The ToGIF Function

void gif_ToGIF(void*& pBuf,unsigned long& BufSz,ImgGIFInfo& Info)
{
	bool DoWrite = false;
	char TableIndex;

	if(Info.BitCount == 8)
	{
		TableIndex = TABLE_8BIT;
		DoWrite = true;
	}
	else
	if(Info.BitCount == 4)
	{
		TableIndex = TABLE_4BIT;
		DoWrite = true;
	}
	else
	if(Info.BitCount == 1)
	{
		TableIndex = TABLE_1BIT;
		DoWrite = true;
	}

	if(DoWrite)
	{
		void* pPalette = pBuf;
		void* pPixel = &(((char*)pBuf)[(PaletteSize[TableIndex] * 4)]);

		Gif* pGif = new_gif(Info.Trns);

		GifScreen* pGS = pGif->screen;
		pGS->width = Info.XDim;
		pGS->height = Info.YDim;
		pGS->has_cmap = 1;
		pGS->color_res = BitCount[TableIndex];
		pGS->sorted = 0;
		pGS->cmap_depth = BitCount[TableIndex];
		pGS->bgcolour = 0;
		pGS->aspect = 0;

		GifPalette* pGL = pGS->cmap;
		pGL->length = PaletteSize[TableIndex];
		pGL->colours = (Colour*) img_malloc(pGL->length * sizeof(Colour));

		unsigned long Index;
		for(Index=0;Index<PaletteSize[TableIndex];Index++)
		{
			pGL->colours[Index].blue = ((unsigned char*)pPalette)[(Index * 4) + 0];
			pGL->colours[Index].green = ((unsigned char*)pPalette)[(Index * 4) + 1];
			pGL->colours[Index].red = ((unsigned char*)pPalette)[(Index * 4) + 2];
		}

		GifBlock* pGBTrns = NULL;
		GifBlock* pGBImg = NULL;

		if(Info.Trns)
		{
			pGBTrns = new_gif_block();
			pGBImg = new_gif_block();
			pGif->blocks = (GifBlock**) img_malloc(sizeof(GifBlock*) * 2);
			pGif->blocks[0] = pGBTrns;
			pGif->blocks[1] = pGBImg;
			pGif->block_count = 2;
		}
		else
		{
			pGBImg = new_gif_block();
			pGif->blocks = (GifBlock**) img_malloc(sizeof(GifBlock*));
			pGif->blocks[0] = pGBImg;
			pGif->block_count = 1;
		}

		if(pGBTrns != NULL)
		{
			GifExtension* pGE = new_gif_extension();

			pGBTrns->intro = BLOCK_INTRO_EXTENSION;
			pGBTrns->ext = pGE;

			pGE->marker = 0xF9;
			pGE->data = (GifData**) img_malloc(sizeof(GifData*));

			GifData* pGD = new_gif_data(4);
			pGE->data_count = 1;
			pGE->data[0] = pGD;

			pGD->bytes[0] |= 0x01;
			pGD->bytes[3] = Info.TrnsIndex;
		}

		pGBImg->intro = BLOCK_INTRO_PICTURE;
		GifPicture* pGP = new_gif_picture();
		pGBImg->pic = pGP;

		pGP->width = Info.XDim;
		pGP->height = Info.YDim;
		pGP->cmap_depth = BitCount[TableIndex];

		unsigned long x,y;
		pGP->data = (unsigned char**) img_malloc(Info.YDim * sizeof(unsigned char*));

		for(y=0;y<Info.YDim;y++)
		{
			pGP->data[y] = (unsigned char*) img_malloc(Info.XDim * sizeof(unsigned char));
			img_memset(pGP->data[y],0,(Info.XDim * sizeof(unsigned char)));
		}
		 

		for(y=0;y<Info.YDim;y++)
		{
			unsigned char* pDestRow = pGP->data[((Info.YDim - 1) - y)];
			unsigned char* pSrcRow = &(((unsigned char*)pPixel)[(y * Info.LineSize)]);
			for(x=0;x<Info.XDim;x++)
			{
				unsigned long TableOffs = (x & AddressMaskTable[TableIndex]);
				unsigned char Data = pSrcRow[(x >> AddressShiftTable[TableIndex])];

				Data &= MaskTable[TableIndex][TableOffs];
				Data >>= ShiftTable[TableIndex][TableOffs];

				pDestRow[x] |= Data;
			}
		}

		GifBuffer aGB;
		aGB.pBuf = NULL;
		aGB.Size = 0;
		aGB.Ptr = 0;
		
		write_gif_file(&aGB,pGif);

		del_gif(pGif);

		img_free(pBuf);
		pBuf = aGB.pBuf;
		BufSz = aGB.Size;
	}
	else
	{
		img_free(pBuf);
		pBuf = NULL;
		BufSz = 0;
	}
}