started work on an atlas interface, DOES NOT WORK

TODO

@@ -1,4 +1,6 @@
 # TODOs, semi-random sorting
+
+[ ] Check every instance of foreach to see if I am using by-copy or by-reference correctly
 [x] Implement glyph draw command
 [x] Implement div.view and scrollbars
 [ ] Port font system from C to C3 (rewrite1)
@@ -7,26 +9,33 @@
 [ ] Use an arena allocator for cache
 [ ] Do not redraw if there was no update (no layout and no draw)
 [ ] Better handling of the active and focused widgets, try
-    to maintain focus until mouse release (fix scroll bars)
+to maintain focus until mouse release (fix scroll bars)
+[ ] Write a description for each file and the structs, interfaces provided
 
 ## Commands
+
 [x] rect commads should have:
-	* border width
-	* border radius
+_ border width
+_ border radius
 [x] add a command to update an atlas
 
 ## Atlases
+
 [ ] Add an interface to create, destroy, update and get atlases based on their ids
 [ ] Implement multiple font atlases
+[ ] Create and use ShortIds for atlases
 
 ## Fonts
+
 [ ] Fix the missing alpha channel
 [x] Fix the alignment
 
 ## Raylib
+
 [ ] Implement type (Rect, Color, Point) conversion functions between rl:: and ugui::
 [x] Implement pixel radius rounding for border radius
 
 ## Widgets
+
 [ ] Dynamic text box to implement an fps counter
 [ ] Button with label

src/ugui_atlas.c3

@@ -0,0 +1,183 @@
+module ugui;
+
+import std::core::mem;
+import std::math::random;
+
+random::SimpleRandom atlas_seed;
+
+fault UgAtlasError {
+	CANNOT_PLACE,
+	INVALID_FORMAT,
+	MISSING_ATLAS,
+}
+
+enum AtlasFormat {
+	ATLAS_GRAYSCALE,
+	ATLAS_ALPHA,
+}
+
+// black and white atlas
+struct Atlas {
+	AtlasFormat format;
+	Id id;
+	ushort width, height;
+	char[] buffer;
+
+	Point row;
+	ushort row_h;
+}
+
+// FIXME: allocate atlases dynamically
+fn void! Ctx.init_atlases(&ctx)
+{
+	atlas_seed.set_seed("ciao mamma");
+	ctx.atlas = mem::new_array(Atlas, MAX_ATLAS);
+}
+
+fn void Ctx.free_atlases(&ctx)
+{
+	foreach (a: ctx.atlas) {
+		a.free();
+	}
+	mem::free(ctx.atlas);
+}
+
+// FIXME: this could be slow
+fn Atlas*! Ctx.get_atlas(&ctx, Id id)
+{
+	foreach (i, a: ctx.atlas) {
+		if (a.id == id) {
+			return &ctx.atlas[i];
+		}
+	}
+	return UgAtlasError.MISSING_ATLAS?;
+}
+
+// TODO: use the same allocator as all the other parts of the code
+fn Atlas*! Ctx.request_new_atlas(&ctx, AtlasFormat format, Id *rid, ushort width, ushort height)
+{
+	usz idx;
+	bool free = false;
+	for (; idx < ctx.atlas.len; idx++) {
+		if (ctx.atlas[idx].id == 0) {
+			free = true;
+			break;
+		}
+	}
+
+	if (free) {
+		*rid = ctx.unique_atlas_id();
+		ctx.atlas[idx].new(format, *rid, width, height)!;
+		return &ctx.atlas[idx];
+	} else {
+		// TODO: reallocate the atlas vector
+		return UgAtlasError.MISSING_ATLAS?;
+	}
+}
+
+// FIXME: WTF
+fn Id Ctx.unique_atlas_id(&ctx) {
+	Id id = atlas_seed.next_long();
+	bool ok = true;
+	foreach (a: ctx.atlas) {
+		if (a.id == id) {
+			ok = false;
+		}
+	}
+	return ok ? id : ctx.unique_atlas_id();
+}
+
+fn void Ctx.discard_atlas(&ctx, Id id)
+{
+	foreach (&a: ctx.atlas) {
+		if (a.id == id) {
+			a.free();
+			*a = Atlas{};
+		}
+	}
+}
+
+// Try to place a sprite into an atlas of the correct type and return it's id
+// new_width and new_height are used in case a new atlas has to be requested, in that
+// case they are used as width and height for the new atlas
+// FIXME: maybe there has to be a default value
+fn Id! Ctx.place_sprite(&ctx, Point* uv, AtlasFormat format, char[] pixels, ushort w, ushort h, ushort new_width, ushort new_height)
+{
+	// try to place the sprite into an existing atlas
+	foreach (&a: ctx.atlas) {
+		if (a.id != 0 && a.format == format) {
+			Point! ouv = a.place(pixels, w, h);
+			if (catch ouv) {
+				continue;
+			}
+			*uv = ouv;
+			return a.id;
+		}
+	}
+
+	// fail... try to request a new atlas and place it there
+	Id id;
+	Atlas* atlas = ctx.request_new_atlas(format, &id, new_width, new_height)!;
+	*uv = atlas.place(pixels, w, h)!;
+	return id;
+}
+
+fn void! Atlas.new(&atlas, AtlasFormat format, Id id, ushort width, ushort height)
+{
+	atlas.format = format;
+	atlas.id = id;
+	atlas.width = width;
+	atlas.height = height;
+
+	usz bpp = 1;
+	switch (format) {
+	case ATLAS_GRAYSCALE: nextcase;
+	case ATLAS_ALPHA:
+		bpp = 1;
+	default:
+		return UgAtlasError.INVALID_FORMAT?;
+	}
+	usz size = ((usz)atlas.width*atlas.height) * bpp;
+	atlas.buffer = mem::new_array(char, size);
+}
+
+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/
+// FIXME: untested with non-1bpp buffer depths
+fn Point! Atlas.place(&atlas, char[] pixels, ushort w, ushort h)
+{
+	Point p;
+
+	// TODO: simplify this and use rect_collision() and such
+	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;
+}

src/ugui_data.c3

@@ -127,6 +127,7 @@ const uint STACK_STEP = 10;
 const uint MAX_ELEMS  = 128;
 const uint MAX_CMDS   = 256;
 const uint ROOT_ID    = 1;
+const uint MAX_ATLAS  = 2;
 
 // command type
 enum CmdType {
@@ -193,6 +194,8 @@ struct Ctx {
 	// total size in pixels of the context
 	ushort width, height;
 	Style style;
+
+	Atlas[] atlas;
 	Font font;
 
 	bool has_focus;

src/ugui_font.c3

@@ -34,7 +34,7 @@ struct Glyph {
 	ushort u, v;
 	ushort w, h;
 	short adv, ox, oy;
-	short idx; // atlas index
+	Id atlas_id;
 }
 
 const uint FONT_CACHED = 512;
@@ -47,19 +47,6 @@ 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;
@@ -67,59 +54,14 @@ struct Font {
 
 	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);
-}
-
-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! Ctx.font_load(&cxt, String path, uint height, float scale = 1)
 {
+	Font* font = ctx.font;
 	font.table.new_init(capacity: FONT_CACHED);
-	
+
 	font.size = height*scale;
 
 	font.sft = schrift::Sft{
@@ -139,24 +81,14 @@ fn void! Font.load(&font, String path, uint height, float scale = 1)
 	font.descender = (float)lmetrics.descender;
 	font.linegap   = (float)lmetrics.lineGap;
 	//io::printfn("ascender:%d, descender:%d, linegap:%d", font.ascender, font.descender, font.linegap);
-
-	// 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)!;
-	
-	// 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*! Ctx.get_glyph(&ctx, Codepoint code, bool* is_new = null)
 {
+	Font* font = &ctx.font;
 	Glyph*! gp;
 	gp = font.table.get_ref(code);
-	
+
 	if (catch excuse = gp) {
 		if (excuse != SearchResult.MISSING) {
 			return excuse?;
@@ -171,7 +103,7 @@ 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 +131,12 @@ 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;
+	// TODO: allocate buffer based on FONT_CACHED and the size of a sample letter
+	//       like the letter 'A'
+	ushort size = (ushort)font.size*256;
+	Point uv;
+	Id id = ctx.place_sprite(&uv, ATLAS_ALPHA, pixels, glyph.w, glyph.h, size, size)!;
+	glyph.atlas_id = id;
 	glyph.u = uv.x;
 	glyph.v = uv.y;
 
@@ -212,10 +148,8 @@ fn Glyph*! Font.get_glyph(&font, Codepoint code, bool* is_new = null)
 	return font.table.get_ref(code);
 }
 
+// FIXME: maybe some atlases should be exclusive to fonts
 fn void Font.free(&font)
 {
-	foreach (atlas: font.atlas) {
-		atlas.free();
-	}
 	schrift::freefont(font.sft.font);
 }

src/ugui_text.c3

@@ -34,7 +34,7 @@ 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.get_glyph(cp, &n)!;
 			line_len += gp.adv;
 			if (n) { *update_atlas = true; }
 		} else if (cp == '\n'){