ui/ozone/platform/dri/dri_vsync_provider.cc

   1 // Copyright 2014 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 #include "ui/ozone/platform/dri/dri_vsync_provider.h"
   6
   7 #include "base/time/time.h"
   8 #include "ui/ozone/platform/dri/dri_window_delegate.h"
   9 #include "ui/ozone/platform/dri/hardware_display_controller.h"
  10
  11 namespace ui {
  12
  13 DriVSyncProvider::DriVSyncProvider(DriWindowDelegate* window_delegate)
  14     : window_delegate_(window_delegate) {
  15 }
  16
  17 DriVSyncProvider::~DriVSyncProvider() {}
  18
  19 void DriVSyncProvider::GetVSyncParameters(const UpdateVSyncCallback& callback) {
  20   HardwareDisplayController* controller = window_delegate_->GetController();
  21   if (!controller)
  22     return;
  23
  24   // The value is invalid, so we can't update the parameters.
  25   if (controller->GetTimeOfLastFlip() == 0 ||
  26       controller->get_mode().vrefresh == 0)
  27     return;
  28
  29   // Stores the time of the last refresh.
  30   base::TimeTicks timebase =
  31       base::TimeTicks::FromInternalValue(controller->GetTimeOfLastFlip());
  32   // Stores the refresh rate.
  33   base::TimeDelta interval =
  34       base::TimeDelta::FromSeconds(1) / controller->get_mode().vrefresh;
  35
  36   callback.Run(timebase, interval);
  37 }
  38
  39 }  // namespace ui