third_party/WebKit/Source/platform/audio/EqualPowerPanner.h

/*
 * 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 (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 EqualPowerPanner_h
#define EqualPowerPanner_h

#include "platform/audio/Panner.h"

namespace blink {

// Common type of stereo panner as found in normal audio mixing equipment.

class PLATFORM_EXPORT EqualPowerPanner final : public Panner {
 public:
  EqualPowerPanner(float sampleRate);

  void pan(double azimuth,
           double elevation,
           const AudioBus* inputBus,
           AudioBus* outputBuf,
           size_t framesToProcess,
           AudioBus::ChannelInterpretation) override;
  void panWithSampleAccurateValues(double* azimuth,
                                   double* elevation,
                                   const AudioBus* inputBus,
                                   AudioBus* outputBus,
                                   size_t framesToProcess,
                                   AudioBus::ChannelInterpretation) override;

  void reset() override {}

  double tailTime() const override { return 0; }
  double latencyTime() const override { return 0; }

 private:
  void calculateDesiredGain(double& desiredGainL,
                            double& desiredGainR,
                            double azimuth,
                            int numberOfChannels);
};

}  // namespace blink

#endif  // EqualPowerPanner_h