From 9be258994deba79dc97f31940bdc4e5a2bd562c5 Mon Sep 17 00:00:00 2001
From: Alexander Orzechowski <alex@ozal.ski>
Date: Thu, 4 Jul 2024 13:13:52 -0400
Subject: [PATCH] wlr_scene: wlr_scene_subsurface_tree_set_clip takes struct
 wlr_scene_subsurface_tree

---
 include/wlr/types/wlr_scene.h |  4 ++-
 types/scene/subsurface_tree.c | 61 ++++++++---------------------------
 2 files changed, 16 insertions(+), 49 deletions(-)

diff --git a/include/wlr/types/wlr_scene.h b/include/wlr/types/wlr_scene.h
index c1b4b6345..4568c670a 100644
--- a/include/wlr/types/wlr_scene.h
+++ b/include/wlr/types/wlr_scene.h
@@ -131,12 +131,14 @@ struct wlr_scene_surface {
 	struct wl_listener surface_commit;
 };
 
+struct wlr_scene_subsurface_tree_surface;
 struct wlr_scene_subsurface_tree {
 	struct wlr_scene_tree *tree;
 
 	// private state
 
 	struct wl_list surfaces;
+	struct wlr_scene_subsurface_tree_surface *root;
 };
 
 /** A scene-graph node displaying a solid-colored rectangle */
@@ -565,7 +567,7 @@ struct wlr_scene_subsurface_tree *wlr_scene_subsurface_tree_create(
  *
  * A NULL or empty clip will disable clipping
  */
-void wlr_scene_subsurface_tree_set_clip(struct wlr_scene_node *node,
+void wlr_scene_subsurface_tree_set_clip(struct wlr_scene_subsurface_tree *tree,
 	const struct wlr_box *clip);
 
 /**
diff --git a/types/scene/subsurface_tree.c b/types/scene/subsurface_tree.c
index e7ba5bbb0..494d07e13 100644
--- a/types/scene/subsurface_tree.c
+++ b/types/scene/subsurface_tree.c
@@ -328,62 +328,27 @@ struct wlr_scene_subsurface_tree *wlr_scene_subsurface_tree_create(
 		return NULL;
 	}
 
+	subsurface_tree->root = subsurface_tree_surface;
 	subsurface_tree->tree = subsurface_tree_surface->tree;
 	return subsurface_tree;
 }
 
-static struct wlr_scene_subsurface_tree_surface *get_subsurface_tree_from_node(
-		struct wlr_scene_node *node) {
-	struct wlr_addon *addon = wlr_addon_find(&node->addons, NULL, &subsurface_tree_addon_impl);
-	if (!addon) {
-		return NULL;
-	}
-
-	struct wlr_scene_subsurface_tree_surface *tree =
-		wl_container_of(addon, tree, scene_addon);
-	return tree;
-}
-
-static bool subsurface_tree_set_clip(struct wlr_scene_node *node,
+void wlr_scene_subsurface_tree_set_clip(struct wlr_scene_subsurface_tree *tree,
 		const struct wlr_box *clip) {
-	if (node->type != WLR_SCENE_NODE_TREE) {
-		return false;
+	if (wlr_box_equal(&tree->root->clip, clip)) {
+		return;
 	}
 
-	bool discovered_subsurface_tree = false;
-	struct wlr_scene_subsurface_tree_surface *tree = get_subsurface_tree_from_node(node);
-	if (tree) {
-		if (tree->parent == NULL) {
-			if (wlr_box_equal(&tree->clip, clip)) {
-				return true;
-			}
-
-			if (clip) {
-				tree->clip = *clip;
-			} else {
-				tree->clip = (struct wlr_box){0};
-			}
-		}
-
-		discovered_subsurface_tree = true;
-		subsurface_tree_reconfigure_clip(tree);
+	if (clip) {
+		tree->root->clip = *clip;
+	} else {
+		tree->root->clip = (struct wlr_box){0};
 	}
 
-	struct wlr_scene_tree *scene_tree = wlr_scene_tree_from_node(node);
-	struct wlr_scene_node *child;
-	wl_list_for_each(child, &scene_tree->children, link) {
-		discovered_subsurface_tree |= subsurface_tree_set_clip(child, clip);
+	// iterate in reverse because children of parent subsurface will appear
+	// earlier in the list.
+	struct wlr_scene_subsurface_tree_surface *surface;
+	wl_list_for_each_reverse(surface, &tree->surfaces, link) {
+		subsurface_tree_reconfigure_clip(surface);
 	}
-
-	return discovered_subsurface_tree;
-}
-
-void wlr_scene_subsurface_tree_set_clip(struct wlr_scene_node *node,
-		const struct wlr_box *clip) {
-#ifndef NDEBUG
-	bool found =
-#endif
-		subsurface_tree_set_clip(node, clip);
-
-	assert(found);
 }