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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/Forward.h"
35 #include "wtf/Threading.h"
36 #include "wtf/Vector.h"
37 
38 namespace blink {
39 
40 class AudioParamTimeline {
41 public:
AudioParamTimeline()42     AudioParamTimeline()
43     {
44     }
45 
46     void setValueAtTime(float value, double time, ExceptionState&);
47     void linearRampToValueAtTime(float value, double time, ExceptionState&);
48     void exponentialRampToValueAtTime(float value, double time, ExceptionState&);
49     void setTargetAtTime(float target, double time, double timeConstant, ExceptionState&);
50     void setValueCurveAtTime(Float32Array* curve, double time, double duration, ExceptionState&);
51     void cancelScheduledValues(double startTime, ExceptionState&);
52 
53     // hasValue is set to true if a valid timeline value is returned.
54     // otherwise defaultValue is returned.
55     float valueForContextTime(AudioContext*, float defaultValue, bool& hasValue);
56 
57     // Given the time range, calculates parameter values into the values buffer
58     // and returns the last parameter value calculated for "values" or the defaultValue if none were calculated.
59     // controlRate is the rate (number per second) at which parameter values will be calculated.
60     // It should equal sampleRate for sample-accurate parameter changes, and otherwise will usually match
61     // the render quantum size such that the parameter value changes once per render quantum.
62     float valuesForTimeRange(double startTime, double endTime, float defaultValue, float* values, unsigned numberOfValues, double sampleRate, double controlRate);
63 
hasValues()64     bool hasValues() { return m_events.size(); }
65 
66 private:
67     class ParamEvent {
68     public:
69         enum Type {
70             SetValue,
71             LinearRampToValue,
72             ExponentialRampToValue,
73             SetTarget,
74             SetValueCurve,
75             LastType
76         };
77 
ParamEvent(Type type,float value,double time,double timeConstant,double duration,PassRefPtr<Float32Array> curve)78         ParamEvent(Type type, float value, double time, double timeConstant, double duration, PassRefPtr<Float32Array> curve)
79             : m_type(type)
80             , m_value(value)
81             , m_time(time)
82             , m_timeConstant(timeConstant)
83             , m_duration(duration)
84             , m_curve(curve)
85         {
86         }
87 
type()88         unsigned type() const { return m_type; }
value()89         float value() const { return m_value; }
time()90         double time() const { return m_time; }
timeConstant()91         double timeConstant() const { return m_timeConstant; }
duration()92         double duration() const { return m_duration; }
curve()93         Float32Array* curve() { return m_curve.get(); }
94 
95     private:
96         unsigned m_type;
97         float m_value;
98         double m_time;
99         double m_timeConstant;
100         double m_duration;
101         RefPtr<Float32Array> m_curve;
102     };
103 
104     void insertEvent(const ParamEvent&);
105     float valuesForTimeRangeImpl(double startTime, double endTime, float defaultValue, float* values, unsigned numberOfValues, double sampleRate, double controlRate);
106 
107     Vector<ParamEvent> m_events;
108 
109     Mutex m_eventsLock;
110 };
111 
112 } // namespace blink
113 
114 #endif // AudioParamTimeline_h
115