auts: depth-sort sprites in spritesys

isotest/spritesys.v

@@ -4,6 +4,24 @@ interface Drawable {
 	draw()
 }
 
+fn depth_compare(a, b &Sprite) int {
+
+	//println(a.y)
+	//println(b.y)
+
+	if a.y < b.y {
+		//println("ret -1")
+		return -1
+	}
+	if a.y > b.y {
+		//println("ret 1")
+		return 1
+	}
+	//println("ret 0")
+	//pp(4)
+	return 0
+}
+
 struct SpriteSys {
 mut:
 	sys &System // Embed
@@ -32,6 +50,26 @@ fn (mut s SpriteSys) draw() {
 
 	// XXX TODO sort sprites by z
 
+	//mut sorted_elems := s.sys.elems.clone()
+	//sorted_elems.sort_with_compare(depth_compare)
+
+	mut sorted_sprites := []Sprite{}
+	for el in s.sys.elems {
+		mut x := &Sprite(el)
+		sorted_sprites << x
+	}
+
+	sorted_sprites.sort_with_compare(depth_compare)
+
+	for x in sorted_sprites {
+		mut z := x
+		z.draw()
+		//println(z.y)
+	}
+
+	//pp(3)
+
+	/*
 	for el in s.sys.elems {
 		//el.draw()
 		//x := Drawable{el}
@@ -39,7 +77,10 @@ fn (mut s SpriteSys) draw() {
 		//mut x := &Drawable(el)
 		mut x := &Sprite(el)
 		x.draw()
+		
+		println(x.y)
 	}
+	*/
 }
 
 fn (mut s SpriteSys) update(dt f32) {