GDK W32: set update frequency and timestamp

There is no easily apparent way of being notified when frame updates
happene exactly, so we just query frame info at the end of each paint.
If we query too often (faster than DWM refresh rate), we just get
the same values twice in a row, but that is, hopefully, highly unlikely.

diff --git a/gdk/win32/gdksurface-win32.c b/gdk/win32/gdksurface-win32.c
index 9fc030395edbbfef825c0534c73d752ea019cc55..ed128137d1813bee888ffcbe99258d4a1c4f63c4 100644 (file)
--- a/gdk/win32/gdksurface-win32.c
+++ b/gdk/win32/gdksurface-win32.c
@@ -36,6 +36,7 @@
 #include "gdkenumtypes.h"
 #include "gdkwin32.h"
 #include "gdkdisplayprivate.h"
+#include "gdkframeclockprivate.h"
 #include "gdkmonitorprivate.h"
 #include "gdkwin32surface.h"
 #include "gdkwin32cursor.h"
@@ -337,12 +338,43 @@ gdk_win32_surface_begin_paint (GdkSurface *window)
 {
   GdkSurfaceImplWin32 *impl;
   RECT window_rect;
+  DWM_TIMING_INFO timing_info;
+  LARGE_INTEGER tick_frequency;
+  GdkFrameTimings *timings = NULL;
+  GdkFrameClock *clock = NULL;
 
   if (window == NULL || GDK_SURFACE_DESTROYED (window))
     return TRUE;
 
   impl = GDK_SURFACE_IMPL_WIN32 (window->impl);
 
+  clock = gdk_surface_get_frame_clock (window);
+
+  if (clock)
+    timings = gdk_frame_clock_get_timings (clock, gdk_frame_clock_get_frame_counter (clock));
+
+  if (timings)
+    {
+      timings->refresh_interval = 16667; /* default to 1/60th of a second */
+      timings->presentation_time = 0;
+
+      if (QueryPerformanceFrequency (&tick_frequency))
+        {
+          HRESULT hr;
+
+          timing_info.cbSize = sizeof (timing_info);
+          hr = DwmGetCompositionTimingInfo (NULL, &timing_info);
+
+          if (SUCCEEDED (hr))
+            {
+              timings->refresh_interval = timing_info.qpcRefreshPeriod * (gdouble)G_USEC_PER_SEC / tick_frequency.QuadPart;
+              timings->presentation_time = timing_info.qpcCompose * (gdouble)G_USEC_PER_SEC / tick_frequency.QuadPart;
+            }
+        }
+
+      timings->complete = TRUE;
+    }
+
   /* Layered windows are moved *after* repaint.
    * We supply our own surface, return FALSE to make GDK use it.
    */