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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 2
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
// Based off ffmpeg's msrledec.c
#include "image/codecs/msrle.h"
#include "common/stream.h"
#include "common/textconsole.h"
namespace Image {
MSRLEDecoder::MSRLEDecoder(uint16 width, uint16 height, byte bitsPerPixel) {
_surface = new Graphics::Surface();
_surface->create(width, height, Graphics::PixelFormat::createFormatCLUT8());
_bitsPerPixel = bitsPerPixel;
}
MSRLEDecoder::~MSRLEDecoder() {
_surface->free();
delete _surface;
}
const Graphics::Surface *MSRLEDecoder::decodeFrame(Common::SeekableReadStream &stream) {
if (_bitsPerPixel == 8) {
decode8(stream);
} else
error("Unhandled %d bit Microsoft RLE encoding", _bitsPerPixel);
return _surface;
}
void MSRLEDecoder::decode8(Common::SeekableReadStream &stream) {
int x = 0;
int y = _surface->h - 1;
byte *data = (byte *) _surface->getPixels();
uint16 width = _surface->w;
uint16 height = _surface->h;
byte *output = data + ((height - 1) * width);
byte *output_end = data + ((height) * width);
while (!stream.eos()) {
byte count = stream.readByte();
byte value = stream.readByte();
if (count == 0) {
if (value == 0) {
// End of line
x = 0;
y--;
output = data + (y * width);
} else if (value == 1) {
// End of image
return;
} else if (value == 2) {
// Skip
count = stream.readByte();
value = stream.readByte();
y -= value;
x += count;
if (y < 0) {
warning("MS RLE Codec: Skip beyond picture bounds");
return;
}
output = data + ((y * width) + x);
} else {
// Copy data
if (y < 0) {
warning("MS RLE Codec: Copy data is beyond picture bounds");
return;
}
if (output + value > output_end) {
if (stream.pos() + value >= stream.size())
break;
else
stream.skip(value);
continue;
}
for (int i = 0; i < value; i++)
*output++ = stream.readByte();
if (value & 1)
stream.skip(1);
x += value;
}
} else {
// Run data
if (y < 0) {
warning("MS RLE Codec: Run data is beyond picture bounds");
return;
}
if (output + count > output_end)
continue;
for (int i = 0; i < count; i++, x++)
*output++ = value;
}
}
warning("MS RLE Codec: No end-of-picture code");
}
} // End of namespace Image
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