[mutter] clutter/frame-clock: Remember the refresh interval

[Marge Bot <marge-bot src gnome org>]

commit ba1490ec9c8dd7b02cf082a3e4c7cc07ad9aa6a1
Author: Daniel van Vugt <daniel van vugt canonical com>
Date:   Wed Jul 15 17:03:27 2020 +0800

    clutter/frame-clock: Remember the refresh interval
    
    Instead of recalculating it every time we need it. The performance
    gain is not important; this is more because it will be needed in
    multiple functions soon.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1826>

 clutter/clutter/clutter-frame-clock.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)
---
diff --git a/clutter/clutter/clutter-frame-clock.c b/clutter/clutter/clutter-frame-clock.c
index 9b3b10ebac..dc5a608348 100644
--- a/clutter/clutter/clutter-frame-clock.c
+++ b/clutter/clutter/clutter-frame-clock.c
@@ -77,6 +77,7 @@ struct _ClutterFrameClock
   GObject parent;
 
   float refresh_rate;
+  int64_t refresh_interval_us;
   ClutterFrameListener listener;
 
   GSource *source;
@@ -131,6 +132,15 @@ clutter_frame_clock_get_refresh_rate (ClutterFrameClock *frame_clock)
   return frame_clock->refresh_rate;
 }
 
+static void
+clutter_frame_clock_set_refresh_rate (ClutterFrameClock *frame_clock,
+                                      float              refresh_rate)
+{
+  frame_clock->refresh_rate = refresh_rate;
+  frame_clock->refresh_interval_us =
+    (int64_t) (0.5 + G_USEC_PER_SEC / refresh_rate);
+}
+
 void
 clutter_frame_clock_add_timeline (ClutterFrameClock *frame_clock,
                                   ClutterTimeline   *timeline)
@@ -255,7 +265,10 @@ clutter_frame_clock_notify_presented (ClutterFrameClock *frame_clock,
     }
 
   if (frame_info->refresh_rate > 1)
-    frame_clock->refresh_rate = frame_info->refresh_rate;
+    {
+      clutter_frame_clock_set_refresh_rate (frame_clock,
+                                            frame_info->refresh_rate);
+    }
 
   switch (frame_clock->state)
     {
@@ -349,7 +362,6 @@ calculate_next_update_time_us (ClutterFrameClock *frame_clock,
 {
   int64_t last_presentation_time_us;
   int64_t now_us;
-  float refresh_rate;
   int64_t refresh_interval_us;
   int64_t min_render_time_allowed_us;
   int64_t max_render_time_allowed_us;
@@ -360,8 +372,7 @@ calculate_next_update_time_us (ClutterFrameClock *frame_clock,
 
   now_us = g_get_monotonic_time ();
 
-  refresh_rate = frame_clock->refresh_rate;
-  refresh_interval_us = (int64_t) (0.5 + G_USEC_PER_SEC / refresh_rate);
+  refresh_interval_us = frame_clock->refresh_interval_us;
 
   if (frame_clock->last_presentation_time_us == 0)
     {
@@ -767,7 +778,7 @@ clutter_frame_clock_new (float                            refresh_rate,
 
   init_frame_clock_source (frame_clock);
 
-  frame_clock->refresh_rate = refresh_rate;
+  clutter_frame_clock_set_refresh_rate (frame_clock, refresh_rate);
   frame_clock->vblank_duration_us = vblank_duration_us;
 
   return frame_clock;