pitch in a windows 24bit bmp

#define _RGB32BIT(a,r,g,b) ((b) + ((g) << 8) + ((r) << 16) + ((a) << 24))typedef struct _DIBPIXEL{	BYTE blue, green, red;} DIBPIXEL, *LPDIBPIXEL;	LONG *video_buffer = reinterpret_cast<LONG*>(ddsd.lpSurface);	DIBPIXEL dibPixel; // stored in the bmp file, <b,g,r>		int width = m_Width*3;								//this solution gives me three mini-copies.	unsigned long padding = (4 - (width&3)) & ~4;		//ULONG pitch = bminfo.biSizeImage/m_Height;		// old solution, obsolete	//unsigned long pitch = (m_Width * bminfo.biBitCount + 3) & (~3); // Kippesoep's pitch		for (int y = 0; y < m_Height; y++)		for (int x = 0; x < m_Width; x++)		{			// three mini copies			dibPixel = *((DIBPIXEL*)(DataBuffer) + (x*3 + y * (width + padding)));			// one 1/3 tall copy			//dibPixel = *((DIBPIXEL*)((unsigned char*)DataBuffer) + (x + (m_Width + padding) * y) * 3);			// Kippesoep's proposed solution...			//dibPixel = *((DIBPIXEL*)((unsigned char*)DataBuffer) + (x + (pitch * y)));			// put it in the ddraw surface			(video_buffer[x+y*(ddsd.lPitch>>2)]) = _RGB32BIT(0, dibPixel.red, dibPixel.green, dibPixel.blue);		}

// here are the member variables of the class//////////////////////////////////////////////////BITMAPFILEHEADER m_bmfh; // file headerBITMAPINFOHEADER m_bmih; // info headerBYTE	*m_pbits; // array of bitsint	m_width; // width of bitmap in pixelsint	m_height; // height of bitmap in pixels/////////////////////////////////////////////////void CDIBBMP::SaveToFile( char *strFile ){    FILE *fp = NULL;    int y, pad_bytes;    BYTE pad[4] = {0,0,0,0};    if ( (fp = fopen( strFile, "wb" )) == NULL )    {	// error msg	return;    }    // here is where I figure out how many bytes    // to pad onto the end of a scan line.    // basicly each scanline has to end on a DWORD    // or 4 byte block. By using the mod operator    // on the width of the bitmap * bytesperpixel    // I am left with the remaining bytes needed to    // end on a DWORD value.    if ( (pad_bytes = sizeof(BYTE)*m_width*3 % 4) )	pad_bytes = 4 - pad_bytes;    m_bmfh.bfSize	= sizeof( m_bmfh ) + sizeof( m_bmih ) + 		(sizeof(BYTE)*m_width*m_height*3) + (pad_bytes*m_height);    m_bmfh.bfOffBits	= sizeof( m_bmfh ) + sizeof( m_bmih );    m_bmfh.bfType	= 'MB';    m_bmfh.bfReserved1	= 0;    m_bmfh.bfReserved2	= 0;    fwrite( &m_bmfh, sizeof(m_bmfh), 1, fp );    fwrite( &m_bmih, sizeof(m_bmih), 1, fp );    // bitmaps are saved upside down for some reason so we flip it    // and save one scanline at a time    for ( y = m_height -1; y >=0; y-- )    {	fwrite( &m_pbits[y*m_width*3], sizeof(BYTE)*3, m_width, fp );        // add the scanline padding	fwrite( pad, sizeof(BYTE), pad_bytes, fp );    }    fclose(fp);}

	m_FileToReadFrom.seekg(bmheader.bfOffBits, std::ifstream::beg);	LPDIBPIXEL DataBuffer = NULL;	DataBuffer = new DIBPIXEL[bminfo.biSizeImage];	//m_FileToReadFrom.read(reinterpret_cast<char*>(DataBuffer), bminfo.biSizeImage); // this loads entire file at once	for (int scanlines = 0; scanlines < m_Height; scanlines++)		m_FileToReadFrom.read(reinterpret_cast<char*>(DataBuffer) + (m_Width*3*scanlines), m_Width*3); // skip pad bytes!

	m_bmih.biWidth			= width;	m_bmih.biHeight			= height;	m_bmih.biPlanes			= 1;	m_bmih.biBitCount		= 24;	// only supports 24 bpp	m_bmih.biSizeImage		= 0;	m_bmih.biSize			= sizeof(m_bmih);	m_bmih.biXPelsPerMeter	= 0;	m_bmih.biYPelsPerMeter	= 0;	m_bmih.biClrUsed			= 0;	m_bmih.biClrImportant	= 0;

void CDIBBMP::LoadFromFile( char *strFile ){    int y, pad_bytes;    BYTE pad[4] = {0,0,0,0};    FILE *fp = NULL;    if ( (fp = fopen( strFile, "rb" )) == NULL )    {	// error msg	return;    }    // read in the headers    fread( &m_bmfh, sizeof(m_bmfh), 1, fp );    fread( &m_bmih, sizeof(m_bmih), 1, fp );    m_width	= m_bmih.biWidth;    m_height	= m_bmih.biHeight;    // only supports 24 bpp    if ( m_bmih.biBitCount != 24 )    {	// error msg	return;    }    // create the array    // the byte array has no padding in it    m_pbits = new BYTE[m_width*m_height*3];    // the padding is still in there to throw us off    // so we need to figure out what kind of padding there is    if ( (pad_bytes = sizeof(BYTE)*m_width*3 % 4) )	pad_bytes = 4 - pad_bytes;    // Jump to the place the BITMAPFILEHEADER says the bitmap bits are    // don't want to assume anything here.    fseek( fp, m_bmfh.bfOffBits, SEEK_SET );    // bitmaps are saved upside down for some reason so we    // place the scanlines accordingly    for ( y = m_height -1; y >=0; y-- )    {	fread( &m_pbits[y*m_width*3], sizeof(BYTE)*3, m_width, fp );	// read the pad bytes to increment the file pointer 	// but we never use them anyway	// could just jump over the bytes with fseek	// but this tends to be more clear as to whats going on	fread( pad, sizeof(BYTE), pad_bytes, fp );    }    fclose(fp);}