[mpeg-OTspec] New cmap format

[Opstad, Dave]

On Apr 3, 2012, at 5:32 PM, John Hudson wrote:

> On 03/04/12 5:20 PM, Opstad, Dave wrote:
> 
> > The 'Zapf' table, documented here:
> >
> > https://developer.apple.com/fonts/TTRefMan/RM06/Chap6Zapf.html
> >
> > has as a component the FeatureInfo structure. Perhaps this would be interesting to look at another take on how this capability could be implemented?
> 
> Is this really the capability that the FeatureInfo structure implements? 
> My understanding of the Zapf table spec is that the FeatureInfo 
> structure specifies line layout contexts for displaying particular glyphs.
> 
> Now that is a very, very cool thing that I wish OpenType supported, but 
> I think it is different from the kind of character code to multiple 
> glyph mapping that I am suggesting.

Sorry, John, I was thinking of the unicodes[] array in the GlyphInfo structure of the 'Zapf' table, not the FeatureInfo structure. This is a list of Unicodes associated with the glyph. Presumably, when combined with the FeatureInfo to identify which feature needs to be used to trigger formation, this might move us along the path to your goal.

So if my font has, say, an "abc' precomposed form, its unicodes[] array in its GlyphInfo structure could have the three Unicodes 'a', 'b', and 'c' in that order, and the FeatureInfo for the glyph could identify the features (OpenType and AAT) that cause the precomposed form to be made. It's not exactly the same as your notion, in that 'Zapf' provides a list of Unicodes and not glyphs, but it's quite similar, I think.

Dave