scummvm/engines/lastexpress/data/background.cpp
2011-05-12 01:16:22 +02:00

142 lines
4.3 KiB
C++

/* 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 on Deniz Oezmen's code and Xentax Wiki documentation
// http://oezmen.eu/
// http://wiki.xentax.com/index.php/The_Last_Express_BG
#include "lastexpress/data/background.h"
#include "lastexpress/debug.h"
#include "common/rect.h"
#include "common/stream.h"
namespace LastExpress {
Background::Background() : _data(NULL) {
memset(&_header, 0, sizeof(BackgroundHeader));
}
Background::~Background() {
delete[] _data;
}
bool Background::load(Common::SeekableReadStream *stream) {
if (!stream)
return false;
// Reset data
delete[] _data;
// Load Background header
_header.posX = stream->readUint32LE();
_header.posY = stream->readUint32LE();
_header.width = stream->readUint32LE();
_header.height = stream->readUint32LE();
_header.redSize = stream->readUint32LE();
_header.blueSize = stream->readUint32LE();
_header.greenSize = stream->readUint32LE();
debugC(3, kLastExpressDebugGraphics, "Background Info: (%d, %d) - (%d x %d) - (%d, %d, %d)",
_header.posX, _header.posY, _header.width, _header.height,
_header.redSize, _header.blueSize, _header.greenSize);
// Load and decompress Background channel data
uint32 numPix = _header.width * _header.height;
byte *dataR = decodeComponent(stream, _header.redSize, numPix);
byte *dataB = decodeComponent(stream, _header.blueSize, numPix);
byte *dataG = decodeComponent(stream, _header.greenSize, numPix);
// Save to pixel buffer
// FIXME handle big-endian case
_data = new uint16[_header.width * _header.height];
for (uint i = 0; i < _header.width * _header.height; i++)
_data[i] = (uint16)((dataR[i] << 10) + (dataG[i] << 5) + dataB[i]);
// Cleanup buffers
delete[] dataR;
delete[] dataG;
delete[] dataB;
delete stream;
return true;
}
Common::Rect Background::draw(Graphics::Surface *surface) {
if (!_data) {
debugC(2, kLastExpressDebugGraphics, "Trying to show a background before loading data!");
return Common::Rect();
}
int i = 0;
for (uint16 y = 0; y < _header.height; y++) {
for (uint16 x = 0; x < _header.width; x++) {
surface->fillRect(Common::Rect((int16)(_header.posX + x), (int16)(_header.posY + y), (int16)(_header.posX + x + 1), (int16)(_header.posY + y + 1)), _data[i]);
i ++;
}
}
return Common::Rect((int16)_header.posX, (int16)_header.posY, (int16)(_header.posX + _header.width), (int16)(_header.posY + _header.height));
}
byte *Background::decodeComponent(Common::SeekableReadStream *in, uint32 inSize, uint32 outSize) const {
// Create the destination array
byte *out = new byte[outSize];
if (!out)
return NULL;
// Initialize the decoding
uint32 inPos = 0;
uint32 outPos = 0;
// Decode
while (inPos < inSize) {
byte inByte = in->readByte();
inPos++;
if (inByte < 0x80) {
// Direct decompression (RLE)
byte len = (inByte >> 5) + 1;
byte data = inByte & 0x1f;
for (int i = 0; i < len && outPos < outSize; i++)
out[outPos++] = data;
} else {
// Buffer back reference, 4096 byte window
// Take inByte and the following value as a big endian
// OfsLen while zeroing the first bit
uint16 ofsLen = ((inByte & 0x7F) << 8) | in->readByte();
inPos++;
int32 len = (ofsLen >> 12) + 3;
int32 hisPos = (int32)(outPos + (ofsLen & 0x0FFF) - 4096);
for (int i = 0; i < len && outPos < outSize; i++)
out[outPos++] = out[hisPos++];
}
}
return out;
}
} // End of namespace LastExpress