cc/frame_rate_controller.h

   1 // Copyright 2011 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 CC_FRAME_RATE_CONTROLLER_H_
   6 #define CC_FRAME_RATE_CONTROLLER_H_
   7
   8 #include "base/memory/ref_counted.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/time.h"
  12 #include "cc/cc_export.h"
  13
  14 namespace cc {
  15
  16 class Thread;
  17 class TimeSource;
  18
  19 class CC_EXPORT FrameRateControllerClient {
  20 public:
  21     // Throttled is true when we have a maximum number of frames pending.
  22     virtual void vsyncTick(bool throttled) = 0;
  23
  24 protected:
  25     virtual ~FrameRateControllerClient() {}
  26 };
  27
  28 class FrameRateControllerTimeSourceAdapter;
  29
  30 class CC_EXPORT FrameRateController {
  31 public:
  32     enum {
  33         kDefaultMaxFramesPending = 2
  34     };
  35
  36     explicit FrameRateController(scoped_refptr<TimeSource>);
  37     // Alternate form of FrameRateController with unthrottled frame-rate.
  38     explicit FrameRateController(Thread*);
  39     virtual ~FrameRateController();
  40
  41     void setClient(FrameRateControllerClient* client) { m_client = client; }
  42
  43     void setActive(bool);
  44
  45     // Use the following methods to adjust target frame rate.
  46     //
  47     // Multiple frames can be in-progress, but for every didBeginFrame, a
  48     // didFinishFrame should be posted.
  49     //
  50     // If the rendering pipeline crashes, call didAbortAllPendingFrames.
  51     void didBeginFrame();
  52     void didFinishFrame();
  53     void didAbortAllPendingFrames();
  54     void setMaxFramesPending(int); // 0 for unlimited.
  55     int maxFramesPending() const { return m_maxFramesPending; }
  56
  57     // This returns null for unthrottled frame-rate.
  58     base::TimeTicks nextTickTime();
  59
  60     void setTimebaseAndInterval(base::TimeTicks timebase, base::TimeDelta interval);
  61     void setSwapBuffersCompleteSupported(bool);
  62
  63 protected:
  64     friend class FrameRateControllerTimeSourceAdapter;
  65     void onTimerTick();
  66
  67     void postManualTick();
  68     void manualTick();
  69
  70     FrameRateControllerClient* m_client;
  71     int m_numFramesPending;
  72     int m_maxFramesPending;
  73     scoped_refptr<TimeSource> m_timeSource;
  74     scoped_ptr<FrameRateControllerTimeSourceAdapter> m_timeSourceClientAdapter;
  75     bool m_active;
  76     bool m_swapBuffersCompleteSupported;
  77
  78     // Members for unthrottled frame-rate.
  79     bool m_isTimeSourceThrottling;
  80     base::WeakPtrFactory<FrameRateController> m_weakFactory;
  81     Thread* m_thread;
  82
  83     DISALLOW_COPY_AND_ASSIGN(FrameRateController);
  84 };
  85
  86 }  // namespace cc
  87
  88 #endif  // CC_FRAME_RATE_CONTROLLER_H_