blob: 32b4c2c24f167602e536aac7a4b36ff5eb0ea316 [file] [log] [blame]
// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/basictypes.h"
#include "base/memory/scoped_ptr.h"
#include "base/time/time.h"
#include "cc/debug/ring_buffer.h"
namespace cc {
// This class maintains a history of timestamps, and provides functionality to
// intelligently compute average frames per second.
class FrameRateCounter {
static scoped_ptr<FrameRateCounter> Create(bool has_impl_thread);
int current_frame_number() const { return ring_buffer_.CurrentIndex(); }
int dropped_frame_count() const { return dropped_frame_count_; }
size_t time_stamp_history_size() const { return ring_buffer_.BufferSize(); }
void SaveTimeStamp(base::TimeTicks timestamp);
// n = 0 returns the oldest frame interval retained in the history, while n =
// time_stamp_history_size() - 1 returns the most recent frame interval.
base::TimeDelta RecentFrameInterval(size_t n) const;
// This is a heuristic that can be used to ignore frames in a reasonable way.
// Returns true if the given frame interval is too fast or too slow, based on
// constant thresholds.
bool IsBadFrameInterval(
base::TimeDelta interval_between_consecutive_frames) const;
void GetMinAndMaxFPS(double* min_fps, double* max_fps) const;
double GetAverageFPS() const;
typedef RingBuffer<base::TimeTicks, 136> RingBufferType;
RingBufferType::Iterator begin() const { return ring_buffer_.Begin(); }
RingBufferType::Iterator end() const { return ring_buffer_.End(); }
explicit FrameRateCounter(bool has_impl_thread);
RingBufferType ring_buffer_;
bool has_impl_thread_;
int dropped_frame_count_;
} // namespace cc