C / C++ / MFC

DLLEXPORT int writeVariableImage (HBITMAP staticBlackLayer, HBITMAP varLayer,
						VariableObject* varObj, int numVarObjects,
						char* fileName)
{
	if (!criticalSectionInitialized)
	{
		InitializeCriticalSection (&cs);
		criticalSectionInitialized = true;
	}

	EnterCriticalSection(&cs);

	try
	{							// Make copy of black
		if (!copyBitmap (varLayer, staticBlackLayer))	// layer to mark up:
			throw 666;				// Problem found.

		HDC memDc = CreateCompatibleDC (NULL);		// Prepare to draw:
		HGDIOBJ Obmp  = SelectObject(memDc, varLayer);

		if (!memDc  ||  !Obmp)
			throw 666;				// Problem found.

								// Go through objects:
		for (int i = 0;   i < numVarObjects;   ++i)	// Draw markup:
			drawVariableObject (memDc, &varObj [i]);// Draw next var object.

		invertLayer (memDc, varLayer); 
		writeToTiffFile (varLayer, fileName);		// Write to file.

		if (!SelectObject (memDc, Obmp)  ||		// Clean up:
			!DeleteDC (memDc))
			throw 666;				// Problem found.
	}
	catch (...)
	{
		DWORD err = GetLastError ();

		if (err)
		{
			LPTSTR s;				// Show error message:
			FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
				NULL, err, 0, (LPTSTR)&s, 0, NULL);
			MessageBox (NULL, s, L"Error", 0);
			LocalFree (s);
		}

		LeaveCriticalSection(&cs);
		return 0;					// Failed.
	}

	LeaveCriticalSection(&cs);
	return 1;						// Success.
}