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/*
* Copyright (c) 2008, 2009, 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:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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.
* * Neither the name of Google Inc. 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT
* OWNER OR 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 "config.h"
#include "BMPImageDecoder.h"
#include "BMPImageReader.h"
namespace WebCore {
// Number of bits in .BMP used to store the file header (doesn't match
// "sizeof(BMPImageDecoder::BitmapFileHeader)" since we omit some fields and
// don't pack).
static const size_t sizeOfFileHeader = 14;
BMPImageDecoder::BMPImageDecoder(bool premultiplyAlpha)
: ImageDecoder(premultiplyAlpha)
, m_decodedOffset(0)
{
}
void BMPImageDecoder::setData(SharedBuffer* data, bool allDataReceived)
{
if (failed())
return;
ImageDecoder::setData(data, allDataReceived);
if (m_reader)
m_reader->setData(data);
}
bool BMPImageDecoder::isSizeAvailable()
{
if (!ImageDecoder::isSizeAvailable())
decode(true);
return ImageDecoder::isSizeAvailable();
}
RGBA32Buffer* BMPImageDecoder::frameBufferAtIndex(size_t index)
{
if (index)
return 0;
if (m_frameBufferCache.isEmpty()) {
m_frameBufferCache.resize(1);
m_frameBufferCache.first().setPremultiplyAlpha(m_premultiplyAlpha);
}
RGBA32Buffer* buffer = &m_frameBufferCache.first();
if (buffer->status() != RGBA32Buffer::FrameComplete)
decode(false);
return buffer;
}
bool BMPImageDecoder::setFailed()
{
m_reader.clear();
return ImageDecoder::setFailed();
}
void BMPImageDecoder::decode(bool onlySize)
{
if (failed())
return;
// If we couldn't decode the image but we've received all the data, decoding
// has failed.
if (!decodeHelper(onlySize) && isAllDataReceived())
setFailed();
// If we're done decoding the image, we don't need the BMPImageReader
// anymore. (If we failed, |m_reader| has already been cleared.)
else if (!m_frameBufferCache.isEmpty() && (m_frameBufferCache.first().status() == RGBA32Buffer::FrameComplete))
m_reader.clear();
}
bool BMPImageDecoder::decodeHelper(bool onlySize)
{
size_t imgDataOffset = 0;
if ((m_decodedOffset < sizeOfFileHeader) && !processFileHeader(&imgDataOffset))
return false;
if (!m_reader) {
m_reader.set(new BMPImageReader(this, m_decodedOffset, imgDataOffset, false));
m_reader->setData(m_data.get());
}
if (!m_frameBufferCache.isEmpty())
m_reader->setBuffer(&m_frameBufferCache.first());
return m_reader->decodeBMP(onlySize);
}
bool BMPImageDecoder::processFileHeader(size_t* imgDataOffset)
{
ASSERT(imgDataOffset);
// Read file header.
ASSERT(!m_decodedOffset);
if (m_data->size() < sizeOfFileHeader)
return false;
const uint16_t fileType = (m_data->data()[0] << 8) | static_cast<uint8_t>(m_data->data()[1]);
*imgDataOffset = readUint32(10);
m_decodedOffset = sizeOfFileHeader;
// See if this is a bitmap filetype we understand.
enum {
BMAP = 0x424D, // "BM"
// The following additional OS/2 2.x header values (see
// http://www.fileformat.info/format/os2bmp/egff.htm ) aren't widely
// decoded, and are unlikely to be in much use.
/*
ICON = 0x4943, // "IC"
POINTER = 0x5054, // "PT"
COLORICON = 0x4349, // "CI"
COLORPOINTER = 0x4350, // "CP"
BITMAPARRAY = 0x4241, // "BA"
*/
};
return (fileType == BMAP) || setFailed();
}
} // namespace WebCore
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