xref: /external/chromium_org/third_party/WebKit/Source/platform/audio/ZeroPole.h

/*
 * 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.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE 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 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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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ZeroPole_h
#define ZeroPole_h

#include "platform/PlatformExport.h"

namespace blink {

// ZeroPole is a simple filter with one zero and one pole.

class PLATFORM_EXPORT ZeroPole {
public:
    ZeroPole()
        : m_zero(0)
        , m_pole(0)
        , m_lastX(0)
        , m_lastY(0)
    {
    }

    void process(const float *source, float *destination, unsigned framesToProcess);

    // Reset filter state.
    void reset() { m_lastX = 0; m_lastY = 0; }

    void setZero(float zero) { m_zero = zero; }
    void setPole(float pole) { m_pole = pole; }

    float zero() const { return m_zero; }
    float pole() const { return m_pole; }

private:
    float m_zero;
    float m_pole;
    float m_lastX;
    float m_lastY;
};

} // namespace blink

#endif // ZeroPole_h