Re: [gnome-print] Font subsetting, incremental downloading et al in0.35

[Chema Celorio <chema ximian com>]

sorry for the delayed response.

On Fri, 2002-03-29 at 07:08, Richard Chan wrote:
> Hi, I'm trying to understand the fontsubsetting architecture in 0.35.
> 
> 1. In order to support incremental downloading of fonts, say for large
> CID or TTF fonts, does gnome-print have the concept of
>  
> 1. "a list of all the glyphs from Font ABCD used on page N"
> 2. In the ps target, can one
> 	(a) Write the basic font directory 
> 	(b) Add charstrings/ttf glyphs on the fly

No, gnome-print does not currently implement font subsetting. There is
an attempt at font subsetting inside gnome-print but it is not being
used.

We need to implement font subsettting specially with the increase use of
Unicode, because fonts with large coverage are huge.

> 	
> Something like
> 	gff_pso_create_font( ...from ttf,otf,pfb or whatever)
> 	
> 	%%Page N
> 	save
> 	gff_so_add_glyphs(...from a vector of glyphs)	
> 	restore
> 	%%Page N+1
> 	gff_pso_add_glyphs(...)
> 
> The idea is something along the lines of what Adobe calls
> "incremental font downloading" in its documentation.
> 
> I suppose this is similar to fontsubsetting, but the glyphs
> are not all added at once but on a "just-in-time" basis.

This is one of the nice things about moving to PDF. In PDF we can just
write the text and keep track of the glyhs that we used, then we can
great the font object. I think it is better to work towards moving to
PDF than to fix the PS backend, but that is arguable.

regards,
Chema