michael@0: /*
michael@0:  * Copyright (C) 2012 Google Inc. All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  *
michael@0:  * 1.  Redistributions of source code must retain the above copyright
michael@0:  *     notice, this list of conditions and the following disclaimer.
michael@0:  * 2.  Redistributions in binary form must reproduce the above copyright
michael@0:  *     notice, this list of conditions and the following disclaimer in the
michael@0:  *     documentation and/or other materials provided with the distribution.
michael@0:  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
michael@0:  *     its contributors may be used to endorse or promote products derived
michael@0:  *     from this software without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
michael@0:  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
michael@0:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
michael@0:  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
michael@0:  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
michael@0:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
michael@0:  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
michael@0:  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
michael@0:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: 
michael@0: #ifndef PeriodicWave_h
michael@0: #define PeriodicWave_h
michael@0: 
michael@0: #include "mozilla/dom/OscillatorNodeBinding.h"
michael@0: #include <nsAutoPtr.h>
michael@0: #include <nsTArray.h>
michael@0: #include "mozilla/MemoryReporting.h"
michael@0: 
michael@0: namespace WebCore {
michael@0: 
michael@0: typedef nsTArray<float> AudioFloatArray;
michael@0: 
michael@0: class PeriodicWave {
michael@0: public:
michael@0:     static PeriodicWave* createSine(float sampleRate);
michael@0:     static PeriodicWave* createSquare(float sampleRate);
michael@0:     static PeriodicWave* createSawtooth(float sampleRate);
michael@0:     static PeriodicWave* createTriangle(float sampleRate);
michael@0: 
michael@0:     // Creates an arbitrary periodic wave given the frequency components
michael@0:     // (Fourier coefficients).
michael@0:     static PeriodicWave* create(float sampleRate,
michael@0:                                 const float* real,
michael@0:                                 const float* imag,
michael@0:                                 size_t numberOfComponents);
michael@0: 
michael@0:     // Returns pointers to the lower and higher wave data for the pitch range
michael@0:     // containing the given fundamental frequency. These two tables are in
michael@0:     // adjacent "pitch" ranges where the higher table will have the maximum
michael@0:     // number of partials which won't alias when played back at this
michael@0:     // fundamental frequency. The lower wave is the next range containing fewer
michael@0:     // partials than the higher wave. Interpolation between these two tables
michael@0:     // can be made according to tableInterpolationFactor. Where values
michael@0:     // from 0 -> 1 interpolate between lower -> higher.
michael@0:     void waveDataForFundamentalFrequency(float, float* &lowerWaveData, float* &higherWaveData, float& tableInterpolationFactor);
michael@0: 
michael@0:     // Returns the scalar multiplier to the oscillator frequency to calculate
michael@0:     // wave buffer phase increment.
michael@0:     float rateScale() const { return m_rateScale; }
michael@0: 
michael@0:     unsigned periodicWaveSize() const { return m_periodicWaveSize; }
michael@0:     float sampleRate() const { return m_sampleRate; }
michael@0: 
michael@0:     size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
michael@0: 
michael@0: private:
michael@0:     explicit PeriodicWave(float sampleRate);
michael@0: 
michael@0:     void generateBasicWaveform(mozilla::dom::OscillatorType);
michael@0: 
michael@0:     float m_sampleRate;
michael@0:     unsigned m_periodicWaveSize;
michael@0:     unsigned m_numberOfRanges;
michael@0:     float m_centsPerRange;
michael@0: 
michael@0:     // The lowest frequency (in Hertz) where playback will include all of the
michael@0:     // partials.  Playing back lower than this frequency will gradually lose
michael@0:     // more high-frequency information.
michael@0:     // This frequency is quite low (~10Hz @ // 44.1KHz)
michael@0:     float m_lowestFundamentalFrequency;
michael@0: 
michael@0:     float m_rateScale;
michael@0: 
michael@0:     unsigned numberOfRanges() const { return m_numberOfRanges; }
michael@0: 
michael@0:     // Maximum possible number of partials (before culling).
michael@0:     unsigned maxNumberOfPartials() const;
michael@0: 
michael@0:     unsigned numberOfPartialsForRange(unsigned rangeIndex) const;
michael@0: 
michael@0:     // Creates tables based on numberOfComponents Fourier coefficients.
michael@0:     void createBandLimitedTables(const float* real, const float* imag, unsigned numberOfComponents);
michael@0:     nsTArray<nsAutoPtr<AudioFloatArray> > m_bandLimitedTables;
michael@0: };
michael@0: 
michael@0: } // namespace WebCore
michael@0: 
michael@0: #endif // PeriodicWave_h