Re: Reference Scheme for Mongolian Rendering

On 14 August 2015 at 11:10, Greg Eck <> wrote:
> 2.) I am not sure I would say "normally". Baiti and probably most of the
> other fonts use direct OT substitutions. I have experimented with the Type
> 14 Encoding Table successfully, but don't know that it is needed in every
> case. Where we are using the standard FVS1-3, I would say we continue to use
> the standard method with OT substitution rulings. If we leave the realm of
> the FVS set, then we should probably consider using the Type 14 CMAP table.
> Could we have some discussion here? Is anyone using the Type 14 CMAP table
> yet? The area where we experimented with the Type 14 table was in the
> rotation of digits. We used the VS01 as our selector.

Personally, I do not think it makes much sense to use the Format 14
subtable for Mongolian FVS.  As the final glyph is determined by
context, you would have to substitute a special temporary glyph (one
unique glyph for each base character + FVS combination) in the Format
14 table, and still apply all the contextual substitution rules in the
GSUB table to transform the temporary glyph to the correct glyph.
Adding the Format 14 table has no advantages that I can see, and
seriously complicates the process (having implemented Format 14 for my
Phags-pa fonts I can say that I really loathe Format 14, and think it
was an awful mistake).

I seem to recall that Peter Constable once (on the unicore list?)
stated that Format 14 was not intended for use with Mongolian (and
certainly Microsoft has not implemented Format 14 for its Mongolian
font), but I cannot find this email any longer.


Received on Friday, 14 August 2015 10:54:38 UTC