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 /*

  * Copyright (C) 2010 Google Inc. All rights reserved.

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  * modification, are permitted provided that the following conditions

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  *     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

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  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

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 #include "HRTFDatabase.h"

 #include "HRTFElevation.h"

 using namespace std;

 namespace WebCore {

 const int HRTFDatabase::MinElevation = -45;

 const int HRTFDatabase::MaxElevation = 90;

 const unsigned HRTFDatabase::RawElevationAngleSpacing = 15;

 const unsigned HRTFDatabase::NumberOfRawElevations = 10; // -45 -> +90 (each 15 degrees)

 const unsigned HRTFDatabase::InterpolationFactor = 1;

 const unsigned HRTFDatabase::NumberOfTotalElevations = NumberOfRawElevations * InterpolationFactor;

 nsReturnRef<HRTFDatabase> HRTFDatabase::create(float sampleRate)

 {

     return nsReturnRef<HRTFDatabase>(new HRTFDatabase(sampleRate));

 }

 HRTFDatabase::HRTFDatabase(float sampleRate)

     : m_sampleRate(sampleRate)

 {

     m_elevations.SetLength(NumberOfTotalElevations);

     unsigned elevationIndex = 0;

     for (int elevation = MinElevation; elevation <= MaxElevation; elevation += RawElevationAngleSpacing) {

         nsAutoRef<HRTFElevation> hrtfElevation(HRTFElevation::createBuiltin(elevation, sampleRate));

         MOZ_ASSERT(hrtfElevation.get());

         if (!hrtfElevation.get())

             return;

         m_elevations[elevationIndex] = hrtfElevation.out();

         elevationIndex += InterpolationFactor;

     }

     // Now, go back and interpolate elevations.

     if (InterpolationFactor > 1) {

         for (unsigned i = 0; i < NumberOfTotalElevations; i += InterpolationFactor) {

             unsigned j = (i + InterpolationFactor);

             if (j >= NumberOfTotalElevations)

                 j = i; // for last elevation interpolate with itself

             // Create the interpolated convolution kernels and delays.

             for (unsigned jj = 1; jj < InterpolationFactor; ++jj) {

                 float x = static_cast<float>(jj) / static_cast<float>(InterpolationFactor);

                 m_elevations[i + jj] = HRTFElevation::createByInterpolatingSlices(m_elevations[i].get(), m_elevations[j].get(), x, sampleRate);

                 MOZ_ASSERT(m_elevations[i + jj].get());

             }

         }

     }

 }

 size_t HRTFDatabase::sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const

 {

     size_t amount = aMallocSizeOf(this);

     amount += m_elevations.SizeOfExcludingThis(aMallocSizeOf);

     for (size_t i = 0; i < m_elevations.Length(); i++) {

       amount += m_elevations[i]->sizeOfIncludingThis(aMallocSizeOf);

     }

     return amount;

 }

 void HRTFDatabase::getKernelsFromAzimuthElevation(double azimuthBlend, unsigned azimuthIndex, double elevationAngle, HRTFKernel* &kernelL, HRTFKernel* &kernelR,

                                                   double& frameDelayL, double& frameDelayR)

 {

     unsigned elevationIndex = indexFromElevationAngle(elevationAngle);

     MOZ_ASSERT(elevationIndex < m_elevations.Length() && m_elevations.Length() > 0);

     if (!m_elevations.Length()) {

         kernelL = 0;

         kernelR = 0;

         return;

     }

     if (elevationIndex > m_elevations.Length() - 1)

         elevationIndex = m_elevations.Length() - 1;

     HRTFElevation* hrtfElevation = m_elevations[elevationIndex].get();

     MOZ_ASSERT(hrtfElevation);

     if (!hrtfElevation) {

         kernelL = 0;

         kernelR = 0;

         return;

     }

     hrtfElevation->getKernelsFromAzimuth(azimuthBlend, azimuthIndex, kernelL, kernelR, frameDelayL, frameDelayR);

 }                                                     

 unsigned HRTFDatabase::indexFromElevationAngle(double elevationAngle)

 {

     // Clamp to allowed range.

     elevationAngle = mozilla::clamped(elevationAngle,

                                       static_cast<double>(MinElevation),

                                       static_cast<double>(MaxElevation));

     unsigned elevationIndex = static_cast<int>(InterpolationFactor * (elevationAngle - MinElevation) / RawElevationAngleSpacing);    

     return elevationIndex;

 }

 } // namespace WebCore