/*
 * Copyright (C) 2012, Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1.  Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "AudioScheduledSourceNode.h"
#include <wtf/Lock.h>

namespace WebCore {

class PeriodicWave;

// OscillatorNode is an audio generator of periodic waveforms.

class OscillatorNode final : public AudioScheduledSourceNode {
public:
    // The waveform type.
    enum class Type {
        Sine,
        Square,
        Sawtooth,
        Triangle,
        Custom
    };

    static Ref<OscillatorNode> create(AudioContext&, float sampleRate);

    virtual ~OscillatorNode();

    Type type() const { return m_type; }
    ExceptionOr<void> setType(Type);

    AudioParam* frequency() { return m_frequency.get(); }
    AudioParam* detune() { return m_detune.get(); }

    void setPeriodicWave(PeriodicWave*);

private:
    OscillatorNode(AudioContext&, float sampleRate);

    void process(size_t framesToProcess) final;
    void reset() final;

    double tailTime() const final { return 0; }
    double latencyTime() const final { return 0; }

    // Returns true if there are sample-accurate timeline parameter changes.
    bool calculateSampleAccuratePhaseIncrements(size_t framesToProcess);

    bool propagatesSilence() const final;

    // One of the waveform types defined in the enum.
    Type m_type { Type::Sine };
    
    // Frequency value in Hertz.
    RefPtr<AudioParam> m_frequency;

    // Detune value (deviating from the frequency) in Cents.
    RefPtr<AudioParam> m_detune;

    bool m_firstRender;

    // m_virtualReadIndex is a sample-frame index into our buffer representing the current playback position.
    // Since it's floating-point, it has sub-sample accuracy.
    double m_virtualReadIndex;

    // This synchronizes process().
    mutable Lock m_processMutex;

    // Stores sample-accurate values calculated according to frequency and detune.
    AudioFloatArray m_phaseIncrements;
    AudioFloatArray m_detuneValues;
    
    RefPtr<PeriodicWave> m_periodicWave;

    // Cache the wave tables for different waveform types, except CUSTOM.
    static PeriodicWave* s_periodicWaveSine;
    static PeriodicWave* s_periodicWaveSquare;
    static PeriodicWave* s_periodicWaveSawtooth;
    static PeriodicWave* s_periodicWaveTriangle;
};

} // namespace WebCore