1/*
2 * Copyright (C) 2010 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 AudioParam_h
30#define AudioParam_h
31
32#include "bindings/core/v8/ScriptWrappable.h"
33#include "modules/webaudio/AudioContext.h"
34#include "modules/webaudio/AudioParamTimeline.h"
35#include "modules/webaudio/AudioSummingJunction.h"
36#include <sys/types.h>
37#include "wtf/Float32Array.h"
38#include "wtf/PassRefPtr.h"
39#include "wtf/text/WTFString.h"
40
41namespace blink {
42
43class AudioNodeOutput;
44
45class AudioParam FINAL : public AudioSummingJunction, public ScriptWrappable {
46    DEFINE_WRAPPERTYPEINFO();
47public:
48    static const double DefaultSmoothingConstant;
49    static const double SnapThreshold;
50
51    static AudioParam* create(AudioContext* context, double defaultValue)
52    {
53        return new AudioParam(context, defaultValue);
54    }
55
56    // AudioSummingJunction
57    virtual void didUpdate() OVERRIDE { }
58
59    // Intrinsic value.
60    float value();
61    void setValue(float);
62
63    // Final value for k-rate parameters, otherwise use calculateSampleAccurateValues() for a-rate.
64    // Must be called in the audio thread.
65    float finalValue();
66
67    float defaultValue() const { return static_cast<float>(m_defaultValue); }
68
69    // Value smoothing:
70
71    // When a new value is set with setValue(), in our internal use of the parameter we don't immediately jump to it.
72    // Instead we smoothly approach this value to avoid glitching.
73    float smoothedValue();
74
75    // Smoothly exponentially approaches to (de-zippers) the desired value.
76    // Returns true if smoothed value has already snapped exactly to value.
77    bool smooth();
78
79    void resetSmoothedValue() { m_smoothedValue = m_value; }
80
81    // Parameter automation.
82    void setValueAtTime(float value, double time, ExceptionState& exceptionState)
83    {
84        m_timeline.setValueAtTime(value, time, exceptionState);
85    }
86    void linearRampToValueAtTime(float value, double time, ExceptionState& exceptionState)
87    {
88        m_timeline.linearRampToValueAtTime(value, time, exceptionState);
89    }
90    void exponentialRampToValueAtTime(float value, double time, ExceptionState& es)
91    {
92        m_timeline.exponentialRampToValueAtTime(value, time, es);
93    }
94    void setTargetAtTime(float target, double time, double timeConstant, ExceptionState& exceptionState)
95    {
96        m_timeline.setTargetAtTime(target, time, timeConstant, exceptionState);
97    }
98    void setValueCurveAtTime(Float32Array* curve, double time, double duration, ExceptionState& exceptionState)
99    {
100        m_timeline.setValueCurveAtTime(curve, time, duration, exceptionState);
101    }
102    void cancelScheduledValues(double startTime, ExceptionState& exceptionState)
103    {
104        m_timeline.cancelScheduledValues(startTime, exceptionState);
105    }
106
107    bool hasSampleAccurateValues() { return m_timeline.hasValues() || numberOfRenderingConnections(); }
108
109    // Calculates numberOfValues parameter values starting at the context's current time.
110    // Must be called in the context's render thread.
111    void calculateSampleAccurateValues(float* values, unsigned numberOfValues);
112
113    // Connect an audio-rate signal to control this parameter.
114    void connect(AudioNodeOutput&);
115    void disconnect(AudioNodeOutput&);
116
117private:
118    AudioParam(AudioContext* context, double defaultValue)
119        : AudioSummingJunction(context)
120        , m_value(defaultValue)
121        , m_defaultValue(defaultValue)
122        , m_smoothedValue(defaultValue) { }
123
124    // sampleAccurate corresponds to a-rate (audio rate) vs. k-rate in the Web Audio specification.
125    void calculateFinalValues(float* values, unsigned numberOfValues, bool sampleAccurate);
126    void calculateTimelineValues(float* values, unsigned numberOfValues);
127
128    double m_value;
129    double m_defaultValue;
130
131    // Smoothing (de-zippering)
132    double m_smoothedValue;
133
134    AudioParamTimeline m_timeline;
135};
136
137} // namespace blink
138
139#endif // AudioParam_h
140