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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "image/gif.h"
#include "common/array.h"
#include "common/stream.h"
#include "common/textconsole.h"
#include "common/util.h"
#include "graphics/surface.h"
#include "graphics/pixelformat.h"
#ifdef USE_GIF
#include <gif_lib.h>
#endif
namespace Image {
GIFDecoder::GIFDecoder() : _outputSurface(0), _palette(0), _colorCount(0) {
}
GIFDecoder::~GIFDecoder() {
destroy();
}
#ifdef USE_GIF
static int gifReadFromStream(GifFileType *gif, GifByteType *bytes, int size) {
Common::SeekableReadStream *stream = (Common::SeekableReadStream *)gif->UserData;
return stream->read(bytes, size);
}
#endif
bool GIFDecoder::loadStream(Common::SeekableReadStream &stream) {
destroy();
#ifdef USE_GIF
int error = 0;
GifFileType *gif = DGifOpen(&stream, gifReadFromStream, &error);
if (!gif) {
warning("GIF open failed with error %s", GifErrorString(error));
return false;
}
const int errcode = DGifSlurp(gif);
if (errcode != GIF_OK) {
warning("GIF failed to load");
DGifCloseFile(gif, 0);
return false;
}
if (gif->ImageCount <= 0) {
warning("GIF doesn't contain valid image data");
DGifCloseFile(gif, 0);
return false;
}
if (gif->ImageCount > 1) {
warning("GIF contains more than one frame - only loading the first one");
}
const SavedImage *gifImage = gif->SavedImages;
const int width = gif->SWidth;
const int height = gif->SHeight;
const ColorMapObject *colorMap = gif->SColorMap;
_hasTransparentColor = false;
for (int i = 0; i < gif->ExtensionBlockCount; ++i) {
const ExtensionBlock &eb = gif->ExtensionBlocks[i];
GraphicsControlBlock gcb;
DGifExtensionToGCB(eb.ByteCount, eb.Bytes, &gcb);
if (gcb.TransparentColor != NO_TRANSPARENT_COLOR) {
_hasTransparentColor = true;
_transparentColor = gcb.TransparentColor;
break;
}
}
_colorCount = colorMap->ColorCount;
_outputSurface = new Graphics::Surface();
_palette = new uint8[_colorCount * 3];
const Graphics::PixelFormat format = Graphics::PixelFormat::createFormatCLUT8();
for (int i = 0; i < _colorCount; ++i) {
_palette[(i * 3) + 0] = colorMap->Colors[i].Red;
_palette[(i * 3) + 1] = colorMap->Colors[i].Green;
_palette[(i * 3) + 2] = colorMap->Colors[i].Blue;
}
// TODO: support transparency
_outputSurface->create(width, height, format);
const uint8 *in = (const uint8 *)gifImage->RasterBits;
uint8 *pixelPtr = (uint8 *)_outputSurface->getBasePtr(0, 0);
if (gif->Image.Interlace) {
const int interlacedOffset[] = {0, 4, 2, 1};
const int interlacedJumps[] = {8, 8, 4, 2};
for (int i = 0; i < 4; ++i) {
for (int row = interlacedOffset[i]; row < height; row += interlacedJumps[i]) {
memcpy(pixelPtr + width * row, in, width);
in += width;
}
}
} else {
memcpy(pixelPtr, in, width * height);
}
DGifCloseFile(gif, 0);
return true;
#else
return false;
#endif
}
void GIFDecoder::destroy() {
if (_outputSurface) {
_outputSurface->free();
delete _outputSurface;
_outputSurface = 0;
}
if (_palette) {
delete[] _palette;
_palette = 0;
}
}
} // End of namespace Image
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