Re: Suggest installing more fonts?

[Gregory Heytings]

> > Apparently it's not clear, so I'll say one last time that the feature I 
> > propose does _not_ require to install Unifont system-wide.  It is to 
> > include Unifont in Emacs (say in etc/unifont), and to offer it as an 
> > additional option for glyphless-char-display, along with hex-code, 
> > empty-box, thin-space, and zero-width.  The bitmap data would be used 
> > to draw the glyph in produce_glyphless_glyph() .
>
> I don't understand this proposal.  Are you saying Emacs can already use 
> a font that is not installed?  If so, can you tell how to do that?

I don't (yet) know, but I'd be surprised if this could not be done. 
Emacs already creates glyphs dynamically for tofus, and already uses 
black-and-white bitmaps at least in fringes.

> The way Emacs uses fonts is by using various system libraries, such as 
> Fontconfig, to find fonts that match certain criteria (script, encoding, 
> character codepoint, size, slant, etc.).  How do you propose to do that 
> if, for example, Fontconfig knows nothing about a font?

The proposal is not to change anything to the way Emacs uses fonts, but to 
change something to the way Emacs behaves when it does not find an 
appropriate font to display a character.  In that case Emacs would display 
a "degraded" glyph (from Unifont), and would issue a warning that the user 
should install another font.

> > FYI, that feature is not "already in Emacs", as you said: when Unifont 
> > is installed, it takes precedence over some (but not all, I'm not sure 
> > why) of the better-looking available fonts.  One example: DejaVu Sans 
> > has hebrew characters, but with Unifont installed hebrew characters are 
> > displayed with Unifont.
>
> This actually means that Unifont is more "in Emacs" than I thought. ;-)
>
> Anyway, did you check the coverage of Hebrew by DejaVu Sans? does it 
> cover Hebrew?

Yes, DejaVu Sans covers Hebrew (100% coverage).