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/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/RefCounted.h" 40 #include "wtf/text/WTFString.h" 41 42 namespace WebCore { 43 44 class AudioNodeOutput; 45 46 class AudioParam : public RefCounted<AudioParam>, public ScriptWrappable, public AudioSummingJunction { 47 public: 48 static const double DefaultSmoothingConstant; 49 static const double SnapThreshold; 50 51 static PassRefPtr<AudioParam> create(AudioContext* context, const String& name, double defaultValue, double minValue, double maxValue, unsigned units = 0) 52 { 53 return adoptRef(new AudioParam(context, name, defaultValue, minValue, maxValue, units)); 54 } 55 56 // AudioSummingJunction canUpdateState()57 virtual bool canUpdateState() OVERRIDE { return true; } didUpdate()58 virtual void didUpdate() OVERRIDE { } 59 60 // Intrinsic value. 61 float value(); 62 void setValue(float); 63 64 // Final value for k-rate parameters, otherwise use calculateSampleAccurateValues() for a-rate. 65 // Must be called in the audio thread. 66 float finalValue(); 67 name()68 String name() const { return m_name; } 69 minValue()70 float minValue() const { return static_cast<float>(m_minValue); } maxValue()71 float maxValue() const { return static_cast<float>(m_maxValue); } defaultValue()72 float defaultValue() const { return static_cast<float>(m_defaultValue); } units()73 unsigned units() const { return m_units; } 74 75 // Value smoothing: 76 77 // When a new value is set with setValue(), in our internal use of the parameter we don't immediately jump to it. 78 // Instead we smoothly approach this value to avoid glitching. 79 float smoothedValue(); 80 81 // Smoothly exponentially approaches to (de-zippers) the desired value. 82 // Returns true if smoothed value has already snapped exactly to value. 83 bool smooth(); 84 resetSmoothedValue()85 void resetSmoothedValue() { m_smoothedValue = m_value; } setSmoothingConstant(double k)86 void setSmoothingConstant(double k) { m_smoothingConstant = k; } 87 88 // Parameter automation. setValueAtTime(float value,double time)89 void setValueAtTime(float value, double time) { m_timeline.setValueAtTime(value, time); } linearRampToValueAtTime(float value,double time)90 void linearRampToValueAtTime(float value, double time) { m_timeline.linearRampToValueAtTime(value, time); } exponentialRampToValueAtTime(float value,double time)91 void exponentialRampToValueAtTime(float value, double time) { m_timeline.exponentialRampToValueAtTime(value, time); } setTargetAtTime(float target,double time,double timeConstant)92 void setTargetAtTime(float target, double time, double timeConstant) { m_timeline.setTargetAtTime(target, time, timeConstant); } setValueCurveAtTime(Float32Array * curve,double time,double duration)93 void setValueCurveAtTime(Float32Array* curve, double time, double duration) { m_timeline.setValueCurveAtTime(curve, time, duration); } cancelScheduledValues(double startTime)94 void cancelScheduledValues(double startTime) { m_timeline.cancelScheduledValues(startTime); } 95 hasSampleAccurateValues()96 bool hasSampleAccurateValues() { return m_timeline.hasValues() || numberOfRenderingConnections(); } 97 98 // Calculates numberOfValues parameter values starting at the context's current time. 99 // Must be called in the context's render thread. 100 void calculateSampleAccurateValues(float* values, unsigned numberOfValues); 101 102 // Connect an audio-rate signal to control this parameter. 103 void connect(AudioNodeOutput*); 104 void disconnect(AudioNodeOutput*); 105 106 protected: 107 AudioParam(AudioContext* context, const String& name, double defaultValue, double minValue, double maxValue, unsigned units = 0) AudioSummingJunction(context)108 : AudioSummingJunction(context) 109 , m_name(name) 110 , m_value(defaultValue) 111 , m_defaultValue(defaultValue) 112 , m_minValue(minValue) 113 , m_maxValue(maxValue) 114 , m_units(units) 115 , m_smoothedValue(defaultValue) 116 , m_smoothingConstant(DefaultSmoothingConstant) 117 { 118 ScriptWrappable::init(this); 119 } 120 121 private: 122 // sampleAccurate corresponds to a-rate (audio rate) vs. k-rate in the Web Audio specification. 123 void calculateFinalValues(float* values, unsigned numberOfValues, bool sampleAccurate); 124 void calculateTimelineValues(float* values, unsigned numberOfValues); 125 126 String m_name; 127 double m_value; 128 double m_defaultValue; 129 double m_minValue; 130 double m_maxValue; 131 unsigned m_units; 132 133 // Smoothing (de-zippering) 134 double m_smoothedValue; 135 double m_smoothingConstant; 136 137 AudioParamTimeline m_timeline; 138 }; 139 140 } // namespace WebCore 141 142 #endif // AudioParam_h 143