15c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)/* 25c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * Copyright (C) 2010 Google Inc. All rights reserved. 35c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 45c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * Redistribution and use in source and binary forms, with or without 55c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * modification, are permitted provided that the following conditions 65c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * are met: 75c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 85c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 1. Redistributions of source code must retain the above copyright 95c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * notice, this list of conditions and the following disclaimer. 105c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 2. Redistributions in binary form must reproduce the above copyright 115c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * notice, this list of conditions and the following disclaimer in the 125c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * documentation and/or other materials provided with the distribution. 135c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 145c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * its contributors may be used to endorse or promote products derived 155c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * from this software without specific prior written permission. 165c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * 175c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 185c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 195c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 205c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 215c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 225c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 235c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 245c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 255c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 265c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 275c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) */ 285c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 295c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#include "config.h" 305c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 315c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#if ENABLE(WEB_AUDIO) 325c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 331e202183a5dc46166763171984b285173f8585e5Torne (Richard Coles)#include "platform/audio/Distance.h" 34f5e4ad553afbc08dd2e729bb77e937a9a94d5827Torne (Richard Coles)#include "wtf/Assertions.h" 355c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 365c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#include <math.h> 3753e740f4a82e17f3ae59772501622dc354e42336Torne (Richard Coles)#include <algorithm> 385c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 39c1847b1379d12d0e05df27436bf19a9b1bf12deaTorne (Richard Coles)namespace blink { 405c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 415c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)DistanceEffect::DistanceEffect() 425c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) : m_model(ModelInverse) 435c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) , m_isClamped(true) 445c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) , m_refDistance(1.0) 455c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) , m_maxDistance(10000.0) 465c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) , m_rolloffFactor(1.0) 475c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 485c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 495c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 505c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)double DistanceEffect::gain(double distance) 515c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 525c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // don't go beyond maximum distance 537242dc3dbeb210b5e876a3c42d1ec1a667fc621aPrimiano Tucci distance = std::min(distance, m_maxDistance); 545c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 555c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // if clamped, don't get closer than reference distance 565c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) if (m_isClamped) 577242dc3dbeb210b5e876a3c42d1ec1a667fc621aPrimiano Tucci distance = std::max(distance, m_refDistance); 585c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 595c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) switch (m_model) { 605c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) case ModelLinear: 615c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return linearGain(distance); 625c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) case ModelInverse: 635c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return inverseGain(distance); 645c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) case ModelExponential: 655c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return exponentialGain(distance); 665c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) } 675c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) ASSERT_NOT_REACHED(); 685c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return 0.0; 695c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 705c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 715c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)double DistanceEffect::linearGain(double distance) 725c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 735c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // We want a gain that decreases linearly from m_refDistance to 745c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) // m_maxDistance. The gain is 1 at m_refDistance. 755c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return (1.0 - m_rolloffFactor * (distance - m_refDistance) / (m_maxDistance - m_refDistance)); 765c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 775c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 785c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)double DistanceEffect::inverseGain(double distance) 795c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 805c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return m_refDistance / (m_refDistance + m_rolloffFactor * (distance - m_refDistance)); 815c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 825c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 835c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)double DistanceEffect::exponentialGain(double distance) 845c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles){ 855c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) return pow(distance / m_refDistance, -m_rolloffFactor); 865c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)} 875c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 88c1847b1379d12d0e05df27436bf19a9b1bf12deaTorne (Richard Coles)} // namespace blink 895c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles) 905c87bf8b86a7c82ef50fb7a89697d8e02e2553beTorne (Richard Coles)#endif // ENABLE(WEB_AUDIO) 91