[XeTeX] Font protrusion --- new or old ?

[Peter Baker]

Florian Grammel wrote:
> Personally I would love to see XeTeX at least do character-protrusion.  
> But as Jonathan Kew has pointed out earlier: According to XeTeX's  
> basic idea this should be done using an OpenType-feature
>
> http://www.microsoft.com/OpenType/otspec/features_ko.htm#opbd
>
> Unfortunately I haven't been able to find any further description of  
> how to implement it (e.g.. precise OT syntax) or just evidence of that  
> it actually has been used at all in any font.
> I'd be very grateful, if anybody here had further information on this...
>   
I put this question to the OT list a year or so ago and got no answer at 
all. Seems everyone is so comfortable with protrusion as implemented in 
software (InDesign, etc.) that there has been little incentive to 
develop the OT feature and support in rendering engines.

Peter