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25 #ifndef OscillatorNode_h
26 #define OscillatorNode_h
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"
41 // OscillatorNode is an audio generator of periodic waveforms.
43 class OscillatorNode : public AudioScheduledSourceNode {
46 // These must be defined as in the .idl file.
55 static PassRefPtr<OscillatorNode> create(AudioContext*, float sampleRate);
57 virtual ~OscillatorNode();
60 virtual void process(size_t framesToProcess);
65 bool setType(unsigned); // Returns true on success.
66 void setType(const String&);
68 AudioParam* frequency() { return m_frequency.get(); }
69 AudioParam* detune() { return m_detune.get(); }
71 void setPeriodicWave(PeriodicWave*);
74 OscillatorNode(AudioContext*, float sampleRate);
76 // Returns true if there are sample-accurate timeline parameter changes.
77 bool calculateSampleAccuratePhaseIncrements(size_t framesToProcess);
79 virtual bool propagatesSilence() const OVERRIDE;
81 // One of the waveform types defined in the enum.
82 unsigned short m_type;
84 // Frequency value in Hertz.
85 RefPtr<AudioParam> m_frequency;
87 // Detune value (deviating from the frequency) in Cents.
88 RefPtr<AudioParam> m_detune;
92 // m_virtualReadIndex is a sample-frame index into our buffer representing the current playback position.
93 // Since it's floating-point, it has sub-sample accuracy.
94 double m_virtualReadIndex;
96 // This synchronizes process().
97 mutable Mutex m_processLock;
99 // Stores sample-accurate values calculated according to frequency and detune.
100 AudioFloatArray m_phaseIncrements;
101 AudioFloatArray m_detuneValues;
103 RefPtr<PeriodicWave> m_periodicWave;
105 // Cache the wave tables for different waveform types, except CUSTOM.
106 static PeriodicWave* s_periodicWaveSine;
107 static PeriodicWave* s_periodicWaveSquare;
108 static PeriodicWave* s_periodicWaveSawtooth;
109 static PeriodicWave* s_periodicWaveTriangle;
112 } // namespace WebCore
114 #endif // OscillatorNode_h