gif89a.cpp

在 WINCE下 显示 GIF图片 GIF89A类

		{	delete[] curFrame.dataBuf;
			curFrame.dataBuf = NULL;
		}
		ZeroMemory(&curFrame,sizeof(FRAME));
		while(TRUE)
		{	//ifs.read((char*)&be,1);
			fread((char*)&be,1,1,m_file);
			switch(be)
			{	case 0x21:
					//ifs.read((char*)&be,1);
					fread((char*)&be,1,1,m_file);
					switch(be)
					{	case 0xf9:
							while(!feof(m_file))//ifs.eof())
							{	//ifs.read((char*)&be,1);
								fread((char*)&be,1,1,m_file);
								if(be == 0)
									break;
								if(be == 4)
								{	ctrlExt.active = TRUE;
									//ifs.read((char*)&be,1);
									fread((char*)&be,1,1,m_file);
									ctrlExt.disposalMethod = (be&0x1c)>>2;
									if((be&0x02) != 0)
										ctrlExt.userInputFlag = TRUE;
									else
										ctrlExt.userInputFlag = FALSE;
									if((be&0x01) != 0)
										ctrlExt.trsFlag = TRUE;
									else
										ctrlExt.trsFlag = FALSE;
									//ifs.read((char*)&ctrlExt.delayTime,2);									
									//ifs.read((char*)&be,1);
									fread((char*)&ctrlExt.delayTime,2,1,m_file);
									fread((char*)&be,1,1,m_file);
									ctrlExt.trsColorIndex = be;
								}
								else
								{
									//ifs.seekg(be,ios::cur);
									fseek(m_file,be,SEEK_CUR);
								}
							}
							break;
						case 0xfe:
						case 0x01:
						case 0xff:
							while(!feof(m_file))//ifs.eof())
							{	//ifs.read((char*)&be,1);
								fread((char*)&be,1,1,m_file);
								if(be == 0)
									break;
								//ifs.seekg(be,ios::cur);
								fseek(m_file,be,SEEK_CUR);
							}
							break;
						default:
							goto error;
					}
					break;
				case 0x2c:
				{	BYTE bp;
					//ifs.read((char*)&curFrame.imageLPos,2);
					//ifs.read((char*)&curFrame.imageTPos,2);
					//ifs.read((char*)&curFrame.imageWidth,2);
					//ifs.read((char*)&curFrame.imageHeight,2);
					//ifs.read((char*)&bp,1);
					fread((char*)&curFrame.imageLPos,2,1,m_file);
					fread((char*)&curFrame.imageTPos,2,1,m_file);
					fread((char*)&curFrame.imageWidth,2,1,m_file);
					fread((char*)&curFrame.imageHeight,2,1,m_file);
					fread((char*)&bp,1,1,m_file);
					if((bp&0x80) != 0)
						curFrame.lFlag = TRUE;
					if((bp&0x40) != 0)
						curFrame.interlaceFlag = TRUE;
					if((bp&0x20) != 0)
						curFrame.sortFlag = TRUE;
					curFrame.lSize = 1;
					curFrame.lSize <<= ((bp&0x07)+1);
					if((curFrame.pColorTable = new BYTE[curFrame.lSize*3]) == NULL)
						goto error;
					if(curFrame.lFlag)
					{
						//ifs.read((char*)curFrame.pColorTable,curFrame.lSize*3);
						fread((char*)curFrame.pColorTable,curFrame.lSize*3,1,m_file);
					}
					if(ferror(m_file))//!ifs.good())
						goto error;
					if(!extractData(&curFrame,m_file//ifs
						))
						goto error;
					curFrame.ctrlExt = ctrlExt;
					if(ctrlExt.active = TRUE)
						ctrlExt.active = FALSE;
					return &curFrame;
				}
				case 0x3b:
					//ifs.seekg(dataStart);
					fseek(m_file,dataStart,SEEK_SET);
					break;
				case 0x00:
					break;
				default:
					goto error;
			}
		}	
		return &curFrame;
error:
		if(curFrame.pColorTable != NULL)
		{	delete[] curFrame.pColorTable;
			curFrame.pColorTable = NULL;
		}
		if(curFrame.dataBuf != NULL)
		{	delete[] curFrame.dataBuf;
			curFrame.dataBuf = NULL;
		}
		return NULL;
	}
}

BOOL CGif89a::initStrTable(STRING_TABLE_ENTRY* strTable,UINT rootSize)
{	UINT i;
	unsigned char *cc;
	for(i=0;i<rootSize;i++)
	{	if((cc = new unsigned char[2]) == NULL)
			goto error;
		cc[0] = i,cc[1] = 0;
		strTable[i].p = cc;
		strTable[i].len = 1;
	}
	return TRUE;
error:
	for(i=0;i<rootSize;i++)
		if(strTable[i].p != NULL)
		{	delete[] strTable[i].p;
			strTable[i].p = NULL;
		}
	return FALSE;
}

BOOL CGif89a::addStrTable(STRING_TABLE_ENTRY* strTable,UINT addIdx,UINT idx,unsigned char c)
{	unsigned char *cc;
	UINT l = strTable[idx].len;
	if(addIdx >= 4096)
		return FALSE;
	if((cc = new unsigned char[l+2]) == NULL)
		return FALSE;
	for(UINT i=0;i<l;i++)
		cc[i] = strTable[idx].p[i];
	cc[l] = c;
	cc[l+1] = 0;
	strTable[addIdx].p = cc;
	strTable[addIdx].len = strTable[idx].len +1;
	return TRUE;
}

BOOL CGif89a::extractData(FRAME* f,FILE *file)//ifstream& ifs)
{	STRING_TABLE_ENTRY *strTable;
	UINT codeSize,rootSize,tableIndex,codeSizeBK;
	int remainInBuf = 0,i;
	UINT bufIndex = 0,outIndex = 0;
	UINT bitIndex = 0;
	DWORD code,oldCode;
	BYTE be,*outP;
	BYTE buf[262];
	BOOL readOK = FALSE;
	UINT bufLen = f->imageWidth*f->imageHeight;
	if((strTable = new STRING_TABLE_ENTRY[4096]) == NULL)
		return FALSE;
	ZeroMemory(strTable,sizeof(STRING_TABLE_ENTRY)*4096);
	outP = f->dataBuf = new BYTE[bufLen];
	if(f->dataBuf == NULL)
	{	delete[] strTable;
		return FALSE;
	}
	//ifs.read((char*)&be,1);
	fread((char*)&be,1,1,file);
	codeSizeBK = codeSize = be+1;
	rootSize = 1;
	rootSize <<= be; 
	tableIndex = rootSize+2;
	if(!initStrTable(strTable,rootSize))
		goto error;

begin:
	if(remainInBuf<=4 && !readOK)
	{	for(i=0;i<remainInBuf;i++)
			buf[i] = buf[bufIndex+i];
		bufIndex = 0;
		//ifs.read((char*)&be,1);
		fread((char*)&be,1,1,file);
		if(be != 0)
		{	//ifs.read((char*)(buf+remainInBuf),be);
			fread((char*)(buf+remainInBuf),be,1,file);
			remainInBuf += be;
		}
		else
			readOK = TRUE;
		if(ferror(file))//!ifs.good())
			goto error;
	}
	if(remainInBuf<=4)
		if(remainInBuf<=0 || codeSize > (remainInBuf*8-bitIndex))
			goto done;
	//code = *((DWORD*)(buf+bufIndex));
	code = buf[bufIndex+3]*16777216+buf[bufIndex+2]*65536+buf[bufIndex+1]*256+buf[bufIndex];
	code <<= 32-codeSize-bitIndex;
	code >>= 32-codeSize;
	bitIndex += codeSize;
	bufIndex += bitIndex/8;
	remainInBuf -= bitIndex/8;
	bitIndex %= 8;
	if(code >= rootSize+1)
		goto error;
	if(code == rootSize)
		goto begin;
	else
	{	outP[outIndex++] = *strTable[code].p;
		oldCode = code;
	}
	for(;;)
	{	if(remainInBuf<=4 && !readOK)
		{	for(i=0;i<remainInBuf;i++)
				buf[i] = buf[bufIndex+i];
			bufIndex = 0;
			//ifs.read((char*)&be,1);
			fread((char*)&be,1,1,file);
			if(be != 0)
			{	//ifs.read((char*)(buf+remainInBuf),be);
				fread((char*)(buf+remainInBuf),be,1,file);
				remainInBuf += be;
			}
			else
				readOK = TRUE;
			if(ferror(file))//!ifs.good())
				goto error;
		}
		if(remainInBuf<=4)
			if(remainInBuf<=0 || codeSize > (remainInBuf*8-bitIndex))
				break;
		//code = *((DWORD*)(buf+bufIndex));
		code = buf[bufIndex+3]*16777216+buf[bufIndex+2]*65536+buf[bufIndex+1]*256+buf[bufIndex];
		code <<= 32-codeSize-bitIndex;
		code >>= 32-codeSize;
		bitIndex += codeSize;
		bufIndex += bitIndex/8;
		remainInBuf -= bitIndex/8;
		bitIndex %= 8;
		if(code == rootSize)
		{	codeSize = codeSizeBK;
			for(i=rootSize;i<4096;i++)
				if(strTable[i].p != NULL)
				{	delete strTable[i].p;
					strTable[i].p = NULL;
					strTable[i].len = 0;
				}
			tableIndex = rootSize+2;
			goto begin;
		}
		else if(code == rootSize+1)
			break;
		else
		{	unsigned char *p = strTable[code].p;
			int l = strTable[code].len;
			unsigned char c;
			if(p != NULL)
			{	c = *p;
				if(outIndex+l <= bufLen)
					for(i=0;i<l;i++)
						outP[outIndex++] = *p++;
				else
					goto error;
				if(!addStrTable(strTable,tableIndex++,oldCode,c))
					goto error;
				oldCode = code;
			}
			else
			{	p = strTable[oldCode].p;
				l = strTable[oldCode].len;
				c = *p;
				if(outIndex+l+1 <= bufLen)
				{	for(i=0;i<l;i++)
						outP[outIndex++] = *p++;
					outP[outIndex++] = c;
				}
				else
					goto error;
				if(!addStrTable(strTable,tableIndex++,oldCode,c))
					goto error;
				oldCode = code;
			}
			if(tableIndex == (((UINT)1)<<codeSize) && codeSize != 12)
				codeSize++;
		}
	}
done:
	for(i=0;i<4096;i++)
		if(strTable[i].p != NULL)
		{	delete strTable[i].p;
			strTable[i].p = NULL;
		}
	delete[] strTable;
	return TRUE;
error:
	for(i=0;i<4096;i++)
		if(strTable[i].p != NULL)
		{	delete strTable[i].p;
			strTable[i].p = NULL;
		}
	delete[] strTable;
	delete[] f->dataBuf;
	f->dataBuf = NULL;
	return FALSE;
}

LPCGLOBAL_INFO CGif89a::getGlobalInfo()
{	return &gInfo;
}

void CGif89a::close()
{	if(opened)
	{	opened = FALSE;
		if(inMem && allFrames != NULL)
		{	FRAME* pf = allFrames;
			for(UINT i=0;i<gInfo.frames;i++)
			{	if(pf->pColorTable != NULL)
				{	delete[] pf->pColorTable;
					pf->pColorTable = NULL;
				}
				if(pf->dataBuf != NULL)
				{	delete[] pf->dataBuf;
					pf->dataBuf = NULL;
				}
			}
			delete[] allFrames;
			allFrames = NULL;
		}
		if(!inMem)
		{	if(curFrame.pColorTable != NULL)
			{	delete[] curFrame.pColorTable;
				curFrame.pColorTable = NULL;
			}
			if(curFrame.dataBuf != NULL)
			{	delete[] curFrame.dataBuf;
				curFrame.dataBuf = NULL;
			}
			//ifs.close();
			fclose(m_file);
		}
	}
}

LPCSTR CGif89a::getVer()
{	return version;
}