Scientific charting control

HANDLE DDBToDIB( CBitmap& bitmap, DWORD dwCompression, CPalette* pPal ) <br />
{<br />
	BITMAP			bm;<br />
	BITMAPINFOHEADER	bi;<br />
	LPBITMAPINFOHEADER 	lpbi;<br />
	DWORD			dwLen;<br />
	HANDLE			hDIB;<br />
	HANDLE			handle;<br />
	HDC 			hDC;<br />
	HPALETTE		hPal;<br />
<br />
<br />
	ASSERT( bitmap.GetSafeHandle() );<br />
<br />
	// The function has no arg for bitfields<br />
	if( dwCompression == BI_BITFIELDS )<br />
		return NULL;<br />
<br />
	// If a palette has not been supplied use defaul palette<br />
	hPal = (HPALETTE) pPal->GetSafeHandle();<br />
	if (hPal==NULL)<br />
		hPal = (HPALETTE) GetStockObject(DEFAULT_PALETTE);<br />
<br />
	// Get bitmap information<br />
	bitmap.GetObject(sizeof(bm),(LPSTR)&bm);<br />
<br />
	// Initialize the bitmapinfoheader<br />
	bi.biSize		= sizeof(BITMAPINFOHEADER);<br />
	bi.biWidth		= bm.bmWidth;<br />
	bi.biHeight 		= bm.bmHeight;<br />
	bi.biPlanes 		= 1;<br />
	bi.biBitCount		= bm.bmPlanes * bm.bmBitsPixel;<br />
	bi.biCompression	= dwCompression;<br />
	bi.biSizeImage		= 0;<br />
	bi.biXPelsPerMeter	= 0;<br />
	bi.biYPelsPerMeter	= 0;<br />
	bi.biClrUsed		= 0;<br />
	bi.biClrImportant	= 0;<br />
<br />
	// Compute the size of the  infoheader and the color table<br />
	int nColors = (1 << bi.biBitCount);<br />
	if( nColors > 256 ) <br />
		nColors = 0;<br />
	dwLen  = bi.biSize + nColors * sizeof(RGBQUAD);<br />
<br />
	// We need a device context to get the DIB from<br />
	hDC = GetDC(NULL);<br />
	hPal = SelectPalette(hDC,hPal,FALSE);<br />
	RealizePalette(hDC);<br />
<br />
	// Allocate enough memory to hold bitmapinfoheader and color table<br />
	hDIB = GlobalAlloc(GMEM_FIXED,dwLen);<br />
<br />
	if (!hDIB){<br />
		SelectPalette(hDC,hPal,FALSE);<br />
		ReleaseDC(NULL,hDC);<br />
		return NULL;<br />
	}<br />
<br />
	lpbi = (LPBITMAPINFOHEADER)hDIB;<br />
<br />
	*lpbi = bi;<br />
<br />
	// Call GetDIBits with a NULL lpBits param, so the device driver <br />
	// will calculate the biSizeImage field <br />
	GetDIBits(hDC, (HBITMAP)bitmap.GetSafeHandle(), 0L, (DWORD)bi.biHeight,<br />
			(LPBYTE)NULL, (LPBITMAPINFO)lpbi, (DWORD)DIB_RGB_COLORS);<br />
<br />
	bi = *lpbi;<br />
<br />
	// If the driver did not fill in the biSizeImage field, then compute it<br />
	// Each scan line of the image is aligned on a DWORD (32bit) boundary<br />
	if (bi.biSizeImage == 0){<br />
		bi.biSizeImage = ((((bi.biWidth * bi.biBitCount) + 31) & ~31) / 8) <br />
						* bi.biHeight;<br />
<br />
		// If a compression scheme is used the result may infact be larger<br />
		// Increase the size to account for this.<br />
		if (dwCompression != BI_RGB)<br />
			bi.biSizeImage = (bi.biSizeImage * 3) / 2;<br />
	}<br />
<br />
	// Realloc the buffer so that it can hold all the bits<br />
	dwLen += bi.biSizeImage;<br />
	if (handle = GlobalReAlloc(hDIB, dwLen, GMEM_MOVEABLE))<br />
		hDIB = handle;<br />
	else{<br />
		GlobalFree(hDIB);<br />
<br />
		// Reselect the original palette<br />
		SelectPalette(hDC,hPal,FALSE);<br />
		ReleaseDC(NULL,hDC);<br />
		return NULL;<br />
	}<br />
<br />
	// Get the bitmap bits<br />
	lpbi = (LPBITMAPINFOHEADER)hDIB;<br />
<br />
	// FINALLY get the DIB<br />
	BOOL bGotBits = GetDIBits( hDC, (HBITMAP)bitmap.GetSafeHandle(),<br />
				0L,				// Start scan line<br />
				(DWORD)bi.biHeight,		// # of scan lines<br />
				(LPBYTE)lpbi 			// address for bitmap bits<br />
				+ (bi.biSize + nColors * sizeof(RGBQUAD)),<br />
				(LPBITMAPINFO)lpbi,		// address of bitmapinfo<br />
				(DWORD)DIB_RGB_COLORS);		// Use RGB for color table<br />
<br />
	if( !bGotBits )<br />
	{<br />
		GlobalFree(hDIB);<br />
		<br />
		SelectPalette(hDC,hPal,FALSE);<br />
		ReleaseDC(NULL,hDC);<br />
		return NULL;<br />
	}<br />
<br />
	SelectPalette(hDC,hPal,FALSE);<br />
	ReleaseDC(NULL,hDC);<br />
	return hDIB;<br />
}<br />
<br />
BOOL WriteDIB( LPTSTR szFile, HANDLE hDIB)<br />
{<br />
	BITMAPFILEHEADER	hdr;<br />
	LPBITMAPINFOHEADER	lpbi;<br />
<br />
	if (!hDIB)<br />
		return FALSE;<br />
<br />
	CFile file;<br />
	if( !file.Open( szFile, CFile::modeWrite|CFile::modeCreate) )<br />
		return FALSE;<br />
<br />
	lpbi = (LPBITMAPINFOHEADER)hDIB;<br />
<br />
	int nColors = 1 << lpbi->biBitCount;<br />
<br />
	// Fill in the fields of the file header <br />
	hdr.bfType		= ((WORD) ('M' << 8) | 'B');	// is always "BM"<br />
	hdr.bfSize		= GlobalSize (hDIB) + sizeof( hdr );<br />
	hdr.bfReserved1 	= 0;<br />
	hdr.bfReserved2 	= 0;<br />
	hdr.bfOffBits		= (DWORD) (sizeof( hdr ) + lpbi->biSize +<br />
						nColors * sizeof(RGBQUAD));<br />
<br />
	// Write the file header <br />
	file.Write( &hdr, sizeof(hdr) );<br />
<br />
	// Write the DIB header and the bits <br />
	file.Write( lpbi, GlobalSize(hDIB) );<br />
<br />
	return TRUE;<br />
}<br />
<br />
BOOL WriteWindowToDIB( LPTSTR szFile, CWnd *pWnd )<br />
{<br />
	CBitmap 	bitmap;<br />
	CWindowDC	dc(pWnd);<br />
	CDC 		memDC;<br />
	CRect		rect;<br />
<br />
	memDC.CreateCompatibleDC(&dc); <br />
<br />
	pWnd->GetWindowRect(rect);<br />
<br />
	bitmap.CreateCompatibleBitmap(&dc, rect.Width(),rect.Height() );<br />
	<br />
	CBitmap* pOldBitmap = memDC.SelectObject(&bitmap);<br />
	memDC.BitBlt(0, 0, rect.Width(),rect.Height(), &dc, 0, 0, SRCCOPY); <br />
<br />
	// Create logical palette if device support a palette<br />
	CPalette pal;<br />
	if( dc.GetDeviceCaps(RASTERCAPS) & RC_PALETTE )<br />
	{<br />
		UINT nSize = sizeof(LOGPALETTE) + (sizeof(PALETTEENTRY) * 256);<br />
		LOGPALETTE *pLP = (LOGPALETTE *) new BYTE[nSize];<br />
		pLP->palVersion = 0x300;<br />
<br />
		pLP->palNumEntries = <br />
			GetSystemPaletteEntries( dc, 0, 255, pLP->palPalEntry );<br />
<br />
		// Create the palette<br />
		pal.CreatePalette( pLP );<br />
<br />
		delete[] pLP;<br />
	}<br />
<br />
	memDC.SelectObject(pOldBitmap);<br />
<br />
	// Convert the bitmap to a DIB<br />
	HANDLE hDIB = DDBToDIB( bitmap, BI_RGB, &pal );<br />
<br />
	if( hDIB == NULL )<br />
		return FALSE;<br />
<br />
	// Write it to file<br />
	WriteDIB( szFile, hDIB );<br />
<br />
	// Free the memory allocated by DDBToDIB for the DIB<br />
	GlobalFree( hDIB );<br />
	return TRUE;<br />
}<br />