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      1 /*
      2  * Copyright (C) 2010 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1.  Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  * 2.  Redistributions in binary form must reproduce the above copyright
     11  *     notice, this list of conditions and the following disclaimer in the
     12  *     documentation and/or other materials provided with the distribution.
     13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
     14  *     its contributors may be used to endorse or promote products derived
     15  *     from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #ifndef HRTFDatabase_h
     30 #define HRTFDatabase_h
     31 
     32 #include "HRTFElevation.h"
     33 #include <wtf/HashMap.h>
     34 #include <wtf/Noncopyable.h>
     35 #include <wtf/OwnPtr.h>
     36 #include <wtf/PassRefPtr.h>
     37 #include <wtf/Vector.h>
     38 #include <wtf/text/CString.h>
     39 #include <wtf/text/StringHash.h>
     40 #include <wtf/text/WTFString.h>
     41 
     42 namespace WebCore {
     43 
     44 class HRTFKernel;
     45 
     46 class HRTFDatabase {
     47     WTF_MAKE_NONCOPYABLE(HRTFDatabase);
     48 public:
     49     static PassOwnPtr<HRTFDatabase> create(double sampleRate);
     50 
     51     // getKernelsFromAzimuthElevation() returns a left and right ear kernel, and an interpolated left and right frame delay for the given azimuth and elevation.
     52     // azimuthBlend must be in the range 0 -> 1.
     53     // Valid values for azimuthIndex are 0 -> HRTFElevation::NumberOfTotalAzimuths - 1 (corresponding to angles of 0 -> 360).
     54     // Valid values for elevationAngle are MinElevation -> MaxElevation.
     55     void getKernelsFromAzimuthElevation(double azimuthBlend, unsigned azimuthIndex, double elevationAngle, HRTFKernel* &kernelL, HRTFKernel* &kernelR, double& frameDelayL, double& frameDelayR);
     56 
     57     // Returns the number of different azimuth angles.
     58     static unsigned numberOfAzimuths() { return HRTFElevation::NumberOfTotalAzimuths; }
     59 
     60     double sampleRate() const { return m_sampleRate; }
     61 
     62 private:
     63     explicit HRTFDatabase(double sampleRate);
     64 
     65     // Minimum and maximum elevation angles (inclusive) for a HRTFDatabase.
     66     static const int MinElevation;
     67     static const int MaxElevation;
     68     static const unsigned RawElevationAngleSpacing;
     69 
     70     // Number of elevations loaded from resource.
     71     static const unsigned NumberOfRawElevations;
     72 
     73     // Interpolates by this factor to get the total number of elevations from every elevation loaded from resource.
     74     static const unsigned InterpolationFactor;
     75 
     76     // Total number of elevations after interpolation.
     77     static const unsigned NumberOfTotalElevations;
     78 
     79     // Returns the index for the correct HRTFElevation given the elevation angle.
     80     static unsigned indexFromElevationAngle(double);
     81 
     82     Vector<OwnPtr<HRTFElevation> > m_elevations;
     83     double m_sampleRate;
     84 };
     85 
     86 } // namespace WebCore
     87 
     88 #endif // HRTFDatabase_h
     89