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/webaudio/AudioParam.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/webaudio/AudioParam.cpp')
-rw-r--r-- | Source/WebCore/webaudio/AudioParam.cpp | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/Source/WebCore/webaudio/AudioParam.cpp b/Source/WebCore/webaudio/AudioParam.cpp new file mode 100644 index 0000000..dcf918f --- /dev/null +++ b/Source/WebCore/webaudio/AudioParam.cpp @@ -0,0 +1,66 @@ +/* + * 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. + * + * 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 "AudioParam.h" + +#include <wtf/MathExtras.h> + +namespace WebCore { + +const double AudioParam::DefaultSmoothingConstant = 0.05; +const double AudioParam::SnapThreshold = 0.001; + +void AudioParam::setValue(float value) +{ + // Check against JavaScript giving us bogus floating-point values. + // Don't ASSERT, since this can happen if somebody writes bad JS. + if (!isnan(value) && !isinf(value)) + m_value = value; +} + +bool AudioParam::smooth() +{ + if (m_smoothedValue == m_value) { + // Smoothed value has already approached and snapped to value. + return true; + } + + // Exponential approach + m_smoothedValue += (m_value - m_smoothedValue) * m_smoothingConstant; + + // If we get close enough then snap to actual value. + if (fabs(m_smoothedValue - m_value) < SnapThreshold) // FIXME: the threshold needs to be adjustable depending on range - but this is OK general purpose value. + m_smoothedValue = m_value; + + return false; +} + +} // namespace WebCore + +#endif // ENABLE(WEB_AUDIO) |