diff options
Diffstat (limited to 'engines/cryomni3d/image/codecs/hlz.cpp')
-rw-r--r-- | engines/cryomni3d/image/codecs/hlz.cpp | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/engines/cryomni3d/image/codecs/hlz.cpp b/engines/cryomni3d/image/codecs/hlz.cpp new file mode 100644 index 0000000000..146336efdc --- /dev/null +++ b/engines/cryomni3d/image/codecs/hlz.cpp @@ -0,0 +1,140 @@ +/* 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. + * + */ + +#include "cryomni3d/image/codecs/hlz.h" + +#include "common/stream.h" +#include "common/textconsole.h" +#include "graphics/surface.h" + +namespace Image { + +HLZDecoder::HLZDecoder(int width, int height) : Codec(), + _width(width), _height(height), _surface(nullptr) { +} + +HLZDecoder::~HLZDecoder() { + if (_surface) { + _surface->free(); + delete _surface; + } +} + +const Graphics::Surface *HLZDecoder::decodeFrame(Common::SeekableReadStream &stream) { + if (!_surface) { + _surface = new Graphics::Surface(); + } + + _surface->create(_width, _height, Graphics::PixelFormat::createFormatCLUT8()); + + byte *dst = (byte *)_surface->getPixels(); + decodeFrameInPlace(stream, -1, dst); + + return _surface; +} + +Graphics::PixelFormat HLZDecoder::getPixelFormat() const { + return Graphics::PixelFormat::createFormatCLUT8(); +} + +static inline bool getReg(Common::SeekableReadStream &stream, uint32 *size, uint32 *reg, + int *regBits) { + if (*regBits == 0) { + if (*size < 4) { + error("Can't feed register: not enough data"); + } + *reg = stream.readUint32LE(); + *size -= 4; + *regBits = 32; + } + bool ret = (*reg >> 31) != 0; + *reg <<= 1; + (*regBits)--; + return ret; +} + +void HLZDecoder::decodeFrameInPlace(Common::SeekableReadStream &stream, uint32 size, byte *dst) { + bool eof = false; + bool checkSize = (size != (uint32) - 1); + byte *orig = dst; + uint32 reg; + int regBits = 0; +#define GETREG() getReg(stream, &size, ®, ®Bits) + + while (!eof) { + if (GETREG()) { + if (size < 1) { + error("Can't read pixel byte"); + } + byte c = stream.readByte(); + *(dst++) = c; + size--; + } else { + int offset, repeat_count; + if (GETREG()) { + // Long repeat + if (size < 2) { + error("Can't read repeat count/offset"); + } + uint16 tmp = stream.readUint16LE(); + size -= 2; + repeat_count = tmp & 0x7; + offset = (tmp >> 3) - 0x2000; + if (repeat_count == 0) { + if (size < 1) { + error("Can't read long repeat count"); + } + repeat_count = stream.readByte(); + size--; + if (repeat_count == 0) { + eof = true; + continue; + } + } + } else { + // Short repeat + repeat_count = GETREG() << 1; + repeat_count |= GETREG(); + if (size < 1) { + error("Can't read offset byte"); + } + offset = stream.readByte() - 0x100; + size--; + } + repeat_count += 2; + if (dst + offset < orig) { + error("Invalid offset %d, dst is %d", offset, (int)(dst - orig)); + } + for (; repeat_count > 0; repeat_count--) { + // offset is always < 0 + *dst = *(dst + offset); + dst++; + } + } + } + if (checkSize && size != 0) { + stream.skip(size); + } +#undef GETREG +} + +} // End of namespace Image |