diff options
author | Steve Block <steveblock@google.com> | 2011-05-06 11:45:16 +0100 |
---|---|---|
committer | Steve Block <steveblock@google.com> | 2011-05-12 13:44:10 +0100 |
commit | cad810f21b803229eb11403f9209855525a25d57 (patch) | |
tree | 29a6fd0279be608e0fe9ffe9841f722f0f4e4269 /Source/WebCore/platform/audio/Distance.cpp | |
parent | 121b0cf4517156d0ac5111caf9830c51b69bae8f (diff) | |
download | external_webkit-cad810f21b803229eb11403f9209855525a25d57.zip external_webkit-cad810f21b803229eb11403f9209855525a25d57.tar.gz external_webkit-cad810f21b803229eb11403f9209855525a25d57.tar.bz2 |
Merge WebKit at r75315: Initial merge by git.
Change-Id: I570314b346ce101c935ed22a626b48c2af266b84
Diffstat (limited to 'Source/WebCore/platform/audio/Distance.cpp')
-rw-r--r-- | Source/WebCore/platform/audio/Distance.cpp | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/Source/WebCore/platform/audio/Distance.cpp b/Source/WebCore/platform/audio/Distance.cpp new file mode 100644 index 0000000..0f1b005 --- /dev/null +++ b/Source/WebCore/platform/audio/Distance.cpp @@ -0,0 +1,93 @@ +/* + * Copyright (C) 2010 Google Inc. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of + * its contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "config.h" + +#if ENABLE(WEB_AUDIO) + +#include "Distance.h" + +#include <algorithm> +#include <math.h> + +using namespace std; + +namespace WebCore { + +DistanceEffect::DistanceEffect() + : m_model(ModelInverse) + , m_isClamped(true) + , m_refDistance(1.0) + , m_maxDistance(10000.0) + , m_rolloffFactor(1.0) +{ +} + +double DistanceEffect::gain(double distance) +{ + // don't go beyond maximum distance + distance = min(distance, m_maxDistance); + + // if clamped, don't get closer than reference distance + if (m_isClamped) + distance = max(distance, m_refDistance); + + switch (m_model) { + case ModelLinear: + return linearGain(distance); + break; + case ModelInverse: + return inverseGain(distance); + break; + case ModelExponential: + return exponentialGain(distance); + break; + + default: + return 0.0; + } +} + +double DistanceEffect::linearGain(double distance) +{ + return (1.0 - m_rolloffFactor * (distance - m_refDistance)) / (m_maxDistance - m_refDistance); +} + +double DistanceEffect::inverseGain(double distance) +{ + return m_refDistance / (m_refDistance + m_rolloffFactor * (distance - m_refDistance)); +} + +double DistanceEffect::exponentialGain(double distance) +{ + return pow(distance / m_refDistance, -m_rolloffFactor); +} + +} // namespace WebCore + +#endif // ENABLE(WEB_AUDIO) |