Hi all,

I've been playing around with D2D and Directwrite, to add text rendering in my 3d engine/ framework.
Using system fonts all works fine, by loading them up using directwrite factory -> CreateTextFormat("font name", nullptr...) etc.

But now I'd also like to load in an external truetype font file (TTF), also using DirectWrite. After trying a lot of options and looking at examples, I just can't figure out how to turn a TTF font file into a usable custom font collection (which I can then use in CreateTextFormat).

Below are some snippets of things I'm trying.
Any hints what I should look for/ try, are appreciated.

	std::wstring fontFilename = L"WESTTEST.TTF";

	CComPtr<IDWriteFontFile> tFontFile = NULL;
	m_dwFactory->CreateFontFileReference(fontFilename.c_str(), NULL, &tFontFile);
	IDWriteFontFile* fontFileArray[] = {tFontFile};

	CComPtr<IDWriteFontFileLoader> fontFileLoader;
	m_dwFactory->RegisterFontFileLoader(fontFileLoader);
	int tkey = 3;
	m_dwFactory->CreateCustomFontFileReference(&tkey, sizeof(int), fontFileLoader, &tFontFile); 

	CComPtr<IDWriteFontCollectionLoader> fontCollLoader;
	m_dwFactory->RegisterFontCollectionLoader(fontCollLoader);

	m_dwFactory->CreateCustomFontCollection(fontCollLoader, &tkey, sizeof(int), &m_dwFontColl);

	// continue - working code

	HRESULT result = m_dwFactory->CreateTextFormat(L"Arial", nullptr, DWRITE_FONT_WEIGHT_NORMAL, DWRITE_FONT_STYLE_NORMAL, DWRITE_FONT_STRETCH_NORMAL, 14.0f, L"", &m_dwFormat); 

Resolved.
For who's interested:

	std::wstring fontFilename = L"westtest.TTF";
	if(AddFontResource(fontFilename.c_str()) == 0)
	{
		OutputDebugString(L"Error adding font resource!\n");
	}

	if(FAILED(m_dwFactory->GetSystemFontCollection(&m_dwFontColl, false)))
	{
		OutputDebugString(L"Failed to retrieve system font collection.\n");
		return false; 
	}

	if(FAILED(m_dwFactory->CreateTextFormat(L"West Test", m_dwFontColl, DWRITE_FONT_WEIGHT_NORMAL, DWRITE_FONT_STYLE_NORMAL, DWRITE_FONT_STRETCH_NORMAL, 24.0f, L"", &m_dwFormat)))
	{
		OutputDebugString(L"Failed to create DirectWrite text format.\n");
		return false; 
	}

And don't forget to unregister the added font (dtor or cleanup):

	std::wstring fontFilename = L"WESTTEST.TTF";
	RemoveFontResource(fontFilename.c_str());

You might prefer to use AddFontResourceEx() with the FR_PRIVATE flag, that way the font is only available for your game, and will be automatically unregistered when the process exits.

Thanks, I actually tried that first. But somehow that didn’t work, that’s why I switched to this version. The return value seemed correct though (1), but CreateTextFormat still called/ used the fallback font.

Just tried it again, with FR_NOT_ENUM it works, but with FR_PRIVATE, it doesn't. Documentation says that when using FR_PRIVATE, the font is available for the process the called AddFontResourceEx, whatever 'the process' might mean, it looks like it doesn't stay available during the runtime of my application.

Hmm. Maybe as that CreateTextFormat() call is done using COM, it's actually talking to another process.

@Adam_42 thanks. I did some more tests, and it's kind off unpredictable, also had it working a few runs with FR_PRIVATE. Better not use FR_PRIVATE and Unregister in the CTor to be on the safe side.