output: add comment about needs_frame in wlr_output_schedule_frame
Add a comment to not forget why this call is necessary.
References:
@@ -621,6 +621,9 @@ static void schedule_frame_handle_idle_timer(void *data) {
}
void wlr_output_schedule_frame(struct wlr_output *output) {
+ // Make sure the compositor commits a new frame. This is necessary to make
+ // clients which ask for frame callbacks without submitting a new buffer
+ // work.
wlr_output_update_needs_frame(output);
if (output->frame_pending || output->idle_frame != NULL) {
