scene: constify region APIs

include/wlr/types/wlr_scene.h

@@ -338,14 +338,14 @@ void wlr_scene_buffer_set_buffer(struct wlr_scene_buffer *scene_buffer,
  * the whole buffer node will be damaged.
  */
 void wlr_scene_buffer_set_buffer_with_damage(struct wlr_scene_buffer *scene_buffer,
-	struct wlr_buffer *buffer, pixman_region32_t *region);
+	struct wlr_buffer *buffer, const pixman_region32_t *region);
 
 /**
  * Sets the buffer's opaque region. This is an optimization hint used to
  * determine if buffers which reside under this one need to be rendered or not.
  */
 void wlr_scene_buffer_set_opaque_region(struct wlr_scene_buffer *scene_buffer,
-	pixman_region32_t *region);
+	const pixman_region32_t *region);
 
 /**
  * Set the source rectangle describing the region of the buffer which will be

types/scene/wlr_scene.c

@@ -560,7 +560,7 @@ struct wlr_scene_buffer *wlr_scene_buffer_create(struct wlr_scene_tree *parent,
 }
 
 void wlr_scene_buffer_set_buffer_with_damage(struct wlr_scene_buffer *scene_buffer,
-		struct wlr_buffer *buffer, pixman_region32_t *damage) {
+		struct wlr_buffer *buffer, const pixman_region32_t *damage) {
 	// specifying a region for a NULL buffer doesn't make sense. We need to know
 	// about the buffer to scale the buffer local coordinates down to scene
 	// coordinates.
@@ -682,7 +682,7 @@ void wlr_scene_buffer_set_buffer(struct wlr_scene_buffer *scene_buffer,
 }
 
 void wlr_scene_buffer_set_opaque_region(struct wlr_scene_buffer *scene_buffer,
-		pixman_region32_t *region) {
+		const pixman_region32_t *region) {
 	if (pixman_region32_equal(&scene_buffer->opaque_region, region)) {
 		return;
 	}