somewhat functional text rendering

src/ugui_text.c3

@@ -0,0 +1,81 @@
+module ugui;
+
+import std::io;
+
+fn void! Ctx.text_unbounded(&ctx, String label, String text)
+{
+	Id id = label.hash();
+
+	Elem *parent = ctx.get_parent()!;
+	Elem *c_elem = ctx.get_elem(id)!;
+	// add it to the tree
+	ctx.tree.add(id, ctx.active_div)!;
+
+	// 1. Fill the element fields
+	// this resets the flags
+	c_elem.type     = ETYPE_TEXT;
+
+	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;
+		Glyph* gp;
+
+		// FIXME: newlines are not counted
+		foreach (c: text) {
+			Codepoint cp = (Codepoint)c;
+			bool n;
+			gp = ctx.font.get_glyph(cp, &n)!;
+			text_size.w += gp.w + gp.ox + gp.adv;
+			text_size.h += gp.h + gp.oy;
+			if (n) { update_atlas = true; }
+		}
+		
+		// 2. Layout
+		c_elem.bounds = ctx.position_element(parent, text_size, true);
+
+		// 3. Fill the button specific fields
+		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)!;
+	}
+
+	Point orig = {
+		.x = c_elem.bounds.x,
+		.y = c_elem.bounds.y,
+	};
+	foreach (c: text) {
+		Glyph* gp;
+		Codepoint cp = (Codepoint)c;
+		gp = ctx.font.get_glyph(cp)!;
+		
+		Cmd cmd = {
+			.type = CMD_SPRITE,
+			.sprite.rect = {
+				.x = orig.x + gp.ox,
+				.y = orig.y + gp.oy,
+				.w = gp.w,
+				.h = gp.h,
+			},
+			.sprite.texture_rect = {
+				.x = gp.u,
+				.y = gp.v,
+				.w = gp.w,
+				.h = gp.h,
+			},
+		};
+		orig.x += gp.w + gp.ox;
+		ctx.cmd_queue.enqueue(&cmd)!;
+	}
+}