1 /* 2 * Copyright (C) 2012, 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 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY 17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25 #ifndef OscillatorNode_h 26 #define OscillatorNode_h 27 28 #include "platform/audio/AudioBus.h" 29 #include "modules/webaudio/AudioParam.h" 30 #include "modules/webaudio/AudioScheduledSourceNode.h" 31 #include "wtf/OwnPtr.h" 32 #include "wtf/PassRefPtr.h" 33 #include "wtf/RefPtr.h" 34 #include "wtf/Threading.h" 35 36 namespace WebCore { 37 38 class AudioContext; 39 class PeriodicWave; 40 41 // OscillatorNode is an audio generator of periodic waveforms. 42 43 class OscillatorNode FINAL : public AudioScheduledSourceNode { 44 public: 45 // The waveform type. 46 // These must be defined as in the .idl file. 47 enum { 48 SINE = 0, 49 SQUARE = 1, 50 SAWTOOTH = 2, 51 TRIANGLE = 3, 52 CUSTOM = 4 53 }; 54 55 static PassRefPtrWillBeRawPtr<OscillatorNode> create(AudioContext*, float sampleRate); 56 57 virtual ~OscillatorNode(); 58 59 // AudioNode 60 virtual void process(size_t framesToProcess) OVERRIDE; 61 62 String type() const; 63 64 void setType(const String&); 65 frequency()66 AudioParam* frequency() { return m_frequency.get(); } detune()67 AudioParam* detune() { return m_detune.get(); } 68 69 void setPeriodicWave(PeriodicWave*); 70 71 virtual void trace(Visitor*) OVERRIDE; 72 73 private: 74 OscillatorNode(AudioContext*, float sampleRate); 75 76 bool setType(unsigned); // Returns true on success. 77 78 // Returns true if there are sample-accurate timeline parameter changes. 79 bool calculateSampleAccuratePhaseIncrements(size_t framesToProcess); 80 81 virtual bool propagatesSilence() const OVERRIDE; 82 83 // One of the waveform types defined in the enum. 84 unsigned short m_type; 85 86 // Frequency value in Hertz. 87 RefPtrWillBeMember<AudioParam> m_frequency; 88 89 // Detune value (deviating from the frequency) in Cents. 90 RefPtrWillBeMember<AudioParam> m_detune; 91 92 bool m_firstRender; 93 94 // m_virtualReadIndex is a sample-frame index into our buffer representing the current playback position. 95 // Since it's floating-point, it has sub-sample accuracy. 96 double m_virtualReadIndex; 97 98 // This synchronizes process(). 99 mutable Mutex m_processLock; 100 101 // Stores sample-accurate values calculated according to frequency and detune. 102 AudioFloatArray m_phaseIncrements; 103 AudioFloatArray m_detuneValues; 104 105 RefPtrWillBeMember<PeriodicWave> m_periodicWave; 106 }; 107 108 } // namespace WebCore 109 110 #endif // OscillatorNode_h 111