[mpeg-OTspec] [OpenType] TrueType-flavored ".otf"

[John Hudson]

On 15/01/13 2:47 PM, Ken Lunde wrote:

> Of course, there's no harm, but continuing to include such
> recommendations, particularly when they're no longer being enforced,
> doesn't seem to make much sense today. Consider converting
> PostScript-based fonts into TrueType. I work primarily with very large
> (in terms of the number of glyphs) CID-keyed fonts, and for such fonts,
> only CID+0 (GID+0) is fixed. All other glyphs are arbitrary. The benefit
> is that the GIDs can be preserved during the conversion process, which
> allows many of the tables, such as GSUB, GPOS, and cmap to name a few,
> to be used as-is. By enforcing GIDs 1 through 3, it requires that these
> tables be touched. Preserving GIDs makes the conversion cleaner, and
> *much* easier to test.

Just so I understand: you already had CID-keyed fonts in which only the 
first glyph = .notdef restriction was implemented, prior to conversion 
of the Adobe library to OpenType? I've wondered why Adobe decided to 
make their OT fonts contrary to the then sfnt recommendation.

When we made the Adobe Arabic, Hebrew and Thai fonts, we found that the 
Unicode cmaps were being written by VOLT in a way that presumed the 
first-four-glyph rule. I believe it was Read Roberts who had to provide 
us with a list of mappings for the first portion of the cmap, which we 
then had to implement in the fonts, post-VOLT, using TTX. As Behdad 
says, this as a workflow issue is irrelevant to the value of the 
published recommendation. But in the absence of the NULL and CR glyphs, 
what is the recommendation for mapping low ASCII control characters in 
cmap tables?


JH



-- 

Tiro Typeworks        www.tiro.com
Gulf Islands, BC      tiro at tiro.com

The criminologist's definition of 'public order
crimes' comes perilously close to the historian's
description of 'working-class leisure-time activity.'
  - Sidney Harring, _Policing a Class Society_