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 #include "config.h" 30 31 #if ENABLE(WEB_AUDIO) 32 33 #include "platform/audio/Cone.h" 34 #include "wtf/MathExtras.h" 35 36 namespace blink { 37 38 ConeEffect::ConeEffect() 39 : m_innerAngle(360.0) 40 , m_outerAngle(360.0) 41 , m_outerGain(0.0) 42 { 43 } 44 45 double 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 blink 84 85 #endif // ENABLE(WEB_AUDIO) 86