1 // Copyright 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef UI_GL_SYNC_CONTROL_VSYNC_PROVIDER_H_ 6 #define UI_GL_SYNC_CONTROL_VSYNC_PROVIDER_H_ 7 8 #include <queue> 9 10 #include "ui/gfx/vsync_provider.h" 11 12 namespace gfx { 13 14 // Base class for providers based on extensions like GLX_OML_sync_control and 15 // EGL_CHROMIUM_sync_control. 16 class SyncControlVSyncProvider : public VSyncProvider { 17 public: 18 SyncControlVSyncProvider(); 19 virtual ~SyncControlVSyncProvider(); 20 21 virtual void GetVSyncParameters(const UpdateVSyncCallback& callback) OVERRIDE; 22 23 protected: 24 virtual bool GetSyncValues(int64* system_time, 25 int64* media_stream_counter, 26 int64* swap_buffer_counter) = 0; 27 28 virtual bool GetMscRate(int32* numerator, int32* denominator) = 0; 29 30 private: 31 base::TimeTicks last_timebase_; 32 uint64 last_media_stream_counter_; 33 base::TimeDelta last_good_interval_; 34 35 // A short history of the last few computed intervals. 36 // We use this to filter out the noise in the computation resulting 37 // from configuration change (monitor reconfiguration, moving windows 38 // between monitors, suspend and resume, etc.). 39 std::queue<base::TimeDelta> last_computed_intervals_; 40 41 DISALLOW_COPY_AND_ASSIGN(SyncControlVSyncProvider); 42 }; 43 44 } // namespace gfx 45 46 #endif // UI_GL_SYNC_CONTROL_VSYNC_PROVIDER_H_ 47
