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#include "cc/output/begin_frame_args.h"
6
7#include "base/debug/trace_event_argument.h"
8#include "ui/gfx/frame_time.h"
9
10namespace cc {
11
12BeginFrameArgs::BeginFrameArgs()
13  : frame_time(base::TimeTicks()),
14    deadline(base::TimeTicks()),
15    interval(base::TimeDelta::FromMicroseconds(-1)) {
16}
17
18BeginFrameArgs::BeginFrameArgs(base::TimeTicks frame_time,
19                               base::TimeTicks deadline,
20                               base::TimeDelta interval)
21  : frame_time(frame_time),
22    deadline(deadline),
23    interval(interval)
24{}
25
26BeginFrameArgs BeginFrameArgs::Create(base::TimeTicks frame_time,
27                                      base::TimeTicks deadline,
28                                      base::TimeDelta interval) {
29  return BeginFrameArgs(frame_time, deadline, interval);
30}
31
32scoped_refptr<base::debug::ConvertableToTraceFormat> BeginFrameArgs::AsValue()
33    const {
34  scoped_refptr<base::debug::TracedValue> state =
35      new base::debug::TracedValue();
36  AsValueInto(state.get());
37  return state;
38}
39
40void BeginFrameArgs::AsValueInto(base::debug::TracedValue* state) const {
41  state->SetString("type", "BeginFrameArgs");
42  state->SetDouble("frame_time_us", frame_time.ToInternalValue());
43  state->SetDouble("deadline_us", deadline.ToInternalValue());
44  state->SetDouble("interval_us", interval.InMicroseconds());
45}
46
47BeginFrameArgs BeginFrameArgs::CreateForSynchronousCompositor(
48    base::TimeTicks now) {
49  // For WebView/SynchronousCompositor, we always want to draw immediately,
50  // so we set the deadline to 0 and guess that the interval is 16 milliseconds.
51  if (now.is_null())
52    now = gfx::FrameTime::Now();
53  return BeginFrameArgs(now, base::TimeTicks(), DefaultInterval());
54}
55
56// This is a hard-coded deadline adjustment that assumes 60Hz, to be used in
57// cases where a good estimated draw time is not known. Using 1/3 of the vsync
58// as the default adjustment gives the Browser the last 1/3 of a frame to
59// produce output, the Renderer Impl thread the middle 1/3 of a frame to produce
60// ouput, and the Renderer Main thread the first 1/3 of a frame to produce
61// output.
62base::TimeDelta BeginFrameArgs::DefaultEstimatedParentDrawTime() {
63  return base::TimeDelta::FromMicroseconds(16666 / 3);
64}
65
66base::TimeDelta BeginFrameArgs::DefaultInterval() {
67  return base::TimeDelta::FromMicroseconds(16666);
68}
69
70base::TimeDelta BeginFrameArgs::DefaultRetroactiveBeginFramePeriod() {
71  return base::TimeDelta::FromMicroseconds(4444);
72}
73
74}  // namespace cc
75