root/WaveShaperProcessor.h

INCLUDED FROM

/*
 * Copyright (C) 2011, 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
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef WaveShaperProcessor_h
#define WaveShaperProcessor_h

#include "core/platform/audio/AudioDSPKernel.h"
#include "core/platform/audio/AudioDSPKernelProcessor.h"
#include "modules/webaudio/AudioNode.h"
#include "wtf/Float32Array.h"
#include "wtf/RefPtr.h"
#include "wtf/Threading.h"

namespace WebCore {

// WaveShaperProcessor is an AudioDSPKernelProcessor which uses WaveShaperDSPKernel objects to implement non-linear distortion effects.

class WaveShaperProcessor : public AudioDSPKernelProcessor {
public:
    enum OverSampleType {
        OverSampleNone,
        OverSample2x,
        OverSample4x
    };

    WaveShaperProcessor(float sampleRate, size_t numberOfChannels);

    virtual ~WaveShaperProcessor();

    virtual PassOwnPtr<AudioDSPKernel> createKernel();

    virtual void process(const AudioBus* source, AudioBus* destination, size_t framesToProcess);

    void setCurve(Float32Array*);
    Float32Array* curve() { return m_curve.get(); }

    void setOversample(OverSampleType);
    OverSampleType oversample() const { return m_oversample; }

private:
    // m_curve represents the non-linear shaping curve.
    RefPtr<Float32Array> m_curve;

    OverSampleType m_oversample;

    // This synchronizes process() with setCurve().
    mutable Mutex m_processLock;
};

} // namespace WebCore

#endif // WaveShaperProcessor_h