/*
 * 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
 * OWNER OR 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,
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 */

#include "config.h"

#if ENABLE(WEB_AUDIO)

#include "AudioDSPKernelProcessor.h"

#include "AudioDSPKernel.h"

namespace WebCore {

// setNumberOfChannels() may later be called if the object is not yet in an "initialized" state.
AudioDSPKernelProcessor::AudioDSPKernelProcessor(float sampleRate, unsigned numberOfChannels)
    : AudioProcessor(sampleRate, numberOfChannels)
{
}

void AudioDSPKernelProcessor::initialize()
{
    if (isInitialized())
        return;

    ASSERT(!m_kernels.size());
    {
        // Heap allocations are forbidden on the audio thread for performance reasons so we need to
        // explicitly allow the following allocation(s).
        DisableMallocRestrictionsForCurrentThreadScope disableMallocRestrictions;

        // Create processing kernels, one per channel.
        for (unsigned i = 0; i < numberOfChannels(); ++i)
            m_kernels.append(createKernel());
    }
    m_initialized = true;
    m_hasJustReset = true;
}

void AudioDSPKernelProcessor::uninitialize()
{
    if (!isInitialized())
        return;
        
    m_kernels.clear();

    m_initialized = false;
}

void AudioDSPKernelProcessor::process(const AudioBus* source, AudioBus* destination, size_t framesToProcess)
{
    ASSERT(source && destination);
    if (!source || !destination)
        return;
        
    if (!isInitialized()) {
        destination->zero();
        return;
    }

    bool channelCountMatches = source->numberOfChannels() == destination->numberOfChannels() && source->numberOfChannels() == m_kernels.size();
    ASSERT(channelCountMatches);
    if (!channelCountMatches)
        return;
        
    for (unsigned i = 0; i < m_kernels.size(); ++i)
        m_kernels[i]->process(source->channel(i)->data(), destination->channel(i)->mutableData(), framesToProcess);
}

void AudioDSPKernelProcessor::processOnlyAudioParams(size_t framesToProcess)
{
    if (!isInitialized())
        return;

    for (unsigned i = 0; i < m_kernels.size(); ++i)
        m_kernels[i]->processOnlyAudioParams(framesToProcess);
}

// Resets filter state
void AudioDSPKernelProcessor::reset()
{
    if (!isInitialized())
        return;

    // Forces snap to parameter values - first time.
    // Any processing depending on this value must set it to false at the appropriate time.
    m_hasJustReset = true;

    for (unsigned i = 0; i < m_kernels.size(); ++i)
        m_kernels[i]->reset();
}

void AudioDSPKernelProcessor::setNumberOfChannels(unsigned numberOfChannels)
{
    if (numberOfChannels == m_numberOfChannels)
        return;
        
    ASSERT(!isInitialized());
    if (!isInitialized())
        m_numberOfChannels = numberOfChannels;
}

double AudioDSPKernelProcessor::tailTime() const
{
    // It is expected that all the kernels have the same tailTime.
    return !m_kernels.isEmpty() ? m_kernels.first()->tailTime() : 0;
}

double AudioDSPKernelProcessor::latencyTime() const
{
    // It is expected that all the kernels have the same latencyTime.
    return !m_kernels.isEmpty() ? m_kernels.first()->latencyTime() : 0;
}

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

} // namespace WebCore

#endif // ENABLE(WEB_AUDIO)