bug#3174: NS font selection still broken

[Adrian Robert]

Hi,

For debugging it will be more useful to compare with another port on  
Emacs-23 (e.g., X11) than Carbon Emacs 22, as character rendering and  
font selection was changed completely.

For differences from w32 or x11 that show up on Emacs 23, font  
selection is handled through ns_findfonts() in nsfont.m.  The rewrite  
of a few months ago brought this mostly in line with other ports, but  
some crucial differences may still remain (though I'm not sure what  
they are).  I'm afraid it will take a fairly significant effort at  
turning on tracing in that file (NSFONT_TRACE at the top), and working  
through the logic of what font.c is doing and what nsfont.m is doing,  
for the characters in question.  I can't think of any shortcuts, and I  
have to admit these mathematical symbol ranges have long been a  
problem eluding my efforts, though I believe the rewrite lessened the  
number of erroneously-handled characters.

The actual "bugs" could be either in nsfont.m or font.c -- sometimes  
in the past nsfont's different implementation sometimes revealed  
problems in font.c that did not affect other ports.  (Of course the  
nsfont.m impl should continue to be normalized to the other ports so  
such bugs can remain mercifully hidden.)

I'm not sure #3588 is related, as the 'italic' property is a confound  
there.

-Adrian



On Oct 29, 2009, at 2:18 PM, David Reitter wrote:

> Adrian, readers of bugs 3174 and 3588,
>
> There are still some bad issues with the font selection in the NS  
> port.
>
> For example, take the following unicode characters:
>
> [∃]  2203  THERE EXISTS
> [∄]  2204  THERE DOES NOT EXIST
> [∈]  2208  ELEMENT OF
>
> They are rendered perfectly in the Carbon port (at least in Aquamacs).
>
> In NS, it uses Symbol for 2203, even though the glyph is available  
> in the default font (like Monaco or Lucida Grande).
> As a consequence, the symbol looks very small and is unreadable.
>
> As for 2203, it also uses Symbol, even though Symbol doesn't even  
> have the glyph.
>
> This is on Snow Leopard.
>
> I'm wondering if this is this the same bug as #3588.  I would write  
> to emacs-devel to ask for help, but I don't even know what exactly  
> the problem is in the underlying code, and whether this is NS  
> specific (I guess so)...   I can happily file another bug report so  
> we've got something to ignore :)
>
> Let me know what if I can help.
>
> Thanks
> - David