++i;
-				}
-			} else if (code == 18) /*repeat "0" 11-138 times*/ {
-				u32 replength = 11; /*read in the bits that indicate repeat length*/
-				replength += readBits(reader, 7);
-
-				/*repeat this value in the next lengths*/
-				for (n = 0; n < replength; ++n) {
-					if (i >= HLIT + HDIST)
-						ERROR_BREAK(
-							15); /*error: i is larger than the amount of codes*/
-
-					if (i < HLIT)
-						bitlen_ll[i] = 0;
-					else
-						bitlen_d[i - HLIT] = 0;
-					++i;
-				}
-			} else /*if(code == INVALIDSYMBOL)*/ {
-				ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
-			}
-			/*check if any of the ensureBits above went out of bounds*/
-			if (reader->bp > reader->bitsize) {
-				/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
-        (10=no endcode, 11=wrong jump outside of tree)*/
-				/* TODO: revise error codes 10,11,50: the above comment is no longer valid */
-				ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
-			}
-		}
-		if (error)
-			break;
-
-		if (bitlen_ll[256] == 0)
-			ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
-
-		/*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
-		error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS,
-						    15);
-		if (error)
-			break;
-		error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15);
-
-		break; /*end of error-while*/
-	}
-
-	png_free(bitlen_cl);
-	png_free(bitlen_ll);
-	png_free(bitlen_d);
-	HuffmanTree_cleanup(&tree_cl);
-
-	return error;
-}
-
-/*inflate a block with dynamic of fixed Huffman tree. btype must be 1 or 2.*/
-static u32 inflateHuffmanBlock(ucvector *out, pngBitReader *reader, u32 btype, u32 max_output_size)
-{
-	u32 error = 0;
-	HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
-	HuffmanTree tree_d; /*the huffman tree for distance codes*/
-
-	HuffmanTree_init(&tree_ll);
-	HuffmanTree_init(&tree_d);
-
-	if (btype == 1)
-		error = getTreeInflateFixed(&tree_ll, &tree_d);
-	else /*if(btype == 2)*/
-		error = getTreeInflateDynamic(&tree_ll, &tree_d, reader);
-
-	while (!error) /*decode all symbols until end reached, breaks at end code*/ {
-		/*code_ll is literal, length or end code*/
-		u32 code_ll;
-		ensureBits25(
-			reader,
-			20); /* up to 15 for the huffman symbol, up to 5 for the length extra bits */
-		code_ll = huffmanDecodeSymbol(reader, &tree_ll);
-		if (code_ll <= 255) /*literal symbol*/ {
-			if (!ucvector_resize(out, out->size + 1))
-				ERROR_BREAK(83 /*alloc fail*/);
-			out->data[out->size - 1] = (u8)code_ll;
-		} else if (code_ll >= FIRST_LENGTH_CODE_INDEX &&
-			   code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ {
-			u32 code_d, distance;
-			u32 numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
-			u32 start, backward, length;
-
-			/*part 1: get length base*/
-			length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
-
-			/*part 2: get extra bits and add the value of that to length*/
-			numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
-			if (numextrabits_l != 0) {
-				/* bits already ensured above */
-				length += readBits(reader, numextrabits_l);
-			}
-
-			/*part 3: get distance code*/
-			ensureBits32(
-				reader,
-				28); /* up to 15 for the huffman symbol, up to 13 for the extra bits */
-			code_d = huffmanDecodeSymbol(reader, &tree_d);
-			if (code_d > 29) {
-				if (code_d <= 31) {
-					ERROR_BREAK(
-						18); /*error: invalid distance code (30-31 are never used)*/
-				} else /* if(code_d == INVALIDSYMBOL) */ {
-					ERROR_BREAK(
-						16); /*error: tried to read disallowed huffman symbol*/
-				}
-			}
-			distance = DISTANCEBASE[code_d];
-
-			/*part 4: get extra bits from distance*/
-			numextrabits_d = DISTANCEEXTRA[code_d];
-			if (numextrabits_d != 0) {
-				/* bits already ensured above */
-				distance += readBits(reader, numextrabits_d);
-			}
-
-			/*part 5: fill in all the out[n] values based on the length and dist*/
-			start = out->size;
-			if (distance > start)
-				ERROR_BREAK(52); /*too long backward distance*/
-			backward = start - distance;
-
-			if (!ucvector_resize(out, out->size + length))
-				ERROR_BREAK(83 /*alloc fail*/);
-			if (distance < length) {
-				u32 forward;
-				png_memcpy(out->data + start, out->data + backward, distance);
-				start += distance;
-				for (forward = distance; forward < length; ++forward) {
-					out->data[start++] = out->data[backward++];
-				}
-			} else {
-				png_memcpy(out->data + start, out->data + backward, length);
-			}
-		} else if (code_ll == 256) {
-			break; /*end code, break the loop*/
-		} else /*if(code_ll == INVALIDSYMBOL)*/ {
-			ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
-		}
-		/*check if any of the ensureBits above went out of bounds*/
-		if (reader->bp > reader->bitsize) {
-			/*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
-      (10=no endcode, 11=wrong jump outside of tree)*/
-			/* TODO: revise error codes 10,11,50: the above comment is no longer valid */
-			ERROR_BREAK(51); /*error, bit pointer jumps past memory*/
-		}
-		if (max_output_size && out->size > max_output_size) {
-			ERROR_BREAK(109); /*error, larger than max size*/
-		}
-	}
-
-	HuffmanTree_cleanup(&tree_ll);
-	HuffmanTree_cleanup(&tree_d);
-
-	return error;
-}
-
-static u32 inflateNoCompression(ucvector *out, pngBitReader *reader,
-				const pngDecompressSettings *settings)
-{
-	u32 bytepos;
-	u32 size = reader->size;
-	u32 LEN, NLEN, error = 0;
-
-	/*go to first boundary of byte*/
-	bytepos = (reader->bp + 7u) >> 3u;
-
-	/*read LEN (2 bytes) and NLEN (2 bytes)*/
-	if (bytepos + 4 >= size)
-		return 52; /*error, bit pointer will jump past memory*/
-	LEN = (u32)reader->data[bytepos] + ((u32)reader->data[bytepos + 1] << 8u);
-	bytepos += 2;
-	NLEN = (u32)reader->data[bytepos] + ((u32)reader->data[bytepos + 1] << 8u);
-	bytepos += 2;
-
-	/*check if 16-bit NLEN is really the one's complement of LEN*/
-	if (!settings->ignore_nlen && LEN + NLEN != 65535) {
-		return 21; /*error: NLEN is not one's complement of LEN*/
-	}
-
-	if (!ucvector_resize(out, out->size + LEN))
-		return 83; /*alloc fail*/
-
-	/*read the literal data: LEN bytes are now stored in the out buffer*/
-	if (bytepos + LEN > size)
-		return 23; /*error: reading outside of in buffer*/
-
-	png_memcpy(out->data + out->size - LEN, reader->data + bytepos, LEN);
-	bytepos += LEN;
-
-	reader->bp = bytepos << 3u;
-
-	return error;
-}
-
-static u32 png_inflatev(ucvector *out, const u8 *in, u32 insize,
-			const pngDecompressSettings *settings)
-{
-	u32 BFINAL = 0;
-	pngBitReader reader;
-	u32 error = pngBitReader_init(&reader, in, insize);
-
-	if (error)
-		return error;
-
-	while (!BFINAL) {
-		u32 BTYPE;
-		if (!ensureBits9(&reader, 3))
-			return 52; /*error, bit pointer will jump past memory*/
-		BFINAL = readBits(&reader, 1);
-		BTYPE = readBits(&reader, 2);
-
-		if (BTYPE == 3)
-			return 20; /*error: invalid BTYPE*/
-		else if (BTYPE == 0)
-			error = inflateNoCompression(out, &reader, settings); /*no compression*/
-		else
-			error = inflateHuffmanBlock(
-				out, &reader, BTYPE,
-				settings->max_output_size); /*compression, BTYPE 01 or 10*/
-		if (!error && settings->max_output_size && out->size > settings->max_output_size)
-			error = 109;
-		if (error)
-			break;
-	}
-
-	return error;
-}
-
-u32 png_inflate(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-		const pngDecompressSettings *settings)
-{
-	ucvector v = ucvector_init(*out, *outsize);
-	u32 error = png_inflatev(&v, in, insize, settings);
-	*out = v.data;
-	*outsize = v.size;
-	return error;
-}
-
-static u32 inflatev(ucvector *out, const u8 *in, u32 insize, const pngDecompressSettings *settings)
-{
-	if (settings->custom_inflate) {
-		u32 error = settings->custom_inflate(&out->data, &out->size, in, insize, settings);
-		out->allocsize = out->size;
-		if (error) {
-			/*the custom inflate is allowed to have its own error codes, however, we translate it to code 110*/
-			error = 110;
-			/*if there's a max output size, and the custom zlib returned error, then indicate that error instead*/
-			if (settings->max_output_size && out->size > settings->max_output_size)
-				error = 109;
-		}
-		return error;
-	} else {
-		return png_inflatev(out, in, insize, settings);
-	}
-}
-
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_ENCODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Deflator (Compressor)                                                  / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-static const u32 MAX_SUPPORTED_DEFLATE_LENGTH = 258;
-
-/*search the index in the array, that has the largest value smaller than or equal to the given value,
-given array must be sorted (if no value is smaller, it returns the size of the given array)*/
-static u32 searchCodeIndex(const u32 *array, u32 array_size, u32 value)
-{
-	/*binary search (only small gain over linear). TODO: use CPU log2 instruction for getting symbols instead*/
-	u32 left = 1;
-	u32 right = array_size - 1;
-
-	while (left <= right) {
-		u32 mid = (left + right) >> 1;
-		if (array[mid] >= value)
-			right = mid - 1;
-		else
-			left = mid + 1;
-	}
-	if (left >= array_size || array[left] > value)
-		left--;
-	return left;
-}
-
-static void addLengthDistance(uivector *values, u32 length, u32 distance)
-{
-	/*values in encoded vector are those used by deflate:
-  0-255: literal bytes
-  256: end
-  257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
-  286-287: invalid*/
-
-	u32 length_code = (u32)searchCodeIndex(LENGTHBASE, 29, length);
-	u32 extra_length = (u32)(length - LENGTHBASE[length_code]);
-	u32 dist_code = (u32)searchCodeIndex(DISTANCEBASE, 30, distance);
-	u32 extra_distance = (u32)(distance - DISTANCEBASE[dist_code]);
-
-	u32 pos = values->size;
-	/*TODO: return error when this fails (out of memory)*/
-	u32 ok = uivector_resize(values, values->size + 4);
-	if (ok) {
-		values->data[pos + 0] = length_code + FIRST_LENGTH_CODE_INDEX;
-		values->data[pos + 1] = extra_length;
-		values->data[pos + 2] = dist_code;
-		values->data[pos + 3] = extra_distance;
-	}
-}
-
-/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3
-bytes as input because 3 is the minimum match length for deflate*/
-static const u32 HASH_NUM_VALUES = 65536;
-static const u32 HASH_BIT_MASK =
-	65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/
-
-typedef struct Hash {
-	int *head; /*hash value to head circular pos - can be outdated if went around window*/
-	/*circular pos to prev circular pos*/
-	u16 *chain;
-	int *val; /*circular pos to hash value*/
-
-	/*TODO: do this not only for zeros but for any repeated byte. However for PNG
-  it's always going to be the zeros that dominate, so not important for PNG*/
-	int *headz; /*similar to head, but for chainz*/
-	u16 *chainz; /*those with same amount of zeros*/
-	u16 *zeros; /*length of zeros streak, used as a second hash chain*/
-} Hash;
-
-static u32 hash_init(Hash *hash, u32 windowsize)
-{
-	u32 i;
-	hash->head = (int *)png_malloc(sizeof(int) * HASH_NUM_VALUES);
-	hash->val = (int *)png_malloc(sizeof(int) * windowsize);
-	hash->chain = (u16 *)png_malloc(sizeof(u16) * windowsize);
-
-	hash->zeros = (u16 *)png_malloc(sizeof(u16) * windowsize);
-	hash->headz = (int *)png_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1));
-	hash->chainz = (u16 *)png_malloc(sizeof(u16) * windowsize);
-
-	if (!hash->head || !hash->chain || !hash->val || !hash->headz || !hash->chainz ||
-	    !hash->zeros) {
-		return 83; /*alloc fail*/
-	}
-
-	/*initialize hash table*/
-	for (i = 0; i != HASH_NUM_VALUES; ++i)
-		hash->head[i] = -1;
-	for (i = 0; i != windowsize; ++i)
-		hash->val[i] = -1;
-	for (i = 0; i != windowsize; ++i)
-		hash->chain[i] = i; /*same value as index indicates uninitialized*/
-
-	for (i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; ++i)
-		hash->headz[i] = -1;
-	for (i = 0; i != windowsize; ++i)
-		hash->chainz[i] = i; /*same value as index indicates uninitialized*/
-
-	return 0;
-}
-
-static void hash_cleanup(Hash *hash)
-{
-	png_free(hash->head);
-	png_free(hash->val);
-	png_free(hash->chain);
-
-	png_free(hash->zeros);
-	png_free(hash->headz);
-	png_free(hash->chainz);
-}
-
-static u32 getHash(const u8 *data, u32 size, u32 pos)
-{
-	u32 result = 0;
-	if (pos + 2 < size) {
-		/*A simple shift and xor hash is used. Since the data of PNGs is dominated
-    by zeroes due to the filters, a better hash does not have a significant
-    effect on speed in traversing the chain, and causes more time spend on
-    calculating the hash.*/
-		result ^= ((u32)data[pos + 0] << 0u);
-		result ^= ((u32)data[pos + 1] << 4u);
-		result ^= ((u32)data[pos + 2] << 8u);
-	} else {
-		u32 amount, i;
-		if (pos >= size)
-			return 0;
-		amount = size - pos;
-		for (i = 0; i != amount; ++i)
-			result ^= ((u32)data[pos + i] << (i * 8u));
-	}
-	return result & HASH_BIT_MASK;
-}
-
-static u32 countZeros(const u8 *data, u32 size, u32 pos)
-{
-	const u8 *start = data + pos;
-	const u8 *end = start + MAX_SUPPORTED_DEFLATE_LENGTH;
-	if (end > data + size)
-		end = data + size;
-	data = start;
-	while (data != end && *data == 0)
-		++data;
-	/*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/
-	return (u32)(data - start);
-}
-
-/*wpos = pos & (windowsize - 1)*/
-static void updateHashChain(Hash *hash, u32 wpos, u32 hashval, u16 numzeros)
-{
-	hash->val[wpos] = (int)hashval;
-	if (hash->head[hashval] != -1)
-		hash->chain[wpos] = hash->head[hashval];
-	hash->head[hashval] = (int)wpos;
-
-	hash->zeros[wpos] = numzeros;
-	if (hash->headz[numzeros] != -1)
-		hash->chainz[wpos] = hash->headz[numzeros];
-	hash->headz[numzeros] = (int)wpos;
-}
-
-/*
-LZ77-encode the data. Return value is error code. The input are raw bytes, the output
-is in the form of u32 integers with codes representing for example literal bytes, or
-length/distance pairs.
-It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a
-sliding window (of windowsize) is used, and all past bytes in that window can be used as
-the "dictionary". A brute force search through all possible distances would be slow, and
-this hash technique is one out of several ways to speed this up.
-*/
-static u32 encodeLZ77(uivector *out, Hash *hash, const u8 *in, u32 inpos, u32 insize,
-		      u32 windowsize, u32 minmatch, u32 nicematch, u32 lazymatching)
-{
-	u32 pos;
-	u32 i, error = 0;
-	/*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/
-	u32 maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8u;
-	u32 maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64;
-
-	u32 usezeros =
-		1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/
-	u32 numzeros = 0;
-
-	u32 offset; /*the offset represents the distance in LZ77 terminology*/
-	u32 length;
-	u32 lazy = 0;
-	u32 lazylength = 0, lazyoffset = 0;
-	u32 hashval;
-	u32 current_offset, current_length;
-	u32 prev_offset;
-	const u8 *lastptr, *foreptr, *backptr;
-	u32 hashpos;
-
-	if (windowsize == 0 || windowsize > 32768)
-		return 60; /*error: windowsize smaller/larger than allowed*/
-	if ((windowsize & (windowsize - 1)) != 0)
-		return 90; /*error: must be power of two*/
-
-	if (nicematch > MAX_SUPPORTED_DEFLATE_LENGTH)
-		nicematch = MAX_SUPPORTED_DEFLATE_LENGTH;
-
-	for (pos = inpos; pos < insize; ++pos) {
-		u32 wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/
-		u32 chainlength = 0;
-
-		hashval = getHash(in, insize, pos);
-
-		if (usezeros && hashval == 0) {
-			if (numzeros == 0)
-				numzeros = countZeros(in, insize, pos);
-			else if (pos + numzeros > insize || in[pos + numzeros - 1] != 0)
-				--numzeros;
-		} else {
-			numzeros = 0;
-		}
-
-		updateHashChain(hash, wpos, hashval, numzeros);
-
-		/*the length and offset found for the current position*/
-		length = 0;
-		offset = 0;
-
-		hashpos = hash->chain[wpos];
-
-		lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ?
-					    insize :
-					    pos + MAX_SUPPORTED_DEFLATE_LENGTH];
-
-		/*search for the longest string*/
-		prev_offset = 0;
-		for (;;) {
-			if (chainlength++ >= maxchainlength)
-				break;
-			current_offset = (u32)(hashpos <= wpos ? wpos - hashpos :
-								       wpos - hashpos + windowsize);
-
-			if (current_offset < prev_offset)
-				break; /*stop when went completely around the circular buffer*/
-			prev_offset = current_offset;
-			if (current_offset > 0) {
-				/*test the next characters*/
-				foreptr = &in[pos];
-				backptr = &in[pos - current_offset];
-
-				/*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/
-				if (numzeros >= 3) {
-					u32 skip = hash->zeros[hashpos];
-					if (skip > numzeros)
-						skip = numzeros;
-					backptr += skip;
-					foreptr += skip;
-				}
-
-				while (foreptr != lastptr &&
-				       *backptr ==
-					       *foreptr) /*maximum supported length by deflate is max length*/
-				{
-					++backptr;
-					++foreptr;
-				}
-				current_length = (u32)(foreptr - &in[pos]);
-
-				if (current_length > length) {
-					length = current_length; /*the longest length*/
-					offset =
-						current_offset; /*the offset that is related to this longest length*/
-					/*jump out once a length of max length is found (speed gain). This also jumps
-          out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/
-					if (current_length >= nicematch)
-						break;
-				}
-			}
-
-			if (hashpos == hash->chain[hashpos])
-				break;
-
-			if (numzeros >= 3 && length > numzeros) {
-				hashpos = hash->chainz[hashpos];
-				if (hash->zeros[hashpos] != numzeros)
-					break;
-			} else {
-				hashpos = hash->chain[hashpos];
-				/*outdated hash value, happens if particular value was not encountered in whole last window*/
-				if (hash->val[hashpos] != (int)hashval)
-					break;
-			}
-		}
-
-		if (lazymatching) {
-			if (!lazy && length >= 3 && length <= maxlazymatch &&
-			    length < MAX_SUPPORTED_DEFLATE_LENGTH) {
-				lazy = 1;
-				lazylength = length;
-				lazyoffset = offset;
-				continue; /*try the next byte*/
-			}
-			if (lazy) {
-				lazy = 0;
-				if (pos == 0)
-					ERROR_BREAK(81);
-				if (length > lazylength + 1) {
-					/*push the previous character as literal*/
-					if (!uivector_push_back(out, in[pos - 1]))
-						ERROR_BREAK(83 /*alloc fail*/);
-				} else {
-					length = lazylength;
-					offset = lazyoffset;
-					hash->head[hashval] =
-						-1; /*the same hashchain update will be done, this ensures no wrong alteration*/
-					hash->headz[numzeros] = -1; /*idem*/
-					--pos;
-				}
-			}
-		}
-		if (length >= 3 && offset > windowsize)
-			ERROR_BREAK(86 /*too big (or overflown negative) offset*/);
-
-		/*encode it as length/distance pair or literal value*/
-		if (length <
-		    3) /*only lengths of 3 or higher are supported as length/distance pair*/ {
-			if (!uivector_push_back(out, in[pos]))
-				ERROR_BREAK(83 /*alloc fail*/);
-		} else if (length < minmatch || (length == 3 && offset > 4096)) {
-			/*compensate for the fact that longer offsets have more extra bits, a
-      length of only 3 may be not worth it then*/
-			if (!uivector_push_back(out, in[pos]))
-				ERROR_BREAK(83 /*alloc fail*/);
-		} else {
-			addLengthDistance(out, length, offset);
-			for (i = 1; i < length; ++i) {
-				++pos;
-				wpos = pos & (windowsize - 1);
-				hashval = getHash(in, insize, pos);
-				if (usezeros && hashval == 0) {
-					if (numzeros == 0)
-						numzeros = countZeros(in, insize, pos);
-					else if (pos + numzeros > insize ||
-						 in[pos + numzeros - 1] != 0)
-						--numzeros;
-				} else {
-					numzeros = 0;
-				}
-				updateHashChain(hash, wpos, hashval, numzeros);
-			}
-		}
-	} /*end of the loop through each character of input*/
-
-	return error;
-}
-
-/* /////////////////////////////////////////////////////////////////////////// */
-
-static u32 deflateNoCompression(ucvector *out, const u8 *data, u32 datasize)
-{
-	/*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte,
-  2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
-
-	u32 i, numdeflateblocks = (datasize + 65534u) / 65535u;
-	u32 datapos = 0;
-	for (i = 0; i != numdeflateblocks; ++i) {
-		u32 BFINAL, BTYPE, LEN, NLEN;
-		u8 firstbyte;
-		u32 pos = out->size;
-
-		BFINAL = (i == numdeflateblocks - 1);
-		BTYPE = 0;
-
-		LEN = 65535;
-		if (datasize - datapos < 65535u)
-			LEN = (u32)datasize - datapos;
-		NLEN = 65535 - LEN;
-
-		if (!ucvector_resize(out, out->size + LEN + 5))
-			return 83; /*alloc fail*/
-
-		firstbyte = (u8)(BFINAL + ((BTYPE & 1u) << 1u) + ((BTYPE & 2u) << 1u));
-		out->data[pos + 0] = firstbyte;
-		out->data[pos + 1] = (u8)(LEN & 255);
-		out->data[pos + 2] = (u8)(LEN >> 8u);
-		out->data[pos + 3] = (u8)(NLEN & 255);
-		out->data[pos + 4] = (u8)(NLEN >> 8u);
-		png_memcpy(out->data + pos + 5, data + datapos, LEN);
-		datapos += LEN;
-	}
-
-	return 0;
-}
-
-/*
-write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees.
-tree_ll: the tree for lit and len codes.
-tree_d: the tree for distance codes.
-*/
-static void writeLZ77data(pngBitWriter *writer, const uivector *lz77_encoded,
-			  const HuffmanTree *tree_ll, const HuffmanTree *tree_d)
-{
-	u32 i = 0;
-	for (i = 0; i != lz77_encoded->size; ++i) {
-		u32 val = lz77_encoded->data[i];
-		writeBitsReversed(writer, tree_ll->codes[val], tree_ll->lengths[val]);
-		if (val > 256) /*for a length code, 3 more things have to be added*/ {
-			u32 length_index = val - FIRST_LENGTH_CODE_INDEX;
-			u32 n_length_extra_bits = LENGTHEXTRA[length_index];
-			u32 length_extra_bits = lz77_encoded->data[++i];
-
-			u32 distance_code = lz77_encoded->data[++i];
-
-			u32 distance_index = distance_code;
-			u32 n_distance_extra_bits = DISTANCEEXTRA[distance_index];
-			u32 distance_extra_bits = lz77_encoded->data[++i];
-
-			writeBits(writer, length_extra_bits, n_length_extra_bits);
-			writeBitsReversed(writer, tree_d->codes[distance_code],
-					  tree_d->lengths[distance_code]);
-			writeBits(writer, distance_extra_bits, n_distance_extra_bits);
-		}
-	}
-}
-
-/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
-static u32 deflateDynamic(pngBitWriter *writer, Hash *hash, const u8 *data, u32 datapos,
-			  u32 dataend, const pngCompressSettings *settings, u32 final)
-{
-	u32 error = 0;
-
-	/*
-  A block is compressed as follows: The PNG data is lz77 encoded, resulting in
-  literal bytes and length/distance pairs. This is then huffman compressed with
-  two huffman trees. One huffman tree is used for the lit and len values ("ll"),
-  another huffman tree is used for the dist values ("d"). These two trees are
-  stored using their code lengths, and to compress even more these code lengths
-  are also run-length encoded and huffman compressed. This gives a huffman tree
-  of code lengths "cl". The code lengths used to describe this third tree are
-  the code length code lengths ("clcl").
-  */
-
-	/*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/
-	uivector lz77_encoded;
-	HuffmanTree tree_ll; /*tree for lit,len values*/
-	HuffmanTree tree_d; /*tree for distance codes*/
-	HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
-	u32 *frequencies_ll = 0; /*frequency of lit,len codes*/
-	u32 *frequencies_d = 0; /*frequency of dist codes*/
-	u32 *frequencies_cl = 0; /*frequency of code length codes*/
-	u32 *bitlen_lld =
-		0; /*lit,len,dist code lengths (int bits), literally (without repeat codes).*/
-	u32 *bitlen_lld_e =
-		0; /*bitlen_lld encoded with repeat codes (this is a rudimentary run length compression)*/
-	u32 datasize = dataend - datapos;
-
-	/*
-  If we could call "bitlen_cl" the the code length code lengths ("clcl"), that is the bit lengths of codes to represent
-  tree_cl in CLCL_ORDER, then due to the huffman compression of huffman tree representations ("two levels"), there are
-  some analogies:
-  bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
-  bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
-  bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
-  */
-
-	u32 BFINAL = final;
-	u32 i;
-	u32 numcodes_ll, numcodes_d, numcodes_lld, numcodes_lld_e, numcodes_cl;
-	u32 HLIT, HDIST, HCLEN;
-
-	uivector_init(&lz77_encoded);
-	HuffmanTree_init(&tree_ll);
-	HuffmanTree_init(&tree_d);
-	HuffmanTree_init(&tree_cl);
-	/* could fit on stack, but >1KB is on the larger side so allocate instead */
-	frequencies_ll = (u32 *)png_malloc(286 * sizeof(*frequencies_ll));
-	frequencies_d = (u32 *)png_malloc(30 * sizeof(*frequencies_d));
-	frequencies_cl = (u32 *)png_malloc(NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl));
-
-	if (!frequencies_ll || !frequencies_d || !frequencies_cl)
-		error = 83; /*alloc fail*/
-
-	/*This while loop never loops due to a break at the end, it is here to
-  allow breaking out of it to the cleanup phase on error conditions.*/
-	while (!error) {
-		png_memset(frequencies_ll, 0, 286 * sizeof(*frequencies_ll));
-		png_memset(frequencies_d, 0, 30 * sizeof(*frequencies_d));
-		png_memset(frequencies_cl, 0, NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl));
-
-		if (settings->use_lz77) {
-			error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend,
-					   settings->windowsize, settings->minmatch,
-					   settings->nicematch, settings->lazymatching);
-			if (error)
-				break;
-		} else {
-			if (!uivector_resize(&lz77_encoded, datasize))
-				ERROR_BREAK(83 /*alloc fail*/);
-			for (i = datapos; i < dataend; ++i)
-				lz77_encoded.data[i - datapos] =
-					data[i]; /*no LZ77, but still will be Huffman compressed*/
-		}
-
-		/*Count the frequencies of lit, len and dist codes*/
-		for (i = 0; i != lz77_encoded.size; ++i) {
-			u32 symbol = lz77_encoded.data[i];
-			++frequencies_ll[symbol];
-			if (symbol > 256) {
-				u32 dist = lz77_encoded.data[i + 2];
-				++frequencies_d[dist];
-				i += 3;
-			}
-		}
-		frequencies_ll[256] =
-			1; /*there will be exactly 1 end code, at the end of the block*/
-
-		/*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
-		error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll, 257, 286, 15);
-		if (error)
-			break;
-		/*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/
-		error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d, 2, 30, 15);
-		if (error)
-			break;
-
-		numcodes_ll = PNG_MIN(tree_ll.numcodes, 286);
-		numcodes_d = PNG_MIN(tree_d.numcodes, 30);
-		/*store the code lengths of both generated trees in bitlen_lld*/
-		numcodes_lld = numcodes_ll + numcodes_d;
-		bitlen_lld = (u32 *)png_malloc(numcodes_lld * sizeof(*bitlen_lld));
-		/*numcodes_lld_e never needs more size than bitlen_lld*/
-		bitlen_lld_e = (u32 *)png_malloc(numcodes_lld * sizeof(*bitlen_lld_e));
-		if (!bitlen_lld || !bitlen_lld_e)
-			ERROR_BREAK(83); /*alloc fail*/
-		numcodes_lld_e = 0;
-
-		for (i = 0; i != numcodes_ll; ++i)
-			bitlen_lld[i] = tree_ll.lengths[i];
-		for (i = 0; i != numcodes_d; ++i)
-			bitlen_lld[numcodes_ll + i] = tree_d.lengths[i];
-
-		/*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times),
-    17 (3-10 zeroes), 18 (11-138 zeroes)*/
-		for (i = 0; i != numcodes_lld; ++i) {
-			u32 j = 0; /*amount of repetitions*/
-			while (i + j + 1 < numcodes_lld && bitlen_lld[i + j + 1] == bitlen_lld[i])
-				++j;
-
-			if (bitlen_lld[i] == 0 && j >= 2) /*repeat code for zeroes*/ {
-				++j; /*include the first zero*/
-				if (j <= 10) /*repeat code 17 supports max 10 zeroes*/ {
-					bitlen_lld_e[numcodes_lld_e++] = 17;
-					bitlen_lld_e[numcodes_lld_e++] = j - 3;
-				} else /*repeat code 18 supports max 138 zeroes*/ {
-					if (j > 138)
-						j = 138;
-					bitlen_lld_e[numcodes_lld_e++] = 18;
-					bitlen_lld_e[numcodes_lld_e++] = j - 11;
-				}
-				i += (j - 1);
-			} else if (j >= 3) /*repeat code for value other than zero*/ {
-				u32 k;
-				u32 num = j / 6u, rest = j % 6u;
-				bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i];
-				for (k = 0; k < num; ++k) {
-					bitlen_lld_e[numcodes_lld_e++] = 16;
-					bitlen_lld_e[numcodes_lld_e++] = 6 - 3;
-				}
-				if (rest >= 3) {
-					bitlen_lld_e[numcodes_lld_e++] = 16;
-					bitlen_lld_e[numcodes_lld_e++] = rest - 3;
-				} else
-					j -= rest;
-				i += j;
-			} else /*too short to benefit from repeat code*/ {
-				bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i];
-			}
-		}
-
-		/*generate tree_cl, the huffmantree of huffmantrees*/
-		for (i = 0; i != numcodes_lld_e; ++i) {
-			++frequencies_cl[bitlen_lld_e[i]];
-			/*after a repeat code come the bits that specify the number of repetitions,
-      those don't need to be in the frequencies_cl calculation*/
-			if (bitlen_lld_e[i] >= 16)
-				++i;
-		}
-
-		error = HuffmanTree_makeFromFrequencies(
-			&tree_cl, frequencies_cl, NUM_CODE_LENGTH_CODES, NUM_CODE_LENGTH_CODES, 7);
-		if (error)
-			break;
-
-		/*compute amount of code-length-code-lengths to output*/
-		numcodes_cl = NUM_CODE_LENGTH_CODES;
-		/*trim zeros at the end (using CLCL_ORDER), but minimum size must be 4 (see HCLEN below)*/
-		while (numcodes_cl > 4u && tree_cl.lengths[CLCL_ORDER[numcodes_cl - 1u]] == 0) {
-			numcodes_cl--;
-		}
-
-		/*
-    Write everything into the output
-
-    After the BFINAL and BTYPE, the dynamic block consists out of the following:
-    - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
-    - (HCLEN+4)*3 bits code lengths of code length alphabet
-    - HLIT + 257 code lengths of lit/length alphabet (encoded using the code length
-      alphabet, + possible repetition codes 16, 17, 18)
-    - HDIST + 1 code lengths of distance alphabet (encoded using the code length
-      alphabet, + possible repetition codes 16, 17, 18)
-    - compressed data
-    - 256 (end code)
-    */
-
-		/*Write block type*/
-		writeBits(writer, BFINAL, 1);
-		writeBits(writer, 0, 1); /*first bit of BTYPE "dynamic"*/
-		writeBits(writer, 1, 1); /*second bit of BTYPE "dynamic"*/
-
-		/*write the HLIT, HDIST and HCLEN values*/
-		/*all three sizes take trimmed ending zeroes into account, done either by HuffmanTree_makeFromFrequencies
-    or in the loop for numcodes_cl above, which saves space. */
-		HLIT = (u32)(numcodes_ll - 257);
-		HDIST = (u32)(numcodes_d - 1);
-		HCLEN = (u32)(numcodes_cl - 4);
-		writeBits(writer, HLIT, 5);
-		writeBits(writer, HDIST, 5);
-		writeBits(writer, HCLEN, 4);
-
-		/*write the code lengths of the code length alphabet ("bitlen_cl")*/
-		for (i = 0; i != numcodes_cl; ++i)
-			writeBits(writer, tree_cl.lengths[CLCL_ORDER[i]], 3);
-
-		/*write the lengths of the lit/len AND the dist alphabet*/
-		for (i = 0; i != numcodes_lld_e; ++i) {
-			writeBitsReversed(writer, tree_cl.codes[bitlen_lld_e[i]],
-					  tree_cl.lengths[bitlen_lld_e[i]]);
-			/*extra bits of repeat codes*/
-			if (bitlen_lld_e[i] == 16)
-				writeBits(writer, bitlen_lld_e[++i], 2);
-			else if (bitlen_lld_e[i] == 17)
-				writeBits(writer, bitlen_lld_e[++i], 3);
-			else if (bitlen_lld_e[i] == 18)
-				writeBits(writer, bitlen_lld_e[++i], 7);
-		}
-
-		/*write the compressed data symbols*/
-		writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d);
-		/*error: the length of the end code 256 must be larger than 0*/
-		if (tree_ll.lengths[256] == 0)
-			ERROR_BREAK(64);
-
-		/*write the end code*/
-		writeBitsReversed(writer, tree_ll.codes[256], tree_ll.lengths[256]);
-
-		break; /*end of error-while*/
-	}
-
-	/*cleanup*/
-	uivector_cleanup(&lz77_encoded);
-	HuffmanTree_cleanup(&tree_ll);
-	HuffmanTree_cleanup(&tree_d);
-	HuffmanTree_cleanup(&tree_cl);
-	png_free(frequencies_ll);
-	png_free(frequencies_d);
-	png_free(frequencies_cl);
-	png_free(bitlen_lld);
-	png_free(bitlen_lld_e);
-
-	return error;
-}
-
-static u32 deflateFixed(pngBitWriter *writer, Hash *hash, const u8 *data, u32 datapos, u32 dataend,
-			const pngCompressSettings *settings, u32 final)
-{
-	HuffmanTree tree_ll; /*tree for literal values and length codes*/
-	HuffmanTree tree_d; /*tree for distance codes*/
-
-	u32 BFINAL = final;
-	u32 error = 0;
-	u32 i;
-
-	HuffmanTree_init(&tree_ll);
-	HuffmanTree_init(&tree_d);
-
-	error = generateFixedLitLenTree(&tree_ll);
-	if (!error)
-		error = generateFixedDistanceTree(&tree_d);
-
-	if (!error) {
-		writeBits(writer, BFINAL, 1);
-		writeBits(writer, 1, 1); /*first bit of BTYPE*/
-		writeBits(writer, 0, 1); /*second bit of BTYPE*/
-
-		if (settings->use_lz77) /*LZ77 encoded*/ {
-			uivector lz77_encoded;
-			uivector_init(&lz77_encoded);
-			error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend,
-					   settings->windowsize, settings->minmatch,
-					   settings->nicematch, settings->lazymatching);
-			if (!error)
-				writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d);
-			uivector_cleanup(&lz77_encoded);
-		} else /*no LZ77, but still will be Huffman compressed*/ {
-			for (i = datapos; i < dataend; ++i) {
-				writeBitsReversed(writer, tree_ll.codes[data[i]],
-						  tree_ll.lengths[data[i]]);
-			}
-		}
-		/*add END code*/
-		if (!error)
-			writeBitsReversed(writer, tree_ll.codes[256], tree_ll.lengths[256]);
-	}
-
-	/*cleanup*/
-	HuffmanTree_cleanup(&tree_ll);
-	HuffmanTree_cleanup(&tree_d);
-
-	return error;
-}
-
-static u32 png_deflatev(ucvector *out, const u8 *in, u32 insize,
-			const pngCompressSettings *settings)
-{
-	u32 error = 0;
-	u32 i, blocksize, numdeflateblocks;
-	Hash hash;
-	pngBitWriter writer;
-
-	pngBitWriter_init(&writer, out);
-
-	if (settings->btype > 2)
-		return 61;
-	else if (settings->btype == 0)
-		return deflateNoCompression(out, in, insize);
-	else if (settings->btype == 1)
-		blocksize = insize;
-	else /*if(settings->btype == 2)*/ {
-		/*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/
-		blocksize = insize / 8u + 8;
-		if (blocksize < 65536)
-			blocksize = 65536;
-		if (blocksize > 262144)
-			blocksize = 262144;
-	}
-
-	numdeflateblocks = (insize + blocksize - 1) / blocksize;
-	if (numdeflateblocks == 0)
-		numdeflateblocks = 1;
-
-	error = hash_init(&hash, settings->windowsize);
-
-	if (!error) {
-		for (i = 0; i != numdeflateblocks && !error; ++i) {
-			u32 final = (i == numdeflateblocks - 1);
-			u32 start = i * blocksize;
-			u32 end = start + blocksize;
-			if (end > insize)
-				end = insize;
-
-			if (settings->btype == 1)
-				error = deflateFixed(&writer, &hash, in, start, end, settings,
-						     final);
-			else if (settings->btype == 2)
-				error = deflateDynamic(&writer, &hash, in, start, end, settings,
-						       final);
-		}
-	}
-
-	hash_cleanup(&hash);
-
-	return error;
-}
-
-u32 png_deflate(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-		const pngCompressSettings *settings)
-{
-	ucvector v = ucvector_init(*out, *outsize);
-	u32 error = png_deflatev(&v, in, insize, settings);
-	*out = v.data;
-	*outsize = v.size;
-	return error;
-}
-
-static u32 deflate(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-		   const pngCompressSettings *settings)
-{
-	if (settings->custom_deflate) {
-		u32 error = settings->custom_deflate(out, outsize, in, insize, settings);
-		/*the custom deflate is allowed to have its own error codes, however, we translate it to code 111*/
-		return error ? 111 : 0;
-	} else {
-		return png_deflate(out, outsize, in, insize, settings);
-	}
-}
-
-#endif /*PNG_COMPILE_DECODER*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Adler32                                                                / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-static u32 update_adler32(u32 adler, const u8 *data, u32 len)
-{
-	u32 s1 = adler & 0xffffu;
-	u32 s2 = (adler >> 16u) & 0xffffu;
-
-	while (len != 0u) {
-		u32 i;
-		/*at least 5552 sums can be done before the sums overflow, saving a lot of module divisions*/
-		u32 amount = len > 5552u ? 5552u : len;
-		len -= amount;
-		for (i = 0; i != amount; ++i) {
-			s1 += (*data++);
-			s2 += s1;
-		}
-		s1 %= 65521u;
-		s2 %= 65521u;
-	}
-
-	return (s2 << 16u) | s1;
-}
-
-/*Return the adler32 of the bytes data[0..len-1]*/
-static u32 adler32(const u8 *data, u32 len)
-{
-	return update_adler32(1u, data, len);
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Zlib                                                                   / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef PNG_COMPILE_DECODER
-
-static u32 png_zlib_decompressv(ucvector *out, const u8 *in, u32 insize,
-				const pngDecompressSettings *settings)
-{
-	u32 error = 0;
-	u32 CM, CINFO, FDICT;
-
-	if (insize < 2)
-		return 53; /*error, size of zlib data too small*/
-	/*read information from zlib header*/
-	if ((in[0] * 256 + in[1]) % 31 != 0) {
-		/*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
-		return 24;
-	}
-
-	CM = in[0] & 15;
-	CINFO = (in[0] >> 4) & 15;
-	/*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/
-	FDICT = (in[1] >> 5) & 1;
-	/*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
-
-	if (CM != 8 || CINFO > 7) {
-		/*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
-		return 25;
-	}
-	if (FDICT != 0) {
-		/*error: the specification of PNG says about the zlib stream:
-      "The additional flags shall not specify a preset dictionary."*/
-		return 26;
-	}
-
-	error = inflatev(out, in + 2, insize - 2, settings);
-	if (error)
-		return error;
-
-	if (!settings->ignore_adler32) {
-		u32 ADLER32 = png_read32bitInt(&in[insize - 4]);
-		u32 checksum = adler32(out->data, (u32)(out->size));
-		if (checksum != ADLER32)
-			return 58; /*error, adler checksum not correct, data must be corrupted*/
-	}
-
-	return 0; /*no error*/
-}
-
-u32 png_zlib_decompress(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-			const pngDecompressSettings *settings)
-{
-	ucvector v = ucvector_init(*out, *outsize);
-	u32 error = png_zlib_decompressv(&v, in, insize, settings);
-	*out = v.data;
-	*outsize = v.size;
-	return error;
-}
-
-/*expected_size is expected output size, to avoid intermediate allocations. Set to 0 if not known. */
-static u32 zlib_decompress(u8 **out, u32 *outsize, u32 expected_size, const u8 *in, u32 insize,
-			   const pngDecompressSettings *settings)
-{
-	u32 error;
-	if (settings->custom_zlib) {
-		error = settings->custom_zlib(out, outsize, in, insize, settings);
-		if (error) {
-			/*the custom zlib is allowed to have its own error codes, however, we translate it to code 110*/
-			error = 110;
-			/*if there's a max output size, and the custom zlib returned error, then indicate that error instead*/
-			if (settings->max_output_size && *outsize > settings->max_output_size)
-				error = 109;
-		}
-	} else {
-		ucvector v = ucvector_init(*out, *outsize);
-		if (expected_size) {
-			/*reserve the memory to avoid intermediate reallocations*/
-			ucvector_resize(&v, *outsize + expected_size);
-			v.size = *outsize;
-		}
-		error = png_zlib_decompressv(&v, in, insize, settings);
-		*out = v.data;
-		*outsize = v.size;
-	}
-	return error;
-}
-
-#endif /*PNG_COMPILE_DECODER*/
-
-#ifdef PNG_COMPILE_ENCODER
-
-u32 png_zlib_compress(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-		      const pngCompressSettings *settings)
-{
-	u32 i;
-	u32 error;
-	u8 *deflatedata = 0;
-	u32 deflatesize = 0;
-
-	error = deflate(&deflatedata, &deflatesize, in, insize, settings);
-
-	*out = NULL;
-	*outsize = 0;
-	if (!error) {
-		*outsize = deflatesize + 6;
-		*out = (u8 *)png_malloc(*outsize);
-		if (!*out)
-			error = 83; /*alloc fail*/
-	}
-
-	if (!error) {
-		u32 ADLER32 = adler32(in, (u32)insize);
-		/*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
-		u32 CMF =
-			120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
-		u32 FLEVEL = 0;
-		u32 FDICT = 0;
-		u32 CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
-		u32 FCHECK = 31 - CMFFLG % 31;
-		CMFFLG += FCHECK;
-
-		(*out)[0] = (u8)(CMFFLG >> 8);
-		(*out)[1] = (u8)(CMFFLG & 255);
-		for (i = 0; i != deflatesize; ++i)
-			(*out)[i + 2] = deflatedata[i];
-		png_set32bitInt(&(*out)[*outsize - 4], ADLER32);
-	}
-
-	png_free(deflatedata);
-	return error;
-}
-
-/* compress using the default or custom zlib function */
-static u32 zlib_compress(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-			 const pngCompressSettings *settings)
-{
-	if (settings->custom_zlib) {
-		u32 error = settings->custom_zlib(out, outsize, in, insize, settings);
-		/*the custom zlib is allowed to have its own error codes, however, we translate it to code 111*/
-		return error ? 111 : 0;
-	} else {
-		return png_zlib_compress(out, outsize, in, insize, settings);
-	}
-}
-
-#endif /*PNG_COMPILE_ENCODER*/
-
-#else /*no PNG_COMPILE_ZLIB*/
-
-#ifdef PNG_COMPILE_DECODER
-static u32 zlib_decompress(u8 **out, u32 *outsize, u32 expected_size, const u8 *in, u32 insize,
-			   const pngDecompressSettings *settings)
-{
-	if (!settings->custom_zlib)
-		return 87; /*no custom zlib function provided */
-	(void)expected_size;
-	return settings->custom_zlib(out, outsize, in, insize, settings);
-}
-#endif /*PNG_COMPILE_DECODER*/
-#ifdef PNG_COMPILE_ENCODER
-static u32 zlib_compress(u8 **out, u32 *outsize, const u8 *in, u32 insize,
-			 const pngCompressSettings *settings)
-{
-	if (!settings->custom_zlib)
-		return 87; /*no custom zlib function provided */
-	return settings->custom_zlib(out, outsize, in, insize, settings);
-}
-#endif /*PNG_COMPILE_ENCODER*/
-
-#endif /*PNG_COMPILE_ZLIB*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef PNG_COMPILE_ENCODER
-
-/*this is a good tradeoff between speed and compression ratio*/
-#define DEFAULT_WINDOWSIZE 2048
-
-void png_compress_settings_init(pngCompressSettings *settings)
-{
-	/*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
-	settings->btype = 2;
-	settings->use_lz77 = 1;
-	settings->windowsize = DEFAULT_WINDOWSIZE;
-	settings->minmatch = 3;
-	settings->nicematch = 128;
-	settings->lazymatching = 1;
-
-	settings->custom_zlib = 0;
-	settings->custom_deflate = 0;
-	settings->custom_context = 0;
-}
-
-const pngCompressSettings png_default_compress_settings = { 2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0,
-							    0, 0 };
-
-#endif /*PNG_COMPILE_ENCODER*/
-
-#ifdef PNG_COMPILE_DECODER
-
-void png_decompress_settings_init(pngDecompressSettings *settings)
-{
-	settings->ignore_adler32 = 0;
-	settings->ignore_nlen = 0;
-	settings->max_output_size = 0;
-
-	settings->custom_zlib = 0;
-	settings->custom_inflate = 0;
-	settings->custom_context = 0;
-}
-
-const pngDecompressSettings png_default_decompress_settings = { 0, 0, 0, 0, 0, 0 };
-
-#endif /*PNG_COMPILE_DECODER*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // End of Zlib related code. Begin of PNG related code.                 // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef PNG_COMPILE_PNG
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / CRC32                                                                  / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifndef PNG_NO_COMPILE_CRC
-/* CRC polynomial: 0xedb88320 */
-static u32 png_crc32_table[256] = {
-	0u,	     1996959894u, 3993919788u, 2567524794u, 124634137u,	 1886057615u, 3915621685u,
-	2657392035u, 249268274u,  2044508324u, 3772115230u, 2547177864u, 162941995u,  2125561021u,
-	3887607047u, 2428444049u, 498536548u,  1789927666u, 4089016648u, 2227061214u, 450548861u,
-	1843258603u, 4107580753u, 2211677639u, 325883990u,  1684777152u, 4251122042u, 2321926636u,
-	335633487u,  1661365465u, 4195302755u, 2366115317u, 997073096u,	 1281953886u, 3579855332u,
-	2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u, 901097722u,  1119000684u,
-	3686517206u, 2898065728u, 853044451u,  1172266101u, 3705015759u, 2882616665u, 651767980u,
-	1373503546u, 3369554304u, 3218104598u, 565507253u,  1454621731u, 3485111705u, 3099436303u,
-	671266974u,  1594198024u, 3322730930u, 2970347812u, 795835527u,	 1483230225u, 3244367275u,
-	3060149565u, 1994146192u, 31158534u,   2563907772u, 4023717930u, 1907459465u, 112637215u,
-	2680153253u, 3904427059u, 2013776290u, 251722036u,  2517215374u, 3775830040u, 2137656763u,
-	141376813u,  2439277719u, 3865271297u, 1802195444u, 476864866u,	 2238001368u, 4066508878u,
-	1812370925u, 453092731u,  2181625025u, 4111451223u, 1706088902u, 314042704u,  2344532202u,
-	4240017532u, 1658658271u, 366619977u,  2362670323u, 4224994405u, 1303535960u, 984961486u,
-	2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u, 1131014506u,
-	879679996u,  2909243462u, 3663771856u, 1141124467u, 855842277u,	 2852801631u, 3708648649u,
-	1342533948u, 654459306u,  3188396048u, 3373015174u, 1466479909u, 544179635u,  3110523913u,
-	3462522015u, 1591671054u, 702138776u,  2966460450u, 3352799412u, 1504918807u, 783551873u,
-	3082640443u, 3233442989u, 3988292384u, 2596254646u, 62317068u,	 1957810842u, 3939845945u,
-	2647816111u, 81470997u,	  1943803523u, 3814918930u, 2489596804u, 225274430u,  2053790376u,
-	3826175755u, 2466906013u, 167816743u,  2097651377u, 4027552580u, 2265490386u, 503444072u,
-	1762050814u, 4150417245u, 2154129355u, 426522225u,  1852507879u, 4275313526u, 2312317920u,
-	282753626u,  1742555852u, 4189708143u, 2394877945u, 397917763u,	 1622183637u, 3604390888u,
-	2714866558u, 953729732u,  1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u,
-	3624741850u, 2936675148u, 906185462u,  1090812512u, 3747672003u, 2825379669u, 829329135u,
-	1181335161u, 3412177804u, 3160834842u, 628085408u,  1382605366u, 3423369109u, 3138078467u,
-	570562233u,  1426400815u, 3317316542u, 2998733608u, 733239954u,	 1555261956u, 3268935591u,
-	3050360625u, 752459403u,  1541320221u, 2607071920u, 3965973030u, 1969922972u, 40735498u,
-	2617837225u, 3943577151u, 1913087877u, 83908371u,   2512341634u, 3803740692u, 2075208622u,
-	213261112u,  2463272603u, 3855990285u, 2094854071u, 198958881u,	 2262029012u, 4057260610u,
-	1759359992u, 534414190u,  2176718541u, 4139329115u, 1873836001u, 414664567u,  2282248934u,
-	4279200368u, 1711684554u, 285281116u,  2405801727u, 4167216745u, 1634467795u, 376229701u,
-	2685067896u, 3608007406u, 1308918612u, 956543938u,  2808555105u, 3495958263u, 1231636301u,
-	1047427035u, 2932959818u, 3654703836u, 1088359270u, 936918000u,	 2847714899u, 3736837829u,
-	1202900863u, 817233897u,  3183342108u, 3401237130u, 1404277552u, 615818150u,  3134207493u,
-	3453421203u, 1423857449u, 601450431u,  3009837614u, 3294710456u, 1567103746u, 711928724u,
-	3020668471u, 3272380065u, 1510334235u, 755167117u
-};
-
-/*Return the CRC of the bytes buf[0..len-1].*/
-u32 png_crc32(const u8 *data, u32 length)
-{
-	u32 r = 0xffffffffu;
-	u32 i;
-	for (i = 0; i < length; ++i) {
-		r = png_crc32_table[(r ^ data[i]) & 0xffu] ^ (r >> 8u);
-	}
-	return r ^ 0xffffffffu;
-}
-#else /* !PNG_NO_COMPILE_CRC */
-u32 png_crc32(const u8 *data, u32 length);
-#endif /* !PNG_NO_COMPILE_CRC */
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Reading and writing PNG color channel bits                             / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/* The color channel bits of less-than-8-bit pixels are read with the MSB of bytes first,
-so pngBitWriter and pngBitReader can't be used for those. */
-
-static u8 readBitFromReversedStream(u32 *bitpointer, const u8 *bitstream)
-{
-	u8 result = (u8)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
-	++(*bitpointer);
-	return result;
-}
-
-/* TODO: make this faster */
-static u32 readBitsFromReversedStream(u32 *bitpointer, const u8 *bitstream, u32 nbits)
-{
-	u32 result = 0;
-	u32 i;
-	for (i = 0; i < nbits; ++i) {
-		result <<= 1u;
-		result |= (u32)readBitFromReversedStream(bitpointer, bitstream);
-	}
-	return result;
-}
-
-static void setBitOfReversedStream(u32 *bitpointer, u8 *bitstream, u8 bit)
-{
-	/*the current bit in bitstream may be 0 or 1 for this to work*/
-	if (bit == 0)
-		bitstream[(*bitpointer) >> 3u] &= (u8)(~(1u << (7u - ((*bitpointer) & 7u))));
-	else
-		bitstream[(*bitpointer) >> 3u] |= (1u << (7u - ((*bitpointer) & 7u)));
-	++(*bitpointer);
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / PNG chunks                                                             / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-u32 png_chunk_length(const u8 *chunk)
-{
-	return png_read32bitInt(&chunk[0]);
-}
-
-void png_chunk_type(char type[5], const u8 *chunk)
-{
-	u32 i;
-	for (i = 0; i != 4; ++i)
-		type[i] = (char)chunk[4 + i];
-	type[4] = 0; /*null termination char*/
-}
-
-u8 png_chunk_type_equals(const u8 *chunk, const char *type)
-{
-	if (png_strlen(type) != 4)
-		return 0;
-	return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] &&
-		chunk[7] == type[3]);
-}
-
-u8 png_chunk_ancillary(const u8 *chunk)
-{
-	return ((chunk[4] & 32) != 0);
-}
-
-u8 png_chunk_private(const u8 *chunk)
-{
-	return ((chunk[6] & 32) != 0);
-}
-
-u8 png_chunk_safetocopy(const u8 *chunk)
-{
-	return ((chunk[7] & 32) != 0);
-}
-
-u8 *png_chunk_data(u8 *chunk)
-{
-	return &chunk[8];
-}
-
-const u8 *png_chunk_data_const(const u8 *chunk)
-{
-	return &chunk[8];
-}
-
-u32 png_chunk_check_crc(const u8 *chunk)
-{
-	u32 length = png_chunk_length(chunk);
-	u32 CRC = png_read32bitInt(&chunk[length + 8]);
-	/*the CRC is taken of the data and the 4 chunk type letters, not the length*/
-	u32 checksum = png_crc32(&chunk[4], length + 4);
-	if (CRC != checksum)
-		return 1;
-	else
-		return 0;
-}
-
-void png_chunk_generate_crc(u8 *chunk)
-{
-	u32 length = png_chunk_length(chunk);
-	u32 CRC = png_crc32(&chunk[4], length + 4);
-	png_set32bitInt(chunk + 8 + length, CRC);
-}
-
-u8 *png_chunk_next(u8 *chunk, u8 *end)
-{
-	if (chunk >= end || end - chunk < 12)
-		return end; /*too small to contain a chunk*/
-	if (chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 &&
-	    chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) {
-		/* Is PNG magic header at start of PNG file. Jump to first actual chunk. */
-		return chunk + 8;
-	} else {
-		u32 total_chunk_length;
-		u8 *result;
-		if (png_addofl(png_chunk_length(chunk), 12, &total_chunk_length))
-			return end;
-		result = chunk + total_chunk_length;
-		if (result < chunk)
-			return end; /*pointer overflow*/
-		return result;
-	}
-}
-
-const u8 *png_chunk_next_const(const u8 *chunk, const u8 *end)
-{
-	if (chunk >= end || end - chunk < 12)
-		return end; /*too small to contain a chunk*/
-	if (chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 &&
-	    chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) {
-		/* Is PNG magic header at start of PNG file. Jump to first actual chunk. */
-		return chunk + 8;
-	} else {
-		u32 total_chunk_length;
-		const u8 *result;
-		if (png_addofl(png_chunk_length(chunk), 12, &total_chunk_length))
-			return end;
-		result = chunk + total_chunk_length;
-		if (result < chunk)
-			return end; /*pointer overflow*/
-		return result;
-	}
-}
-
-u8 *png_chunk_find(u8 *chunk, u8 *end, const char type[5])
-{
-	for (;;) {
-		if (chunk >= end || end - chunk < 12)
-			return 0; /* past file end: chunk + 12 > end */
-		if (png_chunk_type_equals(chunk, type))
-			return chunk;
-		chunk = png_chunk_next(chunk, end);
-	}
-}
-
-const u8 *png_chunk_find_const(const u8 *chunk, const u8 *end, const char type[5])
-{
-	for (;;) {
-		if (chunk >= end || end - chunk < 12)
-			return 0; /* past file end: chunk + 12 > end */
-		if (png_chunk_type_equals(chunk, type))
-			return chunk;
-		chunk = png_chunk_next_const(chunk, end);
-	}
-}
-
-u32 png_chunk_append(u8 **out, u32 *outsize, const u8 *chunk)
-{
-	u32 i;
-	u32 total_chunk_length, new_length;
-	u8 *chunk_start, *new_buffer;
-
-	if (png_addofl(png_chunk_length(chunk), 12, &total_chunk_length))
-		return 77;
-	if (png_addofl(*outsize, total_chunk_length, &new_length))
-		return 77;
-
-	new_buffer = (u8 *)png_realloc(*out, new_length);
-	if (!new_buffer)
-		return 83; /*alloc fail*/
-	(*out) = new_buffer;
-	(*outsize) = new_length;
-	chunk_start = &(*out)[new_length - total_chunk_length];
-
-	for (i = 0; i != total_chunk_length; ++i)
-		chunk_start[i] = chunk[i];
-
-	return 0;
-}
-
-/*Sets length and name and allocates the space for data and crc but does not
-set data or crc yet. Returns the start of the chunk in chunk. The start of
-the data is at chunk + 8. To finalize chunk, add the data, then use
-png_chunk_generate_crc */
-static u32 png_chunk_init(u8 **chunk, ucvector *out, u32 length, const char *type)
-{
-	u32 new_length = out->size;
-	if (png_addofl(new_length, length, &new_length))
-		return 77;
-	if (png_addofl(new_length, 12, &new_length))
-		return 77;
-	if (!ucvector_resize(out, new_length))
-		return 83; /*alloc fail*/
-	*chunk = out->data + new_length - length - 12u;
-
-	/*1: length*/
-	png_set32bitInt(*chunk, length);
-
-	/*2: chunk name (4 letters)*/
-	png_memcpy(*chunk + 4, type, 4);
-
-	return 0;
-}
-
-/* like png_chunk_create but with custom allocsize */
-static u32 png_chunk_createv(ucvector *out, u32 length, const char *type, const u8 *data)
-{
-	u8 *chunk;
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, length, type));
-
-	/*3: the data*/
-	png_memcpy(chunk + 8, data, length);
-
-	/*4: CRC (of the chunkname characters and the data)*/
-	png_chunk_generate_crc(chunk);
-
-	return 0;
-}
-
-u32 png_chunk_create(u8 **out, u32 *outsize, u32 length, const char *type, const u8 *data)
-{
-	ucvector v = ucvector_init(*out, *outsize);
-	u32 error = png_chunk_createv(&v, length, type, data);
-	*out = v.data;
-	*outsize = v.size;
-	return error;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Color types, channels, bits                                            / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*checks if the colortype is valid and the bitdepth bd is allowed for this colortype.
-Return value is a png error code.*/
-static u32 checkColorValidity(pngColorType colortype, u32 bd)
-{
-	switch (colortype) {
-	case LCT_GREY:
-		if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16))
-			return 37;
-		break;
-	case LCT_RGB:
-		if (!(bd == 8 || bd == 16))
-			return 37;
-		break;
-	case LCT_PALETTE:
-		if (!(bd == 1 || bd == 2 || bd == 4 || bd == 8))
-			return 37;
-		break;
-	case LCT_GREY_ALPHA:
-		if (!(bd == 8 || bd == 16))
-			return 37;
-		break;
-	case LCT_RGBA:
-		if (!(bd == 8 || bd == 16))
-			return 37;
-		break;
-	case LCT_MAX_OCTET_VALUE:
-		return 31; /* invalid color type */
-	default:
-		return 31; /* invalid color type */
-	}
-	return 0; /*allowed color type / bits combination*/
-}
-
-static u32 getNumColorChannels(pngColorType colortype)
-{
-	switch (colortype) {
-	case LCT_GREY:
-		return 1;
-	case LCT_RGB:
-		return 3;
-	case LCT_PALETTE:
-		return 1;
-	case LCT_GREY_ALPHA:
-		return 2;
-	case LCT_RGBA:
-		return 4;
-	case LCT_MAX_OCTET_VALUE:
-		return 0; /* invalid color type */
-	default:
-		return 0; /*invalid color type*/
-	}
-}
-
-static u32 png_get_bpp_lct(pngColorType colortype, u32 bitdepth)
-{
-	/*bits per pixel is amount of channels * bits per channel*/
-	return getNumColorChannels(colortype) * bitdepth;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-void png_color_mode_init(pngColorMode *info)
-{
-	info->key_defined = 0;
-	info->key_r = info->key_g = info->key_b = 0;
-	info->colortype = LCT_RGBA;
-	info->bitdepth = 8;
-	info->palette = 0;
-	info->palettesize = 0;
-}
-
-/*allocates palette memory if needed, and initializes all colors to black*/
-static void png_color_mode_alloc_palette(pngColorMode *info)
-{
-	u32 i;
-	/*if the palette is already allocated, it will have size 1024 so no reallocation needed in that case*/
-	/*the palette must have room for up to 256 colors with 4 bytes each.*/
-	if (!info->palette)
-		info->palette = (u8 *)png_malloc(1024);
-	if (!info->palette)
-		return; /*alloc fail*/
-	for (i = 0; i != 256; ++i) {
-		/*Initialize all unused colors with black, the value used for invalid palette indices.
-    This is an error according to the PNG spec, but common PNG decoders make it black instead.
-    That makes color conversion slightly faster due to no error handling needed.*/
-		info->palette[i * 4 + 0] = 0;
-		info->palette[i * 4 + 1] = 0;
-		info->palette[i * 4 + 2] = 0;
-		info->palette[i * 4 + 3] = 255;
-	}
-}
-
-void png_color_mode_cleanup(pngColorMode *info)
-{
-	png_palette_clear(info);
-}
-
-u32 png_color_mode_copy(pngColorMode *dest, const pngColorMode *source)
-{
-	png_color_mode_cleanup(dest);
-	png_memcpy(dest, source, sizeof(pngColorMode));
-	if (source->palette) {
-		dest->palette = (u8 *)png_malloc(1024);
-		if (!dest->palette && source->palettesize)
-			return 83; /*alloc fail*/
-		png_memcpy(dest->palette, source->palette, source->palettesize * 4);
-	}
-	return 0;
-}
-
-pngColorMode png_color_mode_make(pngColorType colortype, u32 bitdepth)
-{
-	pngColorMode result;
-	png_color_mode_init(&result);
-	result.colortype = colortype;
-	result.bitdepth = bitdepth;
-	return result;
-}
-
-static int png_color_mode_equal(const pngColorMode *a, const pngColorMode *b)
-{
-	u32 i;
-	if (a->colortype != b->colortype)
-		return 0;
-	if (a->bitdepth != b->bitdepth)
-		return 0;
-	if (a->key_defined != b->key_defined)
-		return 0;
-	if (a->key_defined) {
-		if (a->key_r != b->key_r)
-			return 0;
-		if (a->key_g != b->key_g)
-			return 0;
-		if (a->key_b != b->key_b)
-			return 0;
-	}
-	if (a->palettesize != b->palettesize)
-		return 0;
-	for (i = 0; i != a->palettesize * 4; ++i) {
-		if (a->palette[i] != b->palette[i])
-			return 0;
-	}
-	return 1;
-}
-
-void png_palette_clear(pngColorMode *info)
-{
-	if (info->palette)
-		png_free(info->palette);
-	info->palette = 0;
-	info->palettesize = 0;
-}
-
-u32 png_palette_add(pngColorMode *info, u8 r, u8 g, u8 b, u8 a)
-{
-	if (!info->palette) /*allocate palette if empty*/ {
-		png_color_mode_alloc_palette(info);
-		if (!info->palette)
-			return 83; /*alloc fail*/
-	}
-	if (info->palettesize >= 256) {
-		return 108; /*too many palette values*/
-	}
-	info->palette[4 * info->palettesize + 0] = r;
-	info->palette[4 * info->palettesize + 1] = g;
-	info->palette[4 * info->palettesize + 2] = b;
-	info->palette[4 * info->palettesize + 3] = a;
-	++info->palettesize;
-	return 0;
-}
-
-/*calculate bits per pixel out of colortype and bitdepth*/
-u32 png_get_bpp(const pngColorMode *info)
-{
-	return png_get_bpp_lct(info->colortype, info->bitdepth);
-}
-
-u32 png_get_channels(const pngColorMode *info)
-{
-	return getNumColorChannels(info->colortype);
-}
-
-u32 png_is_greyscale_type(const pngColorMode *info)
-{
-	return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA;
-}
-
-u32 png_is_alpha_type(const pngColorMode *info)
-{
-	return (info->colortype & 4) != 0; /*4 or 6*/
-}
-
-u32 png_is_palette_type(const pngColorMode *info)
-{
-	return info->colortype == LCT_PALETTE;
-}
-
-u32 png_has_palette_alpha(const pngColorMode *info)
-{
-	u32 i;
-	for (i = 0; i != info->palettesize; ++i) {
-		if (info->palette[i * 4 + 3] < 255)
-			return 1;
-	}
-	return 0;
-}
-
-u32 png_can_have_alpha(const pngColorMode *info)
-{
-	return info->key_defined || png_is_alpha_type(info) || png_has_palette_alpha(info);
-}
-
-static u32 png_get_raw_size_lct(u32 w, u32 h, pngColorType colortype, u32 bitdepth)
-{
-	u32 bpp = png_get_bpp_lct(colortype, bitdepth);
-	u32 n = (u32)w * (u32)h;
-	return ((n / 8u) * bpp) + ((n & 7u) * bpp + 7u) / 8u;
-}
-
-u32 png_get_raw_size(u32 w, u32 h, const pngColorMode *color)
-{
-	return png_get_raw_size_lct(w, h, color->colortype, color->bitdepth);
-}
-
-#ifdef PNG_COMPILE_PNG
-
-/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the png output buffer,
-and in addition has one extra byte per line: the filter byte. So this gives a larger
-result than png_get_raw_size. Set h to 1 to get the size of 1 row including filter byte. */
-static u32 png_get_raw_size_idat(u32 w, u32 h, u32 bpp)
-{
-	/* + 1 for the filter byte, and possibly plus padding bits per line. */
-	/* Ignoring casts, the expression is equal to (w * bpp + 7) / 8 + 1, but avoids overflow of w * bpp */
-	u32 line = ((u32)(w / 8u) * bpp) + 1u + ((w & 7u) * bpp + 7u) / 8u;
-	return (u32)h * line;
-}
-
-#ifdef PNG_COMPILE_DECODER
-/*Safely checks whether u32 overflow can be caused due to amount of pixels.
-This check is overcautious rather than precise. If this check indicates no overflow,
-you can safely compute in a u32 (but not an u32):
--(u32)w * (u32)h * 8
--amount of bytes in IDAT (including filter, padding and Adam7 bytes)
--amount of bytes in raw color model
-Returns 1 if overflow possible, 0 if not.
-*/
-static int png_pixel_overflow(u32 w, u32 h, const pngColorMode *pngcolor,
-			      const pngColorMode *rawcolor)
-{
-	u32 bpp = PNG_MAX(png_get_bpp(pngcolor), png_get_bpp(rawcolor));
-	u32 numpixels, total;
-	u32 line; /* bytes per line in worst case */
-
-	if (png_mulofl((u32)w, (u32)h, &numpixels))
-		return 1;
-	if (png_mulofl(numpixels, 8, &total))
-		return 1; /* bit pointer with 8-bit color, or 8 bytes per channel color */
-
-	/* Bytes per scanline with the expression "(w / 8u) * bpp) + ((w & 7u) * bpp + 7u) / 8u" */
-	if (png_mulofl((u32)(w / 8u), bpp, &line))
-		return 1;
-	if (png_addofl(line, ((w & 7u) * bpp + 7u) / 8u, &line))
-		return 1;
-
-	if (png_addofl(line, 5, &line))
-		return 1; /* 5 bytes overhead per line: 1 filterbyte, 4 for Adam7 worst case */
-	if (png_mulofl(line, h, &total))
-		return 1; /* Total bytes in worst case */
-
-	return 0; /* no overflow */
-}
-#endif /*PNG_COMPILE_DECODER*/
-#endif /*PNG_COMPILE_PNG*/
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-
-static void pngUnknownChunks_init(pngInfo *info)
-{
-	u32 i;
-	for (i = 0; i != 3; ++i)
-		info->unknown_chunks_data[i] = 0;
-	for (i = 0; i != 3; ++i)
-		info->unknown_chunks_size[i] = 0;
-}
-
-static void pngUnknownChunks_cleanup(pngInfo *info)
-{
-	u32 i;
-	for (i = 0; i != 3; ++i)
-		png_free(info->unknown_chunks_data[i]);
-}
-
-static u32 pngUnknownChunks_copy(pngInfo *dest, const pngInfo *src)
-{
-	u32 i;
-
-	pngUnknownChunks_cleanup(dest);
-
-	for (i = 0; i != 3; ++i) {
-		u32 j;
-		dest->unknown_chunks_size[i] = src->unknown_chunks_size[i];
-		dest->unknown_chunks_data[i] = (u8 *)png_malloc(src->unknown_chunks_size[i]);
-		if (!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i])
-			return 83; /*alloc fail*/
-		for (j = 0; j < src->unknown_chunks_size[i]; ++j) {
-			dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j];
-		}
-	}
-
-	return 0;
-}
-
-/******************************************************************************/
-
-static void pngText_init(pngInfo *info)
-{
-	info->text_num = 0;
-	info->text_keys = NULL;
-	info->text_strings = NULL;
-}
-
-static void pngText_cleanup(pngInfo *info)
-{
-	u32 i;
-	for (i = 0; i != info->text_num; ++i) {
-		string_cleanup(&info->text_keys[i]);
-		string_cleanup(&info->text_strings[i]);
-	}
-	png_free(info->text_keys);
-	png_free(info->text_strings);
-}
-
-static u32 pngText_copy(pngInfo *dest, const pngInfo *source)
-{
-	u32 i = 0;
-	dest->text_keys = NULL;
-	dest->text_strings = NULL;
-	dest->text_num = 0;
-	for (i = 0; i != source->text_num; ++i) {
-		CERROR_TRY_RETURN(
-			png_add_text(dest, source->text_keys[i], source->text_strings[i]));
-	}
-	return 0;
-}
-
-static u32 png_add_text_sized(pngInfo *info, const char *key, const char *str, u32 size)
-{
-	char **new_keys =
-		(char **)(png_realloc(info->text_keys, sizeof(char *) * (info->text_num + 1)));
-	char **new_strings =
-		(char **)(png_realloc(info->text_strings, sizeof(char *) * (info->text_num + 1)));
-
-	if (new_keys)
-		info->text_keys = new_keys;
-	if (new_strings)
-		info->text_strings = new_strings;
-
-	if (!new_keys || !new_strings)
-		return 83; /*alloc fail*/
-
-	++info->text_num;
-	info->text_keys[info->text_num - 1] = alloc_string(key);
-	info->text_strings[info->text_num - 1] = alloc_string_sized(str, size);
-	if (!info->text_keys[info->text_num - 1] || !info->text_strings[info->text_num - 1])
-		return 83; /*alloc fail*/
-
-	return 0;
-}
-
-u32 png_add_text(pngInfo *info, const char *key, const char *str)
-{
-	return png_add_text_sized(info, key, str, png_strlen(str));
-}
-
-void png_clear_text(pngInfo *info)
-{
-	pngText_cleanup(info);
-}
-
-/******************************************************************************/
-
-static void pngIText_init(pngInfo *info)
-{
-	info->itext_num = 0;
-	info->itext_keys = NULL;
-	info->itext_langtags = NULL;
-	info->itext_transkeys = NULL;
-	info->itext_strings = NULL;
-}
-
-static void pngIText_cleanup(pngInfo *info)
-{
-	u32 i;
-	for (i = 0; i != info->itext_num; ++i) {
-		string_cleanup(&info->itext_keys[i]);
-		string_cleanup(&info->itext_langtags[i]);
-		string_cleanup(&info->itext_transkeys[i]);
-		string_cleanup(&info->itext_strings[i]);
-	}
-	png_free(info->itext_keys);
-	png_free(info->itext_langtags);
-	png_free(info->itext_transkeys);
-	png_free(info->itext_strings);
-}
-
-static u32 pngIText_copy(pngInfo *dest, const pngInfo *source)
-{
-	u32 i = 0;
-	dest->itext_keys = NULL;
-	dest->itext_langtags = NULL;
-	dest->itext_transkeys = NULL;
-	dest->itext_strings = NULL;
-	dest->itext_num = 0;
-	for (i = 0; i != source->itext_num; ++i) {
-		CERROR_TRY_RETURN(
-			png_add_itext(dest, source->itext_keys[i], source->itext_langtags[i],
-				      source->itext_transkeys[i], source->itext_strings[i]));
-	}
-	return 0;
-}
-
-void png_clear_itext(pngInfo *info)
-{
-	pngIText_cleanup(info);
-}
-
-static u32 png_add_itext_sized(pngInfo *info, const char *key, const char *langtag,
-			       const char *transkey, const char *str, u32 size)
-{
-	char **new_keys =
-		(char **)(png_realloc(info->itext_keys, sizeof(char *) * (info->itext_num + 1)));
-	char **new_langtags = (char **)(png_realloc(info->itext_langtags,
-						    sizeof(char *) * (info->itext_num + 1)));
-	char **new_transkeys = (char **)(png_realloc(info->itext_transkeys,
-						     sizeof(char *) * (info->itext_num + 1)));
-	char **new_strings =
-		(char **)(png_realloc(info->itext_strings, sizeof(char *) * (info->itext_num + 1)));
-
-	if (new_keys)
-		info->itext_keys = new_keys;
-	if (new_langtags)
-		info->itext_langtags = new_langtags;
-	if (new_transkeys)
-		info->itext_transkeys = new_transkeys;
-	if (new_strings)
-		info->itext_strings = new_strings;
-
-	if (!new_keys || !new_langtags || !new_transkeys || !new_strings)
-		return 83; /*alloc fail*/
-
-	++info->itext_num;
-
-	info->itext_keys[info->itext_num - 1] = alloc_string(key);
-	info->itext_langtags[info->itext_num - 1] = alloc_string(langtag);
-	info->itext_transkeys[info->itext_num - 1] = alloc_string(transkey);
-	info->itext_strings[info->itext_num - 1] = alloc_string_sized(str, size);
-
-	return 0;
-}
-
-u32 png_add_itext(pngInfo *info, const char *key, const char *langtag, const char *transkey,
-		  const char *str)
-{
-	return png_add_itext_sized(info, key, langtag, transkey, str, png_strlen(str));
-}
-
-/* same as set but does not delete */
-static u32 png_assign_icc(pngInfo *info, const char *name, const u8 *profile, u32 profile_size)
-{
-	if (profile_size == 0)
-		return 100; /*invalid ICC profile size*/
-
-	info->iccp_name = alloc_string(name);
-	info->iccp_profile = (u8 *)png_malloc(profile_size);
-
-	if (!info->iccp_name || !info->iccp_profile)
-		return 83; /*alloc fail*/
-
-	png_memcpy(info->iccp_profile, profile, profile_size);
-	info->iccp_profile_size = profile_size;
-
-	return 0; /*ok*/
-}
-
-u32 png_set_icc(pngInfo *info, const char *name, const u8 *profile, u32 profile_size)
-{
-	if (info->iccp_name)
-		png_clear_icc(info);
-	info->iccp_defined = 1;
-
-	return png_assign_icc(info, name, profile, profile_size);
-}
-
-void png_clear_icc(pngInfo *info)
-{
-	string_cleanup(&info->iccp_name);
-	png_free(info->iccp_profile);
-	info->iccp_profile = NULL;
-	info->iccp_profile_size = 0;
-	info->iccp_defined = 0;
-}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-void png_info_init(pngInfo *info)
-{
-	png_color_mode_init(&info->color);
-	info->interlace_method = 0;
-	info->compression_method = 0;
-	info->filter_method = 0;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	info->background_defined = 0;
-	info->background_r = info->background_g = info->background_b = 0;
-
-	pngText_init(info);
-	pngIText_init(info);
-
-	info->time_defined = 0;
-	info->phys_defined = 0;
-
-	info->gama_defined = 0;
-	info->chrm_defined = 0;
-	info->srgb_defined = 0;
-	info->iccp_defined = 0;
-	info->iccp_name = NULL;
-	info->iccp_profile = NULL;
-
-	pngUnknownChunks_init(info);
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-}
-
-void png_info_cleanup(pngInfo *info)
-{
-	png_color_mode_cleanup(&info->color);
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	pngText_cleanup(info);
-	pngIText_cleanup(info);
-
-	png_clear_icc(info);
-
-	pngUnknownChunks_cleanup(info);
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-}
-
-u32 png_info_copy(pngInfo *dest, const pngInfo *source)
-{
-	png_info_cleanup(dest);
-	png_memcpy(dest, source, sizeof(pngInfo));
-	png_color_mode_init(&dest->color);
-	CERROR_TRY_RETURN(png_color_mode_copy(&dest->color, &source->color));
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	CERROR_TRY_RETURN(pngText_copy(dest, source));
-	CERROR_TRY_RETURN(pngIText_copy(dest, source));
-	if (source->iccp_defined) {
-		CERROR_TRY_RETURN(png_assign_icc(dest, source->iccp_name, source->iccp_profile,
-						 source->iccp_profile_size));
-	}
-
-	pngUnknownChunks_init(dest);
-	CERROR_TRY_RETURN(pngUnknownChunks_copy(dest, source));
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-	return 0;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/
-static void addColorBits(u8 *out, u32 index, u32 bits, u32 in)
-{
-	u32 m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/
-	/*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/
-	u32 p = index & m;
-	in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/
-	in = in << (bits * (m - p));
-	if (p == 0)
-		out[index * bits / 8u] = in;
-	else
-		out[index * bits / 8u] |= in;
-}
-
-typedef struct ColorTree ColorTree;
-
-/*
-One node of a color tree
-This is the data structure used to count the number of unique colors and to get a palette
-index for a color. It's like an octree, but because the alpha channel is used too, each
-node has 16 instead of 8 children.
-*/
-struct ColorTree {
-	ColorTree *children[16]; /*up to 16 pointers to ColorTree of next level*/
-	int index; /*the payload. Only has a meaningful value if this is in the last level*/
-};
-
-static void color_tree_init(ColorTree *tree)
-{
-	png_memset(tree->children, 0, 16 * sizeof(*tree->children));
-	tree->index = -1;
-}
-
-static void color_tree_cleanup(ColorTree *tree)
-{
-	int i;
-	for (i = 0; i != 16; ++i) {
-		if (tree->children[i]) {
-			color_tree_cleanup(tree->children[i]);
-			png_free(tree->children[i]);
-		}
-	}
-}
-
-/*returns -1 if color not present, its index otherwise*/
-static int color_tree_get(ColorTree *tree, u8 r, u8 g, u8 b, u8 a)
-{
-	int bit = 0;
-	for (bit = 0; bit < 8; ++bit) {
-		int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) +
-			1 * ((a >> bit) & 1);
-		if (!tree->children[i])
-			return -1;
-		else
-			tree = tree->children[i];
-	}
-	return tree ? tree->index : -1;
-}
-
-#ifdef PNG_COMPILE_ENCODER
-static int color_tree_has(ColorTree *tree, u8 r, u8 g, u8 b, u8 a)
-{
-	return color_tree_get(tree, r, g, b, a) >= 0;
-}
-#endif /*PNG_COMPILE_ENCODER*/
-
-/*color is not allowed to already exist.
-Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")
-Returns error code, or 0 if ok*/
-static u32 color_tree_add(ColorTree *tree, u8 r, u8 g, u8 b, u8 a, u32 index)
-{
-	int bit;
-	for (bit = 0; bit < 8; ++bit) {
-		int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) +
-			1 * ((a >> bit) & 1);
-		if (!tree->children[i]) {
-			tree->children[i] = (ColorTree *)png_malloc(sizeof(ColorTree));
-			if (!tree->children[i])
-				return 83; /*alloc fail*/
-			color_tree_init(tree->children[i]);
-		}
-		tree = tree->children[i];
-	}
-	tree->index = (int)index;
-	return 0;
-}
-
-/*put a pixel, given its RGBA color, into image of any color type*/
-static u32 rgba8ToPixel(u8 *out, u32 i, const pngColorMode *mode, ColorTree *tree /*for palette*/,
-			u8 r, u8 g, u8 b, u8 a)
-{
-	if (mode->colortype == LCT_GREY) {
-		u8 gray = r; /*((u16)r + g + b) / 3u;*/
-		if (mode->bitdepth == 8)
-			out[i] = gray;
-		else if (mode->bitdepth == 16)
-			out[i * 2 + 0] = out[i * 2 + 1] = gray;
-		else {
-			/*take the most significant bits of gray*/
-			gray = ((u32)gray >> (8u - mode->bitdepth)) & ((1u << mode->bitdepth) - 1u);
-			addColorBits(out, i, mode->bitdepth, gray);
-		}
-	} else if (mode->colortype == LCT_RGB) {
-		if (mode->bitdepth == 8) {
-			out[i * 3 + 0] = r;
-			out[i * 3 + 1] = g;
-			out[i * 3 + 2] = b;
-		} else {
-			out[i * 6 + 0] = out[i * 6 + 1] = r;
-			out[i * 6 + 2] = out[i * 6 + 3] = g;
-			out[i * 6 + 4] = out[i * 6 + 5] = b;
-		}
-	} else if (mode->colortype == LCT_PALETTE) {
-		int index = color_tree_get(tree, r, g, b, a);
-		if (index < 0)
-			return 82; /*color not in palette*/
-		if (mode->bitdepth == 8)
-			out[i] = index;
-		else
-			addColorBits(out, i, mode->bitdepth, (u32)index);
-	} else if (mode->colortype == LCT_GREY_ALPHA) {
-		u8 gray = r; /*((u16)r + g + b) / 3u;*/
-		if (mode->bitdepth == 8) {
-			out[i * 2 + 0] = gray;
-			out[i * 2 + 1] = a;
-		} else if (mode->bitdepth == 16) {
-			out[i * 4 + 0] = out[i * 4 + 1] = gray;
-			out[i * 4 + 2] = out[i * 4 + 3] = a;
-		}
-	} else if (mode->colortype == LCT_RGBA) {
-		if (mode->bitdepth == 8) {
-			out[i * 4 + 0] = r;
-			out[i * 4 + 1] = g;
-			out[i * 4 + 2] = b;
-			out[i * 4 + 3] = a;
-		} else {
-			out[i * 8 + 0] = out[i * 8 + 1] = r;
-			out[i * 8 + 2] = out[i * 8 + 3] = g;
-			out[i * 8 + 4] = out[i * 8 + 5] = b;
-			out[i * 8 + 6] = out[i * 8 + 7] = a;
-		}
-	}
-
-	return 0; /*no error*/
-}
-
-/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/
-static void rgba16ToPixel(u8 *out, u32 i, const pngColorMode *mode, u16 r, u16 g, u16 b, u16 a)
-{
-	if (mode->colortype == LCT_GREY) {
-		u16 gray = r; /*((u32)r + g + b) / 3u;*/
-		out[i * 2 + 0] = (gray >> 8) & 255;
-		out[i * 2 + 1] = gray & 255;
-	} else if (mode->colortype == LCT_RGB) {
-		out[i * 6 + 0] = (r >> 8) & 255;
-		out[i * 6 + 1] = r & 255;
-		out[i * 6 + 2] = (g >> 8) & 255;
-		out[i * 6 + 3] = g & 255;
-		out[i * 6 + 4] = (b >> 8) & 255;
-		out[i * 6 + 5] = b & 255;
-	} else if (mode->colortype == LCT_GREY_ALPHA) {
-		u16 gray = r; /*((u32)r + g + b) / 3u;*/
-		out[i * 4 + 0] = (gray >> 8) & 255;
-		out[i * 4 + 1] = gray & 255;
-		out[i * 4 + 2] = (a >> 8) & 255;
-		out[i * 4 + 3] = a & 255;
-	} else if (mode->colortype == LCT_RGBA) {
-		out[i * 8 + 0] = (r >> 8) & 255;
-		out[i * 8 + 1] = r & 255;
-		out[i * 8 + 2] = (g >> 8) & 255;
-		out[i * 8 + 3] = g & 255;
-		out[i * 8 + 4] = (b >> 8) & 255;
-		out[i * 8 + 5] = b & 255;
-		out[i * 8 + 6] = (a >> 8) & 255;
-		out[i * 8 + 7] = a & 255;
-	}
-}
-
-/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/
-static void getPixelColorRGBA8(u8 *r, u8 *g, u8 *b, u8 *a, const u8 *in, u32 i,
-			       const pngColorMode *mode)
-{
-	if (mode->colortype == LCT_GREY) {
-		if (mode->bitdepth == 8) {
-			*r = *g = *b = in[i];
-			if (mode->key_defined && *r == mode->key_r)
-				*a = 0;
-			else
-				*a = 255;
-		} else if (mode->bitdepth == 16) {
-			*r = *g = *b = in[i * 2 + 0];
-			if (mode->key_defined &&
-			    256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r)
-				*a = 0;
-			else
-				*a = 255;
-		} else {
-			u32 highest = ((1U << mode->bitdepth) -
-				       1U); /*highest possible value for this bit depth*/
-			u32 j = i * mode->bitdepth;
-			u32 value = readBitsFromReversedStream(&j, in, mode->bitdepth);
-			*r = *g = *b = (value * 255) / highest;
-			if (mode->key_defined && value == mode->key_r)
-				*a = 0;
-			else
-				*a = 255;
-		}
-	} else if (mode->colortype == LCT_RGB) {
-		if (mode->bitdepth == 8) {
-			*r = in[i * 3 + 0];
-			*g = in[i * 3 + 1];
-			*b = in[i * 3 + 2];
-			if (mode->key_defined && *r == mode->key_r && *g == mode->key_g &&
-			    *b == mode->key_b)
-				*a = 0;
-			else
-				*a = 255;
-		} else {
-			*r = in[i * 6 + 0];
-			*g = in[i * 6 + 2];
-			*b = in[i * 6 + 4];
-			if (mode->key_defined &&
-			    256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r &&
-			    256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g &&
-			    256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b)
-				*a = 0;
-			else
-				*a = 255;
-		}
-	} else if (mode->colortype == LCT_PALETTE) {
-		u32 index;
-		if (mode->bitdepth == 8)
-			index = in[i];
-		else {
-			u32 j = i * mode->bitdepth;
-			index = readBitsFromReversedStream(&j, in, mode->bitdepth);
-		}
-		/*out of bounds of palette not checked: see png_color_mode_alloc_palette.*/
-		*r = mode->palette[index * 4 + 0];
-		*g = mode->palette[index * 4 + 1];
-		*b = mode->palette[index * 4 + 2];
-		*a = mode->palette[index * 4 + 3];
-	} else if (mode->colortype == LCT_GREY_ALPHA) {
-		if (mode->bitdepth == 8) {
-			*r = *g = *b = in[i * 2 + 0];
-			*a = in[i * 2 + 1];
-		} else {
-			*r = *g = *b = in[i * 4 + 0];
-			*a = in[i * 4 + 2];
-		}
-	} else if (mode->colortype == LCT_RGBA) {
-		if (mode->bitdepth == 8) {
-			*r = in[i * 4 + 0];
-			*g = in[i * 4 + 1];
-			*b = in[i * 4 + 2];
-			*a = in[i * 4 + 3];
-		} else {
-			*r = in[i * 8 + 0];
-			*g = in[i * 8 + 2];
-			*b = in[i * 8 + 4];
-			*a = in[i * 8 + 6];
-		}
-	}
-}
-
-/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color
-mode test cases, optimized to convert the colors much faster, when converting
-to the common case of RGBA with 8 bit per channel. buffer must be RGBA with
-enough memory.*/
-static void getPixelColorsRGBA8(u8 *PNG_RESTRICT buffer, u32 numpixels, const u8 *PNG_RESTRICT in,
-				const pngColorMode *mode)
-{
-	u32 num_channels = 4;
-	u32 i;
-	if (mode->colortype == LCT_GREY) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i];
-				buffer[3] = 255;
-			}
-			if (mode->key_defined) {
-				buffer -= numpixels * num_channels;
-				for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-					if (buffer[0] == mode->key_r)
-						buffer[3] = 0;
-				}
-			}
-		} else if (mode->bitdepth == 16) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i * 2];
-				buffer[3] =
-					mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] ==
-								     mode->key_r ?
-						      0 :
-						      255;
-			}
-		} else {
-			u32 highest = ((1U << mode->bitdepth) -
-				       1U); /*highest possible value for this bit depth*/
-			u32 j = 0;
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				u32 value = readBitsFromReversedStream(&j, in, mode->bitdepth);
-				buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
-				buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255;
-			}
-		}
-	} else if (mode->colortype == LCT_RGB) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				png_memcpy(buffer, &in[i * 3], 3);
-				buffer[3] = 255;
-			}
-			if (mode->key_defined) {
-				buffer -= numpixels * num_channels;
-				for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-					if (buffer[0] == mode->key_r && buffer[1] == mode->key_g &&
-					    buffer[2] == mode->key_b)
-						buffer[3] = 0;
-				}
-			}
-		} else {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = in[i * 6 + 0];
-				buffer[1] = in[i * 6 + 2];
-				buffer[2] = in[i * 6 + 4];
-				buffer[3] = mode->key_defined &&
-							    256U * in[i * 6 + 0] + in[i * 6 + 1] ==
-								    mode->key_r &&
-							    256U * in[i * 6 + 2] + in[i * 6 + 3] ==
-								    mode->key_g &&
-							    256U * in[i * 6 + 4] + in[i * 6 + 5] ==
-								    mode->key_b ?
-							  0 :
-							  255;
-			}
-		}
-	} else if (mode->colortype == LCT_PALETTE) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				u32 index = in[i];
-				/*out of bounds of palette not checked: see png_color_mode_alloc_palette.*/
-				png_memcpy(buffer, &mode->palette[index * 4], 4);
-			}
-		} else {
-			u32 j = 0;
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				u32 index = readBitsFromReversedStream(&j, in, mode->bitdepth);
-				/*out of bounds of palette not checked: see png_color_mode_alloc_palette.*/
-				png_memcpy(buffer, &mode->palette[index * 4], 4);
-			}
-		}
-	} else if (mode->colortype == LCT_GREY_ALPHA) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
-				buffer[3] = in[i * 2 + 1];
-			}
-		} else {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
-				buffer[3] = in[i * 4 + 2];
-			}
-		}
-	} else if (mode->colortype == LCT_RGBA) {
-		if (mode->bitdepth == 8) {
-			png_memcpy(buffer, in, numpixels * 4);
-		} else {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = in[i * 8 + 0];
-				buffer[1] = in[i * 8 + 2];
-				buffer[2] = in[i * 8 + 4];
-				buffer[3] = in[i * 8 + 6];
-			}
-		}
-	}
-}
-
-/*Similar to getPixelColorsRGBA8, but with 3-channel RGB output.*/
-static void getPixelColorsRGB8(u8 *PNG_RESTRICT buffer, u32 numpixels, const u8 *PNG_RESTRICT in,
-			       const pngColorMode *mode)
-{
-	const u32 num_channels = 3;
-	u32 i;
-	if (mode->colortype == LCT_GREY) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i];
-			}
-		} else if (mode->bitdepth == 16) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i * 2];
-			}
-		} else {
-			u32 highest = ((1U << mode->bitdepth) -
-				       1U); /*highest possible value for this bit depth*/
-			u32 j = 0;
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				u32 value = readBitsFromReversedStream(&j, in, mode->bitdepth);
-				buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
-			}
-		}
-	} else if (mode->colortype == LCT_RGB) {
-		if (mode->bitdepth == 8) {
-			png_memcpy(buffer, in, numpixels * 3);
-		} else {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = in[i * 6 + 0];
-				buffer[1] = in[i * 6 + 2];
-				buffer[2] = in[i * 6 + 4];
-			}
-		}
-	} else if (mode->colortype == LCT_PALETTE) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				u32 index = in[i];
-				/*out of bounds of palette not checked: see png_color_mode_alloc_palette.*/
-				png_memcpy(buffer, &mode->palette[index * 4], 3);
-			}
-		} else {
-			u32 j = 0;
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				u32 index = readBitsFromReversedStream(&j, in, mode->bitdepth);
-				/*out of bounds of palette not checked: see png_color_mode_alloc_palette.*/
-				png_memcpy(buffer, &mode->palette[index * 4], 3);
-			}
-		}
-	} else if (mode->colortype == LCT_GREY_ALPHA) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
-			}
-		} else {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
-			}
-		}
-	} else if (mode->colortype == LCT_RGBA) {
-		if (mode->bitdepth == 8) {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				png_memcpy(buffer, &in[i * 4], 3);
-			}
-		} else {
-			for (i = 0; i != numpixels; ++i, buffer += num_channels) {
-				buffer[0] = in[i * 8 + 0];
-				buffer[1] = in[i * 8 + 2];
-				buffer[2] = in[i * 8 + 4];
-			}
-		}
-	}
-}
-
-/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
-given color type, but the given color type must be 16-bit itself.*/
-static void getPixelColorRGBA16(u16 *r, u16 *g, u16 *b, u16 *a, const u8 *in, u32 i,
-				const pngColorMode *mode)
-{
-	if (mode->colortype == LCT_GREY) {
-		*r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1];
-		if (mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r)
-			*a = 0;
-		else
-			*a = 65535;
-	} else if (mode->colortype == LCT_RGB) {
-		*r = 256u * in[i * 6 + 0] + in[i * 6 + 1];
-		*g = 256u * in[i * 6 + 2] + in[i * 6 + 3];
-		*b = 256u * in[i * 6 + 4] + in[i * 6 + 5];
-		if (mode->key_defined && 256u * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r &&
-		    256u * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g &&
-		    256u * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b)
-			*a = 0;
-		else
-			*a = 65535;
-	} else if (mode->colortype == LCT_GREY_ALPHA) {
-		*r = *g = *b = 256u * in[i * 4 + 0] + in[i * 4 + 1];
-		*a = 256u * in[i * 4 + 2] + in[i * 4 + 3];
-	} else if (mode->colortype == LCT_RGBA) {
-		*r = 256u * in[i * 8 + 0] + in[i * 8 + 1];
-		*g = 256u * in[i * 8 + 2] + in[i * 8 + 3];
-		*b = 256u * in[i * 8 + 4] + in[i * 8 + 5];
-		*a = 256u * in[i * 8 + 6] + in[i * 8 + 7];
-	}
-}
-
-u32 png_convert(u8 *out, const u8 *in, const pngColorMode *mode_out, const pngColorMode *mode_in,
-		u32 w, u32 h)
-{
-	u32 i;
-	ColorTree tree;
-	u32 numpixels = (u32)w * (u32)h;
-	u32 error = 0;
-
-	if (mode_in->colortype == LCT_PALETTE && !mode_in->palette) {
-		return 107; /* error: must provide palette if input mode is palette */
-	}
-
-	if (png_color_mode_equal(mode_out, mode_in)) {
-		u32 numbytes = png_get_raw_size(w, h, mode_in);
-		png_memcpy(out, in, numbytes);
-		return 0;
-	}
-
-	if (mode_out->colortype == LCT_PALETTE) {
-		u32 palettesize = mode_out->palettesize;
-		const u8 *palette = mode_out->palette;
-		u32 palsize = (u32)1u << mode_out->bitdepth;
-		/*if the user specified output palette but did not give the values, assume
-    they want the values of the input color type (assuming that one is palette).
-    Note that we never create a new palette ourselves.*/
-		if (palettesize == 0) {
-			palettesize = mode_in->palettesize;
-			palette = mode_in->palette;
-			/*if the input was also palette with same bitdepth, then the color types are also
-      equal, so copy literally. This to preserve the exact indices that were in the PNG
-      even in case there are duplicate colors in the palette.*/
-			if (mode_in->colortype == LCT_PALETTE &&
-			    mode_in->bitdepth == mode_out->bitdepth) {
-				u32 numbytes = png_get_raw_size(w, h, mode_in);
-				png_memcpy(out, in, numbytes);
-				return 0;
-			}
-		}
-		if (palettesize < palsize)
-			palsize = palettesize;
-		color_tree_init(&tree);
-		for (i = 0; i != palsize; ++i) {
-			const u8 *p = &palette[i * 4];
-			error = color_tree_add(&tree, p[0], p[1], p[2], p[3], (u32)i);
-			if (error)
-				break;
-		}
-	}
-
-	if (!error) {
-		if (mode_in->bitdepth == 16 && mode_out->bitdepth == 16) {
-			for (i = 0; i != numpixels; ++i) {
-				u16 r = 0, g = 0, b = 0, a = 0;
-				getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
-				rgba16ToPixel(out, i, mode_out, r, g, b, a);
-			}
-		} else if (mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) {
-			getPixelColorsRGBA8(out, numpixels, in, mode_in);
-		} else if (mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) {
-			getPixelColorsRGB8(out, numpixels, in, mode_in);
-		} else {
-			u8 r = 0, g = 0, b = 0, a = 0;
-			for (i = 0; i != numpixels; ++i) {
-				getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
-				error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
-				if (error)
-					break;
-			}
-		}
-	}
-
-	if (mode_out->colortype == LCT_PALETTE) {
-		color_tree_cleanup(&tree);
-	}
-
-	return error;
-}
-
-#ifdef PNG_COMPILE_ENCODER
-
-/* Converts a single rgb color without alpha from one type to another, color bits truncated to
-their bitdepth. In case of single channel (gray or palette), only the r channel is used. Slow
-function, do not use to process all pixels of an image. Alpha channel not supported on purpose:
-this is for bKGD, supporting alpha may prevent it from finding a color in the palette, from the
-specification it looks like bKGD should ignore the alpha values of the palette since it can use
-any palette index but doesn't have an alpha channel. Idem with ignoring color key. */
-static u32 png_convert_rgb(u32 *r_out, u32 *g_out, u32 *b_out, u32 r_in, u32 g_in, u32 b_in,
-			   const pngColorMode *mode_out, const pngColorMode *mode_in)
-{
-	u32 r = 0, g = 0, b = 0;
-	u32 mul = 65535 / ((1u << mode_in->bitdepth) - 1u); /*65535, 21845, 4369, 257, 1*/
-	u32 shift = 16 - mode_out->bitdepth;
-
-	if (mode_in->colortype == LCT_GREY || mode_in->colortype == LCT_GREY_ALPHA) {
-		r = g = b = r_in * mul;
-	} else if (mode_in->colortype == LCT_RGB || mode_in->colortype == LCT_RGBA) {
-		r = r_in * mul;
-		g = g_in * mul;
-		b = b_in * mul;
-	} else if (mode_in->colortype == LCT_PALETTE) {
-		if (r_in >= mode_in->palettesize)
-			return 82;
-		r = mode_in->palette[r_in * 4 + 0] * 257u;
-		g = mode_in->palette[r_in * 4 + 1] * 257u;
-		b = mode_in->palette[r_in * 4 + 2] * 257u;
-	} else {
-		return 31;
-	}
-
-	/* now convert to output format */
-	if (mode_out->colortype == LCT_GREY || mode_out->colortype == LCT_GREY_ALPHA) {
-		*r_out = r >> shift;
-	} else if (mode_out->colortype == LCT_RGB || mode_out->colortype == LCT_RGBA) {
-		*r_out = r >> shift;
-		*g_out = g >> shift;
-		*b_out = b >> shift;
-	} else if (mode_out->colortype == LCT_PALETTE) {
-		u32 i;
-		/* a 16-bit color cannot be in the palette */
-		if ((r >> 8) != (r & 255) || (g >> 8) != (g & 255) || (b >> 8) != (b & 255))
-			return 82;
-		for (i = 0; i < mode_out->palettesize; i++) {
-			u32 j = i * 4;
-			if ((r >> 8) == mode_out->palette[j + 0] &&
-			    (g >> 8) == mode_out->palette[j + 1] &&
-			    (b >> 8) == mode_out->palette[j + 2]) {
-				*r_out = i;
-				return 0;
-			}
-		}
-		return 82;
-	} else {
-		return 31;
-	}
-
-	return 0;
-}
-
-void png_color_stats_init(pngColorStats *stats)
-{
-	/*stats*/
-	stats->colored = 0;
-	stats->key = 0;
-	stats->key_r = stats->key_g = stats->key_b = 0;
-	stats->alpha = 0;
-	stats->numcolors = 0;
-	stats->bits = 1;
-	stats->numpixels = 0;
-	/*settings*/
-	stats->allow_palette = 1;
-	stats->allow_greyscale = 1;
-}
-
-/*function used for debug purposes with C++*/
-/*void printColorStats(pngColorStats* p) {
-  std::cout << "colored: " << (int)p->colored << ", ";
-  std::cout << "key: " << (int)p->key << ", ";
-  std::cout << "key_r: " << (int)p->key_r << ", ";
-  std::cout << "key_g: " << (int)p->key_g << ", ";
-  std::cout << "key_b: " << (int)p->key_b << ", ";
-  std::cout << "alpha: " << (int)p->alpha << ", ";
-  std::cout << "numcolors: " << (int)p->numcolors << ", ";
-  std::cout << "bits: " << (int)p->bits << std::endl;
-}*/
-
-/*Returns how many bits needed to represent given value (max 8 bit)*/
-static u32 getValueRequiredBits(u8 value)
-{
-	if (value == 0 || value == 255)
-		return 1;
-	/*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/
-	if (value % 17 == 0)
-		return value % 85 == 0 ? 2 : 4;
-	return 8;
-}
-
-/*stats must already have been inited. */
-u32 png_compute_color_stats(pngColorStats *stats, const u8 *in, u32 w, u32 h,
-			    const pngColorMode *mode_in)
-{
-	u32 i;
-	ColorTree tree;
-	u32 numpixels = (u32)w * (u32)h;
-	u32 error = 0;
-
-	/* mark things as done already if it would be impossible to have a more expensive case */
-	u32 colored_done = png_is_greyscale_type(mode_in) ? 1 : 0;
-	u32 alpha_done = png_can_have_alpha(mode_in) ? 0 : 1;
-	u32 numcolors_done = 0;
-	u32 bpp = png_get_bpp(mode_in);
-	u32 bits_done = (stats->bits == 1 && bpp == 1) ? 1 : 0;
-	u32 sixteen = 0; /* whether the input image is 16 bit */
-	u32 maxnumcolors = 257;
-	if (bpp <= 8)
-		maxnumcolors = PNG_MIN(257, stats->numcolors + (1u << bpp));
-
-	stats->numpixels += numpixels;
-
-	/*if palette not allowed, no need to compute numcolors*/
-	if (!stats->allow_palette)
-		numcolors_done = 1;
-
-	color_tree_init(&tree);
-
-	/*If the stats was already filled in from previous data, fill its palette in tree
-  and mark things as done already if we know they are the most expensive case already*/
-	if (stats->alpha)
-		alpha_done = 1;
-	if (stats->colored)
-		colored_done = 1;
-	if (stats->bits == 16)
-		numcolors_done = 1;
-	if (stats->bits >= bpp)
-		bits_done = 1;
-	if (stats->numcolors >= maxnumcolors)
-		numcolors_done = 1;
-
-	if (!numcolors_done) {
-		for (i = 0; i < stats->numcolors; i++) {
-			const u8 *color = &stats->palette[i * 4];
-			error = color_tree_add(&tree, color[0], color[1], color[2], color[3], i);
-			if (error)
-				goto cleanup;
-		}
-	}
-
-	/*Check if the 16-bit input is truly 16-bit*/
-	if (mode_in->bitdepth == 16 && !sixteen) {
-		u16 r = 0, g = 0, b = 0, a = 0;
-		for (i = 0; i != numpixels; ++i) {
-			getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
-			if ((r & 255) != ((r >> 8) & 255) || (g & 255) != ((g >> 8) & 255) ||
-			    (b & 255) != ((b >> 8) & 255) ||
-			    (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/ {
-				stats->bits = 16;
-				sixteen = 1;
-				bits_done = 1;
-				numcolors_done =
-					1; /*counting colors no longer useful, palette doesn't support 16-bit*/
-				break;
-			}
-		}
-	}
-
-	if (sixteen) {
-		u16 r = 0, g = 0, b = 0, a = 0;
-
-		for (i = 0; i != numpixels; ++i) {
-			getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
-
-			if (!colored_done && (r != g || r != b)) {
-				stats->colored = 1;
-				colored_done = 1;
-			}
-
-			if (!alpha_done) {
-				u32 matchkey = (r == stats->key_r && g == stats->key_g &&
-						b == stats->key_b);
-				if (a != 65535 && (a != 0 || (stats->key && !matchkey))) {
-					stats->alpha = 1;
-					stats->key = 0;
-					alpha_done = 1;
-				} else if (a == 0 && !stats->alpha && !stats->key) {
-					stats->key = 1;
-					stats->key_r = r;
-					stats->key_g = g;
-					stats->key_b = b;
-				} else if (a == 65535 && stats->key && matchkey) {
-					/* Color key cannot be used if an opaque pixel also has that RGB color. */
-					stats->alpha = 1;
-					stats->key = 0;
-					alpha_done = 1;
-				}
-			}
-			if (alpha_done && numcolors_done && colored_done && bits_done)
-				break;
-		}
-
-		if (stats->key && !stats->alpha) {
-			for (i = 0; i != numpixels; ++i) {
-				getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
-				if (a != 0 && r == stats->key_r && g == stats->key_g &&
-				    b == stats->key_b) {
-					/* Color key cannot be used if an opaque pixel also has that RGB color. */
-					stats->alpha = 1;
-					stats->key = 0;
-					alpha_done = 1;
-				}
-			}
-		}
-	} else /* < 16-bit */ {
-		u8 r = 0, g = 0, b = 0, a = 0;
-		for (i = 0; i != numpixels; ++i) {
-			getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
-
-			if (!bits_done && stats->bits < 8) {
-				/*only r is checked, < 8 bits is only relevant for grayscale*/
-				u32 bits = getValueRequiredBits(r);
-				if (bits > stats->bits)
-					stats->bits = bits;
-			}
-			bits_done = (stats->bits >= bpp);
-
-			if (!colored_done && (r != g || r != b)) {
-				stats->colored = 1;
-				colored_done = 1;
-				if (stats->bits < 8)
-					stats->bits =
-						8; /*PNG has no colored modes with less than 8-bit per channel*/
-			}
-
-			if (!alpha_done) {
-				u32 matchkey = (r == stats->key_r && g == stats->key_g &&
-						b == stats->key_b);
-				if (a != 255 && (a != 0 || (stats->key && !matchkey))) {
-					stats->alpha = 1;
-					stats->key = 0;
-					alpha_done = 1;
-					if (stats->bits < 8)
-						stats->bits =
-							8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
-				} else if (a == 0 && !stats->alpha && !stats->key) {
-					stats->key = 1;
-					stats->key_r = r;
-					stats->key_g = g;
-					stats->key_b = b;
-				} else if (a == 255 && stats->key && matchkey) {
-					/* Color key cannot be used if an opaque pixel also has that RGB color. */
-					stats->alpha = 1;
-					stats->key = 0;
-					alpha_done = 1;
-					if (stats->bits < 8)
-						stats->bits =
-							8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
-				}
-			}
-
-			if (!numcolors_done) {
-				if (!color_tree_has(&tree, r, g, b, a)) {
-					error = color_tree_add(&tree, r, g, b, a, stats->numcolors);
-					if (error)
-						goto cleanup;
-					if (stats->numcolors < 256) {
-						u8 *p = stats->palette;
-						u32 n = stats->numcolors;
-						p[n * 4 + 0] = r;
-						p[n * 4 + 1] = g;
-						p[n * 4 + 2] = b;
-						p[n * 4 + 3] = a;
-					}
-					++stats->numcolors;
-					numcolors_done = stats->numcolors >= maxnumcolors;
-				}
-			}
-
-			if (alpha_done && numcolors_done && colored_done && bits_done)
-				break;
-		}
-
-		if (stats->key && !stats->alpha) {
-			for (i = 0; i != numpixels; ++i) {
-				getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in);
-				if (a != 0 && r == stats->key_r && g == stats->key_g &&
-				    b == stats->key_b) {
-					/* Color key cannot be used if an opaque pixel also has that RGB color. */
-					stats->alpha = 1;
-					stats->key = 0;
-					alpha_done = 1;
-					if (stats->bits < 8)
-						stats->bits =
-							8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
-				}
-			}
-		}
-
-		/*make the stats's key always 16-bit for consistency - repeat each byte twice*/
-		stats->key_r += (stats->key_r << 8);
-		stats->key_g += (stats->key_g << 8);
-		stats->key_b += (stats->key_b << 8);
-	}
-
-cleanup:
-	color_tree_cleanup(&tree);
-	return error;
-}
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-/*Adds a single color to the color stats. The stats must already have been inited. The color must be given as 16-bit
-(with 2 bytes repeating for 8-bit and 65535 for opaque alpha channel). This function is expensive, do not call it for
-all pixels of an image but only for a few additional values. */
-static u32 png_color_stats_add(pngColorStats *stats, u32 r, u32 g, u32 b, u32 a)
-{
-	u32 error = 0;
-	u8 image[8];
-	pngColorMode mode;
-	png_color_mode_init(&mode);
-	image[0] = r >> 8;
-	image[1] = r;
-	image[2] = g >> 8;
-	image[3] = g;
-	image[4] = b >> 8;
-	image[5] = b;
-	image[6] = a >> 8;
-	image[7] = a;
-	mode.bitdepth = 16;
-	mode.colortype = LCT_RGBA;
-	error = png_compute_color_stats(stats, image, 1, 1, &mode);
-	png_color_mode_cleanup(&mode);
-	return error;
-}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-/*Computes a minimal PNG color model that can contain all colors as indicated by the stats.
-The stats should be computed with png_compute_color_stats.
-mode_in is raw color profile of the image the stats were computed on, to copy palette order from when relevant.
-Minimal PNG color model means the color type and bit depth that gives smallest amount of bits in the output image,
-e.g. gray if only grayscale pixels, palette if less than 256 colors, color key if only single transparent color, ...
-This is used if auto_convert is enabled (it is by default).
-*/
-static u32 auto_choose_color(pngColorMode *mode_out, const pngColorMode *mode_in,
-			     const pngColorStats *stats)
-{
-	u32 error = 0;
-	u32 palettebits;
-	u32 i, n;
-	u32 numpixels = stats->numpixels;
-	u32 palette_ok, gray_ok;
-
-	u32 alpha = stats->alpha;
-	u32 key = stats->key;
-	u32 bits = stats->bits;
-
-	mode_out->key_defined = 0;
-
-	if (key && numpixels <= 16) {
-		alpha = 1; /*too few pixels to justify tRNS chunk overhead*/
-		key = 0;
-		if (bits < 8)
-			bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/
-	}
-
-	gray_ok = !stats->colored;
-	if (!stats->allow_greyscale)
-		gray_ok = 0;
-	if (!gray_ok && bits < 8)
-		bits = 8;
-
-	n = stats->numcolors;
-	palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8));
-	palette_ok =
-		n <= 256 && bits <= 8 && n != 0; /*n==0 means likely numcolors wasn't computed*/
-	if (numpixels < n * 2)
-		palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/
-	if (gray_ok && !alpha && bits <= palettebits)
-		palette_ok = 0; /*gray is less overhead*/
-	if (!stats->allow_palette)
-		palette_ok = 0;
-
-	if (palette_ok) {
-		const u8 *p = stats->palette;
-		png_palette_clear(mode_out); /*remove potential earlier palette*/
-		for (i = 0; i != stats->numcolors; ++i) {
-			error = png_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2],
-						p[i * 4 + 3]);
-			if (error)
-				break;
-		}
-
-		mode_out->colortype = LCT_PALETTE;
-		mode_out->bitdepth = palettebits;
-
-		if (mode_in->colortype == LCT_PALETTE &&
-		    mode_in->palettesize >= mode_out->palettesize &&
-		    mode_in->bitdepth == mode_out->bitdepth) {
-			/*If input should have same palette colors, keep original to preserve its order and prevent conversion*/
-			png_color_mode_cleanup(mode_out);
-			png_color_mode_copy(mode_out, mode_in);
-		}
-	} else /*8-bit or 16-bit per channel*/ {
-		mode_out->bitdepth = bits;
-		mode_out->colortype = alpha ? (gray_ok ? LCT_GREY_ALPHA : LCT_RGBA) :
-						    (gray_ok ? LCT_GREY : LCT_RGB);
-		if (key) {
-			u32 mask = (1u << mode_out->bitdepth) -
-				   1u; /*stats always uses 16-bit, mask converts it*/
-			mode_out->key_r = stats->key_r & mask;
-			mode_out->key_g = stats->key_g & mask;
-			mode_out->key_b = stats->key_b & mask;
-			mode_out->key_defined = 1;
-		}
-	}
-
-	return error;
-}
-
-#endif /* #ifdef PNG_COMPILE_ENCODER */
-
-/*
-Paeth predictor, used by PNG filter type 4
-The parameters are of type short, but should come from u8s, the shorts
-are only needed to make the paeth calculation correct.
-*/
-static u8 paethPredictor(short a, short b, short c)
-{
-	short pa = PNG_ABS(b - c);
-	short pb = PNG_ABS(a - c);
-	short pc = PNG_ABS(a + b - c - c);
-	/* return input value associated with smallest of pa, pb, pc (with certain priority if equal) */
-	if (pb < pa) {
-		a = b;
-		pa = pb;
-	}
-	return (pc < pa) ? c : a;
-}
-
-/*shared values used by multiple Adam7 related functions*/
-
-static const u32 ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
-static const u32 ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
-static const u32 ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
-static const u32 ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
-
-/*
-Outputs various dimensions and positions in the image related to the Adam7 reduced images.
-passw: output containing the width of the 7 passes
-passh: output containing the height of the 7 passes
-filter_passstart: output containing the index of the start and end of each
- reduced image with filter bytes
-padded_passstart output containing the index of the start and end of each
- reduced image when without filter bytes but with padded scanlines
-passstart: output containing the index of the start and end of each reduced
- image without padding between scanlines, but still padding between the images
-w, h: width and height of non-interlaced image
-bpp: bits per pixel
-"padded" is only relevant if bpp is less than 8 and a scanline or image does not
- end at a full byte
-*/
-static void Adam7_getpassvalues(u32 passw[7], u32 passh[7], u32 filter_passstart[8],
-				u32 padded_passstart[8], u32 passstart[8], u32 w, u32 h, u32 bpp)
-{
-	/*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/
-	u32 i;
-
-	/*calculate width and height in pixels of each pass*/
-	for (i = 0; i != 7; ++i) {
-		passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
-		passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
-		if (passw[i] == 0)
-			passh[i] = 0;
-		if (passh[i] == 0)
-			passw[i] = 0;
-	}
-
-	filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
-	for (i = 0; i != 7; ++i) {
-		/*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
-		filter_passstart[i + 1] =
-			filter_passstart[i] +
-			((passw[i] && passh[i]) ? passh[i] * (1u + (passw[i] * bpp + 7u) / 8u) : 0);
-		/*bits padded if needed to fill full byte at end of each scanline*/
-		padded_passstart[i + 1] =
-			padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7u) / 8u);
-		/*only padded at end of reduced image*/
-		passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7u) / 8u;
-	}
-}
-
-#ifdef PNG_COMPILE_DECODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / PNG Decoder                                                            / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*read the information from the header and store it in the pngInfo. return value is error*/
-u32 png_inspect(u32 *w, u32 *h, pngState *state, const u8 *in, u32 insize)
-{
-	u32 width, height;
-	pngInfo *info = &state->info_png;
-	if (insize == 0 || in == 0) {
-		CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/
-	}
-	if (insize < 33) {
-		CERROR_RETURN_ERROR(
-			state->error,
-			27); /*error: the data length is smaller than the length of a PNG header*/
-	}
-
-	/*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
-	/* TODO: remove this. One should use a new pngState for new sessions */
-	png_info_cleanup(info);
-	png_info_init(info);
-
-	if (in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 || in[4] != 13 ||
-	    in[5] != 10 || in[6] != 26 || in[7] != 10) {
-		CERROR_RETURN_ERROR(
-			state->error,
-			28); /*error: the first 8 bytes are not the correct PNG signature*/
-	}
-	if (png_chunk_length(in + 8) != 13) {
-		CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/
-	}
-	if (!png_chunk_type_equals(in + 8, "IHDR")) {
-		CERROR_RETURN_ERROR(state->error,
-				    29); /*error: it doesn't start with a IHDR chunk!*/
-	}
-
-	/*read the values given in the header*/
-	width = png_read32bitInt(&in[16]);
-	height = png_read32bitInt(&in[20]);
-	/*TODO: remove the undocumented feature that allows to give null pointers to width or height*/
-	if (w)
-		*w = width;
-	if (h)
-		*h = height;
-	info->color.bitdepth = in[24];
-	info->color.colortype = (pngColorType)in[25];
-	info->compression_method = in[26];
-	info->filter_method = in[27];
-	info->interlace_method = in[28];
-
-	/*errors returned only after the parsing so other values are still output*/
-
-	/*error: invalid image size*/
-	if (width == 0 || height == 0)
-		CERROR_RETURN_ERROR(state->error, 93);
-	/*error: invalid colortype or bitdepth combination*/
-	state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
-	if (state->error)
-		return state->error;
-	/*error: only compression method 0 is allowed in the specification*/
-	if (info->compression_method != 0)
-		CERROR_RETURN_ERROR(state->error, 32);
-	/*error: only filter method 0 is allowed in the specification*/
-	if (info->filter_method != 0)
-		CERROR_RETURN_ERROR(state->error, 33);
-	/*error: only interlace methods 0 and 1 exist in the specification*/
-	if (info->interlace_method > 1)
-		CERROR_RETURN_ERROR(state->error, 34);
-
-	if (!state->decoder.ignore_crc) {
-		u32 CRC = png_read32bitInt(&in[29]);
-		u32 checksum = png_crc32(&in[12], 17);
-		if (CRC != checksum) {
-			CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/
-		}
-	}
-
-	return state->error;
-}
-
-static u32 unfilterScanline(u8 *recon, const u8 *scanline, const u8 *precon, u32 bytewidth,
-			    u8 filterType, u32 length)
-{
-	/*
-  For PNG filter method 0
-  unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte,
-  the filter works byte per byte (bytewidth = 1)
-  precon is the previous unfiltered scanline, recon the result, scanline the current one
-  the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
-  recon and scanline MAY be the same memory address! precon must be disjoint.
-  */
-
-	u32 i;
-	switch (filterType) {
-	case 0:
-		for (i = 0; i != length; ++i)
-			recon[i] = scanline[i];
-		break;
-	case 1:
-		for (i = 0; i != bytewidth; ++i)
-			recon[i] = scanline[i];
-		for (i = bytewidth; i < length; ++i)
-			recon[i] = scanline[i] + recon[i - bytewidth];
-		break;
-	case 2:
-		if (precon) {
-			for (i = 0; i != length; ++i)
-				recon[i] = scanline[i] + precon[i];
-		} else {
-			for (i = 0; i != length; ++i)
-				recon[i] = scanline[i];
-		}
-		break;
-	case 3:
-		if (precon) {
-			for (i = 0; i != bytewidth; ++i)
-				recon[i] = scanline[i] + (precon[i] >> 1u);
-			for (i = bytewidth; i < length; ++i)
-				recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1u);
-		} else {
-			for (i = 0; i != bytewidth; ++i)
-				recon[i] = scanline[i];
-			for (i = bytewidth; i < length; ++i)
-				recon[i] = scanline[i] + (recon[i - bytewidth] >> 1u);
-		}
-		break;
-	case 4:
-		if (precon) {
-			for (i = 0; i != bytewidth; ++i) {
-				recon[i] =
-					(scanline[i] +
-					 precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
-			}
-
-			/* Unroll independent paths of the paeth predictor. A 6x and 8x version would also be possible but that
-        adds too much code. Whether this actually speeds anything up at all depends on compiler and settings. */
-			if (bytewidth >= 4) {
-				for (; i + 3 < length; i += 4) {
-					u32 j = i - bytewidth;
-					u8 s0 = scanline[i + 0], s1 = scanline[i + 1],
-					   s2 = scanline[i + 2], s3 = scanline[i + 3];
-					u8 r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2],
-					   r3 = recon[j + 3];
-					u8 p0 = precon[i + 0], p1 = precon[i + 1],
-					   p2 = precon[i + 2], p3 = precon[i + 3];
-					u8 q0 = precon[j + 0], q1 = precon[j + 1],
-					   q2 = precon[j + 2], q3 = precon[j + 3];
-					recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
-					recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
-					recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
-					recon[i + 3] = s3 + paethPredictor(r3, p3, q3);
-				}
-			} else if (bytewidth >= 3) {
-				for (; i + 2 < length; i += 3) {
-					u32 j = i - bytewidth;
-					u8 s0 = scanline[i + 0], s1 = scanline[i + 1],
-					   s2 = scanline[i + 2];
-					u8 r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2];
-					u8 p0 = precon[i + 0], p1 = precon[i + 1],
-					   p2 = precon[i + 2];
-					u8 q0 = precon[j + 0], q1 = precon[j + 1],
-					   q2 = precon[j + 2];
-					recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
-					recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
-					recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
-				}
-			} else if (bytewidth >= 2) {
-				for (; i + 1 < length; i += 2) {
-					u32 j = i - bytewidth;
-					u8 s0 = scanline[i + 0], s1 = scanline[i + 1];
-					u8 r0 = recon[j + 0], r1 = recon[j + 1];
-					u8 p0 = precon[i + 0], p1 = precon[i + 1];
-					u8 q0 = precon[j + 0], q1 = precon[j + 1];
-					recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
-					recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
-				}
-			}
-
-			for (; i != length; ++i) {
-				recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth],
-									 precon[i],
-									 precon[i - bytewidth]));
-			}
-		} else {
-			for (i = 0; i != bytewidth; ++i) {
-				recon[i] = scanline[i];
-			}
-			for (i = bytewidth; i < length; ++i) {
-				/*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
-				recon[i] = (scanline[i] + recon[i - bytewidth]);
-			}
-		}
-		break;
-	default:
-		return 36; /*error: invalid filter type given*/
-	}
-	return 0;
-}
-
-static u32 unfilter(u8 *out, const u8 *in, u32 w, u32 h, u32 bpp)
-{
-	/*
-  For PNG filter method 0
-  this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times)
-  out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
-  w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
-  in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes)
-  */
-
-	u32 y;
-	u8 *prevline = 0;
-
-	/*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
-	u32 bytewidth = (bpp + 7u) / 8u;
-	/*the width of a scanline in bytes, not including the filter type*/
-	u32 linebytes = png_get_raw_size_idat(w, 1, bpp) - 1u;
-
-	for (y = 0; y < h; ++y) {
-		u32 outindex = linebytes * y;
-		u32 inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
-		u8 filterType = in[inindex];
-
-		CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline,
-						   bytewidth, filterType, linebytes));
-
-		prevline = &out[outindex];
-	}
-
-	return 0;
-}
-
-/*
-in: Adam7 interlaced image, with no padding bits between scanlines, but between
- reduced images so that each reduced image starts at a byte.
-out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h
-bpp: bits per pixel
-out has the following size in bits: w * h * bpp.
-in is possibly bigger due to padding bits between reduced images.
-out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation
-(because that's likely a little bit faster)
-NOTE: comments about padding bits are only relevant if bpp < 8
-*/
-static void Adam7_deinterlace(u8 *out, const u8 *in, u32 w, u32 h, u32 bpp)
-{
-	u32 passw[7], passh[7];
-	u32 filter_passstart[8], padded_passstart[8], passstart[8];
-	u32 i;
-
-	Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
-
-	if (bpp >= 8) {
-		for (i = 0; i != 7; ++i) {
-			u32 x, y, b;
-			u32 bytewidth = bpp / 8u;
-			for (y = 0; y < passh[i]; ++y)
-				for (x = 0; x < passw[i]; ++x) {
-					u32 pixelinstart =
-						passstart[i] + (y * passw[i] + x) * bytewidth;
-					u32 pixeloutstart =
-						((ADAM7_IY[i] + (u32)y * ADAM7_DY[i]) * (u32)w +
-						 ADAM7_IX[i] + (u32)x * ADAM7_DX[i]) *
-						bytewidth;
-					for (b = 0; b < bytewidth; ++b) {
-						out[pixeloutstart + b] = in[pixelinstart + b];
-					}
-				}
-		}
-	} else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {
-		for (i = 0; i != 7; ++i) {
-			u32 x, y, b;
-			u32 ilinebits = bpp * passw[i];
-			u32 olinebits = bpp * w;
-			u32 obp, ibp; /*bit pointers (for out and in buffer)*/
-			for (y = 0; y < passh[i]; ++y)
-				for (x = 0; x < passw[i]; ++x) {
-					ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
-					obp = (ADAM7_IY[i] + (u32)y * ADAM7_DY[i]) * olinebits +
-					      (ADAM7_IX[i] + (u32)x * ADAM7_DX[i]) * bpp;
-					for (b = 0; b < bpp; ++b) {
-						u8 bit = readBitFromReversedStream(&ibp, in);
-						setBitOfReversedStream(&obp, out, bit);
-					}
-				}
-		}
-	}
-}
-
-static void removePaddingBits(u8 *out, const u8 *in, u32 olinebits, u32 ilinebits, u32 h)
-{
-	/*
-  After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
-  to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
-  for the Adam7 code, the color convert code and the output to the user.
-  in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must
-  have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
-  also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
-  only useful if (ilinebits - olinebits) is a value in the range 1..7
-  */
-	u32 y;
-	u32 diff = ilinebits - olinebits;
-	u32 ibp = 0, obp = 0; /*input and output bit pointers*/
-	for (y = 0; y < h; ++y) {
-		u32 x;
-		for (x = 0; x < olinebits; ++x) {
-			u8 bit = readBitFromReversedStream(&ibp, in);
-			setBitOfReversedStream(&obp, out, bit);
-		}
-		ibp += diff;
-	}
-}
-
-/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from
-the IDAT chunks (with filter index bytes and possible padding bits)
-return value is error*/
-static u32 postProcessScanlines(u8 *out, u8 *in, u32 w, u32 h, const pngInfo *info_png)
-{
-	/*
-  This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
-  Steps:
-  *) if no Adam7: 1) unfilter 2) remove padding bits (= possible extra bits per scanline if bpp < 8)
-  *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
-  NOTE: the in buffer will be overwritten with intermediate data!
-  */
-	u32 bpp = png_get_bpp(&info_png->color);
-	if (bpp == 0)
-		return 31; /*error: invalid colortype*/
-
-	if (info_png->interlace_method == 0) {
-		if (bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) {
-			CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp));
-			removePaddingBits(out, in, w * bpp, ((w * bpp + 7u) / 8u) * 8u, h);
-		}
-		/*we can immediately filter into the out buffer, no other steps needed*/
-		else
-			CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp));
-	} else /*interlace_method is 1 (Adam7)*/ {
-		u32 passw[7], passh[7];
-		u32 filter_passstart[8], padded_passstart[8], passstart[8];
-		u32 i;
-
-		Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w,
-				    h, bpp);
-
-		for (i = 0; i != 7; ++i) {
-			CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]],
-						   &in[filter_passstart[i]], passw[i], passh[i],
-						   bpp));
-			/*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline,
-      move bytes instead of bits or move not at all*/
-			if (bpp < 8) {
-				/*remove padding bits in scanlines; after this there still may be padding
-        bits between the different reduced images: each reduced image still starts nicely at a byte*/
-				removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]],
-						  passw[i] * bpp, ((passw[i] * bpp + 7u) / 8u) * 8u,
-						  passh[i]);
-			}
-		}
-
-		Adam7_deinterlace(out, in, w, h, bpp);
-	}
-
-	return 0;
-}
-
-static u32 readChunk_PLTE(pngColorMode *color, const u8 *data, u32 chunkLength)
-{
-	u32 pos = 0, i;
-	color->palettesize = chunkLength / 3u;
-	if (color->palettesize == 0 || color->palettesize > 256)
-		return 38; /*error: palette too small or big*/
-	png_color_mode_alloc_palette(color);
-	if (!color->palette && color->palettesize) {
-		color->palettesize = 0;
-		return 83; /*alloc fail*/
-	}
-
-	for (i = 0; i != color->palettesize; ++i) {
-		color->palette[4 * i + 0] = data[pos++]; /*R*/
-		color->palette[4 * i + 1] = data[pos++]; /*G*/
-		color->palette[4 * i + 2] = data[pos++]; /*B*/
-		color->palette[4 * i + 3] = 255; /*alpha*/
-	}
-
-	return 0; /* OK */
-}
-
-static u32 readChunk_tRNS(pngColorMode *color, const u8 *data, u32 chunkLength)
-{
-	u32 i;
-	if (color->colortype == LCT_PALETTE) {
-		/*error: more alpha values given than there are palette entries*/
-		if (chunkLength > color->palettesize)
-			return 39;
-
-		for (i = 0; i != chunkLength; ++i)
-			color->palette[4 * i + 3] = data[i];
-	} else if (color->colortype == LCT_GREY) {
-		/*error: this chunk must be 2 bytes for grayscale image*/
-		if (chunkLength != 2)
-			return 30;
-
-		color->key_defined = 1;
-		color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1];
-	} else if (color->colortype == LCT_RGB) {
-		/*error: this chunk must be 6 bytes for RGB image*/
-		if (chunkLength != 6)
-			return 41;
-
-		color->key_defined = 1;
-		color->key_r = 256u * data[0] + data[1];
-		color->key_g = 256u * data[2] + data[3];
-		color->key_b = 256u * data[4] + data[5];
-	} else
-		return 42; /*error: tRNS chunk not allowed for other color models*/
-
-	return 0; /* OK */
-}
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-/*background color chunk (bKGD)*/
-static u32 readChunk_bKGD(pngInfo *info, const u8 *data, u32 chunkLength)
-{
-	if (info->color.colortype == LCT_PALETTE) {
-		/*error: this chunk must be 1 byte for indexed color image*/
-		if (chunkLength != 1)
-			return 43;
-
-		/*error: invalid palette index, or maybe this chunk appeared before PLTE*/
-		if (data[0] >= info->color.palettesize)
-			return 103;
-
-		info->background_defined = 1;
-		info->background_r = info->background_g = info->background_b = data[0];
-	} else if (info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) {
-		/*error: this chunk must be 2 bytes for grayscale image*/
-		if (chunkLength != 2)
-			return 44;
-
-		/*the values are truncated to bitdepth in the PNG file*/
-		info->background_defined = 1;
-		info->background_r = info->background_g = info->background_b =
-			256u * data[0] + data[1];
-	} else if (info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) {
-		/*error: this chunk must be 6 bytes for grayscale image*/
-		if (chunkLength != 6)
-			return 45;
-
-		/*the values are truncated to bitdepth in the PNG file*/
-		info->background_defined = 1;
-		info->background_r = 256u * data[0] + data[1];
-		info->background_g = 256u * data[2] + data[3];
-		info->background_b = 256u * data[4] + data[5];
-	}
-
-	return 0; /* OK */
-}
-
-/*text chunk (tEXt)*/
-static u32 readChunk_tEXt(pngInfo *info, const u8 *data, u32 chunkLength)
-{
-	u32 error = 0;
-	char *key = 0, *str = 0;
-
-	while (!error) /*not really a while loop, only used to break on error*/ {
-		u32 length, string2_begin;
-
-		length = 0;
-		while (length < chunkLength && data[length] != 0)
-			++length;
-		/*even though it's not allowed by the standard, no error is thrown if
-    there's no null termination char, if the text is empty*/
-		if (length < 1 || length > 79)
-			CERROR_BREAK(error, 89); /*keyword too short or long*/
-
-		key = (char *)png_malloc(length + 1);
-		if (!key)
-			CERROR_BREAK(error, 83); /*alloc fail*/
-
-		png_memcpy(key, data, length);
-		key[length] = 0;
-
-		string2_begin = length + 1; /*skip keyword null terminator*/
-
-		length = (u32)(chunkLength < string2_begin ? 0 : chunkLength - string2_begin);
-		str = (char *)png_malloc(length + 1);
-		if (!str)
-			CERROR_BREAK(error, 83); /*alloc fail*/
-
-		png_memcpy(str, data + string2_begin, length);
-		str[length] = 0;
-
-		error = png_add_text(info, key, str);
-
-		break;
-	}
-
-	png_free(key);
-	png_free(str);
-
-	return error;
-}
-
-/*compressed text chunk (zTXt)*/
-static u32 readChunk_zTXt(pngInfo *info, const pngDecoderSettings *decoder, const u8 *data,
-			  u32 chunkLength)
-{
-	u32 error = 0;
-
-	/*copy the object to change parameters in it*/
-	pngDecompressSettings zlibsettings = decoder->zlibsettings;
-
-	u32 length, string2_begin;
-	char *key = 0;
-	u8 *str = 0;
-	u32 size = 0;
-
-	while (!error) /*not really a while loop, only used to break on error*/ {
-		for (length = 0; length < chunkLength && data[length] != 0; ++length)
-			;
-		if (length + 2 >= chunkLength)
-			CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
-		if (length < 1 || length > 79)
-			CERROR_BREAK(error, 89); /*keyword too short or long*/
-
-		key = (char *)png_malloc(length + 1);
-		if (!key)
-			CERROR_BREAK(error, 83); /*alloc fail*/
-
-		png_memcpy(key, data, length);
-		key[length] = 0;
-
-		if (data[length + 1] != 0)
-			CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
-
-		string2_begin = length + 2;
-		if (string2_begin > chunkLength)
-			CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
-
-		length = (u32)chunkLength - string2_begin;
-		zlibsettings.max_output_size = decoder->max_text_size;
-		/*will fail if zlib error, e.g. if length is too small*/
-		error = zlib_decompress(&str, &size, 0, &data[string2_begin], length,
-					&zlibsettings);
-		/*error: compressed text larger than  decoder->max_text_size*/
-		if (error && size > zlibsettings.max_output_size)
-			error = 112;
-		if (error)
-			break;
-		error = png_add_text_sized(info, key, (char *)str, size);
-		break;
-	}
-
-	png_free(key);
-	png_free(str);
-
-	return error;
-}
-
-/*international text chunk (iTXt)*/
-static u32 readChunk_iTXt(pngInfo *info, const pngDecoderSettings *decoder, const u8 *data,
-			  u32 chunkLength)
-{
-	u32 error = 0;
-	u32 i;
-
-	/*copy the object to change parameters in it*/
-	pngDecompressSettings zlibsettings = decoder->zlibsettings;
-
-	u32 length, begin, compressed;
-	char *key = 0, *langtag = 0, *transkey = 0;
-
-	while (!error) /*not really a while loop, only used to break on error*/ {
-		/*Quick check if the chunk length isn't too small. Even without check
-    it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
-		if (chunkLength < 5)
-			CERROR_BREAK(error, 30); /*iTXt chunk too short*/
-
-		/*read the key*/
-		for (length = 0; length < chunkLength && data[length] != 0; ++length)
-			;
-		if (length + 3 >= chunkLength)
-			CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/
-		if (length < 1 || length > 79)
-			CERROR_BREAK(error, 89); /*keyword too short or long*/
-
-		key = (char *)png_malloc(length + 1);
-		if (!key)
-			CERROR_BREAK(error, 83); /*alloc fail*/
-
-		png_memcpy(key, data, length);
-		key[length] = 0;
-
-		/*read the compression method*/
-		compressed = data[length + 1];
-		if (data[length + 2] != 0)
-			CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
-
-		/*even though it's not allowed by the standard, no error is thrown if
-    there's no null termination char, if the text is empty for the next 3 texts*/
-
-		/*read the langtag*/
-		begin = length + 3;
-		length = 0;
-		for (i = begin; i < chunkLength && data[i] != 0; ++i)
-			++length;
-
-		langtag = (char *)png_malloc(length + 1);
-		if (!langtag)
-			CERROR_BREAK(error, 83); /*alloc fail*/
-
-		png_memcpy(langtag, data + begin, length);
-		langtag[length] = 0;
-
-		/*read the transkey*/
-		begin += length + 1;
-		length = 0;
-		for (i = begin; i < chunkLength && data[i] != 0; ++i)
-			++length;
-
-		transkey = (char *)png_malloc(length + 1);
-		if (!transkey)
-			CERROR_BREAK(error, 83); /*alloc fail*/
-
-		png_memcpy(transkey, data + begin, length);
-		transkey[length] = 0;
-
-		/*read the actual text*/
-		begin += length + 1;
-
-		length = (u32)chunkLength < begin ? 0 : (u32)chunkLength - begin;
-
-		if (compressed) {
-			u8 *str = 0;
-			u32 size = 0;
-			zlibsettings.max_output_size = decoder->max_text_size;
-			/*will fail if zlib error, e.g. if length is too small*/
-			error = zlib_decompress(&str, &size, 0, &data[begin], length,
-						&zlibsettings);
-			/*error: compressed text larger than  decoder->max_text_size*/
-			if (error && size > zlibsettings.max_output_size)
-				error = 112;
-			if (!error)
-				error = png_add_itext_sized(info, key, langtag, transkey,
-							    (char *)str, size);
-			png_free(str);
-		} else {
-			error = png_add_itext_sized(info, key, langtag, transkey,
-						    (const char *)(data + begin), length);
-		}
-
-		break;
-	}
-
-	png_free(key);
-	png_free(langtag);
-	png_free(transkey);
-
-	return error;
-}
-
-static u32 readChunk_tIME(pngInfo *info, const u8 *data, u32 chunkLength)
-{
-	if (chunkLength != 7)
-		return 73; /*invalid tIME chunk size*/
-
-	info->time_defined = 1;
-	info->time.year = 256u * data[0] + data[1];
-	info->time.month = data[2];
-	info->time.day = data[3];
-	info->time.hour = data[4];
-	info->time.minute = data[5];
-	info->time.second = data[6];
-
-	return 0; /* OK */
-}
-
-static u32 readChunk_pHYs(pngInfo *info, const u8 *data, u32 chunkLength)
-{
-	if (chunkLength != 9)
-		return 74; /*invalid pHYs chunk size*/
-
-	info->phys_defined = 1;
-	info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
-	info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7];
-	info->phys_unit = data[8];
-
-	return 0; /* OK */
-}
-
-static u32 readChunk_gAMA(pngInfo *info, const u8 *data, u32 chunkLength)
-{
-	if (chunkLength != 4)
-		return 96; /*invalid gAMA chunk size*/
-
-	info->gama_defined = 1;
-	info->gama_gamma = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
-
-	return 0; /* OK */
-}
-
-static u32 readChunk_cHRM(pngInfo *info, const u8 *data, u32 chunkLength)
-{
-	if (chunkLength != 32)
-		return 97; /*invalid cHRM chunk size*/
-
-	info->chrm_defined = 1;
-	info->chrm_white_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3];
-	info->chrm_white_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7];
-	info->chrm_red_x = 16777216u * data[8] + 65536u * data[9] + 256u * data[10] + data[11];
-	info->chrm_red_y = 16777216u * data[12] + 65536u * data[13] + 256u * data[14] + data[15];
-	info->chrm_green_x = 16777216u * data[16] + 65536u * data[17] + 256u * data[18] + data[19];
-	info->chrm_green_y = 16777216u * data[20] + 65536u * data[21] + 256u * data[22] + data[23];
-	info->chrm_blue_x = 16777216u * data[24] + 65536u * data[25] + 256u * data[26] + data[27];
-	info->chrm_blue_y = 16777216u * data[28] + 65536u * data[29] + 256u * data[30] + data[31];
-
-	return 0; /* OK */
-}
-
-static u32 readChunk_sRGB(pngInfo *info, const u8 *data, u32 chunkLength)
-{
-	if (chunkLength != 1)
-		return 98; /*invalid sRGB chunk size (this one is never ignored)*/
-
-	info->srgb_defined = 1;
-	info->srgb_intent = data[0];
-
-	return 0; /* OK */
-}
-
-static u32 readChunk_iCCP(pngInfo *info, const pngDecoderSettings *decoder, const u8 *data,
-			  u32 chunkLength)
-{
-	u32 error = 0;
-	u32 i;
-	u32 size = 0;
-	/*copy the object to change parameters in it*/
-	pngDecompressSettings zlibsettings = decoder->zlibsettings;
-
-	u32 length, string2_begin;
-
-	info->iccp_defined = 1;
-	if (info->iccp_name)
-		png_clear_icc(info);
-
-	for (length = 0; length < chunkLength && data[length] != 0; ++length)
-		;
-	if (length + 2 >= chunkLength)
-		return 75; /*no null termination, corrupt?*/
-	if (length < 1 || length > 79)
-		return 89; /*keyword too short or long*/
-
-	info->iccp_name = (char *)png_malloc(length + 1);
-	if (!info->iccp_name)
-		return 83; /*alloc fail*/
-
-	info->iccp_name[length] = 0;
-	for (i = 0; i != length; ++i)
-		info->iccp_name[i] = (char)data[i];
-
-	if (data[length + 1] != 0)
-		return 72; /*the 0 byte indicating compression must be 0*/
-
-	string2_begin = length + 2;
-	if (string2_begin > chunkLength)
-		return 75; /*no null termination, corrupt?*/
-
-	length = (u32)chunkLength - string2_begin;
-	zlibsettings.max_output_size = decoder->max_icc_size;
-	error = zlib_decompress(&info->iccp_profile, &size, 0, &data[string2_begin], length,
-				&zlibsettings);
-	/*error: ICC profile larger than  decoder->max_icc_size*/
-	if (error && size > zlibsettings.max_output_size)
-		error = 113;
-	info->iccp_profile_size = size;
-	if (!error && !info->iccp_profile_size)
-		error = 100; /*invalid ICC profile size*/
-	return error;
-}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-u32 png_inspect_chunk(pngState *state, u32 pos, const u8 *in, u32 insize)
-{
-	const u8 *chunk = in + pos;
-	u32 chunkLength;
-	const u8 *data;
-	u32 unhandled = 0;
-	u32 error = 0;
-
-	if (pos + 4 > insize)
-		return 30;
-	chunkLength = png_chunk_length(chunk);
-	if (chunkLength > 2147483647)
-		return 63;
-	data = png_chunk_data_const(chunk);
-	if (data + chunkLength + 4 > in + insize)
-		return 30;
-
-	if (png_chunk_type_equals(chunk, "PLTE")) {
-		error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "tRNS")) {
-		error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	} else if (png_chunk_type_equals(chunk, "bKGD")) {
-		error = readChunk_bKGD(&state->info_png, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "tEXt")) {
-		error = readChunk_tEXt(&state->info_png, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "zTXt")) {
-		error = readChunk_zTXt(&state->info_png, &state->decoder, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "iTXt")) {
-		error = readChunk_iTXt(&state->info_png, &state->decoder, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "tIME")) {
-		error = readChunk_tIME(&state->info_png, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "pHYs")) {
-		error = readChunk_pHYs(&state->info_png, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "gAMA")) {
-		error = readChunk_gAMA(&state->info_png, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "cHRM")) {
-		error = readChunk_cHRM(&state->info_png, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "sRGB")) {
-		error = readChunk_sRGB(&state->info_png, data, chunkLength);
-	} else if (png_chunk_type_equals(chunk, "iCCP")) {
-		error = readChunk_iCCP(&state->info_png, &state->decoder, data, chunkLength);
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-	} else {
-		/* unhandled chunk is ok (is not an error) */
-		unhandled = 1;
-	}
-
-	if (!error && !unhandled && !state->decoder.ignore_crc) {
-		if (png_chunk_check_crc(chunk))
-			return 57; /*invalid CRC*/
-	}
-
-	return error;
-}
-
-/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
-static void decodeGeneric(u8 **out, u32 *w, u32 *h, pngState *state, const u8 *in, u32 insize)
-{
-	u8 IEND = 0;
-	const u8 *chunk;
-	u8 *idat; /*the data from idat chunks, zlib compressed*/
-	u32 idatsize = 0;
-	u8 *scanlines = 0;
-	u32 scanlines_size = 0, expected_size = 0;
-	u32 outsize = 0;
-
-	/*for unknown chunk order*/
-	u32 unknown = 0;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	u32 critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-	/* safe output values in case error happens */
-	*out = 0;
-	*w = *h = 0;
-
-	state->error =
-		png_inspect(w, h, state, in,
-			    insize); /*reads header and resets other parameters in state->info_png*/
-	if (state->error)
-		return;
-
-	if (png_pixel_overflow(*w, *h, &state->info_png.color, &state->info_raw)) {
-		CERROR_RETURN(state->error, 92); /*overflow possible due to amount of pixels*/
-	}
-
-	/*the input filesize is a safe upper bound for the sum of idat chunks size*/
-	idat = (u8 *)png_malloc(insize);
-	if (!idat)
-		CERROR_RETURN(state->error, 83); /*alloc fail*/
-
-	chunk = &in[33]; /*first byte of the first chunk after the header*/
-
-	/*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
-  IDAT data is put at the start of the in buffer*/
-	while (!IEND && !state->error) {
-		u32 chunkLength;
-		const u8 *data; /*the data in the chunk*/
-
-		/*error: size of the in buffer too small to contain next chunk*/
-		if ((u32)((chunk - in) + 12) > insize || chunk < in) {
-			if (state->decoder.ignore_end)
-				break; /*other errors may still happen though*/
-			CERROR_BREAK(state->error, 30);
-		}
-
-		/*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
-		chunkLength = png_chunk_length(chunk);
-		/*error: chunk length larger than the max PNG chunk size*/
-		if (chunkLength > 2147483647) {
-			if (state->decoder.ignore_end)
-				break; /*other errors may still happen though*/
-			CERROR_BREAK(state->error, 63);
-		}
-
-		if ((u32)((chunk - in) + chunkLength + 12) > insize ||
-		    (chunk + chunkLength + 12) < in) {
-			CERROR_BREAK(
-				state->error,
-				64); /*error: size of the in buffer too small to contain next chunk*/
-		}
-
-		data = png_chunk_data_const(chunk);
-
-		unknown = 0;
-
-		/*IDAT chunk, containing compressed image data*/
-		if (png_chunk_type_equals(chunk, "IDAT")) {
-			u32 newsize;
-			if (png_addofl(idatsize, chunkLength, &newsize))
-				CERROR_BREAK(state->error, 95);
-			if (newsize > insize)
-				CERROR_BREAK(state->error, 95);
-			png_memcpy(idat + idatsize, data, chunkLength);
-			idatsize += chunkLength;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-			critical_pos = 3;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		} else if (png_chunk_type_equals(chunk, "IEND")) {
-			/*IEND chunk*/
-			IEND = 1;
-		} else if (png_chunk_type_equals(chunk, "PLTE")) {
-			/*palette chunk (PLTE)*/
-			state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
-			if (state->error)
-				break;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-			critical_pos = 2;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		} else if (png_chunk_type_equals(chunk, "tRNS")) {
-			/*palette transparency chunk (tRNS). Even though this one is an ancillary chunk , it is still compiled
-      in without 'PNG_COMPILE_ANCILLARY_CHUNKS' because it contains essential color information that
-      affects the alpha channel of pixels. */
-			state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
-			if (state->error)
-				break;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-			/*background color chunk (bKGD)*/
-		} else if (png_chunk_type_equals(chunk, "bKGD")) {
-			state->error = readChunk_bKGD(&state->info_png, data, chunkLength);
-			if (state->error)
-				break;
-		} else if (png_chunk_type_equals(chunk, "tEXt")) {
-			/*text chunk (tEXt)*/
-			if (state->decoder.read_text_chunks) {
-				state->error = readChunk_tEXt(&state->info_png, data, chunkLength);
-				if (state->error)
-					break;
-			}
-		} else if (png_chunk_type_equals(chunk, "zTXt")) {
-			/*compressed text chunk (zTXt)*/
-			if (state->decoder.read_text_chunks) {
-				state->error = readChunk_zTXt(&state->info_png, &state->decoder,
-							      data, chunkLength);
-				if (state->error)
-					break;
-			}
-		} else if (png_chunk_type_equals(chunk, "iTXt")) {
-			/*international text chunk (iTXt)*/
-			if (state->decoder.read_text_chunks) {
-				state->error = readChunk_iTXt(&state->info_png, &state->decoder,
-							      data, chunkLength);
-				if (state->error)
-					break;
-			}
-		} else if (png_chunk_type_equals(chunk, "tIME")) {
-			state->error = readChunk_tIME(&state->info_png, data, chunkLength);
-			if (state->error)
-				break;
-		} else if (png_chunk_type_equals(chunk, "pHYs")) {
-			state->error = readChunk_pHYs(&state->info_png, data, chunkLength);
-			if (state->error)
-				break;
-		} else if (png_chunk_type_equals(chunk, "gAMA")) {
-			state->error = readChunk_gAMA(&state->info_png, data, chunkLength);
-			if (state->error)
-				break;
-		} else if (png_chunk_type_equals(chunk, "cHRM")) {
-			state->error = readChunk_cHRM(&state->info_png, data, chunkLength);
-			if (state->error)
-				break;
-		} else if (png_chunk_type_equals(chunk, "sRGB")) {
-			state->error = readChunk_sRGB(&state->info_png, data, chunkLength);
-			if (state->error)
-				break;
-		} else if (png_chunk_type_equals(chunk, "iCCP")) {
-			state->error = readChunk_iCCP(&state->info_png, &state->decoder, data,
-						      chunkLength);
-			if (state->error)
-				break;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		} else /*it's not an implemented chunk type, so ignore it: skip over the data*/ {
-			/*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
-			if (!state->decoder.ignore_critical && !png_chunk_ancillary(chunk)) {
-				CERROR_BREAK(state->error, 69);
-			}
-
-			unknown = 1;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-			if (state->decoder.remember_unknown_chunks) {
-				state->error = png_chunk_append(
-					&state->info_png.unknown_chunks_data[critical_pos - 1],
-					&state->info_png.unknown_chunks_size[critical_pos - 1],
-					chunk);
-				if (state->error)
-					break;
-			}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		}
-
-		if (!state->decoder.ignore_crc &&
-		    !unknown) /*check CRC if wanted, only on known chunk types*/ {
-			if (png_chunk_check_crc(chunk))
-				CERROR_BREAK(state->error, 57); /*invalid CRC*/
-		}
-
-		if (!IEND)
-			chunk = png_chunk_next_const(chunk, in + insize);
-	}
-
-	if (!state->error && state->info_png.color.colortype == LCT_PALETTE &&
-	    !state->info_png.color.palette) {
-		state->error =
-			106; /* error: PNG file must have PLTE chunk if color type is palette */
-	}
-
-	if (!state->error) {
-		/*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation.
-    If the decompressed size does not match the prediction, the image must be corrupt.*/
-		if (state->info_png.interlace_method == 0) {
-			u32 bpp = png_get_bpp(&state->info_png.color);
-			expected_size = png_get_raw_size_idat(*w, *h, bpp);
-		} else {
-			u32 bpp = png_get_bpp(&state->info_png.color);
-			/*Adam-7 interlaced: expected size is the sum of the 7 sub-images sizes*/
-			expected_size = 0;
-			expected_size += png_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, bpp);
-			if (*w > 4)
-				expected_size +=
-					png_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, bpp);
-			expected_size += png_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, bpp);
-			if (*w > 2)
-				expected_size +=
-					png_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, bpp);
-			expected_size += png_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, bpp);
-			if (*w > 1)
-				expected_size +=
-					png_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, bpp);
-			expected_size += png_get_raw_size_idat((*w + 0), (*h + 0) >> 1, bpp);
-		}
-
-		state->error = zlib_decompress(&scanlines, &scanlines_size, expected_size, idat,
-					       idatsize, &state->decoder.zlibsettings);
-	}
-	if (!state->error && scanlines_size != expected_size)
-		state->error = 91; /*decompressed size doesn't match prediction*/
-	png_free(idat);
-
-	if (!state->error) {
-		outsize = png_get_raw_size(*w, *h, &state->info_png.color);
-		*out = (u8 *)png_malloc(outsize);
-		if (!*out)
-			state->error = 83; /*alloc fail*/
-	}
-	if (!state->error) {
-		png_memset(*out, 0, outsize);
-		state->error = postProcessScanlines(*out, scanlines, *w, *h, &state->info_png);
-	}
-	png_free(scanlines);
-}
-
-u32 png_decode(u8 **out, u32 *w, u32 *h, pngState *state, const u8 *in, u32 insize)
-{
-	*out = 0;
-	decodeGeneric(out, w, h, state, in, insize);
-	if (state->error)
-		return state->error;
-	if (!state->decoder.color_convert ||
-	    png_color_mode_equal(&state->info_raw, &state->info_png.color)) {
-		/*same color type, no copying or converting of data needed*/
-		/*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype
-    the raw image has to the end user*/
-		if (!state->decoder.color_convert) {
-			state->error =
-				png_color_mode_copy(&state->info_raw, &state->info_png.color);
-			if (state->error)
-				return state->error;
-		}
-	} else { /*color conversion needed*/
-		u8 *data = *out;
-		u32 outsize;
-
-		/*TODO: check if this works according to the statement in the documentation: "The converter can convert
-    from grayscale input color type, to 8-bit grayscale or grayscale with alpha"*/
-		if (!(state->info_raw.colortype == LCT_RGB ||
-		      state->info_raw.colortype == LCT_RGBA) &&
-		    !(state->info_raw.bitdepth == 8)) {
-			return 56; /*unsupported color mode conversion*/
-		}
-
-		outsize = png_get_raw_size(*w, *h, &state->info_raw);
-		*out = (u8 *)png_malloc(outsize);
-		if (!(*out)) {
-			state->error = 83; /*alloc fail*/
-		} else
-			state->error = png_convert(*out, data, &state->info_raw,
-						   &state->info_png.color, *w, *h);
-		png_free(data);
-	}
-	return state->error;
-}
-
-u32 png_decode_memory(u8 **out, u32 *w, u32 *h, const u8 *in, u32 insize, pngColorType colortype,
-		      u32 bitdepth)
-{
-	u32 error;
-	pngState state;
-	png_state_init(&state);
-	state.info_raw.colortype = colortype;
-	state.info_raw.bitdepth = bitdepth;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	/*disable reading things that this function doesn't output*/
-	state.decoder.read_text_chunks = 0;
-	state.decoder.remember_unknown_chunks = 0;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-	error = png_decode(out, w, h, &state, in, insize);
-	png_state_cleanup(&state);
-	return error;
-}
-
-u32 png_decode32(u8 **out, u32 *w, u32 *h, const u8 *in, u32 insize)
-{
-	return png_decode_memory(out, w, h, in, insize, LCT_RGBA, 8);
-}
-
-u32 png_decode24(u8 **out, u32 *w, u32 *h, const u8 *in, u32 insize)
-{
-	return png_decode_memory(out, w, h, in, insize, LCT_RGB, 8);
-}
-
-#ifdef PNG_COMPILE_DISK
-u32 png_decode_file(u8 **out, u32 *w, u32 *h, const char *filename, pngColorType colortype,
-		    u32 bitdepth)
-{
-	u8 *buffer = 0;
-	u32 buffersize;
-	u32 error;
-	/* safe output values in case error happens */
-	*out = 0;
-	*w = *h = 0;
-	error = png_load_file(&buffer, &buffersize, filename);
-	if (!error)
-		error = png_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth);
-	png_free(buffer);
-	return error;
-}
-
-u32 png_decode32_file(u8 **out, u32 *w, u32 *h, const char *filename)
-{
-	return png_decode_file(out, w, h, filename, LCT_RGBA, 8);
-}
-
-u32 png_decode24_file(u8 **out, u32 *w, u32 *h, const char *filename)
-{
-	return png_decode_file(out, w, h, filename, LCT_RGB, 8);
-}
-#endif /*PNG_COMPILE_DISK*/
-
-void png_decoder_settings_init(pngDecoderSettings *settings)
-{
-	settings->color_convert = 1;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	settings->read_text_chunks = 1;
-	settings->remember_unknown_chunks = 0;
-	settings->max_text_size = 16777216;
-	settings->max_icc_size =
-		16777216; /* 16MB is much more than enough for any reasonable ICC profile */
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-	settings->ignore_crc = 0;
-	settings->ignore_critical = 0;
-	settings->ignore_end = 0;
-	png_decompress_settings_init(&settings->zlibsettings);
-}
-
-#endif /*PNG_COMPILE_DECODER*/
-
-#if defined(PNG_COMPILE_DECODER) || defined(PNG_COMPILE_ENCODER)
-
-void png_state_init(pngState *state)
-{
-#ifdef PNG_COMPILE_DECODER
-	png_decoder_settings_init(&state->decoder);
-#endif /*PNG_COMPILE_DECODER*/
-#ifdef PNG_COMPILE_ENCODER
-	png_encoder_settings_init(&state->encoder);
-#endif /*PNG_COMPILE_ENCODER*/
-	png_color_mode_init(&state->info_raw);
-	png_info_init(&state->info_png);
-	state->error = 1;
-}
-
-void png_state_cleanup(pngState *state)
-{
-	png_color_mode_cleanup(&state->info_raw);
-	png_info_cleanup(&state->info_png);
-}
-
-void png_state_copy(pngState *dest, const pngState *source)
-{
-	png_state_cleanup(dest);
-	*dest = *source;
-	png_color_mode_init(&dest->info_raw);
-	png_info_init(&dest->info_png);
-	dest->error = png_color_mode_copy(&dest->info_raw, &source->info_raw);
-	if (dest->error)
-		return;
-	dest->error = png_info_copy(&dest->info_png, &source->info_png);
-	if (dest->error)
-		return;
-}
-
-#endif /* defined(PNG_COMPILE_DECODER) || defined(PNG_COMPILE_ENCODER) */
-
-#ifdef PNG_COMPILE_ENCODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / PNG Encoder                                                            / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-static u32 writeSignature(ucvector *out)
-{
-	u32 pos = out->size;
-	const u8 signature[] = { 137, 80, 78, 71, 13, 10, 26, 10 };
-	/*8 bytes PNG signature, aka the magic bytes*/
-	if (!ucvector_resize(out, out->size + 8))
-		return 83; /*alloc fail*/
-	png_memcpy(out->data + pos, signature, 8);
-	return 0;
-}
-
-static u32 addChunk_IHDR(ucvector *out, u32 w, u32 h, pngColorType colortype, u32 bitdepth,
-			 u32 interlace_method)
-{
-	u8 *chunk, *data;
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 13, "IHDR"));
-	data = chunk + 8;
-
-	png_set32bitInt(data + 0, w); /*width*/
-	png_set32bitInt(data + 4, h); /*height*/
-	data[8] = (u8)bitdepth; /*bit depth*/
-	data[9] = (u8)colortype; /*color type*/
-	data[10] = 0; /*compression method*/
-	data[11] = 0; /*filter method*/
-	data[12] = interlace_method; /*interlace method*/
-
-	png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-/* only adds the chunk if needed (there is a key or palette with alpha) */
-static u32 addChunk_PLTE(ucvector *out, const pngColorMode *info)
-{
-	u8 *chunk;
-	u32 i, j = 8;
-
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, info->palettesize * 3, "PLTE"));
-
-	for (i = 0; i != info->palettesize; ++i) {
-		/*add all channels except alpha channel*/
-		chunk[j++] = info->palette[i * 4 + 0];
-		chunk[j++] = info->palette[i * 4 + 1];
-		chunk[j++] = info->palette[i * 4 + 2];
-	}
-
-	png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_tRNS(ucvector *out, const pngColorMode *info)
-{
-	u8 *chunk = 0;
-
-	if (info->colortype == LCT_PALETTE) {
-		u32 i, amount = info->palettesize;
-		/*the tail of palette values that all have 255 as alpha, does not have to be encoded*/
-		for (i = info->palettesize; i != 0; --i) {
-			if (info->palette[4 * (i - 1) + 3] != 255)
-				break;
-			--amount;
-		}
-		if (amount) {
-			CERROR_TRY_RETURN(png_chunk_init(&chunk, out, amount, "tRNS"));
-			/*add the alpha channel values from the palette*/
-			for (i = 0; i != amount; ++i)
-				chunk[8 + i] = info->palette[4 * i + 3];
-		}
-	} else if (info->colortype == LCT_GREY) {
-		if (info->key_defined) {
-			CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 2, "tRNS"));
-			chunk[8] = (u8)(info->key_r >> 8);
-			chunk[9] = (u8)(info->key_r & 255);
-		}
-	} else if (info->colortype == LCT_RGB) {
-		if (info->key_defined) {
-			CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 6, "tRNS"));
-			chunk[8] = (u8)(info->key_r >> 8);
-			chunk[9] = (u8)(info->key_r & 255);
-			chunk[10] = (u8)(info->key_g >> 8);
-			chunk[11] = (u8)(info->key_g & 255);
-			chunk[12] = (u8)(info->key_b >> 8);
-			chunk[13] = (u8)(info->key_b & 255);
-		}
-	}
-
-	if (chunk)
-		png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_IDAT(ucvector *out, const u8 *data, u32 datasize,
-			 pngCompressSettings *zlibsettings)
-{
-	u32 error = 0;
-	u8 *zlib = 0;
-	u32 zlibsize = 0;
-
-	error = zlib_compress(&zlib, &zlibsize, data, datasize, zlibsettings);
-	if (!error) {
-		error = png_chunk_createv(out, zlibsize, "IDAT", zlib);
-	}
-	png_free(zlib);
-	return error;
-}
-
-static u32 addChunk_IEND(ucvector *out)
-{
-	return png_chunk_createv(out, 0, "IEND", 0);
-}
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-
-static u32 addChunk_tEXt(ucvector *out, const char *keyword, const char *textstring)
-{
-	u8 *chunk = 0;
-	u32 keysize = png_strlen(keyword), textsize = png_strlen(textstring);
-	u32 size = keysize + 1 + textsize;
-	if (keysize < 1 || keysize > 79)
-		return 89; /*error: invalid keyword size*/
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, size, "tEXt"));
-	png_memcpy(chunk + 8, keyword, keysize);
-	chunk[8 + keysize] = 0; /*null termination char*/
-	png_memcpy(chunk + 9 + keysize, textstring, textsize);
-	png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_zTXt(ucvector *out, const char *keyword, const char *textstring,
-			 pngCompressSettings *zlibsettings)
-{
-	u32 error = 0;
-	u8 *chunk = 0;
-	u8 *compressed = 0;
-	u32 compressedsize = 0;
-	u32 textsize = png_strlen(textstring);
-	u32 keysize = png_strlen(keyword);
-	if (keysize < 1 || keysize > 79)
-		return 89; /*error: invalid keyword size*/
-
-	error = zlib_compress(&compressed, &compressedsize, (const u8 *)textstring, textsize,
-			      zlibsettings);
-	if (!error) {
-		u32 size = keysize + 2 + compressedsize;
-		error = png_chunk_init(&chunk, out, size, "zTXt");
-	}
-	if (!error) {
-		png_memcpy(chunk + 8, keyword, keysize);
-		chunk[8 + keysize] = 0; /*null termination char*/
-		chunk[9 + keysize] = 0; /*compression method: 0*/
-		png_memcpy(chunk + 10 + keysize, compressed, compressedsize);
-		png_chunk_generate_crc(chunk);
-	}
-
-	png_free(compressed);
-	return error;
-}
-
-static u32 addChunk_iTXt(ucvector *out, u32 compress, const char *keyword, const char *langtag,
-			 const char *transkey, const char *textstring,
-			 pngCompressSettings *zlibsettings)
-{
-	u32 error = 0;
-	u8 *chunk = 0;
-	u8 *compressed = 0;
-	u32 compressedsize = 0;
-	u32 textsize = png_strlen(textstring);
-	u32 keysize = png_strlen(keyword), langsize = png_strlen(langtag),
-	    transsize = png_strlen(transkey);
-
-	if (keysize < 1 || keysize > 79)
-		return 89; /*error: invalid keyword size*/
-
-	if (compress) {
-		error = zlib_compress(&compressed, &compressedsize, (const u8 *)textstring,
-				      textsize, zlibsettings);
-	}
-	if (!error) {
-		u32 size = keysize + 3 + langsize + 1 + transsize + 1 +
-			   (compress ? compressedsize : textsize);
-		error = png_chunk_init(&chunk, out, size, "iTXt");
-	}
-	if (!error) {
-		u32 pos = 8;
-		png_memcpy(chunk + pos, keyword, keysize);
-		pos += keysize;
-		chunk[pos++] = 0; /*null termination char*/
-		chunk[pos++] = (compress ? 1 : 0); /*compression flag*/
-		chunk[pos++] = 0; /*compression method: 0*/
-		png_memcpy(chunk + pos, langtag, langsize);
-		pos += langsize;
-		chunk[pos++] = 0; /*null termination char*/
-		png_memcpy(chunk + pos, transkey, transsize);
-		pos += transsize;
-		chunk[pos++] = 0; /*null termination char*/
-		if (compress) {
-			png_memcpy(chunk + pos, compressed, compressedsize);
-		} else {
-			png_memcpy(chunk + pos, textstring, textsize);
-		}
-		png_chunk_generate_crc(chunk);
-	}
-
-	png_free(compressed);
-	return error;
-}
-
-static u32 addChunk_bKGD(ucvector *out, const pngInfo *info)
-{
-	u8 *chunk = 0;
-	if (info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) {
-		CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 2, "bKGD"));
-		chunk[8] = (u8)(info->background_r >> 8);
-		chunk[9] = (u8)(info->background_r & 255);
-	} else if (info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) {
-		CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 6, "bKGD"));
-		chunk[8] = (u8)(info->background_r >> 8);
-		chunk[9] = (u8)(info->background_r & 255);
-		chunk[10] = (u8)(info->background_g >> 8);
-		chunk[11] = (u8)(info->background_g & 255);
-		chunk[12] = (u8)(info->background_b >> 8);
-		chunk[13] = (u8)(info->background_b & 255);
-	} else if (info->color.colortype == LCT_PALETTE) {
-		CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 1, "bKGD"));
-		chunk[8] = (u8)(info->background_r & 255); /*palette index*/
-	}
-	if (chunk)
-		png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_tIME(ucvector *out, const pngTime *time)
-{
-	u8 *chunk;
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 7, "tIME"));
-	chunk[8] = (u8)(time->year >> 8);
-	chunk[9] = (u8)(time->year & 255);
-	chunk[10] = (u8)time->month;
-	chunk[11] = (u8)time->day;
-	chunk[12] = (u8)time->hour;
-	chunk[13] = (u8)time->minute;
-	chunk[14] = (u8)time->second;
-	png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_pHYs(ucvector *out, const pngInfo *info)
-{
-	u8 *chunk;
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 9, "pHYs"));
-	png_set32bitInt(chunk + 8, info->phys_x);
-	png_set32bitInt(chunk + 12, info->phys_y);
-	chunk[16] = info->phys_unit;
-	png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_gAMA(ucvector *out, const pngInfo *info)
-{
-	u8 *chunk;
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 4, "gAMA"));
-	png_set32bitInt(chunk + 8, info->gama_gamma);
-	png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_cHRM(ucvector *out, const pngInfo *info)
-{
-	u8 *chunk;
-	CERROR_TRY_RETURN(png_chunk_init(&chunk, out, 32, "cHRM"));
-	png_set32bitInt(chunk + 8, info->chrm_white_x);
-	png_set32bitInt(chunk + 12, info->chrm_white_y);
-	png_set32bitInt(chunk + 16, info->chrm_red_x);
-	png_set32bitInt(chunk + 20, info->chrm_red_y);
-	png_set32bitInt(chunk + 24, info->chrm_green_x);
-	png_set32bitInt(chunk + 28, info->chrm_green_y);
-	png_set32bitInt(chunk + 32, info->chrm_blue_x);
-	png_set32bitInt(chunk + 36, info->chrm_blue_y);
-	png_chunk_generate_crc(chunk);
-	return 0;
-}
-
-static u32 addChunk_sRGB(ucvector *out, const pngInfo *info)
-{
-	u8 data = info->srgb_intent;
-	return png_chunk_createv(out, 1, "sRGB", &data);
-}
-
-static u32 addChunk_iCCP(ucvector *out, const pngInfo *info, pngCompressSettings *zlibsettings)
-{
-	u32 error = 0;
-	u8 *chunk = 0;
-	u8 *compressed = 0;
-	u32 compressedsize = 0;
-	u32 keysize = png_strlen(info->iccp_name);
-
-	if (keysize < 1 || keysize > 79)
-		return 89; /*error: invalid keyword size*/
-	error = zlib_compress(&compressed, &compressedsize, info->iccp_profile,
-			      info->iccp_profile_size, zlibsettings);
-	if (!error) {
-		u32 size = keysize + 2 + compressedsize;
-		error = png_chunk_init(&chunk, out, size, "iCCP");
-	}
-	if (!error) {
-		png_memcpy(chunk + 8, info->iccp_name, keysize);
-		chunk[8 + keysize] = 0; /*null termination char*/
-		chunk[9 + keysize] = 0; /*compression method: 0*/
-		png_memcpy(chunk + 10 + keysize, compressed, compressedsize);
-		png_chunk_generate_crc(chunk);
-	}
-
-	png_free(compressed);
-	return error;
-}
-
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-static void filterScanline(u8 *out, const u8 *scanline, const u8 *prevline, u32 length,
-			   u32 bytewidth, u8 filterType)
-{
-	u32 i;
-	switch (filterType) {
-	case 0: /*None*/
-		for (i = 0; i != length; ++i)
-			out[i] = scanline[i];
-		break;
-	case 1: /*Sub*/
-		for (i = 0; i != bytewidth; ++i)
-			out[i] = scanline[i];
-		for (i = bytewidth; i < length; ++i)
-			out[i] = scanline[i] - scanline[i - bytewidth];
-		break;
-	case 2: /*Up*/
-		if (prevline) {
-			for (i = 0; i != length; ++i)
-				out[i] = scanline[i] - prevline[i];
-		} else {
-			for (i = 0; i != length; ++i)
-				out[i] = scanline[i];
-		}
-		break;
-	case 3: /*Average*/
-		if (prevline) {
-			for (i = 0; i != bytewidth; ++i)
-				out[i] = scanline[i] - (prevline[i] >> 1);
-			for (i = bytewidth; i < length; ++i)
-				out[i] = scanline[i] -
-					 ((scanline[i - bytewidth] + prevline[i]) >> 1);
-		} else {
-			for (i = 0; i != bytewidth; ++i)
-				out[i] = scanline[i];
-			for (i = bytewidth; i < length; ++i)
-				out[i] = scanline[i] - (scanline[i - bytewidth] >> 1);
-		}
-		break;
-	case 4: /*Paeth*/
-		if (prevline) {
-			/*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
-			for (i = 0; i != bytewidth; ++i)
-				out[i] = (scanline[i] - prevline[i]);
-			for (i = bytewidth; i < length; ++i) {
-				out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth],
-								       prevline[i],
-								       prevline[i - bytewidth]));
-			}
-		} else {
-			for (i = 0; i != bytewidth; ++i)
-				out[i] = scanline[i];
-			/*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
-			for (i = bytewidth; i < length; ++i)
-				out[i] = (scanline[i] - scanline[i - bytewidth]);
-		}
-		break;
-	default:
-		return; /*invalid filter type given*/
-	}
-}
-
-/* integer binary logarithm, max return value is 31 */
-static u32 ilog2(u32 i)
-{
-	u32 result = 0;
-	if (i >= 65536) {
-		result += 16;
-		i >>= 16;
-	}
-	if (i >= 256) {
-		result += 8;
-		i >>= 8;
-	}
-	if (i >= 16) {
-		result += 4;
-		i >>= 4;
-	}
-	if (i >= 4) {
-		result += 2;
-		i >>= 2;
-	}
-	if (i >= 2) {
-		result += 1; /*i >>= 1;*/
-	}
-	return result;
-}
-
-/* integer approximation for i * log2(i), helper function for LFS_ENTROPY */
-static u32 ilog2i(u32 i)
-{
-	u32 l;
-	if (i == 0)
-		return 0;
-	l = ilog2(i);
-	/* approximate i*log2(i): l is integer logarithm, ((i - (1u << l)) << 1u)
-  linearly approximates the missing fractional part multiplied by i */
-	return i * l + ((i - (1u << l)) << 1u);
-}
-
-static u32 filter(u8 *out, const u8 *in, u32 w, u32 h, const pngColorMode *color,
-		  const pngEncoderSettings *settings)
-{
-	/*
-  For PNG filter method 0
-  out must be a buffer with as size: h + (w * h * bpp + 7u) / 8u, because there are
-  the scanlines with 1 extra byte per scanline
-  */
-
-	u32 bpp = png_get_bpp(color);
-	/*the width of a scanline in bytes, not including the filter type*/
-	u32 linebytes = png_get_raw_size_idat(w, 1, bpp) - 1u;
-
-	/*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
-	u32 bytewidth = (bpp + 7u) / 8u;
-	const u8 *prevline = 0;
-	u32 x, y;
-	u32 error = 0;
-	pngFilterStrategy strategy = settings->filter_strategy;
-
-	/*
-  There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard:
-   *  If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e.
-      use fixed filtering, with the filter None).
-   * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is
-     not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply
-     all five filters and select the filter that produces the smallest sum of absolute values per row.
-  This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true.
-
-  If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed,
-  but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum
-  heuristic is used.
-  */
-	if (settings->filter_palette_zero &&
-	    (color->colortype == LCT_PALETTE || color->bitdepth < 8))
-		strategy = LFS_ZERO;
-
-	if (bpp == 0)
-		return 31; /*error: invalid color type*/
-
-	if (strategy >= LFS_ZERO && strategy <= LFS_FOUR) {
-		u8 type = (u8)strategy;
-		for (y = 0; y != h; ++y) {
-			u32 outindex =
-				(1 + linebytes) * y; /*the extra filterbyte added to each row*/
-			u32 inindex = linebytes * y;
-			out[outindex] = type; /*filter type byte*/
-			filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes,
-				       bytewidth, type);
-			prevline = &in[inindex];
-		}
-	} else if (strategy == LFS_MINSUM) {
-		/*adaptive filtering*/
-		u8 *attempt[5]; /*five filtering attempts, one for each filter type*/
-		u32 smallest = 0;
-		u8 type, bestType = 0;
-
-		for (type = 0; type != 5; ++type) {
-			attempt[type] = (u8 *)png_malloc(linebytes);
-			if (!attempt[type])
-				error = 83; /*alloc fail*/
-		}
-
-		if (!error) {
-			for (y = 0; y != h; ++y) {
-				/*try the 5 filter types*/
-				for (type = 0; type != 5; ++type) {
-					u32 sum = 0;
-					filterScanline(attempt[type], &in[y * linebytes], prevline,
-						       linebytes, bytewidth, type);
-
-					/*calculate the sum of the result*/
-					if (type == 0) {
-						for (x = 0; x != linebytes; ++x)
-							sum += (u8)(attempt[type][x]);
-					} else {
-						for (x = 0; x != linebytes; ++x) {
-							/*For differences, each byte should be treated as signed, values above 127 are negative
-              (converted to signed char). Filtertype 0 isn't a difference though, so use u32 there.
-              This means filtertype 0 is almost never chosen, but that is justified.*/
-							u8 s = attempt[type][x];
-							sum += s < 128 ? s : (255U - s);
-						}
-					}
-
-					/*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
-					if (type == 0 || sum < smallest) {
-						bestType = type;
-						smallest = sum;
-					}
-				}
-
-				prevline = &in[y * linebytes];
-
-				/*now fill the out values*/
-				out[y * (linebytes + 1)] =
-					bestType; /*the first byte of a scanline will be the filter type*/
-				for (x = 0; x != linebytes; ++x)
-					out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
-			}
-		}
-
-		for (type = 0; type != 5; ++type)
-			png_free(attempt[type]);
-	} else if (strategy == LFS_ENTROPY) {
-		u8 *attempt[5]; /*five filtering attempts, one for each filter type*/
-		u32 bestSum = 0;
-		u32 type, bestType = 0;
-		u32 count[256];
-
-		for (type = 0; type != 5; ++type) {
-			attempt[type] = (u8 *)png_malloc(linebytes);
-			if (!attempt[type])
-				error = 83; /*alloc fail*/
-		}
-
-		if (!error) {
-			for (y = 0; y != h; ++y) {
-				/*try the 5 filter types*/
-				for (type = 0; type != 5; ++type) {
-					u32 sum = 0;
-					filterScanline(attempt[type], &in[y * linebytes], prevline,
-						       linebytes, bytewidth, type);
-					png_memset(count, 0, 256 * sizeof(*count));
-					for (x = 0; x != linebytes; ++x)
-						++count[attempt[type][x]];
-					++count[type]; /*the filter type itself is part of the scanline*/
-					for (x = 0; x != 256; ++x) {
-						sum += ilog2i(count[x]);
-					}
-					/*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
-					if (type == 0 || sum > bestSum) {
-						bestType = type;
-						bestSum = sum;
-					}
-				}
-
-				prevline = &in[y * linebytes];
-
-				/*now fill the out values*/
-				out[y * (linebytes + 1)] =
-					bestType; /*the first byte of a scanline will be the filter type*/
-				for (x = 0; x != linebytes; ++x)
-					out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
-			}
-		}
-
-		for (type = 0; type != 5; ++type)
-			png_free(attempt[type]);
-	} else if (strategy == LFS_PREDEFINED) {
-		for (y = 0; y != h; ++y) {
-			u32 outindex =
-				(1 + linebytes) * y; /*the extra filterbyte added to each row*/
-			u32 inindex = linebytes * y;
-			u8 type = settings->predefined_filters[y];
-			out[outindex] = type; /*filter type byte*/
-			filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes,
-				       bytewidth, type);
-			prevline = &in[inindex];
-		}
-	} else if (strategy == LFS_BRUTE_FORCE) {
-		/*brute force filter chooser.
-    deflate the scanline after every filter attempt to see which one deflates best.
-    This is very slow and gives only slightly smaller, sometimes even larger, result*/
-		u32 size[5];
-		u8 *attempt[5]; /*five filtering attempts, one for each filter type*/
-		u32 smallest = 0;
-		u32 type = 0, bestType = 0;
-		u8 *dummy;
-		pngCompressSettings zlibsettings;
-		png_memcpy(&zlibsettings, &settings->zlibsettings, sizeof(pngCompressSettings));
-		/*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose,
-    to simulate the true case where the tree is the same for the whole image. Sometimes it gives
-    better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare
-    cases better compression. It does make this a bit less slow, so it's worth doing this.*/
-		zlibsettings.btype = 1;
-		/*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG
-    images only, so disable it*/
-		zlibsettings.custom_zlib = 0;
-		zlibsettings.custom_deflate = 0;
-		for (type = 0; type != 5; ++type) {
-			attempt[type] = (u8 *)png_malloc(linebytes);
-			if (!attempt[type])
-				error = 83; /*alloc fail*/
-		}
-		if (!error) {
-			for (y = 0; y != h; ++y) /*try the 5 filter types*/ {
-				for (type = 0; type != 5; ++type) {
-					u32 testsize = (u32)linebytes;
-					/*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/
-
-					filterScanline(attempt[type], &in[y * linebytes], prevline,
-						       linebytes, bytewidth, type);
-					size[type] = 0;
-					dummy = 0;
-					zlib_compress(&dummy, &size[type], attempt[type], testsize,
-						      &zlibsettings);
-					png_free(dummy);
-					/*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
-					if (type == 0 || size[type] < smallest) {
-						bestType = type;
-						smallest = size[type];
-					}
-				}
-				prevline = &in[y * linebytes];
-				out[y * (linebytes + 1)] =
-					bestType; /*the first byte of a scanline will be the filter type*/
-				for (x = 0; x != linebytes; ++x)
-					out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x];
-			}
-		}
-		for (type = 0; type != 5; ++type)
-			png_free(attempt[type]);
-	} else
-		return 88; /* unknown filter strategy */
-
-	return error;
-}
-
-static void addPaddingBits(u8 *out, const u8 *in, u32 olinebits, u32 ilinebits, u32 h)
-{
-	/*The opposite of the removePaddingBits function
-  olinebits must be >= ilinebits*/
-	u32 y;
-	u32 diff = olinebits - ilinebits;
-	u32 obp = 0, ibp = 0; /*bit pointers*/
-	for (y = 0; y != h; ++y) {
-		u32 x;
-		for (x = 0; x < ilinebits; ++x) {
-			u8 bit = readBitFromReversedStream(&ibp, in);
-			setBitOfReversedStream(&obp, out, bit);
-		}
-		/*obp += diff; --> no, fill in some value in the padding bits too, to avoid
-    "Use of uninitialised value of size ###" warning from valgrind*/
-		for (x = 0; x != diff; ++x)
-			setBitOfReversedStream(&obp, out, 0);
-	}
-}
-
-/*
-in: non-interlaced image with size w*h
-out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with
- no padding bits between scanlines, but between reduced images so that each
- reduced image starts at a byte.
-bpp: bits per pixel
-there are no padding bits, not between scanlines, not between reduced images
-in has the following size in bits: w * h * bpp.
-out is possibly bigger due to padding bits between reduced images
-NOTE: comments about padding bits are only relevant if bpp < 8
-*/
-static void Adam7_interlace(u8 *out, const u8 *in, u32 w, u32 h, u32 bpp)
-{
-	u32 passw[7], passh[7];
-	u32 filter_passstart[8], padded_passstart[8], passstart[8];
-	u32 i;
-
-	Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
-
-	if (bpp >= 8) {
-		for (i = 0; i != 7; ++i) {
-			u32 x, y, b;
-			u32 bytewidth = bpp / 8u;
-			for (y = 0; y < passh[i]; ++y)
-				for (x = 0; x < passw[i]; ++x) {
-					u32 pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w +
-							    ADAM7_IX[i] + x * ADAM7_DX[i]) *
-							   bytewidth;
-					u32 pixeloutstart =
-						passstart[i] + (y * passw[i] + x) * bytewidth;
-					for (b = 0; b < bytewidth; ++b) {
-						out[pixeloutstart + b] = in[pixelinstart + b];
-					}
-				}
-		}
-	} else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ {
-		for (i = 0; i != 7; ++i) {
-			u32 x, y, b;
-			u32 ilinebits = bpp * passw[i];
-			u32 olinebits = bpp * w;
-			u32 obp, ibp; /*bit pointers (for out and in buffer)*/
-			for (y = 0; y < passh[i]; ++y)
-				for (x = 0; x < passw[i]; ++x) {
-					ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits +
-					      (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
-					obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
-					for (b = 0; b < bpp; ++b) {
-						u8 bit = readBitFromReversedStream(&ibp, in);
-						setBitOfReversedStream(&obp, out, bit);
-					}
-				}
-		}
-	}
-}
-
-/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image.
-return value is error**/
-static u32 preProcessScanlines(u8 **out, u32 *outsize, const u8 *in, u32 w, u32 h,
-			       const pngInfo *info_png, const pngEncoderSettings *settings)
-{
-	/*
-  This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
-  *) if no Adam7: 1) add padding bits (= possible extra bits per scanline if bpp < 8) 2) filter
-  *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
-  */
-	u32 bpp = png_get_bpp(&info_png->color);
-	u32 error = 0;
-
-	if (info_png->interlace_method == 0) {
-		*outsize =
-			h +
-			(h *
-			 ((w * bpp + 7u) /
-			  8u)); /*image size plus an extra byte per scanline + possible padding bits*/
-		*out = (u8 *)png_malloc(*outsize);
-		if (!(*out) && (*outsize))
-			error = 83; /*alloc fail*/
-
-		if (!error) {
-			/*non multiple of 8 bits per scanline, padding bits needed per scanline*/
-			if (bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) {
-				u8 *padded = (u8 *)png_malloc(h * ((w * bpp + 7u) / 8u));
-				if (!padded)
-					error = 83; /*alloc fail*/
-				if (!error) {
-					addPaddingBits(padded, in, ((w * bpp + 7u) / 8u) * 8u,
-						       w * bpp, h);
-					error = filter(*out, padded, w, h, &info_png->color,
-						       settings);
-				}
-				png_free(padded);
-			} else {
-				/*we can immediately filter into the out buffer, no other steps needed*/
-				error = filter(*out, in, w, h, &info_png->color, settings);
-			}
-		}
-	} else /*interlace_method is 1 (Adam7)*/ {
-		u32 passw[7], passh[7];
-		u32 filter_passstart[8], padded_passstart[8], passstart[8];
-		u8 *adam7;
-
-		Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w,
-				    h, bpp);
-
-		*outsize = filter_passstart
-			[7]; /*image size plus an extra byte per scanline + possible padding bits*/
-		*out = (u8 *)png_malloc(*outsize);
-		if (!(*out))
-			error = 83; /*alloc fail*/
-
-		adam7 = (u8 *)png_malloc(passstart[7]);
-		if (!adam7 && passstart[7])
-			error = 83; /*alloc fail*/
-
-		if (!error) {
-			u32 i;
-
-			Adam7_interlace(adam7, in, w, h, bpp);
-			for (i = 0; i != 7; ++i) {
-				if (bpp < 8) {
-					u8 *padded = (u8 *)png_malloc(padded_passstart[i + 1] -
-								      padded_passstart[i]);
-					if (!padded)
-						ERROR_BREAK(83); /*alloc fail*/
-					addPaddingBits(padded, &adam7[passstart[i]],
-						       ((passw[i] * bpp + 7u) / 8u) * 8u,
-						       passw[i] * bpp, passh[i]);
-					error = filter(&(*out)[filter_passstart[i]], padded,
-						       passw[i], passh[i], &info_png->color,
-						       settings);
-					png_free(padded);
-				} else {
-					error = filter(&(*out)[filter_passstart[i]],
-						       &adam7[padded_passstart[i]], passw[i],
-						       passh[i], &info_png->color, settings);
-				}
-
-				if (error)
-					break;
-			}
-		}
-
-		png_free(adam7);
-	}
-
-	return error;
-}
-
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-static u32 addUnknownChunks(ucvector *out, u8 *data, u32 datasize)
-{
-	u8 *inchunk = data;
-	while ((u32)(inchunk - data) < datasize) {
-		CERROR_TRY_RETURN(png_chunk_append(&out->data, &out->size, inchunk));
-		out->allocsize = out->size; /*fix the allocsize again*/
-		inchunk = png_chunk_next(inchunk, data + datasize);
-	}
-	return 0;
-}
-
-static u32 isGrayICCProfile(const u8 *profile, u32 size)
-{
-	/*
-  It is a gray profile if bytes 16-19 are "GRAY", rgb profile if bytes 16-19
-  are "RGB ". We do not perform any full parsing of the ICC profile here, other
-  than check those 4 bytes to grayscale profile. Other than that, validity of
-  the profile is not checked. This is needed only because the PNG specification
-  requires using a non-gray color model if there is an ICC profile with "RGB "
-  (sadly limiting compression opportunities if the input data is grayscale RGB
-  data), and requires using a gray color model if it is "GRAY".
-  */
-	if (size < 20)
-		return 0;
-	return profile[16] == 'G' && profile[17] == 'R' && profile[18] == 'A' && profile[19] == 'Y';
-}
-
-static u32 isRGBICCProfile(const u8 *profile, u32 size)
-{
-	/* See comment in isGrayICCProfile*/
-	if (size < 20)
-		return 0;
-	return profile[16] == 'R' && profile[17] == 'G' && profile[18] == 'B' && profile[19] == ' ';
-}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-
-u32 png_encode(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h, pngState *state)
-{
-	u8 *data = 0; /*uncompressed version of the IDAT chunk data*/
-	u32 datasize = 0;
-	ucvector outv = ucvector_init(NULL, 0);
-	pngInfo info;
-	const pngInfo *info_png = &state->info_png;
-
-	png_info_init(&info);
-
-	/*provide some proper output values if error will happen*/
-	*out = 0;
-	*outsize = 0;
-	state->error = 0;
-
-	/*check input values validity*/
-	if ((info_png->color.colortype == LCT_PALETTE || state->encoder.force_palette) &&
-	    (info_png->color.palettesize == 0 || info_png->color.palettesize > 256)) {
-		state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/
-		goto cleanup;
-	}
-	if (state->encoder.zlibsettings.btype > 2) {
-		state->error = 61; /*error: invalid btype*/
-		goto cleanup;
-	}
-	if (info_png->interlace_method > 1) {
-		state->error = 71; /*error: invalid interlace mode*/
-		goto cleanup;
-	}
-	state->error = checkColorValidity(info_png->color.colortype, info_png->color.bitdepth);
-	if (state->error)
-		goto cleanup; /*error: invalid color type given*/
-	state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
-	if (state->error)
-		goto cleanup; /*error: invalid color type given*/
-
-	/* color convert and compute scanline filter types */
-	png_info_copy(&info, &state->info_png);
-	if (state->encoder.auto_convert) {
-		pngColorStats stats;
-		png_color_stats_init(&stats);
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-		if (info_png->iccp_defined &&
-		    isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) {
-			/*the PNG specification does not allow to use palette with a GRAY ICC profile, even
-      if the palette has only gray colors, so disallow it.*/
-			stats.allow_palette = 0;
-		}
-		if (info_png->iccp_defined &&
-		    isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) {
-			/*the PNG specification does not allow to use grayscale color with RGB ICC profile, so disallow gray.*/
-			stats.allow_greyscale = 0;
-		}
-#endif /* PNG_COMPILE_ANCILLARY_CHUNKS */
-		state->error = png_compute_color_stats(&stats, image, w, h, &state->info_raw);
-		if (state->error)
-			goto cleanup;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-		if (info_png->background_defined) {
-			/*the background chunk's color must be taken into account as well*/
-			u32 r = 0, g = 0, b = 0;
-			pngColorMode mode16 = png_color_mode_make(LCT_RGB, 16);
-			png_convert_rgb(&r, &g, &b, info_png->background_r, info_png->background_g,
-					info_png->background_b, &mode16, &info_png->color);
-			state->error = png_color_stats_add(&stats, r, g, b, 65535);
-			if (state->error)
-				goto cleanup;
-		}
-#endif /* PNG_COMPILE_ANCILLARY_CHUNKS */
-		state->error = auto_choose_color(&info.color, &state->info_raw, &stats);
-		if (state->error)
-			goto cleanup;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-		/*also convert the background chunk*/
-		if (info_png->background_defined) {
-			if (png_convert_rgb(&info.background_r, &info.background_g,
-					    &info.background_b, info_png->background_r,
-					    info_png->background_g, info_png->background_b,
-					    &info.color, &info_png->color)) {
-				state->error = 104;
-				goto cleanup;
-			}
-		}
-#endif /* PNG_COMPILE_ANCILLARY_CHUNKS */
-	}
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	if (info_png->iccp_defined) {
-		u32 gray_icc =
-			isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size);
-		u32 rgb_icc = isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size);
-		u32 gray_png =
-			info.color.colortype == LCT_GREY || info.color.colortype == LCT_GREY_ALPHA;
-		if (!gray_icc && !rgb_icc) {
-			state->error = 100; /* Disallowed profile color type for PNG */
-			goto cleanup;
-		}
-		if (gray_icc != gray_png) {
-			/*Not allowed to use RGB/RGBA/palette with GRAY ICC profile or vice versa,
-      or in case of auto_convert, it wasn't possible to find appropriate model*/
-			state->error = state->encoder.auto_convert ? 102 : 101;
-			goto cleanup;
-		}
-	}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-	if (!png_color_mode_equal(&state->info_raw, &info.color)) {
-		u8 *converted;
-		u32 size = ((u32)w * (u32)h * (u32)png_get_bpp(&info.color) + 7u) / 8u;
-
-		converted = (u8 *)png_malloc(size);
-		if (!converted && size)
-			state->error = 83; /*alloc fail*/
-		if (!state->error) {
-			state->error =
-				png_convert(converted, image, &info.color, &state->info_raw, w, h);
-		}
-		if (!state->error) {
-			state->error = preProcessScanlines(&data, &datasize, converted, w, h, &info,
-							   &state->encoder);
-		}
-		png_free(converted);
-		if (state->error)
-			goto cleanup;
-	} else {
-		state->error =
-			preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder);
-		if (state->error)
-			goto cleanup;
-	}
-
-	/* output all PNG chunks */ {
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-		u32 i;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		/*write signature and chunks*/
-		state->error = writeSignature(&outv);
-		if (state->error)
-			goto cleanup;
-		/*IHDR*/
-		state->error = addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth,
-					     info.interlace_method);
-		if (state->error)
-			goto cleanup;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-		/*unknown chunks between IHDR and PLTE*/
-		if (info.unknown_chunks_data[0]) {
-			state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0],
-							info.unknown_chunks_size[0]);
-			if (state->error)
-				goto cleanup;
-		}
-		/*color profile chunks must come before PLTE */
-		if (info.iccp_defined) {
-			state->error = addChunk_iCCP(&outv, &info, &state->encoder.zlibsettings);
-			if (state->error)
-				goto cleanup;
-		}
-		if (info.srgb_defined) {
-			state->error = addChunk_sRGB(&outv, &info);
-			if (state->error)
-				goto cleanup;
-		}
-		if (info.gama_defined) {
-			state->error = addChunk_gAMA(&outv, &info);
-			if (state->error)
-				goto cleanup;
-		}
-		if (info.chrm_defined) {
-			state->error = addChunk_cHRM(&outv, &info);
-			if (state->error)
-				goto cleanup;
-		}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		/*PLTE*/
-		if (info.color.colortype == LCT_PALETTE) {
-			state->error = addChunk_PLTE(&outv, &info.color);
-			if (state->error)
-				goto cleanup;
-		}
-		if (state->encoder.force_palette &&
-		    (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) {
-			/*force_palette means: write suggested palette for truecolor in PLTE chunk*/
-			state->error = addChunk_PLTE(&outv, &info.color);
-			if (state->error)
-				goto cleanup;
-		}
-		/*tRNS (this will only add if when necessary) */
-		state->error = addChunk_tRNS(&outv, &info.color);
-		if (state->error)
-			goto cleanup;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-		/*bKGD (must come between PLTE and the IDAt chunks*/
-		if (info.background_defined) {
-			state->error = addChunk_bKGD(&outv, &info);
-			if (state->error)
-				goto cleanup;
-		}
-		/*pHYs (must come before the IDAT chunks)*/
-		if (info.phys_defined) {
-			state->error = addChunk_pHYs(&outv, &info);
-			if (state->error)
-				goto cleanup;
-		}
-
-		/*unknown chunks between PLTE and IDAT*/
-		if (info.unknown_chunks_data[1]) {
-			state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1],
-							info.unknown_chunks_size[1]);
-			if (state->error)
-				goto cleanup;
-		}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		/*IDAT (multiple IDAT chunks must be consecutive)*/
-		state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings);
-		if (state->error)
-			goto cleanup;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-		/*tIME*/
-		if (info.time_defined) {
-			state->error = addChunk_tIME(&outv, &info.time);
-			if (state->error)
-				goto cleanup;
-		}
-		/*tEXt and/or zTXt*/
-		for (i = 0; i != info.text_num; ++i) {
-			if (png_strlen(info.text_keys[i]) > 79) {
-				state->error = 66; /*text chunk too large*/
-				goto cleanup;
-			}
-			if (png_strlen(info.text_keys[i]) < 1) {
-				state->error = 67; /*text chunk too small*/
-				goto cleanup;
-			}
-			if (state->encoder.text_compression) {
-				state->error = addChunk_zTXt(&outv, info.text_keys[i],
-							     info.text_strings[i],
-							     &state->encoder.zlibsettings);
-				if (state->error)
-					goto cleanup;
-			} else {
-				state->error = addChunk_tEXt(&outv, info.text_keys[i],
-							     info.text_strings[i]);
-				if (state->error)
-					goto cleanup;
-			}
-		}
-		/*png version id in text chunk*/
-		if (state->encoder.add_id) {
-			u32 already_added_id_text = 0;
-			for (i = 0; i != info.text_num; ++i) {
-				const char *k = info.text_keys[i];
-				/* Could use strcmp, but we're not calling or reimplementing this C library function for this use only */
-				if (k[0] == 'L' && k[1] == 'o' && k[2] == 'd' && k[3] == 'e' &&
-				    k[4] == 'P' && k[5] == 'N' && k[6] == 'G' && k[7] == '\0') {
-					already_added_id_text = 1;
-					break;
-				}
-			}
-			if (already_added_id_text == 0) {
-				state->error = addChunk_tEXt(
-					&outv, "png",
-					PNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
-				if (state->error)
-					goto cleanup;
-			}
-		}
-		/*iTXt*/
-		for (i = 0; i != info.itext_num; ++i) {
-			if (png_strlen(info.itext_keys[i]) > 79) {
-				state->error = 66; /*text chunk too large*/
-				goto cleanup;
-			}
-			if (png_strlen(info.itext_keys[i]) < 1) {
-				state->error = 67; /*text chunk too small*/
-				goto cleanup;
-			}
-			state->error = addChunk_iTXt(&outv, state->encoder.text_compression,
-						     info.itext_keys[i], info.itext_langtags[i],
-						     info.itext_transkeys[i], info.itext_strings[i],
-						     &state->encoder.zlibsettings);
-			if (state->error)
-				goto cleanup;
-		}
-
-		/*unknown chunks between IDAT and IEND*/
-		if (info.unknown_chunks_data[2]) {
-			state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2],
-							info.unknown_chunks_size[2]);
-			if (state->error)
-				goto cleanup;
-		}
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-		state->error = addChunk_IEND(&outv);
-		if (state->error)
-			goto cleanup;
-	}
-
-cleanup:
-	png_info_cleanup(&info);
-	png_free(data);
-
-	/*instead of cleaning the vector up, give it to the output*/
-	*out = outv.data;
-	*outsize = outv.size;
-
-	return state->error;
-}
-
-u32 png_encode_memory(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h, pngColorType colortype,
-		      u32 bitdepth)
-{
-	u32 error;
-	pngState state;
-	png_state_init(&state);
-	state.info_raw.colortype = colortype;
-	state.info_raw.bitdepth = bitdepth;
-	state.info_png.color.colortype = colortype;
-	state.info_png.color.bitdepth = bitdepth;
-	png_encode(out, outsize, image, w, h, &state);
-	error = state.error;
-	png_state_cleanup(&state);
-	return error;
-}
-
-u32 png_encode32(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h)
-{
-	return png_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8);
-}
-
-u32 png_encode24(u8 **out, u32 *outsize, const u8 *image, u32 w, u32 h)
-{
-	return png_encode_memory(out, outsize, image, w, h, LCT_RGB, 8);
-}
-
-#ifdef PNG_COMPILE_DISK
-u32 png_encode_file(const char *filename, const u8 *image, u32 w, u32 h, pngColorType colortype,
-		    u32 bitdepth)
-{
-	u8 *buffer;
-	u32 buffersize;
-	u32 error = png_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth);
-	if (!error)
-		error = png_save_file(buffer, buffersize, filename);
-	png_free(buffer);
-	return error;
-}
-
-u32 png_encode32_file(const char *filename, const u8 *image, u32 w, u32 h)
-{
-	return png_encode_file(filename, image, w, h, LCT_RGBA, 8);
-}
-
-u32 png_encode24_file(const char *filename, const u8 *image, u32 w, u32 h)
-{
-	return png_encode_file(filename, image, w, h, LCT_RGB, 8);
-}
-#endif /*PNG_COMPILE_DISK*/
-
-void png_encoder_settings_init(pngEncoderSettings *settings)
-{
-	png_compress_settings_init(&settings->zlibsettings);
-	settings->filter_palette_zero = 1;
-	settings->filter_strategy = LFS_MINSUM;
-	settings->auto_convert = 1;
-	settings->force_palette = 0;
-	settings->predefined_filters = 0;
-#ifdef PNG_COMPILE_ANCILLARY_CHUNKS
-	settings->add_id = 0;
-	settings->text_compression = 1;
-#endif /*PNG_COMPILE_ANCILLARY_CHUNKS*/
-}
-
-#endif /*PNG_COMPILE_ENCODER*/
-#endif /*PNG_COMPILE_PNG*/
-
-#ifdef PNG_COMPILE_ERROR_TEXT
-/*
-This returns the description of a numerical error code in English. This is also
-the documentation of all the error codes.
-*/
-const char *png_error_text(u32 code)
-{
-	switch (code) {
-	case 0:
-		return "no error, everything went ok";
-	case 1:
-		return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/
-	case 10:
-		return "end of input memory reached without huffman end code"; /*while huffman decoding*/
-	case 11:
-		return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/
-	case 13:
-		return "problem while processing dynamic deflate block";
-	case 14:
-		return "problem while processing dynamic deflate block";
-	case 15:
-		return "problem while processing dynamic deflate block";
-	/*this error could happen if there are only 0 or 1 symbols present in the huffman code:*/
-	case 16:
-		return "invalid code while processing dynamic deflate block";
-	case 17:
-		return "end of out buffer memory reached while inflating";
-	case 18:
-		return "invalid distance code while inflating";
-	case 19:
-		return "end of out buffer memory reached while inflating";
-	case 20:
-		return "invalid deflate block BTYPE encountered while decoding";
-	case 21:
-		return "NLEN is not ones complement of LEN in a deflate block";
-
-	/*end of out buffer memory reached while inflating:
-    This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
-    all the pixels of the image, given the color depth and image dimensions. Something that doesn't
-    happen in a normal, well encoded, PNG image.*/
-	case 22:
-		return "end of out buffer memory reached while inflating";
-	case 23:
-		return "end of in buffer memory reached while inflating";
-	case 24:
-		return "invalid FCHECK in zlib header";
-	case 25:
-		return "invalid compression method in zlib header";
-	case 26:
-		return "FDICT encountered in zlib header while it's not used for PNG";
-	case 27:
-		return "PNG file is smaller than a PNG header";
-	/*Checks the magic file header, the first 8 bytes of the PNG file*/
-	case 28:
-		return "incorrect PNG signature, it's no PNG or corrupted";
-	case 29:
-		return "first chunk is not the header chunk";
-	case 30:
-		return "chunk length too large, chunk broken off at end of file";
-	case 31:
-		return "illegal PNG color type or bpp";
-	case 32:
-		return "illegal PNG compression method";
-	case 33:
-		return "illegal PNG filter method";
-	case 34:
-		return "illegal PNG interlace method";
-	case 35:
-		return "chunk length of a chunk is too large or the chunk too small";
-	case 36:
-		return "illegal PNG filter type encountered";
-	case 37:
-		return "illegal bit depth for this color type given";
-	case 38:
-		return "the palette is too small or too big"; /*0, or more than 256 colors*/
-	case 39:
-		return "tRNS chunk before PLTE or has more entries than palette size";
-	case 40:
-		return "tRNS chunk has wrong size for grayscale image";
-	case 41:
-		return "tRNS chunk has wrong size for RGB image";
-	case 42:
-		return "tRNS chunk appeared while it was not allowed for this color type";
-	case 43:
-		return "bKGD chunk has wrong size for palette image";
-	case 44:
-		return "bKGD chunk has wrong size for grayscale image";
-	case 45:
-		return "bKGD chunk has wrong size for RGB image";
-	case 48:
-		return "empty input buffer given to decoder. Maybe caused by non-existing file?";
-	case 49:
-		return "jumped past memory while generating dynamic huffman tree";
-	case 50:
-		return "jumped past memory while generating dynamic huffman tree";
-	case 51:
-		return "jumped past memory while inflating huffman block";
-	case 52:
-		return "jumped past memory while inflating";
-	case 53:
-		return "size of zlib data too small";
-	case 54:
-		return "repeat symbol in tree while there was no value symbol yet";
-	/*jumped past tree while generating huffman tree, this could be when the
-    tree will have more leaves than symbols after generating it out of the
-    given lengths. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
-	case 55:
-		return "jumped past tree while generating huffman tree";
-	case 56:
-		return "given output image colortype or bitdepth not supported for color conversion";
-	case 57:
-		return "invalid CRC encountered (checking CRC can be disabled)";
-	case 58:
-		return "invalid ADLER32 encountered (checking ADLER32 can be disabled)";
-	case 59:
-		return "requested color conversion not supported";
-	case 60:
-		return "invalid window size given in the settings of the encoder (must be 0-32768)";
-	case 61:
-		return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)";
-	/*png leaves the choice of RGB to grayscale conversion formula to the user.*/
-	case 62:
-		return "conversion from color to grayscale not supported";
-	/*(2^31-1)*/
-	case 63:
-		return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk";
-	/*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/
-	case 64:
-		return "the length of the END symbol 256 in the Huffman tree is 0";
-	case 66:
-		return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes";
-	case 67:
-		return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte";
-	case 68:
-		return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors";
-	case 69:
-		return "unknown chunk type with 'critical' flag encountered by the decoder";
-	case 71:
-		return "invalid interlace mode given to encoder (must be 0 or 1)";
-	case 72:
-		return "while decoding, invalid compression method encountering in zTXt or iTXt chunk (it must be 0)";
-	case 73:
-		return "invalid tIME chunk size";
-	case 74:
-		return "invalid pHYs chunk size";
-	/*length could be wrong, or data chopped off*/
-	case 75:
-		return "no null termination char found while decoding text chunk";
-	case 76:
-		return "iTXt chunk too short to contain required bytes";
-	case 77:
-		return "integer overflow in buffer size";
-	case 78:
-		return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/
-	case 79:
-		return "failed to open file for writing";
-	case 80:
-		return "tried creating a tree of 0 symbols";
-	case 81:
-		return "lazy matching at pos 0 is impossible";
-	case 82:
-		return "color conversion to palette requested while a color isn't in palette, or index out of bounds";
-	case 83:
-		return "memory allocation failed";
-	case 84:
-		return "given image too small to contain all pixels to be encoded";
-	case 86:
-		return "impossible offset in lz77 encoding (internal bug)";
-	case 87:
-		return "must provide custom zlib function pointer if PNG_COMPILE_ZLIB is not defined";
-	case 88:
-		return "invalid filter strategy given for pngEncoderSettings.filter_strategy";
-	case 89:
-		return "text chunk keyword too short or long: must have size 1-79";
-	/*the windowsize in the pngCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/
-	case 90:
-		return "windowsize must be a power of two";
-	case 91:
-		return "invalid decompressed idat size";
-	case 92:
-		return "integer overflow due to too many pixels";
-	case 93:
-		return "zero width or height is invalid";
-	case 94:
-		return "header chunk must have a size of 13 bytes";
-	case 95:
-		return "integer overflow with combined idat chunk size";
-	case 96:
-		return "invalid gAMA chunk size";
-	case 97:
-		return "invalid cHRM chunk size";
-	case 98:
-		return "invalid sRGB chunk size";
-	case 99:
-		return "invalid sRGB rendering intent";
-	case 100:
-		return "invalid ICC profile color type, the PNG specification only allows RGB or GRAY";
-	case 101:
-		return "PNG specification does not allow RGB ICC profile on gray color types and vice versa";
-	case 102:
-		return "not allowed to set grayscale ICC profile with colored pixels by PNG specification";
-	case 103:
-		return "invalid palette index in bKGD chunk. Maybe it came before PLTE chunk?";
-	case 104:
-		return "invalid bKGD color while encoding (e.g. palette index out of range)";
-	case 105:
-		return "integer overflow of bitsize";
-	case 106:
-		return "PNG file must have PLTE chunk if color type is palette";
-	case 107:
-		return "color convert from palette mode requested without setting the palette data in it";
-	case 108:
-		return "tried to add more than 256 values to a palette";
-	/*this limit can be configured in pngDecompressSettings*/
-	case 109:
-		return "tried to decompress zlib or deflate data larger than desired max_output_size";
-	case 110:
-		return "custom zlib or inflate decompression failed";
-	case 111:
-		return "custom zlib or deflate compression failed";
-	/*max text size limit can be configured in pngDecoderSettings. This error prevents
-    unreasonable memory consumption when decoding due to impossibly large text sizes.*/
-	case 112:
-		return "compressed text unreasonably large";
-	/*max ICC size limit can be configured in pngDecoderSettings. This error prevents
-    unreasonable memory consumption when decoding due to impossibly large ICC profile*/
-	case 113:
-		return "ICC profile unreasonably large";
-	default:
-		return "unknown error code";
-	}
-}
-#endif /*PNG_COMPILE_ERROR_TEXT*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // C++ Wrapper                                                          // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef PNG_COMPILE_CPP
-namespace png
-{
-#ifdef PNG_COMPILE_DISK
-u32 load_file(std::vector<u8> &buffer, const std::string &filename)
-{
-	long size = png_filesize(filename.c_str());
-	if (size < 0)
-		return 78;
-	buffer.resize((u32)size);
-	return size == 0 ? 0 : png_buffer_file(&buffer[0], (u32)size, filename.c_str());
-}
-
-/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
-u32 save_file(const std::vector<u8> &buffer, const std::string &filename)
-{
-	return png_save_file(buffer.empty() ? 0 : &buffer[0], buffer.size(), filename.c_str());
-}
-#endif /* PNG_COMPILE_DISK */
-
-#ifdef PNG_COMPILE_ZLIB
-#ifdef PNG_COMPILE_DECODER
-u32 decompress(std::vector<u8> &out, const u8 *in, u32 insize,
-	       const pngDecompressSettings &settings)
-{
-	u8 *buffer = 0;
-	u32 buffersize = 0;
-	u32 error = zlib_decompress(&buffer, &buffersize, 0, in, insize, &settings);
-	if (buffer) {
-		out.insert(out.end(), &buffer[0], &buffer[buffersize]);
-		png_free(buffer);
-	}
-	return error;
-}
-
-u32 decompress(std::vector<u8> &out, const std::vector<u8> &in,
-	       const pngDecompressSettings &settings)
-{
-	return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
-}
-#endif /* PNG_COMPILE_DECODER */
-
-#ifdef PNG_COMPILE_ENCODER
-u32 compress(std::vector<u8> &out, const u8 *in, u32 insize, const pngCompressSettings &settings)
-{
-	u8 *buffer = 0;
-	u32 buffersize = 0;
-	u32 error = zlib_compress(&buffer, &buffersize, in, insize, &settings);
-	if (buffer) {
-		out.insert(out.end(), &buffer[0], &buffer[buffersize]);
-		png_free(buffer);
-	}
-	return error;
-}
-
-u32 compress(std::vector<u8> &out, const std::vector<u8> &in, const pngCompressSettings &settings)
-{
-	return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
-}
-#endif /* PNG_COMPILE_ENCODER */
-#endif /* PNG_COMPILE_ZLIB */
-
-#ifdef PNG_COMPILE_PNG
-
-State::State()
-{
-	png_state_init(this);
-}
-
-State::State(const State &other)
-{
-	png_state_init(this);
-	png_state_copy(this, &other);
-}
-
-State::~State()
-{
-	png_state_cleanup(this);
-}
-
-State &State::operator=(const State &other)
-{
-	png_state_copy(this, &other);
-	return *this;
-}
-
-#ifdef PNG_COMPILE_DECODER
-
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, const u8 *in, u32 insize, pngColorType colortype,
-	   u32 bitdepth)
-{
-	u8 *buffer = 0;
-	u32 error = png_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth);
-	if (buffer && !error) {
-		State state;
-		state.info_raw.colortype = colortype;
-		state.info_raw.bitdepth = bitdepth;
-		u32 buffersize = png_get_raw_size(w, h, &state.info_raw);
-		out.insert(out.end(), &buffer[0], &buffer[buffersize]);
-	}
-	png_free(buffer);
-	return error;
-}
-
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, const std::vector<u8> &in, pngColorType colortype,
-	   u32 bitdepth)
-{
-	return decode(out, w, h, in.empty() ? 0 : &in[0], (u32)in.size(), colortype, bitdepth);
-}
-
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, State &state, const u8 *in, u32 insize)
-{
-	u8 *buffer = NULL;
-	u32 error = png_decode(&buffer, &w, &h, &state, in, insize);
-	if (buffer && !error) {
-		u32 buffersize = png_get_raw_size(w, h, &state.info_raw);
-		out.insert(out.end(), &buffer[0], &buffer[buffersize]);
-	}
-	png_free(buffer);
-	return error;
-}
-
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, State &state, const std::vector<u8> &in)
-{
-	return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size());
-}
-
-#ifdef PNG_COMPILE_DISK
-u32 decode(std::vector<u8> &out, u32 &w, u32 &h, const std::string &filename,
-	   pngColorType colortype, u32 bitdepth)
-{
-	std::vector<u8> buffer;
-	/* safe output values in case error happens */
-	w = h = 0;
-	u32 error = load_file(buffer, filename);
-	if (error)
-		return error;
-	return decode(out, w, h, buffer, colortype, bitdepth);
-}
-#endif /* PNG_COMPILE_DECODER */
-#endif /* PNG_COMPILE_DISK */
-
-#ifdef PNG_COMPILE_ENCODER
-u32 encode(std::vector<u8> &out, const u8 *in, u32 w, u32 h, pngColorType colortype, u32 bitdepth)
-{
-	u8 *buffer;
-	u32 buffersize;
-	u32 error = png_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth);
-	if (buffer) {
-		out.insert(out.end(), &buffer[0], &buffer[buffersize]);
-		png_free(buffer);
-	}
-	return error;
-}
-
-u32 encode(std::vector<u8> &out, const std::vector<u8> &in, u32 w, u32 h, pngColorType colortype,
-	   u32 bitdepth)
-{
-	if (png_get_raw_size_lct(w, h, colortype, bitdepth) > in.size())
-		return 84;
-	return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
-}
-
-u32 encode(std::vector<u8> &out, const u8 *in, u32 w, u32 h, State &state)
-{
-	u8 *buffer;
-	u32 buffersize;
-	u32 error = png_encode(&buffer, &buffersize, in, w, h, &state);
-	if (buffer) {
-		out.insert(out.end(), &buffer[0], &buffer[buffersize]);
-		png_free(buffer);
-	}
-	return error;
-}
-
-u32 encode(std::vector<u8> &out, const std::vector<u8> &in, u32 w, u32 h, State &state)
-{
-	if (png_get_raw_size(w, h, &state.info_raw) > in.size())
-		return 84;
-	return encode(out, in.empty() ? 0 : &in[0], w, h, state);
-}
-
-#ifdef PNG_COMPILE_DISK
-u32 encode(const std::string &filename, const u8 *in, u32 w, u32 h, pngColorType colortype,
-	   u32 bitdepth)
-{
-	std::vector<u8> buffer;
-	u32 error = encode(buffer, in, w, h, colortype, bitdepth);
-	if (!error)
-		error = save_file(buffer, filename);
-	return error;
-}
-
-u32 encode(const std::string &filename, const std::vector<u8> &in, u32 w, u32 h,
-	   pngColorType colortype, u32 bitdepth)
-{
-	if (png_get_raw_size_lct(w, h, colortype, bitdepth) > in.size())
-		return 84;
-	return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
-}
-#endif /* PNG_COMPILE_DISK */
-#endif /* PNG_COMPILE_ENCODER */
-#endif /* PNG_COMPILE_PNG */
-} /* namespace png */
-#endif /*PNG_COMPILE_CPP*/
diff --git a/libgui/psf.c b/libgui/psf.c
deleted file mode 100644
index e590add..0000000
--- a/libgui/psf.c
+++ /dev/null
@@ -1,60 +0,0 @@
-// MIT License, Copyright (c) 2020 Marvin Borner
-// PSF parser
-
-#include <def.h>
-#include <gfx.h>
-#include <mem.h>
-#include <print.h>
-#include <psf.h>
-
-// Verifies the PSF magics
-// Returns the PSF version or 0
-static int psf_verify(char *data)
-{
-	struct psf1_header *header1 = (struct psf1_header *)data;
-	struct psf2_header *header2 = (struct psf2_header *)data;
-
-	if (header1->magic[0] == PSF1_MAGIC_0 && header1->magic[1] == PSF1_MAGIC_1)
-		return 1;
-	else if (header2->magic[0] == PSF2_MAGIC_0 && header2->magic[1] == PSF2_MAGIC_1 &&
-		 header2->magic[2] == PSF2_MAGIC_2 && header2->magic[3] == PSF2_MAGIC_3)
-		return 2;
-	else
-		return 0;
-}
-
-struct font *psf_parse(char *data)
-{
-	if (!data)
-		return NULL;
-
-	int version = psf_verify(data);
-
-	char *chars;
-	int height;
-	int width;
-	int char_size;
-
-	if (version == 1) {
-		chars = data + sizeof(struct psf1_header);
-		height = ((struct psf1_header *)data)->char_size;
-		width = 8;
-		char_size = ((struct psf1_header *)data)->char_size;
-	} else if (version == 2) {
-		chars = data + ((struct psf2_header *)data)->size;
-		height = ((struct psf2_header *)data)->height;
-		width = ((struct psf2_header *)data)->width;
-		char_size = ((struct psf2_header *)data)->char_size;
-	} else {
-		print("Unknown font!\n");
-		return NULL;
-	}
-
-	struct font *font = malloc(sizeof(*font));
-	font->chars = chars;
-	font->size.x = width;
-	font->size.y = height;
-	font->char_size = char_size;
-
-	return font;
-}