From dbf10ebdf1e785ea63c9b1c346fccb3d55ab97ac Mon Sep 17 00:00:00 2001
From: Alexander Orzechowski <alex@ozal.ski>
Date: Sat, 24 Feb 2024 08:35:56 -0500
Subject: [PATCH] wlr_raster: Introduce invalidated signal

If this raster becomes invalid meaning that the buffer neither
has a buffer or textures. The invalidated signal will be called
to signify to its owner that it should be recreated.
---
 include/wlr/types/wlr_raster.h |  2 ++
 types/wlr_raster.c             | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/wlr/types/wlr_raster.h b/include/wlr/types/wlr_raster.h
index 2857dbe3f..c37d49c0b 100644
--- a/include/wlr/types/wlr_raster.h
+++ b/include/wlr/types/wlr_raster.h
@@ -23,6 +23,7 @@ struct wlr_allocator;
 struct wlr_raster_source {
 	struct wlr_texture *texture;
 	struct wlr_allocator *allocator; // may be NULL
+	struct wlr_raster *raster;
 	struct wl_list link;
 
 	struct wl_listener renderer_destroy;
@@ -43,6 +44,7 @@ struct wlr_raster {
 
 	struct {
 		struct wl_signal destroy;
+		struct wl_signal invalidated;
 	} events;
 
 	// private state
diff --git a/types/wlr_raster.c b/types/wlr_raster.c
index 86303415a..1cf540976 100644
--- a/types/wlr_raster.c
+++ b/types/wlr_raster.c
@@ -23,6 +23,10 @@ static void raster_handle_buffer_release(struct wl_listener *listener, void *dat
 	raster->buffer = NULL;
 	wl_list_remove(&raster->buffer_release.link);
 	wl_list_init(&raster->buffer_release.link);
+
+	if (wl_list_empty(&raster->sources)) {
+		wl_signal_emit_mutable(&raster->events.invalidated, NULL);
+	}
 }
 
 struct wlr_raster *wlr_raster_create(struct wlr_buffer *buffer,
@@ -34,6 +38,7 @@ struct wlr_raster *wlr_raster_create(struct wlr_buffer *buffer,
 
 	wl_list_init(&raster->sources);
 	wl_signal_init(&raster->events.destroy);
+	wl_signal_init(&raster->events.invalidated);
 
 	assert(buffer);
 	raster->opaque = buffer_is_opaque(buffer);
@@ -58,6 +63,11 @@ static void raster_source_destroy(struct wlr_raster_source *source) {
 	wl_list_remove(&source->link);
 	wl_list_remove(&source->renderer_destroy.link);
 	wl_list_remove(&source->allocator_destroy.link);
+
+	if (!source->raster->buffer && wl_list_empty(&source->raster->sources)) {
+		wl_signal_emit_mutable(&source->raster->events.invalidated, NULL);
+	}
+
 	free(source);
 }
 
@@ -68,6 +78,9 @@ static void raster_consider_destroy(struct wlr_raster *raster) {
 
 	wl_signal_emit_mutable(&raster->events.destroy, NULL);
 
+	// we don't want to call invalidation signals as we're destroying the raster
+	wl_signal_init(&raster->events.invalidated);
+
 	struct wlr_raster_source *source, *source_tmp;
 	wl_list_for_each_safe(source, source_tmp, &raster->sources, link) {
 		wlr_texture_destroy(source->texture);
@@ -150,6 +163,7 @@ static void raster_attach_with_allocator(struct wlr_raster *raster,
 	wl_list_insert(&raster->sources, &source->link);
 	source->texture = texture;
 	source->allocator = allocator;
+	source->raster = raster;
 }
 
 static struct wlr_texture *wlr_raster_get_texture(struct wlr_raster *raster,