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 
ReverbInputBuffer(size_t length)37 ReverbInputBuffer::ReverbInputBuffer(size_t length)
38     : m_buffer(length)
39     , m_writeIndex(0)
40 {
41 }
42 
write(float * sourceP,size_t numberOfFrames)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 
directReadFrom(int * readIndex,size_t numberOfFrames)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 
reset()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