scummvm/graphics/iff.h

/* 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.
 *
 * $URL$
 * $Id$
 */

/**
 * Bitmap decoder used in engines:
 *  - parallaction
 *  - saga
 */

#ifndef GRAPHICS_IFF_H
#define GRAPHICS_IFF_H

#include "common/iff_container.h"

namespace Graphics {

struct Surface;


struct BMHD {
	uint16 width, height;
	uint16 x, y;
	byte depth;
	byte masking;
	byte pack;
	byte flags;
	uint16 transparentColor;
	byte xAspect, yAspect;
	uint16 pageWidth, pageHeight;

	BMHD() {
		memset(this, 0, sizeof(*this));
	}

	void load(Common::ReadStream *stream);
};


struct ILBMDecoder {
	/**
	 * ILBM header data, necessary for loadBitmap()
	 */
	Graphics::BMHD	_header;

	/**
	 * Available decoding modes for loadBitmap().
	 */
	enum {
		ILBM_UNPACK_PLANES = 0xFF,		///< Decode all bitplanes, and map 1 pixel to 1 byte.
		ILBM_PACK_PLANES   = 0x100,		///< Request unpacking, used as a mask with below options.

		ILBM_1_PLANES      = 1,									///< Decode only the first bitplane, don't pack.
		ILBM_1_PACK_PLANES = ILBM_1_PLANES | ILBM_PACK_PLANES, 	///< Decode only the first bitplane, pack 8 pixels in 1 byte.
		ILBM_2_PLANES      = 2,									///< Decode first 2 bitplanes, don't pack.
		ILBM_2_PACK_PLANES = ILBM_2_PLANES | ILBM_PACK_PLANES,	///< Decode first 2 bitplanes, pack 4 pixels in 1 byte.
		ILBM_3_PLANES      = 3,									///< Decode first 3 bitplanes, don't pack.
		ILBM_4_PLANES      = 4,									///< Decode first 4 bitplanes, don't pack.
		ILBM_4_PACK_PLANES = ILBM_4_PLANES | ILBM_PACK_PLANES,	///< Decode first 4 bitplanes, pack 2 pixels in 1 byte.
		ILBM_5_PLANES      = 5,									///< Decode first 5 bitplanes, don't pack.
		ILBM_8_PLANES      = 8									///< Decode all 8 bitplanes.
	};

	/**
	 * Fills the _header member from the given stream.
	 */
	void loadHeader(Common::ReadStream *stream);

	/**
	 * Loads and unpacks the ILBM bitmap data from the stream into the buffer.
	 * The functions assumes the buffer is large enough to contain all data.
	 * The caller controls how data should be packed by choosing mode from
	 * the enum above.
	 */
	void loadBitmap(uint32 mode, byte *buffer, Common::ReadStream *stream);

	/**
	 * Converts from bitplanar to chunky representation. Intended for internal
	 * usage, but you can be (ab)use it from client code if you know what you
	 * are doing.
	 */
	void planarToChunky(byte *out, uint32 width, byte *in, uint32 planeWidth, uint32 nPlanes, bool packPlanes);
};




//	handles PBM subtype of IFF FORM files
//
struct PBMDecoder {
	/**
	 * PBM header data, necessary for loadBitmap()
	 */
	Graphics::BMHD	_header;

	/**
	 * Fills the _header member from the given stream.
	 */
	void loadHeader(Common::ReadStream *stream);

	/**
	 * Loads and unpacks the PBM bitmap data from the stream into the buffer.
	 * The functions assumes the buffer is large enough to contain all data.
	 */
	void loadBitmap(byte *buffer, Common::ReadStream *stream);
};

void decodePBM(Common::ReadStream &input, Surface &surface, byte *colors);


/*
	PackBits is a RLE compression algorithm introduced
	by Apple. It is also used to encode ILBM and PBM
	subtypes of IFF files, and some flavours of TIFF.

	As there is no compression across row boundaries
	in the above formats, read() will extract a *new*
	line on each call, discarding any alignment or
	padding.
*/
class PackBitsReadStream : public Common::ReadStream {

protected:
	Common::ReadStream *_input;

public:
	PackBitsReadStream(Common::ReadStream &input);
	~PackBitsReadStream();

	virtual bool eos() const;

	uint32 read(void *dataPtr, uint32 dataSize);
};

}

#endif