[Fontconfig] Problem with bitmap fonts

[Behdad Esfahbod]

Pat Suwalski wrote:
> Behdad Esfahbod wrote:
>> I've got this bug report against pango [1].  In short, the problem is
>> that
>> fontconfig prefers bitmap fonts of the right family name but
>> arbitrarily far
>> away font size over fonts with the right font size (perhaps
>> non-bitmap) but
>> wrong family name.  Sounds useful at first, except that if you happen
>> to ask
>> for "Times 96" and get a bitmap "Times" 12px, that doesn't really help.
> 
> Yes, this is a very real problem for things generated in a classic Mac
> environment where the "Times" font was a scalable font, and, of course,
> the Helvetica font, which is a very common Type1/TrueType font and has a
> bitmap font by default in X.
> 
> Why scale it at all? If the user asks for 18px, we don't want to stretch
> a 12px bitmap font to 18, and we wouldn't want to show it at 12 either.
> I think the bitmap font matching should be an exact thing only. That's
> why bitmap fonts ship with a variety of pixel sizes to start with. If
> they can't satisfy the rendering, don't use it.
> 
> Actually, isn't that exactly how bitmap information embedded into
> True/OpenType is handled?

Oll Korrect.  I agree that rounding to integer and matching is what I prefer.
My main issue with going ahead and doing this is that then when you choose a
bitmap font in a font dialog you see fallback fonts.  Unless the dialog
correctly populates the size column from the actual sizes of the font.  At
least the GTK+ font dialog doesn't do that currently.  Pango has API for this
though, so it's easy fix on my side.

behdad

> --Pat
>