1 files changed, 68 insertions, 0 deletions
diff --git a/kernel/features/gui.c b/kernel/features/gui.c
new file mode 100644
index 0000000..d080cb1
--- /dev/null
+++ b/kernel/features/gui.c
@@ -0,0 +1,68 @@
+// MIT License, Copyright (c) 2020 Marvin Borner
+// Some GUI functions
+
+#include <fs.h>
+#include <gui.h>
+#include <psf.h>
+#include <str.h>
+#include <vesa.h>
+
+struct font *font;
+
+void gui_write_char(int x, int y, const u32 c[3], char ch)
+{
+	int pos = x * vbe_bpl + y * vbe_pitch;
+	char *draw = (char *)&fb[pos];
+
+	u32 stride = font->char_size / font->height;
+	for (int cy = 0; cy < font->height; cy++) {
+		for (int cx = 0; cx < font->width; cx++) {
+			u8 bits = font->chars[ch * font->char_size + cy * stride + cx / 8];
+			u8 bit = bits >> (7 - cx % 8) & 1;
+			if (bit) {
+				draw[vbe_bpl * cx] = c[2];
+				draw[vbe_bpl * cx + 1] = c[1];
+				draw[vbe_bpl * cx + 2] = c[0];
+			}
+		}
+		draw += vbe_pitch;
+	}
+}
+
+void gui_write(int x, int y, const u32 c[3], char *text)
+{
+	for (u32 i = 0; i < strlen(text); i++) {
+		gui_write_char(x + i * font->width, y, c, text[i]);
+	}
+}
+
+// Abstraction
+int x, y = 0;
+const u32 c[3] = { 0xff, 0xff, 0xff };
+void gui_term_write_char(char ch)
+{
+	if (x + font->width > vbe_width) {
+		x = 0;
+		y += font->height;
+	}
+
+	if (ch >= ' ' && ch <= '~') {
+		gui_write_char(x, y, c, ch);
+		x += font->width;
+	} else if (ch == '\n') {
+		x = 0;
+		y += font->height;
+	}
+}
+
+void gui_term_write(char *text)
+{
+	for (u32 i = 0; i < strlen(text); i++) {
+		gui_term_write_char(text[i]);
+	}
+}
+
+void gui_init(char *font_path)
+{
+	font = psf_parse(read_file(font_path));
+}