add an overdraw buffer to allow for layered rendering

src/engine/render/rect.c

@@ -10,20 +10,22 @@
  */ 
 void
 put_rect(
+    framebuffer_e framebuffer,
 	uint32_t x, 
 	uint32_t y, 
 	uint32_t w, 
 	uint32_t h,
 	uint32_t color
-) {
+) { 
 	for (int i = x; i < x + w; i++) {
 		for (int j = y; j < y + h; j++) {
-			put_pixel(i, j, color);
+			put_pixel(framebuffer, i, j, color);
 		}
 	}
 	mark_dirty_rect(x, y, w, h);
 }
 
+// TODO: remove, see rect.h
 void
 clear_rect(int x, int y, int w, int h, uint32_t color)
 {
@@ -33,7 +35,7 @@ clear_rect(int x, int y, int w, int h, uint32_t color)
                 px < game_state->width &&
                 py >= 0 &&
                 py < game_state->height) {
-                game_state->framebuffer[
+                game_state->framebuffer_base[
                     py * game_state->width + px
                 ] = color;
             }