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 /*

  * Copyright (C) 2012 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;

  * 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 PeriodicWave_h

 #define PeriodicWave_h

 #include "mozilla/dom/OscillatorNodeBinding.h"

 #include <nsAutoPtr.h>

 #include <nsTArray.h>

 #include "mozilla/MemoryReporting.h"

 namespace WebCore {

 typedef nsTArray<float> AudioFloatArray;

 class PeriodicWave {

 public:

     static PeriodicWave* createSine(float sampleRate);

     static PeriodicWave* createSquare(float sampleRate);

     static PeriodicWave* createSawtooth(float sampleRate);

     static PeriodicWave* createTriangle(float sampleRate);

     // Creates an arbitrary periodic wave given the frequency components

     // (Fourier coefficients).

     static PeriodicWave* create(float sampleRate,

                                 const float* real,

                                 const float* imag,

                                 size_t numberOfComponents);

     // Returns pointers to the lower and higher wave data for the pitch range

     // containing the given fundamental frequency. These two tables are in

     // adjacent "pitch" ranges where the higher table will have the maximum

     // number of partials which won't alias when played back at this

     // fundamental frequency. The lower wave is the next range containing fewer

     // partials than the higher wave. Interpolation between these two tables

     // can be made according to tableInterpolationFactor. Where values

     // from 0 -> 1 interpolate between lower -> higher.

     void waveDataForFundamentalFrequency(float, float* &lowerWaveData, float* &higherWaveData, float& tableInterpolationFactor);

     // Returns the scalar multiplier to the oscillator frequency to calculate

     // wave buffer phase increment.

     float rateScale() const { return m_rateScale; }

     unsigned periodicWaveSize() const { return m_periodicWaveSize; }

     float sampleRate() const { return m_sampleRate; }

     size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;

 private:

     explicit PeriodicWave(float sampleRate);

     void generateBasicWaveform(mozilla::dom::OscillatorType);

     float m_sampleRate;

     unsigned m_periodicWaveSize;

     unsigned m_numberOfRanges;

     float m_centsPerRange;

     // The lowest frequency (in Hertz) where playback will include all of the

     // partials.  Playing back lower than this frequency will gradually lose

     // more high-frequency information.

     // This frequency is quite low (~10Hz @ // 44.1KHz)

     float m_lowestFundamentalFrequency;

     float m_rateScale;

     unsigned numberOfRanges() const { return m_numberOfRanges; }

     // Maximum possible number of partials (before culling).

     unsigned maxNumberOfPartials() const;

     unsigned numberOfPartialsForRange(unsigned rangeIndex) const;

     // Creates tables based on numberOfComponents Fourier coefficients.

     void createBandLimitedTables(const float* real, const float* imag, unsigned numberOfComponents);

     nsTArray<nsAutoPtr<AudioFloatArray> > m_bandLimitedTables;

 };

 } // namespace WebCore

 #endif // PeriodicWave_h