[DirectWrite] Does not select the right font when 2 fonts have similar attributes

[moi15moi]

[DirectWrite] Does not select the right font when 2 fonts have similar attributes

[astiob]

Yet another reason to migrate away from EnumFontFamilies to direct CreateFontIndirect calls for each font request :-( I’ve been wanting to do that for quite a while, but it requires a (desirable) larger rewrite of our fontselect, so I haven’t found the energy to actually do it.

I think this happens because we call CreateFontIndirect with the LOGFONT returned by EnumFontFamilies, which has only one font name—and it’s apparently the family name, seeing as EnumFontFamilies returns a separate field for the full name. And the family name, of course, is the same for both of these fonts, as are all the other parameters contained within LOGFONT, as you point out:

EnumFontFamiliesW:
family: [SF Pro Display] fullname: [SF Pro Display Bold] style: [Bold] charset: [0] weight: [700] ntmFlags: [0x40] FontType: [4] (TrueType)
family: [SF Pro Display] fullname: [SF Pro Display Bold Italic] style: [Bold Italic] charset: [0] weight: [700] ntmFlags: [0x40] FontType: [4] (TrueType)

So the value libass’s EnumFontFamilies callback gives to CreateFontIndirect is the same for both fonts, resulting naturally in the same font.

[astiob]

A possible solution is to replace the lfFaceName with the elfFullName of the ENUMLOGFONTEXW.

Oh. This sounds interesting. But this is only allowed for TrueType-outline fonts, not for CFF-outline ones. SF Pro Display is indeed a TrueType-outline font (although other affected Apple fonts may not be), but the problem is that our callback can’t know which kind of outlines the font has until it has actually obtained the font!

[moi15moi]

A possible solution is to replace the lfFaceName with the elfFullName of the ENUMLOGFONTEXW.

Oh. This sounds interesting. But this is only allowed for TrueType-outline fonts, not for CFF-outline ones. SF Pro Display is indeed a TrueType-outline font (although other affected Apple fonts may not be), but the problem is that our callback can’t know which kind of outlines the font has until it has actually obtained the font!

Why do you say that? elfFullName represent the postscript name for CFF-outline ones (yes this is a terrible name, but it is GDI...)

[astiob]

Hang on, derp. CFF-outline fonts just return their PostScript name in the elfFullName field. That’s what causes the difference in the first place. So yeah, we should be able to do that!