Remastered-Collection/REDALERT/LZWSTRAW.H

//
// Copyright 2020 Electronic Arts Inc.
//
// TiberianDawn.DLL and RedAlert.dll and corresponding source code 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.

// TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed 
// in the hope that it will be useful, but with permitted additional restrictions 
// under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 
// distributed with this program. You should have received a copy of the 
// GNU General Public License along with permitted additional restrictions 
// with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection

/* $Header: /CounterStrike/LZWSTRAW.H 1     3/03/97 10:25a Joe_bostic $ */
/***********************************************************************************************
 ***              C O N F I D E N T I A L  ---  W E S T W O O D  S T U D I O S               ***
 ***********************************************************************************************
 *                                                                                             *
 *                 Project Name : Command & Conquer                                            *
 *                                                                                             *
 *                    File Name : LZWSTRAW.H                                                   *
 *                                                                                             *
 *                   Programmer : Joe L. Bostic                                                *
 *                                                                                             *
 *                   Start Date : 07/02/96                                                     *
 *                                                                                             *
 *                  Last Update : July 2, 1996 [JLB]                                           *
 *                                                                                             *
 *---------------------------------------------------------------------------------------------*
 * Functions:                                                                                  *
 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */


#ifndef LZWSTRAW_H
#define LZWSTRAW_H


#include	"straw.h"

/*
**	This class handles LZW compression/decompression to the data stream that is drawn through
**	this class. Note that for compression, two internal buffers are required. For decompression
**	only one buffer is required. This changes the memory footprint of this class depending on
**	the process desired.
*/
class LZWStraw : public Straw
{
	public:
		typedef enum CompControl {
			COMPRESS,
			DECOMPRESS
		} CompControl;

		LZWStraw(CompControl control, int blocksize=1024*8);
		virtual ~LZWStraw(void);

		virtual int Get(void * source, int slen);

	private:

		/*
		**	This tells the pipe if it should be decompressing or compressing the data stream.
		*/
		CompControl Control;

		/*
		**	The number of bytes accumulated into the staging buffer.
		*/
		int Counter;

		/*
		**	Pointer to the working buffer that compression/decompression will use.
		*/
		char * Buffer;
		char * Buffer2;

		/*
		**	The working block size. Data will be compressed in chunks of this size.
		*/
		int BlockSize;

		/*
		**	LZW compression requires a safety margin when decompressing over itself. This
		**	margin is only for the worst case situation (very rare).
		*/
		int SafetyMargin;

		/*
		**	Each block has a header of this format.
		*/
		struct {
			unsigned short CompCount;		// Size of data block (compressed).
			unsigned short UncompCount;	// Bytes of uncompressed data it represents.
		} BlockHeader;

		LZWStraw(LZWStraw & rvalue);
		LZWStraw & operator = (LZWStraw const & pipe);
};


#endif