gecko-dev/dom/media/webaudio/blink/ReverbInputBuffer.cpp

88 строки
3.1 KiB
C++

/*
* 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 "ReverbInputBuffer.h"
#include "mozilla/PodOperations.h"
using namespace mozilla;
namespace WebCore {
ReverbInputBuffer::ReverbInputBuffer(size_t length)
: m_writeIndex(0)
{
m_buffer.SetLength(length);
PodZero(m_buffer.Elements(), length);
}
void ReverbInputBuffer::write(const float* sourceP, size_t numberOfFrames)
{
size_t bufferLength = m_buffer.Length();
bool isCopySafe = m_writeIndex + numberOfFrames <= bufferLength;
MOZ_ASSERT(isCopySafe);
if (!isCopySafe)
return;
memcpy(m_buffer.Elements() + m_writeIndex, sourceP, sizeof(float) * numberOfFrames);
m_writeIndex += numberOfFrames;
MOZ_ASSERT(m_writeIndex <= bufferLength);
if (m_writeIndex >= bufferLength)
m_writeIndex = 0;
}
float* ReverbInputBuffer::directReadFrom(int* readIndex, size_t numberOfFrames)
{
size_t bufferLength = m_buffer.Length();
bool isPointerGood = readIndex && *readIndex >= 0 && *readIndex + numberOfFrames <= bufferLength;
MOZ_ASSERT(isPointerGood);
if (!isPointerGood) {
// Should never happen in practice but return pointer to start of buffer (avoid crash)
if (readIndex)
*readIndex = 0;
return m_buffer.Elements();
}
float* sourceP = m_buffer.Elements();
float* p = sourceP + *readIndex;
// Update readIndex
*readIndex = (*readIndex + numberOfFrames) % bufferLength;
return p;
}
void ReverbInputBuffer::reset()
{
PodZero(m_buffer.Elements(), m_buffer.Length());
m_writeIndex = 0;
}
} // namespace WebCore