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| author | brianderson@chromium.org <brianderson@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2013-10-25 19:46:46 +0000 |
|---|---|---|
| committer | brianderson@chromium.org <brianderson@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2013-10-25 19:46:46 +0000 |
| commit | de2cf8caf24f9dff41462b4ed164d18c553b30e3 (patch) | |
| tree | 9b7833a432e15c49b8217d529e17cc474c0e47af /ui/gl | |
| parent | 406e93caa0d00078548cbbb830767f5cc976e32d (diff) | |
| download | chromium_src-de2cf8caf24f9dff41462b4ed164d18c553b30e3.zip chromium_src-de2cf8caf24f9dff41462b4ed164d18c553b30e3.tar.gz chromium_src-de2cf8caf24f9dff41462b4ed164d18c553b30e3.tar.bz2 | |
cc: Use HighResNow as timebase if it is fast and reliable
If base::TimeTicks::HighResNow is fast and reliable, we use it
for frame times, animations, and scheduling. Otherwise, we use
base::TimeTicks::Now and use a timebase of zero to avoid an
incorrect or jittery timebase.
This adds a gfx::FrameTime::Now() function, so the same timebase
is used across the ui and cc directories.
Additionally, the OutputSurface now uses a HighRes version of the
DelayBasedTimesource if gfx::FrameTime::Now() is HighRes.
BUG=303356
Review URL: https://codereview.chromium.org/27710005
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231089 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'ui/gl')
| -rw-r--r-- | ui/gl/gl_surface_win.cc | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/ui/gl/gl_surface_win.cc b/ui/gl/gl_surface_win.cc index d535c06..ff2ed84 100644 --- a/ui/gl/gl_surface_win.cc +++ b/ui/gl/gl_surface_win.cc @@ -11,6 +11,7 @@ #include "base/memory/scoped_ptr.h" #include "base/win/windows_version.h" #include "third_party/mesa/src/include/GL/osmesa.h" +#include "ui/gfx/frame_time.h" #include "ui/gl/gl_bindings.h" #include "ui/gl/gl_implementation.h" #include "ui/gl/gl_surface_egl.h" @@ -56,8 +57,16 @@ class DWMVSyncProvider : public VSyncProvider { if (result != S_OK) return; - base::TimeTicks timebase = base::TimeTicks::FromQPCValue( - static_cast<LONGLONG>(timing_info.qpcVBlank)); + base::TimeTicks timebase; + // If FrameTime is not high resolution, we do not want to translate the + // QPC value provided by DWM into the low-resolution timebase, which + // would be error prone and jittery. As a fallback, we assume the timebase + // is zero. + if (gfx::FrameTime::TimestampsAreHighRes()) { + timebase = gfx::FrameTime::FromQPCValue( + static_cast<LONGLONG>(timing_info.qpcVBlank)); + } + // Swap the numerator/denominator to convert frequency to period. if (timing_info.rateRefresh.uiDenominator > 0 && timing_info.rateRefresh.uiNumerator > 0) { |