scene: add wlr_scene_output_sample_event

This contains the output and a bool indicating direct scan-out.

include/wlr/types/wlr_scene.h

@@ -140,6 +140,11 @@ struct wlr_scene_outputs_update_event {
 	size_t size;
 };
 
+struct wlr_scene_output_sample_event {
+	struct wlr_scene_output *output;
+	bool direct_scanout;
+};
+
 /** A scene-graph node displaying a buffer */
 struct wlr_scene_buffer {
 	struct wlr_scene_node node;
@@ -151,7 +156,7 @@ struct wlr_scene_buffer {
 		struct wl_signal outputs_update; // struct wlr_scene_outputs_update_event
 		struct wl_signal output_enter; // struct wlr_scene_output
 		struct wl_signal output_leave; // struct wlr_scene_output
-		struct wl_signal output_sample; // struct wlr_scene_output
+		struct wl_signal output_sample; // struct wlr_scene_output_sample_event
 		struct wl_signal frame_done; // struct timespec
 	} events;
 

types/scene/surface.c

@@ -40,7 +40,8 @@ static void handle_scene_buffer_output_sample(
 		struct wl_listener *listener, void *data) {
 	struct wlr_scene_surface *surface =
 		wl_container_of(listener, surface, output_sample);
-	struct wlr_scene_output *scene_output = data;
+	const struct wlr_scene_output_sample_event *event = data;
+	struct wlr_scene_output *scene_output = event->output;
 
 	if (surface->buffer->primary_output == scene_output) {
 		struct wlr_scene *root = scene_node_get_root(&surface->buffer->node);

types/scene/wlr_scene.c

@@ -1171,7 +1171,11 @@ static void scene_entry_render(struct render_list_entry *entry, const struct ren
 				WLR_RENDER_BLEND_MODE_PREMULTIPLIED : WLR_RENDER_BLEND_MODE_NONE,
 		});
 
-		wl_signal_emit_mutable(&scene_buffer->events.output_sample, data->output);
+		struct wlr_scene_output_sample_event sample_event = {
+			.output = data->output,
+			.direct_scanout = false,
+		};
+		wl_signal_emit_mutable(&scene_buffer->events.output_sample, &sample_event);
 		break;
 	}
 
@@ -1572,7 +1576,11 @@ static bool scene_entry_try_direct_scanout(struct render_list_entry *entry,
 	wlr_output_state_copy(state, &pending);
 	wlr_output_state_finish(&pending);
 
-	wl_signal_emit_mutable(&buffer->events.output_sample, scene_output);
+	struct wlr_scene_output_sample_event sample_event = {
+		.output = scene_output,
+		.direct_scanout = true,
+	};
+	wl_signal_emit_mutable(&buffer->events.output_sample, &sample_event);
 	return true;
 }