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      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 "ReverbInputBuffer.h"
     34 
     35 namespace WebCore {
     36 
     37 ReverbInputBuffer::ReverbInputBuffer(size_t length)
     38     : m_buffer(length)
     39     , m_writeIndex(0)
     40 {
     41 }
     42 
     43 void ReverbInputBuffer::write(float* sourceP, size_t numberOfFrames)
     44 {
     45     size_t bufferLength = m_buffer.size();
     46     bool isCopySafe = m_writeIndex + numberOfFrames <= bufferLength;
     47     ASSERT(isCopySafe);
     48     if (!isCopySafe)
     49         return;
     50 
     51     memcpy(m_buffer.data() + m_writeIndex, sourceP, sizeof(float) * numberOfFrames);
     52 
     53     m_writeIndex += numberOfFrames;
     54     ASSERT(m_writeIndex <= bufferLength);
     55 
     56     if (m_writeIndex >= bufferLength)
     57         m_writeIndex = 0;
     58 }
     59 
     60 float* ReverbInputBuffer::directReadFrom(int* readIndex, size_t numberOfFrames)
     61 {
     62     size_t bufferLength = m_buffer.size();
     63     bool isPointerGood = readIndex && *readIndex >= 0 && *readIndex + numberOfFrames <= bufferLength;
     64     ASSERT(isPointerGood);
     65     if (!isPointerGood) {
     66         // Should never happen in practice but return pointer to start of buffer (avoid crash)
     67         if (readIndex)
     68             *readIndex = 0;
     69         return m_buffer.data();
     70     }
     71 
     72     float* sourceP = m_buffer.data();
     73     float* p = sourceP + *readIndex;
     74 
     75     // Update readIndex
     76     *readIndex = (*readIndex + numberOfFrames) % bufferLength;
     77 
     78     return p;
     79 }
     80 
     81 void ReverbInputBuffer::reset()
     82 {
     83     m_buffer.zero();
     84     m_writeIndex = 0;
     85 }
     86 
     87 } // namespace WebCore
     88 
     89 #endif // ENABLE(WEB_AUDIO)
     90