1/*
2 * Copyright (c) 2008, 2009, 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 are
6 * met:
7 *
8 *     * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *     * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 *     * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "config.h"
32#include "BMPImageDecoder.h"
33
34#include "BMPImageReader.h"
35
36namespace WebCore {
37
38// Number of bits in .BMP used to store the file header (doesn't match
39// "sizeof(BMPImageDecoder::BitmapFileHeader)" since we omit some fields and
40// don't pack).
41static const size_t sizeOfFileHeader = 14;
42
43BMPImageDecoder::BMPImageDecoder()
44    : ImageDecoder()
45    , m_allDataReceived(false)
46    , m_decodedOffset(0)
47{
48}
49
50void BMPImageDecoder::setData(SharedBuffer* data, bool allDataReceived)
51{
52    if (failed())
53        return;
54
55    ImageDecoder::setData(data, allDataReceived);
56    m_allDataReceived = allDataReceived;
57    if (m_reader)
58        m_reader->setData(data);
59}
60
61bool BMPImageDecoder::isSizeAvailable()
62{
63    if (!ImageDecoder::isSizeAvailable() && !failed())
64        decodeWithCheckForDataEnded(true);
65
66    return ImageDecoder::isSizeAvailable();
67}
68
69RGBA32Buffer* BMPImageDecoder::frameBufferAtIndex(size_t index)
70{
71    if (index)
72        return 0;
73
74    if (m_frameBufferCache.isEmpty())
75        m_frameBufferCache.resize(1);
76
77    RGBA32Buffer* buffer = &m_frameBufferCache.first();
78    if (buffer->status() != RGBA32Buffer::FrameComplete && !failed())
79        decodeWithCheckForDataEnded(false);
80    return buffer;
81}
82
83void BMPImageDecoder::decodeWithCheckForDataEnded(bool onlySize)
84{
85    if (failed())
86        return;
87
88    // If we couldn't decode the image but we've received all the data, decoding
89    // has failed.
90    if (!decode(onlySize) && m_allDataReceived)
91        setFailed();
92}
93
94bool BMPImageDecoder::decode(bool onlySize)
95{
96    size_t imgDataOffset = 0;
97    if ((m_decodedOffset < sizeOfFileHeader)
98        && !processFileHeader(&imgDataOffset))
99        return false;
100
101    if (!m_reader) {
102        m_reader.set(new BMPImageReader(this, m_decodedOffset, imgDataOffset,
103                                        false));
104        m_reader->setData(m_data.get());
105    }
106
107    if (!m_frameBufferCache.isEmpty())
108        m_reader->setBuffer(&m_frameBufferCache.first());
109
110    return m_reader->decodeBMP(onlySize);
111}
112
113bool BMPImageDecoder::processFileHeader(size_t* imgDataOffset)
114{
115    ASSERT(imgDataOffset);
116
117    // Read file header.
118    ASSERT(!m_decodedOffset);
119    if (m_data->size() < sizeOfFileHeader)
120        return false;
121    const uint16_t fileType =
122        (m_data->data()[0] << 8) | static_cast<uint8_t>(m_data->data()[1]);
123    *imgDataOffset = readUint32(10);
124    m_decodedOffset = sizeOfFileHeader;
125
126    // See if this is a bitmap filetype we understand.
127    enum {
128        BMAP = 0x424D,  // "BM"
129        // The following additional OS/2 2.x header values (see
130        // http://www.fileformat.info/format/os2bmp/egff.htm ) aren't widely
131        // decoded, and are unlikely to be in much use.
132        /*
133        ICON = 0x4943,  // "IC"
134        POINTER = 0x5054,  // "PT"
135        COLORICON = 0x4349,  // "CI"
136        COLORPOINTER = 0x4350,  // "CP"
137        BITMAPARRAY = 0x4241,  // "BA"
138        */
139    };
140    if (fileType != BMAP) {
141        setFailed();
142        return false;
143    }
144
145    return true;
146}
147
148} // namespace WebCore
149