Basic FEN parsing, buggy af

The entire GUI system is kinda buggy and sluggish. Might need to
rethink some design choices. I've got some ideas to improve everything
though.

1 files changed, 163 insertions, 26 deletions

diff --git a/apps/chess.c b/apps/chess.c
index 3c4c0c3..b4808b9 100644
--- a/apps/chess.c
+++ b/apps/chess.c
@@ -6,12 +6,13 @@
 #include <libgui/gui.h>
 #include <print.h>
 
+// Config
 #define SIZE 8
 #define TILE 36
 #define WHITE_STARTS 1
-
 #define DARK_COLOR 0xff946f51
 #define LIGHT_COLOR 0xfff0d9b5
+#define START_FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
 
 // Pieces
 #define NONE 0
@@ -41,7 +42,7 @@
 struct piece {
 	u32 piece;
 	u32 widget;
-	const char *icon;
+	char name[8];
 	struct {
 		u8 moved : 1;
 		// idk
@@ -52,49 +53,183 @@ typedef struct piece board[SIZE][SIZE];
 
 static u32 win = 0; // Window
 static board tiles = { 0 }; // Matrix
+static vec2 selected = { -1, -1 }; // Selected tile
+
+static void load_image(struct piece *tile)
+{
+	char icon[48] = { 0 };
+	sprintf(icon, "/icons/chess-%s-%d.png", tile->name, TILE);
+	enum gfx_filter filter = IS_COLOR(tile->piece, BLACK) ? GFX_FILTER_NONE : GFX_FILTER_INVERT;
+
+	/* assert(gui_fill(win, tile->widget, GUI_LAYER_FG, 0) == EOK); */
+	assert(gui_load_image_filter(win, tile->widget, GUI_LAYER_FG, vec2(0, 0), vec2(TILE, TILE),
+				     filter, icon) == EOK);
+}
 
 static void mouseclick(u32 widget_id, vec2 pos)
 {
 	UNUSED(pos);
-	/* log("%d: %d %d\n", widget_id, pos.x, pos.y); */
 
-	u32 x = widget_id / SIZE;
-	u32 y = (widget_id % SIZE) - 1;
-	u32 widget = tiles[x][y].widget;
-	assert(gui_fill(win, widget, GUI_LAYER_BG, COLOR_MAGENTA) == EOK);
-	gui_redraw_widget(win, widget);
+	vec2 clicked = vec2(0, 0);
+	for (u32 x = 0; x < SIZE; x++)
+		for (u32 y = 0; y < SIZE; y++)
+			if (tiles[x][y].widget == widget_id)
+				clicked = vec2(x, y);
+
+	struct piece *clicked_piece = &tiles[clicked.x][clicked.y];
+
+	if (selected.x != (u32)-1) {
+		struct piece *selected_piece = &tiles[selected.x][selected.y];
+
+		clicked_piece->piece = selected_piece->piece;
+		selected_piece->piece = 0;
+
+		strcpy(clicked_piece->name, selected_piece->name);
+		selected_piece->name[0] = '\0';
+
+		/* assert(gui_fill(win, selected_piece->widget, GUI_LAYER_FG, 0) == EOK); */
+		load_image(clicked_piece);
+
+		assert(gui_redraw_window(win) == EOK);
+
+		selected = vec2(-1, -1);
+	} else if (clicked_piece->piece) {
+		assert(gui_redraw_widget(win, clicked_piece->widget) == EOK);
+		selected = clicked;
+	}
 }
 
-static void create_board(void)
+static const char *resolve_name(u32 piece, char *buf)
+{
+	const char *name = NULL;
+	switch (piece & TYPE_MASK) {
+	case KING:
+		name = "king";
+		break;
+	case PAWN:
+		name = "pawn";
+		break;
+	case KNIGHT:
+		name = "knight";
+		break;
+	case BISHOP:
+		name = "bishop";
+		break;
+	case ROOK:
+		name = "rook";
+		break;
+	case QUEEN:
+		name = "queen";
+		break;
+	default:
+		err(1, "Unknown piece %d\n", piece);
+	}
+
+	strcpy(buf, name);
+
+	return buf;
+}
+
+static u32 fen_resolve_letter(char ch)
+{
+	u32 piece = 0;
+
+	switch (ch) {
+	case 'k':
+		piece = KING | BLACK;
+		break;
+	case 'K':
+		piece = KING | WHITE;
+		break;
+	case 'p':
+		piece = PAWN | BLACK;
+		break;
+	case 'P':
+		piece = PAWN | WHITE;
+		break;
+	case 'n':
+		piece = KNIGHT | BLACK;
+		break;
+	case 'N':
+		piece = KNIGHT | WHITE;
+		break;
+	case 'b':
+		piece = BISHOP | BLACK;
+		break;
+	case 'B':
+		piece = BISHOP | WHITE;
+		break;
+	case 'r':
+		piece = ROOK | BLACK;
+		break;
+	case 'R':
+		piece = ROOK | WHITE;
+		break;
+	case 'q':
+		piece = QUEEN | BLACK;
+		break;
+	case 'Q':
+		piece = QUEEN | WHITE;
+		break;
+	default:
+		err(1, "Invalid letter (%c)!\n", ch);
+	}
+
+	return piece;
+}
+
+// TODO: Add more than basic fen support
+static void fen_parse(const char *fen)
+{
+	if (!fen || !*fen)
+		return;
+
+	u8 x = 0, y = 0;
+	for (const char *p = fen; p && *p; p++) {
+		if (*p == ' ')
+			break;
+
+		if (*p == '/') {
+			x = 0;
+			y++;
+			continue;
+		}
+
+		if (*p >= '0' && *p <= '9')
+			continue;
+
+		u32 piece = fen_resolve_letter(*p);
+
+		tiles[x][y].piece = piece;
+		resolve_name(piece, (char *)&tiles[x][y].name);
+
+		x++;
+	}
+}
+
+static void draw_board(void)
 {
-	u32 widget;
 	for (u8 x = 0; x < 8; x++) {
 		for (u8 y = 0; y < 8; y++) {
-			widget = gui_new_widget(win, vec2(TILE, TILE), vec2(TILE * x, TILE * y));
-			assert(widget > 0);
+			u32 widget =
+				gui_new_widget(win, vec2(TILE, TILE), vec2(TILE * x, TILE * y));
+			assert((signed)widget > 0);
 
 			u8 colored = (x + y + 1) % 2 == 0;
-			u8 colored_piece = y < SIZE / 2;
 #if !WHITE_STARTS
 			colored = !colored;
-			colored_piece = !colored_piece;
 #endif
-
-			struct piece *tile = &tiles[x][y];
-			tile->piece |= colored_piece ? BLACK : WHITE;
-			tile->widget = widget;
-			tile->icon = "/icons/chess-king-36.png";
-
 			assert(gui_fill(win, widget, GUI_LAYER_BG,
 					colored ? DARK_COLOR : LIGHT_COLOR) == EOK);
 
-			enum gfx_filter filter =
-				colored_piece ? GFX_FILTER_NONE : GFX_FILTER_INVERT;
-			assert(gui_load_image_filter(win, widget, GUI_LAYER_FG, vec2(0, 0),
-						     vec2(TILE, TILE), filter, tile->icon) == EOK);
-
+			struct piece *tile = &tiles[x][y];
 			assert(gui_listen_widget(win, widget, GUI_LISTEN_MOUSECLICK,
 						 (u32)mouseclick) == EOK);
+
+			tile->widget = widget;
+
+			if (tile->piece)
+				load_image(tile);
 		}
 	}
 
@@ -104,7 +239,9 @@ static void create_board(void)
 int main(void)
 {
 	assert((win = gui_new_window()) > 0);
-	create_board();
+	fen_parse(START_FEN);
+	draw_board();
+
 	gui_loop();
 	return 0;
 }