www.pudn.com > SharedScreen.rar > LZWTABLE.CPP

#include "stdafx.h" 
#include "stdio.h" 
#include "stdlib.h"   
#include "string.h" 
#include "memory.h"          
#include "conio.h" 
#include "lzwcode.h" 
#include "lzwtable.h" 
 
/* 
class CLZWEncodeTable 
*/ 
CLZWDecodeTable::CLZWDecodeTable(BOOL fInit) 
{ 
	m_pbContain=NULL; 
	m_dwTableEntryNumber=0; 
	if(fInit) 
		InitLZWTable(); 
} 
CLZWDecodeTable::~CLZWDecodeTable() 
{ 
	ClearDecodeTable(); 
} 
void CLZWDecodeTable::ClearDecodeTable(void) 
{    
	if(m_pbContain==NULL) 
		return; 
	for(int i=0;i<4096;i++) 
	{ 
		if(m_pbContain[i]) 
			delete (m_pbContain[i]); 
	} 
	delete m_pbContain; 
	m_pbContain=NULL; 
	m_dwTableEntryNumber=0; 
} 
void CLZWDecodeTable::InitLZWTable(void) 
{ 
	ClearDecodeTable(); 
	m_pbContain=new BYTE*[4096]; 
	int iSize=sizeof(m_pbContain); 
	//if(NULL==m_pbContain) 
	//	AfxMessageBox("error new m_pbContain=BYTE*[4096]"); 
	for(int i=0;i<4096;i++) 
	{ 
		m_pbContain[i]=NULL; 
	} 
	for(i=0;i<=255;i++) 
	{ 
		m_pbContain[i]=new BYTE[1+2]; 
		*((WORD*)m_pbContain[i])=1; 
		m_pbContain[i][2]=(BYTE)i; 
	} 
	m_dwTableEntryNumber=LZW_BEGIN_ENTRY; 
} 
BYTE* CLZWDecodeTable::GetMatchData(WORD wCode) 
{ 
	return m_pbContain[wCode]; 
} 
void CLZWDecodeTable::AddToChild(WORD wCode,BYTE *pbContain,int iLength) 
{ 
	ASSERT(wCode<4096); 
	if(m_pbContain[wCode]) 
		delete m_pbContain[wCode]; 
	m_pbContain[wCode]=new BYTE[iLength+2]; 
	*((WORD*)m_pbContain[wCode])=(WORD)iLength; 
	memcpy(m_pbContain[wCode]+2,pbContain,iLength); 
} 
 
/* 
class CLZWEncodeTable 
*/ 
CLZWEncodeTable::CLZWEncodeTable(BOOL fInit) 
{ 
	if(fInit) 
		InitLZWTable(); 
	else 
	{ 
		m_dwTableEntryNumber=0; 
		m_EntryHead.pRightBrother=NULL; 
		m_EntryHead.pChild=NULL; 
	} 
} 
CLZWEncodeTable::~CLZWEncodeTable() 
{ 
	ClearLZWTable(); 
} 
void CLZWEncodeTable::ClearLZWTable(void) 
{ 
	if(m_EntryHead.pChild==NULL) 
		return; 
	m_dwTableEntryNumber=0; 
	int iRe=0; 
	while(m_EntryHead.pChild) 
	{ 
		RemoveFirstChild(); 
		iRe++; 
		//printf("remove %d\n",++iRe);; 
	} 
} 
void CLZWEncodeTable::RemoveFirstChild(void) 
{ 
	PLZWENCODEENTRY pFirstChild=m_EntryHead.pChild;// this child will be removed 
	if(pFirstChild->pChild) 
	{ 
		m_EntryHead.pChild=pFirstChild->pChild; 
		if(m_EntryHead.pChild->pRightBrother) 
		{ 
			PLZWENCODEENTRY pRightBrother=FindRightBrother(m_EntryHead.pChild); 
			pRightBrother->pRightBrother=pFirstChild->pRightBrother; 
		} 
		else 
			(m_EntryHead.pChild)->pRightBrother=pFirstChild->pRightBrother; 
		//delete pFirstChild; 
	} 
	else 
		m_EntryHead.pChild=pFirstChild->pRightBrother; 
	delete pFirstChild; 
} 
PLZWENCODEENTRY CLZWEncodeTable::FindRightBrother(PLZWENCODEENTRY pCurrent) 
{ 
	PLZWENCODEENTRY pFind; 
	pFind=pCurrent; 
	while(pFind->pRightBrother) 
	{ 
		pFind=pFind->pRightBrother; 
	} 
	return pFind; 
} 
void CLZWEncodeTable::InitLZWTable(void) 
{// init the table ,it has 256 items code from 0 to 255 
	ClearLZWTable(); 
	PLZWENCODEENTRY pEntryFirst=new LZWENCODEENTRY; 
	pEntryFirst->wCode=(WORD)0; 
	pEntryFirst->bLast=(BYTE)0; 
	pEntryFirst->pRightBrother=pEntryFirst->pChild=NULL; 
	m_EntryHead.pChild=pEntryFirst; 
	m_EntryHead.pRightBrother=NULL; 
	PLZWENCODEENTRY pPrev=pEntryFirst; 
	for(int i=1;i<=255;i++) 
	{// set the brother nodes 
		PLZWENCODEENTRY pEntry=new LZWENCODEENTRY; 
		pEntry->wCode=(WORD)i; 
		pEntry->bLast=(BYTE)i; 
		pEntry->pChild=pEntry->pRightBrother=NULL; 
		pPrev->pRightBrother=pEntry; 
		pPrev=pEntry; 
	} 
	m_dwTableEntryNumber=258; 
	m_uNextCodeForUse=LZW_BEGIN_ENTRY; 
} 
PLZWENCODEENTRY CLZWEncodeTable::FindMatchChild(BYTE bChildLast,PLZWENCODEENTRY pCurrent) 
{// return the find child entry 
	if(pCurrent->pChild==NULL) 
		return NULL; 
	PLZWENCODEENTRY pChild=pCurrent->pChild; 
	// pChild is the current's child 
	// and all pChild's brother is the current's child 
	while(pChild!=NULL) 
	{ 
		if(pChild->bLast==bChildLast) 
			return pChild; 
		pChild=pChild->pRightBrother; 
	} 
	return NULL; 
} 
PLZWENCODEENTRY CLZWEncodeTable::AddToChild(BYTE bLast,PLZWENCODEENTRY pCurrent) 
{ 
	ASSERT(pCurrent); 
	PLZWENCODEENTRY pChild=new LZWENCODEENTRY; 
	if(pChild==NULL) 
	{ 
		int _j=0; 
	} 
	pChild->pChild=pChild->pRightBrother=NULL; 
	pChild->bLast=bLast; 
	pChild->wCode=(WORD)m_uNextCodeForUse; 
	if(pChild->wCode==LZW_CLEAR_CODE) 
	{ 
		int _i=0; 
	} 
	m_uNextCodeForUse++; 
	m_dwTableEntryNumber++; 
	pChild->pRightBrother=pCurrent->pChild; 
	pCurrent->pChild=pChild; 
	return pChild; 
}