Re: another question about layout in ICU 2.6

Hi Eric,

> I've been looking at the changes I've made to the LayoutEngine since ICU
> 2.6, and I'm not sure that any of them address the problem you describe.

I very much appreciate your support here, thanks.

I want to say again, all this is not an issue with ICU 3.2. It is only visible 
with 2.6 and I took the version without the patch from OOo to be sure it is 
really causes by ICU. 

> Can you please send me an example of a character sequence that is
> rendering incorrectly? Also, let me know if you see the problem with all
> Khmer fonts, or only certain fonts. I'll see if I can figure out what
> other patches you might need to make it work.

You may download:

ftp://ftp.khmeros.info/download/issues/Sample.txt
ftp://ftp.khmeros.info/download/issues/correct-kampongtrach.ttf.png
ftp://ftp.khmeros.info/download/issues/wrong-khmeros.ttf.png

to get an idea what my problem is. 

From inspecting the fonts I can tell you that there is a major difference how 
they define the subscript glyphs. In kampongtrach.ttf happens a simple 
substitution from coeng + consonant -> subscript consonant. In khmeros.ttf 
there are also anchors defined to finetune the position. 
My guess is the calculation with the anchors is broken. 

> One major change I did since 2.6 was to implement the Multiple
> Substitution subtable - it's possible that this is somehow related,
> although this code is not hit in ICU 3.2 using the Khmer samples and
> fonts that I have.

I can not image how this would cause what I see.

Thanks again

Jens