Initial commit

image/iff.cpp

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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/iff.h"
+
+#include "common/formats/iff_container.h"
+#include "common/stream.h"
+#include "common/util.h"
+
+namespace Image {
+
+IFFDecoder::IFFDecoder(): _surface(nullptr), _palette(0) {
+	// these 2 properties are not reset by destroy(), so the default is set here.
+	_numRelevantPlanes = 8;
+	_pixelPacking = false;
+
+	destroy();
+}
+
+IFFDecoder::~IFFDecoder() {
+	destroy();
+}
+
+void IFFDecoder::destroy() {
+	if (_surface) {
+		_surface->free();
+		delete _surface;
+		_surface = nullptr;
+	}
+
+	_palette.clear();
+
+	memset(&_header, 0, sizeof(Header));
+	_paletteRanges.clear();
+	_type = TYPE_UNKNOWN;
+}
+
+bool IFFDecoder::loadStream(Common::SeekableReadStream &stream) {
+	destroy();
+
+	const uint32 form = stream.readUint32BE();
+
+	if (form != ID_FORM) {
+		warning("Failed reading IFF-file");
+		return false;
+	}
+
+	stream.skip(4);
+
+	const uint32 type = stream.readUint32BE();
+
+	switch (type) {
+		case ID_ILBM:
+			_type = TYPE_ILBM;
+			break;
+		case ID_PBM:
+			_type = TYPE_PBM;
+			break;
+		case TYPE_UNKNOWN:
+		default:
+			_type = TYPE_UNKNOWN;
+			break;
+	}
+
+	if (type == TYPE_UNKNOWN) {
+		warning("Failed reading IFF-file");
+		return false;
+	}
+
+	while (1) {
+		if (stream.size() < stream.pos() + 8)
+			break;
+
+		const uint32 chunkType = stream.readUint32BE();
+		uint32 chunkSize = stream.readUint32BE();
+		// According to the format specs:
+		// "If ckData is an odd number of bytes long, a 0 pad byte follows which is not included in ckSize."
+		// => fix the length
+		if (chunkSize % 2)
+			chunkSize++;
+
+		if (stream.eos())
+			break;
+
+		switch (chunkType) {
+		case ID_BMHD:
+			loadHeader(stream);
+			break;
+		case ID_CMAP:
+			loadPalette(stream, chunkSize);
+			break;
+		case ID_CRNG:
+			loadPaletteRange(stream, chunkSize);
+			break;
+		case ID_BODY:
+			loadBitmap(stream);
+			break;
+		default:
+			if (stream.size() < stream.pos() + (int32)chunkSize)
+				break;
+
+			stream.skip(chunkSize);
+		}
+	}
+
+	return true;
+}
+
+void IFFDecoder::loadHeader(Common::SeekableReadStream &stream) {
+	_header.width = stream.readUint16BE();
+	_header.height = stream.readUint16BE();
+	_header.x = stream.readUint16BE();
+	_header.y = stream.readUint16BE();
+	_header.numPlanes = stream.readByte();
+	_header.masking = stream.readByte();
+	_header.compression = stream.readByte();
+	_header.flags = stream.readByte();
+	_header.transparentColor = stream.readUint16BE();
+	_header.xAspect = stream.readByte();
+	_header.yAspect = stream.readByte();
+	_header.pageWidth = stream.readUint16BE();
+	_header.pageHeight = stream.readUint16BE();
+
+	assert(_header.width >= 1);
+	assert(_header.height >= 1);
+	assert(_header.numPlanes >= 1 && _header.numPlanes <= 8 && _header.numPlanes != 7);
+}
+
+void IFFDecoder::loadPalette(Common::SeekableReadStream &stream, const uint32 size) {
+	_palette.resize(size / 3, false);
+	for (uint i = 0; i < _palette.size(); i++) {
+		byte r = stream.readByte();
+		byte g = stream.readByte();
+		byte b = stream.readByte();
+
+		_palette.set(i, r, g, b);
+	}
+}
+
+void IFFDecoder::loadPaletteRange(Common::SeekableReadStream &stream, const uint32 size) {
+	PaletteRange range;
+
+	range.timer = stream.readSint16BE();
+	range.step = stream.readSint16BE();
+	range.flags = stream.readSint16BE();
+	range.first = stream.readByte();
+	range.last = stream.readByte();
+
+	_paletteRanges.push_back(range);
+}
+
+void IFFDecoder::loadBitmap(Common::SeekableReadStream &stream) {
+	_numRelevantPlanes = MIN(_numRelevantPlanes, _header.numPlanes);
+
+	if (_numRelevantPlanes != 1 && _numRelevantPlanes != 2 && _numRelevantPlanes != 4)
+		_pixelPacking = false;
+
+	uint16 outPitch = _header.width;
+
+	if (_pixelPacking)
+		outPitch /= (8 / _numRelevantPlanes);
+
+	// FIXME: CLUT8 is not a proper format for packed bitmaps but there is no way to tell it to use 1, 2 or 4 bits per pixel
+	_surface = new Graphics::Surface();
+	_surface->create(outPitch, _header.height, Graphics::PixelFormat::createFormatCLUT8());
+
+	if (_type == TYPE_ILBM) {
+		uint32 scanlinePitch = ((_header.width + 15) >> 4) << 1;
+		byte *scanlines = new byte[scanlinePitch * _header.numPlanes];
+		byte *data = (byte *)_surface->getPixels();
+
+		for (uint16 i = 0; i < _header.height; ++i) {
+			byte *scanline = scanlines;
+
+			for (uint16 j = 0; j < _header.numPlanes; ++j) {
+				uint16 outSize = scanlinePitch;
+
+				if (_header.compression) {
+					Common::PackBitsReadStream packStream(stream);
+					packStream.read(scanline, outSize);
+				} else {
+					stream.read(scanline, outSize);
+				}
+
+				scanline += outSize;
+			}
+
+			packPixels(scanlines, data, scanlinePitch, outPitch);
+			data += outPitch;
+		}
+
+		delete[] scanlines;
+	} else if (_type == TYPE_PBM) {
+		byte *data = (byte *)_surface->getPixels();
+		uint32 outSize = _header.width * _header.height;
+
+		if (_header.compression) {
+			Common::PackBitsReadStream packStream(stream);
+			packStream.read(data, outSize);
+		} else {
+			stream.read(data, outSize);
+		}
+	}
+}
+
+void IFFDecoder::packPixels(byte *scanlines, byte *data, const uint16 scanlinePitch, const uint16 outPitch) {
+	uint32 numPixels = _header.width;
+
+	if (_pixelPacking)
+		numPixels = outPitch * (8 / _numRelevantPlanes);
+
+	for (uint32 x = 0; x < numPixels; ++x) {
+		byte *scanline = scanlines;
+		byte pixel = 0;
+		byte offset = x >> 3;
+		byte bit = 0x80 >> (x & 7);
+
+		// first build a pixel by scanning all the usable planes in the input
+		for (uint32 plane = 0; plane < _numRelevantPlanes; ++plane) {
+			if (scanline[offset] & bit)
+				pixel |= (1 << plane);
+
+			scanline += scanlinePitch;
+		}
+
+		// then output the pixel according to the requested packing
+		if (!_pixelPacking)
+			data[x] = pixel;
+		else if (_numRelevantPlanes == 1)
+			data[x / 8] |= (pixel << (x & 7));
+		else if (_numRelevantPlanes == 2)
+			data[x / 4] |= (pixel << ((x & 3) << 1));
+		else if (_numRelevantPlanes == 4)
+			data[x / 2] |= (pixel << ((x & 1) << 2));
+	}
+}
+
+} // End of namespace Image