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 "platform/audio/HRTFElevation.h"
33#include "wtf/Forward.h"
34#include "wtf/Noncopyable.h"
35#include "wtf/OwnPtr.h"
36#include "wtf/PassRefPtr.h"
37#include "wtf/Vector.h"
38
39namespace blink {
40
41class HRTFKernel;
42
43class PLATFORM_EXPORT HRTFDatabase {
44    WTF_MAKE_NONCOPYABLE(HRTFDatabase);
45public:
46    static PassOwnPtr<HRTFDatabase> create(float sampleRate);
47
48    // getKernelsFromAzimuthElevation() returns a left and right ear kernel, and an interpolated left and right frame delay for the given azimuth and elevation.
49    // azimuthBlend must be in the range 0 -> 1.
50    // Valid values for azimuthIndex are 0 -> HRTFElevation::NumberOfTotalAzimuths - 1 (corresponding to angles of 0 -> 360).
51    // Valid values for elevationAngle are MinElevation -> MaxElevation.
52    void getKernelsFromAzimuthElevation(double azimuthBlend, unsigned azimuthIndex, double elevationAngle, HRTFKernel* &kernelL, HRTFKernel* &kernelR, double& frameDelayL, double& frameDelayR);
53
54    // Returns the number of different azimuth angles.
55    static unsigned numberOfAzimuths() { return HRTFElevation::NumberOfTotalAzimuths; }
56
57    float sampleRate() const { return m_sampleRate; }
58
59    // Number of elevations loaded from resource.
60    static const unsigned NumberOfRawElevations;
61
62private:
63    explicit HRTFDatabase(float 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    // Interpolates by this factor to get the total number of elevations from every elevation loaded from resource.
71    static const unsigned InterpolationFactor;
72
73    // Total number of elevations after interpolation.
74    static const unsigned NumberOfTotalElevations;
75
76    // Returns the index for the correct HRTFElevation given the elevation angle.
77    static unsigned indexFromElevationAngle(double);
78
79    Vector<OwnPtr<HRTFElevation> > m_elevations;
80    float m_sampleRate;
81};
82
83} // namespace blink
84
85#endif // HRTFDatabase_h
86