better font atlas implementation

src/main.c3

@@ -27,7 +27,7 @@ fn int main(String[] args)
 {
 	ugui::Ctx ui;
 	ui.init()!!;
-	ui.font.load("/usr/share/fonts/TTF/HackNerdFontMono-Regular.ttf", 16)!!;
+	ui.load_font("font1", "/usr/share/fonts/TTF/HackNerdFontMono-Regular.ttf", 16)!!;
 
 	short width = 800;
 	short height = 450;
@@ -195,7 +195,6 @@ fn int main(String[] args)
 
 	rl::close_window();
 
-	ui.font.free();
 	ui.free();
 	return 0;
 }

src/ugui_atlas.c3

@@ -0,0 +1,85 @@
+module ugui;
+
+import std::io;
+
+fault UgAtlasError {
+	CANNOT_PLACE,
+	INVALID_TYPE,
+}
+
+enum AtlasType {
+	ATLAS_GRAYSCALE,
+}
+
+// black and white atlas
+struct Atlas {
+	AtlasType type;
+	Id id;
+
+	ushort width, height;
+	char[] buffer;
+
+	Point row;
+	ushort row_h;
+}
+
+// bytes per pixel
+macro usz AtlasType.bpp(type)
+{
+	switch (type) {
+	case ATLAS_GRAYSCALE: return 1;
+	}
+}
+
+fn void! Atlas.new(&atlas, Id id, AtlasType type, ushort width, ushort height)
+{
+	atlas.id = id;
+	atlas.type = type;
+	atlas.width = width;
+	atlas.height = height;
+
+	atlas.buffer = mem::new_array(char, (usz)atlas.width*atlas.height*type.bpp());
+}
+
+fn void Atlas.free(&atlas)
+{
+	free(atlas.buffer);
+}
+
+// place a rect inside the atlas
+// uses a row first algorithm
+// TODO: use a skyline algorithm https://jvernay.fr/en/blog/skyline-2d-packer/implementation/
+fn Point! Atlas.place(&atlas, char[] pixels, ushort w, ushort h)
+{
+	Point p;
+
+	if (atlas.row.x + w <= atlas.width && atlas.row.y + h <= atlas.height) {
+		p = atlas.row;
+	} else {
+		atlas.row.x = 0;
+		atlas.row.y = atlas.row.y + atlas.row_h;
+		atlas.row_h = 0;
+		if (atlas.row.x + w <= atlas.width && atlas.row.y + h <= atlas.height) {
+			p = atlas.row;
+		} else {
+			return UgAtlasError.CANNOT_PLACE?;
+		}
+	}
+
+	for (usz y = 0; y < h; y++) {
+		for (usz x = 0; x < w; x++) {
+			char[] buf = atlas.buffer[(usz)(p.y+y)*atlas.width + (p.x+x) ..];
+			char[] pix = pixels[y*w + x ..];
+			usz bpp = atlas.type.bpp();
+
+			buf[0..bpp-1] = pix[0..bpp-1];
+		}
+	}
+
+	atlas.row.x += w;
+	if (h > atlas.row_h) {
+		atlas.row_h = h;
+	}
+
+	return p;
+}

src/ugui_cmd.c3

@@ -2,6 +2,45 @@ module ugui;
 
 import std::ascii;
 
+// command type
+enum CmdType {
+	CMD_RECT,
+	CMD_UPDATE_ATLAS,
+	CMD_SPRITE,
+}
+
+// command to draw a rect
+struct CmdRect {
+	Rect rect;
+	ushort radius;
+	Color color;
+}
+
+// FIXME: For now only support black and white atlas, so PIXELFORMAT_UNCOMPRESSED_GRAYSCALE
+struct CmdUpdateAtlas {
+	Id id;
+	char* raw_buffer;
+	short width, height, bpp;
+}
+
+// TODO:
+//    1. Add atlases as a data type
+//    2. Each atlas has an id
+struct CmdSprite {
+	Rect rect;
+	Rect texture_rect;
+}
+
+// command structure
+struct Cmd {
+	CmdType type;
+	union {
+		CmdRect rect;
+		CmdUpdateAtlas update_atlas;
+		CmdSprite sprite;
+	}
+}
+
 // FIXME: is this really the best solution?
 // "rect" is the bounding box of the element, which includes the border and the padding (so not just the content)
 fn void! Ctx.push_rect(&ctx, Rect rect, Color color, bool do_border = false, bool do_padding = false, bool do_radius = false)
@@ -97,3 +136,18 @@ fn void! Ctx.push_string(&ctx, Rect bounds, String text)
 		}
 	}
 }
+
+fn void! Ctx.push_update_atlas(&ctx, Atlas* atlas)
+{
+	Cmd up = {
+		.type = CMD_UPDATE_ATLAS,
+		.update_atlas = {
+			.id = atlas.id,
+			.raw_buffer = atlas.buffer,
+			.width = atlas.width,
+			.height = atlas.height,
+			.bpp = (ushort)atlas.type.bpp(),
+			},
+		};
+	ctx.cmd_queue.enqueue(&up)!;
+}

src/ugui_data.c3

@@ -128,45 +128,6 @@ const uint MAX_ELEMS  = 128;
 const uint MAX_CMDS   = 256;
 const uint ROOT_ID    = 1;
 
-// command type
-enum CmdType {
-	CMD_RECT,
-	CMD_UPDATE_ATLAS,
-	CMD_SPRITE,
-}
-
-// command to draw a rect
-// TODO: implement radius
-struct CmdRect {
-	Rect rect;
-	ushort radius;
-	Color color;
-}
-
-// FIXME: For now only support black and white atlas, so PIXELFORMAT_UNCOMPRESSED_GRAYSCALE
-struct CmdUpdateAtlas {
-	char* raw_buffer;
-	short width, height;
-}
-
-// TODO:
-//    1. Add atlases as a data type
-//    2. Each atlas has an id
-struct CmdSprite {
-	Rect rect;
-	Rect texture_rect;
-}
-
-// command structure
-struct Cmd {
-	CmdType type;
-	union {
-		CmdRect rect;
-		CmdUpdateAtlas update_atlas;
-		CmdSprite sprite;
-	}
-}
-
 enum Layout {
 	ROW,
 	COLUMN,

src/ugui_font.c3

@@ -34,7 +34,6 @@ struct Glyph {
 	ushort u, v;
 	ushort w, h;
 	short adv, ox, oy;
-	short idx; // atlas index
 }
 
 const uint FONT_CACHED = 512;
@@ -47,79 +46,23 @@ fault UgFontError {
 	RENDER_ERROR,
 }
 
-fault UgAtlasError {
-	CANNOT_PLACE,
-}
-
-// black and white atlas
-struct AtlasBW {
-	ushort width, height;
-	char[] buffer;
-
-	Point row;
-	ushort row_h;
-}
-
 struct Font {
 	schrift::Sft sft;
 	String path;
+	Id id; // font id, same as atlas id
 	GlyphTable table;
 
 	float size;
 	float ascender, descender, linegap; // Line Metrics
-	AtlasBW[] atlas;
-}
-
-fn void! AtlasBW.new(&atlas, ushort width, ushort height)
-{
-	atlas.width = width;
-	atlas.height = height;
-	atlas.buffer = mem::new_array(char, (usz)atlas.width*atlas.height);
+	Atlas atlas;
+	bool should_update; // should send update_atlas command, resets at frame_end()
 }
 
-fn void AtlasBW.free(&atlas)
-{
-	free(atlas.buffer);
-}
-
-// place a rect inside the atlas
-// uses a row first algorithm
-// TODO: use a skyline algorithm https://jvernay.fr/en/blog/skyline-2d-packer/implementation/
-fn Point! AtlasBW.place(&atlas, char[] pixels, ushort w, ushort h)
-{
-	Point p;
-
-	if (atlas.row.x + w <= atlas.width && atlas.row.y + h <= atlas.height) {
-		p = atlas.row;
-	} else {
-		atlas.row.x = 0;
-		atlas.row.y = atlas.row.y + atlas.row_h;
-		atlas.row_h = 0;
-		if (atlas.row.x + w <= atlas.width && atlas.row.y + h <= atlas.height) {
-			p = atlas.row;
-		} else {
-			return UgAtlasError.CANNOT_PLACE?;
-		}
-	}
-
-	for (usz y = 0; y < h; y++) {
-		for (usz x = 0; x < w; x++) {
-			atlas.buffer[(usz)(p.y+y)*atlas.width + (p.x+x)] = pixels[y*w + x];
-		}
-	}
-
-	atlas.row.x += w;
-	if (h > atlas.row_h) {
-		atlas.row_h = h;
-	}
-
-	return p;
-}
-
-fn void! Font.load(&font, String path, uint height, float scale = 1)
+fn void! Font.load(&font, String name, String path, uint height, float scale)
 {
 	font.table.new_init(capacity: FONT_CACHED);
-	
+	font.id = name.hash();
+
 	font.size = height*scale;
 
 	font.sft = schrift::Sft{
@@ -142,27 +85,25 @@ fn void! Font.load(&font, String path, uint height, float scale = 1)
 
 	// TODO: allocate buffer based on FONT_CACHED and the size of a sample letter
 	//       like the letter 'A'
-	font.atlas = mem::new_array(AtlasBW, 1);
 	ushort size = (ushort)font.size*256;
-	font.atlas[0].new(size, size)!;
-	
+	font.atlas.new(font.id, ATLAS_GRAYSCALE, size, size)!;
+
 	// preallocate the ASCII range
 //	for (char c = ' '; c < '~'; c++) {
 //		font.get_glyph((Codepoint)c)!;
 //	}
 }
 
-fn Glyph*! Font.get_glyph(&font, Codepoint code, bool* is_new = null)
+fn Glyph*! Font.get_glyph(&font, Codepoint code)
 {
 	Glyph*! gp;
 	gp = font.table.get_ref(code);
-	
+
 	if (catch excuse = gp) {
 		if (excuse != SearchResult.MISSING) {
 			return excuse?;
 		}
 	} else {
-		if (is_new) { *is_new = false; }
 		return gp;
 	}
 
@@ -171,7 +112,7 @@ fn Glyph*! Font.get_glyph(&font, Codepoint code, bool* is_new = null)
 
 	schrift::SftGlyph gid;
 	schrift::SftGMetrics gmtx;
-	
+
 	if (schrift::lookup(&font.sft, code, &gid) < 0) {
 		return UgFontError.MISSING_GLYPH?;
 	}
@@ -199,8 +140,7 @@ fn Glyph*! Font.get_glyph(&font, Codepoint code, bool* is_new = null)
 	//io::printfn("code=%c, w=%d, h=%d, ox=%d, oy=%d, adv=%d",
 	//    glyph.code, glyph.w, glyph.h, glyph.ox, glyph.oy, glyph.adv);
 
-	Point uv = font.atlas[0].place(pixels, glyph.w, glyph.h)!;
-	glyph.idx = 0;
+	Point uv = font.atlas.place(pixels, glyph.w, glyph.h)!;
 	glyph.u = uv.x;
 	glyph.v = uv.y;
 
@@ -208,14 +148,17 @@ fn Glyph*! Font.get_glyph(&font, Codepoint code, bool* is_new = null)
 
 	font.table.set(code, glyph);
 
-	if (is_new) { *is_new = true; }
+	font.should_update = true;
 	return font.table.get_ref(code);
 }
 
 fn void Font.free(&font)
 {
-	foreach (atlas: font.atlas) {
-		atlas.free();
-	}
+	font.atlas.free();
 	schrift::freefont(font.sft.font);
 }
+
+fn void! Ctx.load_font(&ctx, String name, String path, uint height, float scale = 1.0)
+{
+	return ctx.font.load(name, path, height, scale);
+}

src/ugui_impl.c3

@@ -67,6 +67,7 @@ fn void Ctx.free(&ctx)
 	(void)ctx.tree.free();
 	(void)ctx.cache.free();
 	(void)ctx.cmd_queue.free();
+	(void)ctx.font.free();
 }
 
 fn void! Ctx.frame_begin(&ctx)
@@ -127,8 +128,14 @@ fn void! Ctx.frame_end(&ctx)
 	ctx.input.events = (InputEvents)0;
 	ctx.input.events.force_update = f;
 
-	// draw mouse position
+	// send atlas updates
+	if (ctx.font.should_update) {
+		ctx.push_update_atlas(&ctx.font.atlas)!;
+		ctx.font.should_update = false;
+	}
+
 $if 1:
+	// draw mouse position
 	Cmd cmd = {
 		.type = CMD_RECT,
 		.rect.rect = {

src/ugui_text.c3

@@ -18,7 +18,7 @@ fn Codepoint str_to_codepoint(char[] str, usz* off)
 	return cp;
 }
 
-fn Rect! Ctx.get_text_bounds(&ctx, String text, bool* update_atlas)
+fn Rect! Ctx.get_text_bounds(&ctx, String text)
 {
 	Rect text_bounds;
 	short line_height = (short)ctx.font.ascender - (short)ctx.font.descender;
@@ -34,9 +34,8 @@ fn Rect! Ctx.get_text_bounds(&ctx, String text, bool* update_atlas)
 		off += x;
 		bool n;
 		if (!ascii::is_cntrl((char)cp)) {
-			gp = ctx.font.get_glyph(cp, &n)!;
+			gp = ctx.font.get_glyph(cp)!;
 			line_len += gp.adv;
-			if (n) { *update_atlas = true; }
 		} else if (cp == '\n'){
 			text_bounds.h += line_height + line_gap;
 			line_len = 0;
@@ -67,10 +66,9 @@ fn void! Ctx.text_unbounded(&ctx, String label, String text)
 	short baseline = (short)ctx.font.ascender;
 	short line_height = (short)ctx.font.ascender - (short)ctx.font.descender;
 	short line_gap = (short)ctx.font.linegap;
-	bool update_atlas;
 	// if the element is new or the parent was updated then redo layout
 	if (c_elem.flags.is_new || parent.flags.updated) {
-		Rect text_size = ctx.get_text_bounds(text, &update_atlas)!;
+		Rect text_size = ctx.get_text_bounds(text)!;
 
 		// 2. Layout
 		c_elem.bounds = ctx.position_element(parent, text_size, true);
@@ -79,25 +77,5 @@ fn void! Ctx.text_unbounded(&ctx, String label, String text)
 		c_elem.text.str = text;
 	}
 
-	if (update_atlas) {
-		// FIXME: atlas here is hardcoded, look at the todo in ugui_data
-		Cmd up = {
-			.type = CMD_UPDATE_ATLAS,
-			.update_atlas = {
-				.raw_buffer = ctx.font.atlas[0].buffer,
-				.width = ctx.font.atlas[0].width,
-				.height = ctx.font.atlas[0].height,
-			},
-		};
-		ctx.cmd_queue.enqueue(&up)!;
-	}
-
-	Cmd bounds = {
-		.type = CMD_RECT,
-		.rect.rect = c_elem.bounds,
-		.rect.color = uint_to_rgba(0x000000ff),
-	};
-	ctx.cmd_queue.enqueue(&bounds)!;
-
 	ctx.push_string(c_elem.bounds, text)!;
 }