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#pragma once
26
27#include "AudioScheduledSourceNode.h"
28#include <wtf/Lock.h>
29
30namespace WebCore {
31
32class PeriodicWave;
33
34// OscillatorNode is an audio generator of periodic waveforms.
35
36class OscillatorNode final : public AudioScheduledSourceNode {
37 WTF_MAKE_ISO_ALLOCATED(OscillatorNode);
38public:
39 // The waveform type.
40 enum class Type {
41 Sine,
42 Square,
43 Sawtooth,
44 Triangle,
45 Custom
46 };
47
48 static Ref<OscillatorNode> create(AudioContext&, float sampleRate);
49
50 virtual ~OscillatorNode();
51
52 Type type() const { return m_type; }
53 ExceptionOr<void> setType(Type);
54
55 AudioParam* frequency() { return m_frequency.get(); }
56 AudioParam* detune() { return m_detune.get(); }
57
58 void setPeriodicWave(PeriodicWave*);
59
60private:
61 OscillatorNode(AudioContext&, float sampleRate);
62
63 void process(size_t framesToProcess) final;
64 void reset() final;
65
66 double tailTime() const final { return 0; }
67 double latencyTime() const final { return 0; }
68
69 // Returns true if there are sample-accurate timeline parameter changes.
70 bool calculateSampleAccuratePhaseIncrements(size_t framesToProcess);
71
72 bool propagatesSilence() const final;
73
74 // One of the waveform types defined in the enum.
75 Type m_type { Type::Sine };
76
77 // Frequency value in Hertz.
78 RefPtr<AudioParam> m_frequency;
79
80 // Detune value (deviating from the frequency) in Cents.
81 RefPtr<AudioParam> m_detune;
82
83 bool m_firstRender;
84
85 // m_virtualReadIndex is a sample-frame index into our buffer representing the current playback position.
86 // Since it's floating-point, it has sub-sample accuracy.
87 double m_virtualReadIndex;
88
89 // This synchronizes process().
90 mutable Lock m_processMutex;
91
92 // Stores sample-accurate values calculated according to frequency and detune.
93 AudioFloatArray m_phaseIncrements;
94 AudioFloatArray m_detuneValues;
95
96 RefPtr<PeriodicWave> m_periodicWave;
97
98 // Cache the wave tables for different waveform types, except CUSTOM.
99 static PeriodicWave* s_periodicWaveSine;
100 static PeriodicWave* s_periodicWaveSquare;
101 static PeriodicWave* s_periodicWaveSawtooth;
102 static PeriodicWave* s_periodicWaveTriangle;
103};
104
105String convertEnumerationToString(OscillatorNode::Type); // In JSOscillatorNode.cpp
106
107} // namespace WebCore
108
109namespace WTF {
110
111template<> struct LogArgument<WebCore::OscillatorNode::Type> {
112 static String toString(WebCore::OscillatorNode::Type type) { return convertEnumerationToString(type); }
113};
114
115} // namespace WTF
116