From bf72bed1edeeca1875649d9899ae20fd667b80c5 Mon Sep 17 00:00:00 2001
From: Kirill Primak <vyivel@eclair.cafe>
Date: Fri, 15 Nov 2024 20:05:10 +0300
Subject: [PATCH] scene: allow at most one scene surface per surface

---
 include/wlr/types/wlr_scene.h | 11 ++++++++-
 types/scene/surface.c         | 42 ++++++++++++++++++++++++++++-------
 2 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/include/wlr/types/wlr_scene.h b/include/wlr/types/wlr_scene.h
index 0e3e7750a..6e5b8f774 100644
--- a/include/wlr/types/wlr_scene.h
+++ b/include/wlr/types/wlr_scene.h
@@ -123,7 +123,8 @@ struct wlr_scene_surface {
 	struct {
 		struct wlr_box clip;
 
-		struct wlr_addon addon;
+		struct wlr_addon scene_buffer_addon;
+		struct wlr_addon surface_addon;
 
 		struct wl_listener outputs_update;
 		struct wl_listener output_enter;
@@ -402,6 +403,14 @@ struct wlr_scene_rect *wlr_scene_rect_from_node(struct wlr_scene_node *node);
 struct wlr_scene_surface *wlr_scene_surface_try_from_buffer(
 	struct wlr_scene_buffer *scene_buffer);
 
+/**
+ * Get a struct wlr_scene_surface from a struct wlr_surface.
+ *
+ * Returns NULL if there's no struct wlr_scene_surface created for this
+ * struct wlr_surface.
+ */
+struct wlr_scene_surface *wlr_scene_surface_try_from_wlr_surface(struct wlr_surface *surface);
+
 /**
  * Add a node displaying a solid-colored rectangle to the scene-graph.
  *
diff --git a/types/scene/surface.c b/types/scene/surface.c
index 2aff5af37..8708e7bf9 100644
--- a/types/scene/surface.c
+++ b/types/scene/surface.c
@@ -228,12 +228,11 @@ static bool scene_buffer_point_accepts_input(struct wlr_scene_buffer *scene_buff
 	return wlr_surface_point_accepts_input(scene_surface->surface, *sx, *sy);
 }
 
-static void surface_addon_destroy(struct wlr_addon *addon) {
-	struct wlr_scene_surface *surface = wl_container_of(addon, surface, addon);
-
+static void scene_surface_destroy(struct wlr_scene_surface *surface) {
 	scene_buffer_unmark_client_buffer(surface->buffer);
 
-	wlr_addon_finish(&surface->addon);
+	wlr_addon_finish(&surface->scene_buffer_addon);
+	wlr_addon_finish(&surface->surface_addon);
 
 	wl_list_remove(&surface->outputs_update.link);
 	wl_list_remove(&surface->output_enter.link);
@@ -246,6 +245,21 @@ static void surface_addon_destroy(struct wlr_addon *addon) {
 	free(surface);
 }
 
+static void scene_buffer_addon_destroy(struct wlr_addon *addon) {
+	struct wlr_scene_surface *surface = wl_container_of(addon, surface, scene_buffer_addon);
+	scene_surface_destroy(surface);
+}
+
+static const struct wlr_addon_interface scene_buffer_addon_impl = {
+	.name = "wlr_scene_surface",
+	.destroy = scene_buffer_addon_destroy,
+};
+
+static void surface_addon_destroy(struct wlr_addon *addon) {
+	struct wlr_scene_surface *surface = wl_container_of(addon, surface, surface_addon);
+	scene_surface_destroy(surface);
+}
+
 static const struct wlr_addon_interface surface_addon_impl = {
 	.name = "wlr_scene_surface",
 	.destroy = surface_addon_destroy,
@@ -254,15 +268,25 @@ static const struct wlr_addon_interface surface_addon_impl = {
 struct wlr_scene_surface *wlr_scene_surface_try_from_buffer(
 		struct wlr_scene_buffer *scene_buffer) {
 	struct wlr_addon *addon = wlr_addon_find(&scene_buffer->node.addons,
-		scene_buffer, &surface_addon_impl);
+		scene_buffer, &scene_buffer_addon_impl);
 	if (!addon) {
 		return NULL;
 	}
 
-	struct wlr_scene_surface *surface = wl_container_of(addon, surface, addon);
+	struct wlr_scene_surface *surface = wl_container_of(addon, surface, scene_buffer_addon);
 	return surface;
 }
 
+struct wlr_scene_surface *wlr_scene_surface_try_from_wlr_surface(struct wlr_surface *surface) {
+	struct wlr_addon *addon = wlr_addon_find(&surface->addons, NULL, &surface_addon_impl);
+	if (addon == NULL) {
+		return NULL;
+	}
+
+	struct wlr_scene_surface *scene_surface = wl_container_of(addon, scene_surface, surface_addon);
+	return scene_surface;
+}
+
 struct wlr_scene_surface *wlr_scene_surface_create(struct wlr_scene_tree *parent,
 		struct wlr_surface *wlr_surface) {
 	struct wlr_scene_surface *surface = calloc(1, sizeof(*surface));
@@ -301,8 +325,10 @@ struct wlr_scene_surface *wlr_scene_surface_create(struct wlr_scene_tree *parent
 	surface->surface_commit.notify = handle_scene_surface_surface_commit;
 	wl_signal_add(&wlr_surface->events.commit, &surface->surface_commit);
 
-	wlr_addon_init(&surface->addon, &scene_buffer->node.addons,
-		scene_buffer, &surface_addon_impl);
+	wlr_addon_init(&surface->scene_buffer_addon, &scene_buffer->node.addons,
+		scene_buffer, &scene_buffer_addon_impl);
+
+	wlr_addon_init(&surface->surface_addon, &wlr_surface->addons, NULL, &surface_addon_impl);
 
 	surface_reconfigure(surface);