content/media/webaudio/blink/ReverbInputBuffer.cpp

branch
TOR_BUG_9701
changeset 13
44a2da4a2ab2
equal deleted inserted replaced
-1:000000000000 0:9fb3c7a2c538
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 "ReverbInputBuffer.h"
30 #include "mozilla/PodOperations.h"
31
32 using namespace mozilla;
33
34 namespace WebCore {
35
36 ReverbInputBuffer::ReverbInputBuffer(size_t length)
37 : m_writeIndex(0)
38 {
39 m_buffer.SetLength(length);
40 PodZero(m_buffer.Elements(), length);
41 }
42
43 void ReverbInputBuffer::write(const float* sourceP, size_t numberOfFrames)
44 {
45 size_t bufferLength = m_buffer.Length();
46 bool isCopySafe = m_writeIndex + numberOfFrames <= bufferLength;
47 MOZ_ASSERT(isCopySafe);
48 if (!isCopySafe)
49 return;
50
51 memcpy(m_buffer.Elements() + m_writeIndex, sourceP, sizeof(float) * numberOfFrames);
52
53 m_writeIndex += numberOfFrames;
54 MOZ_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.Length();
63 bool isPointerGood = readIndex && *readIndex >= 0 && *readIndex + numberOfFrames <= bufferLength;
64 MOZ_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.Elements();
70 }
71
72 float* sourceP = m_buffer.Elements();
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 PodZero(m_buffer.Elements(), m_buffer.Length());
84 m_writeIndex = 0;
85 }
86
87 } // namespace WebCore

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