[XeTeX] Emulating font extension

[Jonathan Kew]

On 18 Jun 2009, at 11:23, Vadim Radionov wrote:

> Hello,
> Thank you for the great engine!
>
> I'm wondering what exactly the "extend" pseudo-feature does: if set
> unreasonably big (say, 2), the interword spacing shrinks to zero and
> even negative, and if it is as small as .5, the space is doubled or
> so.  I suppose it changes the spacing for "normal" values of 1.01 or
> .99 too, so I would like to know how to correct it by changing the
> space by some amount.
>
> I use XeTeX 3.1415926-2.2-0.9994.0 (Web2C 7.5.6)


Something is wrong there.... the interword spacing should scale along  
with the glyphs. I just tried a small test:

> This is XeTeXk, Version 3.1415926-2.2-0.999.6 (Web2C 7.5.7)
>  %&-line parsing enabled.
> **\relax
> entering extended mode
>
> *\font\x="Times Roman:extend=2" at 12pt \x The quick brown fox jumps  
> over the lazy dog.
>
> *\font\y="Times Roman:extend=0.5" at 12pt \y Pack my box with five  
> dozen liquor jugs.
>
> *\bye
> [1]
> Output written on texput.pdf (1 page).

The result looks fine here (well, it looks ugly but that's expected!).  
What system are you running on?

JK