Writing in Hindi and other scripts (was: Re: [OS X TeX] Installing CJK)

[Thomas Schröder]

Am 15.07.2004 um 16:57 schrieb Jonathan Kew:

>> Well, if Unicode can do it, so can this method because you type your 
>> stuff with the Devanagari keyboard layout. Right?
>
> No, it's not. The Devanagari keyboard layout generates a sequence of 
> Unicode characters. But the mapping from Unicode characters to glyphs 
> in a font is far from a simple one-to-one mapping. There are issues of 
> reordering, contextual selection of various glyphs for a given 
> character, and so on. This method doesn't have any implementation of 
> that layer, as far as I can see.

Yes, you're absolutely right. I was a bit too optimistic, as it seems.

>> My concern was, wether the Titus font could do all the things you 
>> could do with the Devanagari keyboard layout and furthermore wether 
>> you were really able to do everything necessary with the layout.
>
> I expect it probably supports all the *character codes* that the 
> layout will generate, but without some "smart rendering" technology 
> such as AAT or Uniscribe/OpenType, the rendered text will not be 
> correct Devanagari.

Hm, I'm beginning to appreciate OS X more and more every day.

> Using the Devanagari-QWERTY keyboard layout, enter the key sequence
> 	h i n f d I
> which should render as हिन्दी (provided your mail client displays it OK;

I'm using Apple's Mail.app, so no problems there.

>  type it in TextEdit to check!).

I did that, too. It really _is_ nice how everything gets reshaped 
according to context. I mean I've seen this before, but when you know a 
little bit more about the language it's so much nicer :-)

> Try typesetting this with pdflatex and Titus, and see how close it 
> comes to the same result; I'm guessing the short 'i' will not appear 
> in the right place, and the 'nd' cluster will not form correctly.

You guessed 100% right :-)
It looks something like this: ह िनदी , while in TeXShop it looks the way 
it should: हिन्दी . Oh, well.

>> I know, but I wanted to do this with normal pdflatex because if I 
>> understand this correctly, then XeTeX is OS-X-only, at least at the 
>> moment.
>
> Correct. But to do it with normal pdflatex, you'll need (a) access to 
> additional glyphs beyond the nominal forms that are associated with 
> each Unicode codepoint; and (b) some pretty complex processing to 
> handle the character-to-glyph mapping with all its contextual 
> reordering and glyph shaping behavior.

Now that I played a little with XeTeX again it came back to me why I 
didn't use it in the first place: it wasn't so much the platform thing 
but that I'd have to rework quite a bit of my stuff to get to the same 
level where I am now and I didn't really want to do that :-)

> To do it in a platform-independent way, you could use Omega; or you 
> could try to implement all the behavior in TeX macros (you'd be a 
> braver man than I am!); or create a portable pre-processor along the 
> lines of ArabTeX.

Ah, well, all of this is probably very much beyond my capabilities. I 
guess I'll just have to do what I always do: finally forget about 
wanting to use just one tool but use the right tool for every occasion. 
In my case I'll use pdflatex for my thesis and XeTeX for the fun and 
fancy stuff :-)

This has been very instructive, so thanks a lot!

Bye, Thomas

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