/*
 * Copyright (C) 2010, 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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 */

#ifndef AudioDelayDSPKernel_h
#define AudioDelayDSPKernel_h

#include "platform/audio/AudioArray.h"
#include "platform/audio/AudioDSPKernel.h"

namespace blink {

class PLATFORM_EXPORT AudioDelayDSPKernel : public AudioDSPKernel {
public:
    AudioDelayDSPKernel(double maxDelayTime, float sampleRate);

    virtual void process(const float* source, float* destination, size_t framesToProcess) OVERRIDE;
    virtual void reset() OVERRIDE;

    double maxDelayTime() const { return m_maxDelayTime; }

    void setDelayFrames(double numberOfFrames) { m_desiredDelayFrames = numberOfFrames; }

    virtual double tailTime() const OVERRIDE;
    virtual double latencyTime() const OVERRIDE;

protected:
    AudioDelayDSPKernel(AudioDSPKernelProcessor*, size_t processingSizeInFrames);

    virtual bool hasSampleAccurateValues();
    virtual void calculateSampleAccurateValues(float* delayTimes, size_t framesToProcess);
    virtual double delayTime(float sampleRate);

    AudioFloatArray m_buffer;
    double m_maxDelayTime;
    int m_writeIndex;
    double m_currentDelayTime;
    double m_smoothingRate;
    bool m_firstTime;
    double m_desiredDelayFrames;

    AudioFloatArray m_delayTimes;

    size_t bufferLengthForDelay(double delayTime, double sampleRate) const;
};

} // namespace blink

#endif // AudioDelayDSPKernel_h