Re: thai font problem

[Kenichi Handa]

In article <address@hidden>, Werner LEMBERG <address@hidden> writes:
>>  Could you try this?
>>  
>>  (set-fontset-font "fontset-default" 'thai-tis620 '("*" . "TIS620"))
>>  (clear-face-cache t)

> This works, thanks.  Will a similar fix be applied to the CVS?

Here we have a fundamental problem of the current font
selection mechanism.

If a font family is specified (by face or by fontset), Emacs
prefers a font of the specifed family even if the font size
is worse than the other font of different family.  And a
family specification of fontset has higher priority than
that of face.

Before my change, the default fontset specifies the family
"*" for most non-ASCII characters.  So, Emacs finds the best
matching font while ignoring face family for non-ASCII
characters (because any family matches "*").

This setting was good until a while ago because we didn't
have that many family variations for non-ASCII characters.

But, such a setting is just to cheat the font-selection
routine.  And, in these days, for instance, we have many
families of Japanese fonts.  In this environment, people
want to control font-selection by face family even for
Japanese.

So I changed the default fontset not to specify a family for
non-ASCII characters.

Now what happend to you is this.

As your default font is -etl-fixed-..., the default face has
family "etl-fixed".  And you surely have a Thai font of that
family.  So, that font is selected even if the size is worse
than that 24-dot Thai font of family "misc-fixed".

For a workaround, I installed the above change.

But, I think it's basically not the right thing to set "*"
family in the default fontset.  To solve the Thai font
problem, we need fine-tuning mechanism in font selection.
For instance, if the size of a selected font is very
different from the requested size, try to select another
font by ignoring a family.  But, how to decide that the font
size is "very different"?  Don't we have to suppress such a
mechanism for ASCII font?  I'm not sure.

Unfortunetely, I don't have a time to design a better font
selection mechanism for the moment.

---
Ken'ichi HANDA
address@hidden