[XeTeX] letter spacing

[Will Robertson]

On 04/06/2006, at 22:04 , Adam Twardoch wrote:

> For some reason, I always assumed that this would be a trivial  
> thing to
> do in TeX. I guess it's one of the myths of "excellent typographic
> control offered by TeX" that actually turns out to be false :/

:)

Perhaps Knuth thought it trivial to create a new font metric file to  
incorporate spaced caps. I agree a tracking method in XeTeX would be  
nice.

   \font\1="Palatino:tracking=+0.1em"
   V\addkern-0.1em A

In both cases, the natural kerning would be respected and adjusted by  
the specified amount. Contrast this to the present behaviour

   V\kern-0.1em A

which kerns the letters exactly by the specified amount.
This makes fine-tuning slightly more difficult.
\addkern could be implemented, slightly more roundabout, using macros  
such as
   \addkern{VA}{-0.1em}
by measuring boxes.

I can see the disadvantage to allowing tracking (he who would steal  
sheep and all), but  on the whole it does seem strange that the  
capability is lacking.

Will