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;
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26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef Distance_h
30#define Distance_h
31
32namespace WebCore {
33
34// Distance models are defined according to the OpenAL specification:
35// http://connect.creativelabs.com/openal/Documentation/OpenAL%201.1%20Specification.htm.
36
37enum class DistanceModelType {
38 Linear,
39 Inverse,
40 Exponential
41};
42
43class DistanceEffect {
44public:
45 DistanceEffect();
46
47 // Returns scalar gain for the given distance the current distance model is used
48 double gain(double distance);
49
50 DistanceModelType model() { return m_model; }
51
52 void setModel(DistanceModelType model, bool clamped)
53 {
54 m_model = model;
55 m_isClamped = clamped;
56 }
57
58 // Distance params
59 void setRefDistance(double refDistance) { m_refDistance = refDistance; }
60 void setMaxDistance(double maxDistance) { m_maxDistance = maxDistance; }
61 void setRolloffFactor(double rolloffFactor) { m_rolloffFactor = rolloffFactor; }
62
63 double refDistance() const { return m_refDistance; }
64 double maxDistance() const { return m_maxDistance; }
65 double rolloffFactor() const { return m_rolloffFactor; }
66
67protected:
68 double linearGain(double distance);
69 double inverseGain(double distance);
70 double exponentialGain(double distance);
71
72 DistanceModelType m_model;
73 bool m_isClamped;
74 double m_refDistance;
75 double m_maxDistance;
76 double m_rolloffFactor;
77};
78
79} // namespace WebCore
80
81#endif // Distance_h
82