From e5602062e223c2ed079bc42d4d88b1964c0b9cd3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonas=20=C3=85dahl?= <jadahl@gmail.com>
Date: Wed, 26 Oct 2022 19:45:46 +0200
Subject: [PATCH] cogl/frame: Keep track of target presentation time

It's yet to be used for anything, but will later on.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2795>
---
 cogl/cogl/cogl-frame-info-private.h | 7 +++++++
 cogl/cogl/cogl-frame-info.c         | 8 ++++++++
 src/backends/meta-stage-impl.c      | 8 ++++++++
 3 files changed, 23 insertions(+)

diff --git a/cogl/cogl/cogl-frame-info-private.h b/cogl/cogl/cogl-frame-info-private.h
index 2a59288d1..3264ae009 100644
--- a/cogl/cogl/cogl-frame-info-private.h
+++ b/cogl/cogl/cogl-frame-info-private.h
@@ -78,10 +78,17 @@ struct _CoglFrameInfo
   CoglTimestampQuery *timestamp_query;
   int64_t gpu_time_before_buffer_swap_ns;
   int64_t cpu_time_before_buffer_swap_us;
+
+  gboolean has_target_presentation_time;
+  int64_t target_presentation_time_us;
 };
 
 COGL_EXPORT
 CoglFrameInfo *cogl_frame_info_new (CoglContext *context,
                                     int64_t      global_frame_counter);
 
+COGL_EXPORT
+void cogl_frame_info_set_target_presentation_time (CoglFrameInfo *info,
+                                                   int64_t        presentation_time_us);
+
 #endif /* __COGL_FRAME_INFO_PRIVATE_H */
diff --git a/cogl/cogl/cogl-frame-info.c b/cogl/cogl/cogl-frame-info.c
index adaf2bad9..373a2d098 100644
--- a/cogl/cogl/cogl-frame-info.c
+++ b/cogl/cogl/cogl-frame-info.c
@@ -142,3 +142,11 @@ cogl_frame_info_get_time_before_buffer_swap_us (CoglFrameInfo *info)
 {
   return info->cpu_time_before_buffer_swap_us;
 }
+
+void
+cogl_frame_info_set_target_presentation_time (CoglFrameInfo *info,
+                                              int64_t        presentation_time_us)
+{
+  info->has_target_presentation_time = TRUE;
+  info->target_presentation_time_us = presentation_time_us;
+}
diff --git a/src/backends/meta-stage-impl.c b/src/backends/meta-stage-impl.c
index 816f63fa5..7774393e1 100644
--- a/src/backends/meta-stage-impl.c
+++ b/src/backends/meta-stage-impl.c
@@ -265,6 +265,7 @@ swap_framebuffer (ClutterStageWindow *stage_window,
   if (COGL_IS_ONSCREEN (framebuffer))
     {
       CoglOnscreen *onscreen = COGL_ONSCREEN (framebuffer);
+      int64_t target_presentation_time_us;
       int *damage, n_rects, i;
       CoglFrameInfo *frame_info;
 
@@ -285,6 +286,13 @@ swap_framebuffer (ClutterStageWindow *stage_window,
         cogl_frame_info_new (cogl_context, priv->global_frame_counter);
       priv->global_frame_counter++;
 
+      if (clutter_frame_get_target_presentation_time (frame,
+                                                      &target_presentation_time_us))
+        {
+          cogl_frame_info_set_target_presentation_time (frame_info,
+                                                        target_presentation_time_us);
+        }
+
       /* push on the screen */
       if (n_rects > 0 && !swap_with_damage)
         {