/*
 * 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;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * 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.
 */

#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "modules/webaudio/DelayDSPKernel.h"

#include "platform/audio/AudioUtilities.h"
#include "wtf/MathExtras.h"
#include <algorithm>

namespace blink {

const float SmoothingTimeConstant = 0.020f; // 20ms

DelayDSPKernel::DelayDSPKernel(DelayProcessor* processor)
    : AudioDelayDSPKernel(processor, AudioNode::ProcessingSizeInFrames)
{
    ASSERT(processor && processor->sampleRate() > 0);
    if (!(processor && processor->sampleRate() > 0))
        return;

    m_maxDelayTime = processor->maxDelayTime();
    ASSERT(m_maxDelayTime >= 0 && !std::isnan(m_maxDelayTime));
    if (m_maxDelayTime < 0 || std::isnan(m_maxDelayTime))
        return;

    m_buffer.allocate(bufferLengthForDelay(m_maxDelayTime, processor->sampleRate()));
    m_buffer.zero();

    m_smoothingRate = AudioUtilities::discreteTimeConstantForSampleRate(SmoothingTimeConstant, processor->sampleRate());
}

bool DelayDSPKernel::hasSampleAccurateValues()
{
    return delayProcessor()->delayTime()->hasSampleAccurateValues();
}

void DelayDSPKernel::calculateSampleAccurateValues(float* delayTimes, size_t framesToProcess)
{
    delayProcessor()->delayTime()->calculateSampleAccurateValues(delayTimes, framesToProcess);
}

double DelayDSPKernel::delayTime(float)
{
    return delayProcessor()->delayTime()->finalValue();
}

} // namespace blink

#endif // ENABLE(WEB_AUDIO)
