Re: Devanagari question

From: Antoine Leca (
Date: Mon Nov 13 2000 - 13:27:59 EST

Marco Cimarosti wrote:
> Antoine Leca wrote:
> > My understanding is that there are a number of similar cases,
> > which are not
> > officially prohibited (AFAIK), but does not carry any sense.
> I think that the original idea behind having combining marks in Unicode was
> that *any* combination of base + diacritic should be permitted,

The fact that it is permitted (as I said, they "are not prohibited")
does not per se give them any sense...
This was my point, but I was not clear enough.

> and be handled decently by rendering engines.

The question here is the meaning of "decently".

I beg your pardon, but as the programmer of a rendering engine, I cannot
agree that I should spend hours and days, and furthermore adding megabytes
of code, to render "decently" combinations like digits + accents (by
decently, I mean I should check if the glyph for the digit have ascender
above x-height, or being of narrower width, and then adjust the position of
the diacritic accordingly; similarly, adjusting the descender position of the
Nagari virama according to the descender depth of a preceding "g" or "j" or

At the contrary, I believe that when a combination is not expected, the
renderer should have a very basic and straightforward behaviour, and just
"print" the default glyphs in order, with overstriking when the second glyph
is a combining mark. Doing something more complex, in addition to be IMHO
a complete lost of time for both the programmer and the users (to load unusued
code), is also likely to give some users the idea that using some weird
combinations are handled this ("clever") way everywhere, thus leading to chaos
when the datas will be brought elsewhere.

> If font designers and d. engines implementers insist in the idea that an
> "accented letter" may be rendered only if an ad-hoc glyph has been
> anticipated in the font, many minority languages will never have a chance of
> being supported at a reasonable cost.

I never say (nor I hope I implied) such an idea.

Now, insisting that any renderer should align properly any diacritic on the
top (or bottom) middle of the I, M and W glyph, will have for net result
that nobody will never be able to create any renderer...

> Less common combinations, used in less known languages, may get along with a
> less-than-perfect rendering -- but *no* rendering at all is not acceptable,

Where anyone stated such an idea?


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