/*
 * Copyright 2016 The Chromium Authors. All rights reserved.
 * Copyright (C) 2020, Apple 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
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"

#if ENABLE(WEB_AUDIO)
#include "IIRDSPKernel.h"

namespace WebCore {

IIRDSPKernel::IIRDSPKernel(IIRProcessor& processor)
    : AudioDSPKernel(&processor)
    , m_iirFilter(processor.feedforward(), processor.feedback())
    , m_tailTime(m_iirFilter.tailTime(processor.sampleRate(), processor.isFilterStable()))
{
}

void IIRDSPKernel::getFrequencyResponse(unsigned length, const float* frequencyHz, float* magResponse, float* phaseResponse)
{
    ASSERT(frequencyHz);
    ASSERT(magResponse);
    ASSERT(phaseResponse);

    Vector<float> frequency(length);
    double nyquist = this->nyquist();

    // Convert from frequency in Hz to normalized frequency (0 -> 1), with 1 equal to the Nyquist frequency.
    for (unsigned k = 0; k < length; ++k)
        frequency[k] = frequencyHz[k] / nyquist;

    m_iirFilter.getFrequencyResponse(length, frequency.data(), magResponse, phaseResponse);
}

void IIRDSPKernel::process(const float* source, float* destination, size_t framesToProcess)
{
    ASSERT(source);
    ASSERT(destination);

    m_iirFilter.process(source, destination, framesToProcess);
}

void IIRDSPKernel::reset()
{
    m_iirFilter.reset();
}

bool IIRDSPKernel::requiresTailProcessing() const
{
    // Always return true even if the tail time and latency might both be zero.
    return true;
}

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)