scene: add primary output to wlr_scene_surface

This allows compositors to avoid sending multiple frame done events
to a surface that is rendered on multiple outputs at once. This may
also be used in the same way for presentation feedback.

1 files changed, 8 insertions, 0 deletions

diff --git a/include/wlr/types/wlr_scene.h b/include/wlr/types/wlr_scene.h
index 1238653d..6c2928ee 100644
--- a/include/wlr/types/wlr_scene.h
+++ b/include/wlr/types/wlr_scene.h
@@ -74,6 +74,14 @@ struct wlr_scene_surface {
 	struct wlr_scene_node node;
 	struct wlr_surface *surface;
 
+	/**
+	 * The output that the largest area of this surface is displayed on.
+	 * This may be NULL if the surface is not currently displayed on any
+	 * outputs. This is the output that should be used for frame callbacks,
+	 * presentation feedback, etc.
+	 */
+	struct wlr_output *primary_output;
+
 	// private state
 
 	int prev_width, prev_height;