Re: Thai fonts small compared to regular characters

[Theppitak Karoonboonyanan <thep linux thai net>]

On Sun, Jul 25, 2004 at 08:19:16AM +0700, Javier SOLA wrote:
> 
> >The reason is that Thai font designs have to reserve upper and lower
> >space for placing combining characters [1]. So, with the same point size,
> >Thai base characters are always smaller than those of typical Latin fonts.
> >This is true for other multi-level scripts, such as Laos, Khmer, Tibetan
> >as well. However, those fonts always provide English glyphs with proper
> >relative size. So, if the same font is chosen, the relative size would fit
> >well.
> 
> This is because the rule of maintaining total height identical is used.
> 
> For our Khmer fonts (Khmer OS fonts) we have decided to use traditional 
> typographical size for the main consonants. Vertical spacing is twice what 
> it would be in a  pure latin font, but when you use size 10 you can 
> perfectly read the text, and it can be mixed with size 10 of most Latin 
> fonts.

This is interesting, as extra line height can be reserved more than the
point size. Indeed, a Thai font named Loma has been developed as a
pioneer for this idea. It's solely for GUI, not typographically
optimized, anyway. It doesn't care when it puts upper/lower marks
beyond the ascender/descender. But the spill-over is minimized by
reducing the size of upper/lower marks, lessening its typographical
quality a little bit. Nonetheless, when coming to fonts for general
uses, where typography are concerned and glyph proportions can't be
distorted, we can't be sure so far whether the glyphs in extra space
would be clipped when rendered by any application.

This problem has deferred the adoption of the approach in other fonts
than Loma so far. However, FontForge's recent change that results in
increased line spacing had once triggered the adoption, but it still
depends on how applications allocate line spaces, anyway. Mozilla HTML
form widgets, for example, are still allocated based on point size, at
least at the time of that discussion. I haven't checked the latest
version yet.

So, it's interesting if you can cope with this problem. Of course, the
approach would also be useful for Thai.

> The result for both approaches comes to the same when you use it in 
> menus... you can only fit half the number of rows of what you could fit in 
> a latin script language. 

I believe the line spacing is increased as you said. We have experienced
that. Just not sure if it applies to all applications.

-Thep.
-- 
Theppitak Karoonboonyanan     
http://linux.thai.net/~thep/