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 41 namespace blink { 42 43 class AudioNodeOutput; 44 45 class AudioParam FINAL : public AudioSummingJunction, public ScriptWrappable { 46 DEFINE_WRAPPERTYPEINFO(); 47 public: 48 static const double DefaultSmoothingConstant; 49 static const double SnapThreshold; 50 create(AudioContext * context,double defaultValue)51 static AudioParam* create(AudioContext* context, double defaultValue) 52 { 53 return new AudioParam(context, defaultValue); 54 } 55 56 // AudioSummingJunction didUpdate()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 defaultValue()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 resetSmoothedValue()79 void resetSmoothedValue() { m_smoothedValue = m_value; } 80 81 // Parameter automation. setValueAtTime(float value,double time,ExceptionState & exceptionState)82 void setValueAtTime(float value, double time, ExceptionState& exceptionState) 83 { 84 m_timeline.setValueAtTime(value, time, exceptionState); 85 } linearRampToValueAtTime(float value,double time,ExceptionState & exceptionState)86 void linearRampToValueAtTime(float value, double time, ExceptionState& exceptionState) 87 { 88 m_timeline.linearRampToValueAtTime(value, time, exceptionState); 89 } exponentialRampToValueAtTime(float value,double time,ExceptionState & es)90 void exponentialRampToValueAtTime(float value, double time, ExceptionState& es) 91 { 92 m_timeline.exponentialRampToValueAtTime(value, time, es); 93 } setTargetAtTime(float target,double time,double timeConstant,ExceptionState & exceptionState)94 void setTargetAtTime(float target, double time, double timeConstant, ExceptionState& exceptionState) 95 { 96 m_timeline.setTargetAtTime(target, time, timeConstant, exceptionState); 97 } setValueCurveAtTime(Float32Array * curve,double time,double duration,ExceptionState & exceptionState)98 void setValueCurveAtTime(Float32Array* curve, double time, double duration, ExceptionState& exceptionState) 99 { 100 m_timeline.setValueCurveAtTime(curve, time, duration, exceptionState); 101 } cancelScheduledValues(double startTime,ExceptionState & exceptionState)102 void cancelScheduledValues(double startTime, ExceptionState& exceptionState) 103 { 104 m_timeline.cancelScheduledValues(startTime, exceptionState); 105 } 106 hasSampleAccurateValues()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&); 116 117 private: AudioParam(AudioContext * context,double defaultValue)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