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 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 HRTFElevation_h
30#define HRTFElevation_h
31
32#include "HRTFKernel.h"
33#include <memory>
34#include <wtf/Noncopyable.h>
35#include <wtf/PassRefPtr.h>
36#include <wtf/RefCounted.h>
37#include <wtf/RefPtr.h>
38#include <wtf/text/CString.h>
39#include <wtf/text/WTFString.h>
40
41namespace WebCore {
42
43// HRTFElevation contains all of the HRTFKernels (one left ear and one right ear per azimuth angle) for a particular elevation.
44
45class HRTFElevation {
46    WTF_MAKE_NONCOPYABLE(HRTFElevation);
47public:
48    HRTFElevation(std::unique_ptr<HRTFKernelList> kernelListL, std::unique_ptr<HRTFKernelList> kernelListR, int elevation, float sampleRate)
49        : m_kernelListL(WTF::move(kernelListL))
50        , m_kernelListR(WTF::move(kernelListR))
51        , m_elevationAngle(elevation)
52        , m_sampleRate(sampleRate)
53    {
54    }
55
56    // Loads and returns an HRTFElevation with the given HRTF database subject name and elevation from browser (or WebKit.framework) resources.
57    // Normally, there will only be a single HRTF database set, but this API supports the possibility of multiple ones with different names.
58    // Interpolated azimuths will be generated based on InterpolationFactor.
59    // Valid values for elevation are -45 -> +90 in 15 degree increments.
60    static std::unique_ptr<HRTFElevation> createForSubject(const String& subjectName, int elevation, float sampleRate);
61
62    // Given two HRTFElevations, and an interpolation factor x: 0 -> 1, returns an interpolated HRTFElevation.
63    static std::unique_ptr<HRTFElevation> createByInterpolatingSlices(HRTFElevation* hrtfElevation1, HRTFElevation* hrtfElevation2, float x, float sampleRate);
64
65    // Returns the list of left or right ear HRTFKernels for all the azimuths going from 0 to 360 degrees.
66    HRTFKernelList* kernelListL() { return m_kernelListL.get(); }
67    HRTFKernelList* kernelListR() { return m_kernelListR.get(); }
68
69    double elevationAngle() const { return m_elevationAngle; }
70    unsigned numberOfAzimuths() const { return NumberOfTotalAzimuths; }
71    float sampleRate() const { return m_sampleRate; }
72
73    // Returns the left and right kernels for the given azimuth index.
74    // The interpolated delays based on azimuthBlend: 0 -> 1 are returned in frameDelayL and frameDelayR.
75    void getKernelsFromAzimuth(double azimuthBlend, unsigned azimuthIndex, HRTFKernel* &kernelL, HRTFKernel* &kernelR, double& frameDelayL, double& frameDelayR);
76
77    // Spacing, in degrees, between every azimuth loaded from resource.
78    static const unsigned AzimuthSpacing;
79
80    // Number of azimuths loaded from resource.
81    static const unsigned NumberOfRawAzimuths;
82
83    // Interpolates by this factor to get the total number of azimuths from every azimuth loaded from resource.
84    static const unsigned InterpolationFactor;
85
86    // Total number of azimuths after interpolation.
87    static const unsigned NumberOfTotalAzimuths;
88
89    // Given a specific azimuth and elevation angle, returns the left and right HRTFKernel.
90    // Valid values for azimuth are 0 -> 345 in 15 degree increments.
91    // Valid values for elevation are -45 -> +90 in 15 degree increments.
92    // Returns true on success.
93    static bool calculateKernelsForAzimuthElevation(int azimuth, int elevation, float sampleRate, const String& subjectName,
94                                                    RefPtr<HRTFKernel>& kernelL, RefPtr<HRTFKernel>& kernelR);
95
96    // Given a specific azimuth and elevation angle, returns the left and right HRTFKernel in kernelL and kernelR.
97    // This method averages the measured response using symmetry of azimuth (for example by averaging the -30.0 and +30.0 azimuth responses).
98    // Returns true on success.
99    static bool calculateSymmetricKernelsForAzimuthElevation(int azimuth, int elevation, float sampleRate, const String& subjectName,
100                                                             RefPtr<HRTFKernel>& kernelL, RefPtr<HRTFKernel>& kernelR);
101
102private:
103    std::unique_ptr<HRTFKernelList> m_kernelListL;
104    std::unique_ptr<HRTFKernelList> m_kernelListR;
105    double m_elevationAngle;
106    float m_sampleRate;
107};
108
109} // namespace WebCore
110
111#endif // HRTFElevation_h
112