Use wlr_surface_get_effective_damage

sway/desktop/output.c

@@ -415,16 +415,10 @@ static void damage_surface_iterator(struct sway_output *output,
 	int center_y = box.y + box.height/2;
 
 	if (pixman_region32_not_empty(&surface->buffer_damage)) {
-		enum wl_output_transform transform =
-			wlr_output_transform_invert(surface->current.transform);
-
 		pixman_region32_t damage;
 		pixman_region32_init(&damage);
-		pixman_region32_copy(&damage, &surface->buffer_damage);
-		wlr_region_transform(&damage, &damage, transform,
-			surface->current.buffer_width, surface->current.buffer_height);
-		wlr_region_scale(&damage, &damage,
-			output->wlr_output->scale / (float)surface->current.scale);
+		wlr_surface_get_effective_damage(surface, &damage);
+		wlr_region_scale(&damage, &damage, output->wlr_output->scale);
 		if (ceil(output->wlr_output->scale) > surface->current.scale) {
 			// When scaling up a surface, it'll become blurry so we need to
 			// expand the damage region