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#include "config.h"
30
31#if ENABLE(WEB_AUDIO)
32
33#include "Cone.h"
34#include <wtf/MathExtras.h>
35
36namespace WebCore {
37
38ConeEffect::ConeEffect()
39 : m_innerAngle(360.0)
40 , m_outerAngle(360.0)
41 , m_outerGain(0.0)
42{
43}
44
45double ConeEffect::gain(FloatPoint3D sourcePosition, FloatPoint3D sourceOrientation, FloatPoint3D listenerPosition)
46{
47 if (sourceOrientation.isZero() || ((m_innerAngle == 360.0) && (m_outerAngle == 360.0)))
48 return 1.0; // no cone specified - unity gain
49
50 // Normalized source-listener vector
51 FloatPoint3D sourceToListener = listenerPosition - sourcePosition;
52 sourceToListener.normalize();
53
54 FloatPoint3D normalizedSourceOrientation = sourceOrientation;
55 normalizedSourceOrientation.normalize();
56
57 // Angle between the source orientation vector and the source-listener vector
58 double dotProduct = sourceToListener.dot(normalizedSourceOrientation);
59 double angle = 180.0 * acos(dotProduct) / piDouble;
60 double absAngle = fabs(angle);
61
62 // Divide by 2.0 here since API is entire angle (not half-angle)
63 double absInnerAngle = fabs(m_innerAngle) / 2.0;
64 double absOuterAngle = fabs(m_outerAngle) / 2.0;
65 double gain = 1.0;
66
67 if (absAngle <= absInnerAngle)
68 // No attenuation
69 gain = 1.0;
70 else if (absAngle >= absOuterAngle)
71 // Max attenuation
72 gain = m_outerGain;
73 else {
74 // Between inner and outer cones
75 // inner -> outer, x goes from 0 -> 1
76 double x = (absAngle - absInnerAngle) / (absOuterAngle - absInnerAngle);
77 gain = (1.0 - x) + m_outerGain * x;
78 }
79
80 return gain;
81}
82
83} // namespace WebCore
84
85#endif // ENABLE(WEB_AUDIO)
86