1/*
2 * Copyright (C) 2011 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 * 1.  Redistributions of source code must retain the above copyright
9 *     notice, this list of conditions and the following disclaimer.
10 * 2.  Redistributions in binary form must reproduce the above copyright
11 *     notice, this list of conditions and the following disclaimer in the
12 *     documentation and/or other materials provided with the distribution.
13 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
14 *     its contributors may be used to endorse or promote products derived
15 *     from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef AudioParamTimeline_h
30#define AudioParamTimeline_h
31
32#include "modules/webaudio/AudioContext.h"
33#include "wtf/Float32Array.h"
34#include "wtf/PassRefPtr.h"
35#include "wtf/RefCounted.h"
36#include "wtf/Threading.h"
37#include "wtf/Vector.h"
38
39namespace WebCore {
40
41class AudioParamTimeline {
42public:
43    AudioParamTimeline()
44    {
45    }
46
47    void setValueAtTime(float value, double time);
48    void linearRampToValueAtTime(float value, double time);
49    void exponentialRampToValueAtTime(float value, double time, ExceptionState&);
50    void setTargetAtTime(float target, double time, double timeConstant);
51    void setValueCurveAtTime(Float32Array* curve, double time, double duration);
52    void cancelScheduledValues(double startTime);
53
54    // hasValue is set to true if a valid timeline value is returned.
55    // otherwise defaultValue is returned.
56    float valueForContextTime(AudioContext*, float defaultValue, bool& hasValue);
57
58    // Given the time range, calculates parameter values into the values buffer
59    // and returns the last parameter value calculated for "values" or the defaultValue if none were calculated.
60    // controlRate is the rate (number per second) at which parameter values will be calculated.
61    // It should equal sampleRate for sample-accurate parameter changes, and otherwise will usually match
62    // the render quantum size such that the parameter value changes once per render quantum.
63    float valuesForTimeRange(double startTime, double endTime, float defaultValue, float* values, unsigned numberOfValues, double sampleRate, double controlRate);
64
65    bool hasValues() { return m_events.size(); }
66
67private:
68    class ParamEvent {
69    public:
70        enum Type {
71            SetValue,
72            LinearRampToValue,
73            ExponentialRampToValue,
74            SetTarget,
75            SetValueCurve,
76            LastType
77        };
78
79        ParamEvent(Type type, float value, double time, double timeConstant, double duration, PassRefPtr<Float32Array> curve)
80            : m_type(type)
81            , m_value(value)
82            , m_time(time)
83            , m_timeConstant(timeConstant)
84            , m_duration(duration)
85            , m_curve(curve)
86        {
87        }
88
89        unsigned type() const { return m_type; }
90        float value() const { return m_value; }
91        double time() const { return m_time; }
92        double timeConstant() const { return m_timeConstant; }
93        double duration() const { return m_duration; }
94        Float32Array* curve() { return m_curve.get(); }
95
96    private:
97        unsigned m_type;
98        float m_value;
99        double m_time;
100        double m_timeConstant;
101        double m_duration;
102        RefPtr<Float32Array> m_curve;
103    };
104
105    void insertEvent(const ParamEvent&);
106    float valuesForTimeRangeImpl(double startTime, double endTime, float defaultValue, float* values, unsigned numberOfValues, double sampleRate, double controlRate);
107
108    Vector<ParamEvent> m_events;
109
110    Mutex m_eventsLock;
111};
112
113} // namespace WebCore
114
115#endif // AudioParamTimeline_h
116