[MPEG-OTSPEC] "font directory" / "offset table" / "table directory"

[Peter Constable]

Simon, my thinking on this is in line with yours. "Table directory" used in the sense of Apple's "font directory" has the oldest attestation I can find and makes most sense. (And an "offset table" without offsets makes no sense.)


Peter

-----Original Message-----
From: Simon Cozens <simon at simon-cozens.org> 
Sent: Monday, August 31, 2020 1:29 AM
To: Peter Constable <pgcon6 at msn.com>; MPEG OT Spec list (mpeg-otspec at lists.aau.at) <mpeg-otspec at lists.aau.at>
Subject: Re: [MPEG-OTSPEC] "font directory" / "offset table" / "table directory"

On 29/08/2020 23:43, Peter Constable wrote:
> An alternative would be a clean-up of Apple's terminology:
> 
>   * "Font Directory" is comprised of the "Offset Table" followed
>     directly by the "Table Directory".
>   * "Offset Table" is comprised of five members, sfntVersion to rangeShift.

That would mean that the "Offset Table" has neither any offsets in it nor any information relating to offsets...

> Yet another alternative would be to use "Font Directory" as a formal 
> struct name that includes tableRecords[] as a member, so "offset table"
> would not be used in the formal description.

Commontype does something very similar, but with "table directory" 
instead of "font directory" (because that top level structure is a directory... of tables...). So it calls the whole thing from byte 0 of a non-collection file to byte 12+numTables*20 the "table directory", which contains a number of "table directory entries". No "offset table" or "font directory".

S