OT Sub Prioritisation (Need Help)
Options

Lewis MacDonald
Posts: 12
I'm working on a monospaced, and playing around with ligatures for i_i, i_l, l_i, and l_l.
I'm trying to set it up so that the sequence i l l becomes i l_l, not i_l l.
The ordering of my substitution rules for i_l and l_l doesn't make a difference and nothing else I can think of or find online helps either.
Thanks in advance.
I'm trying to set it up so that the sequence i l l becomes i l_l, not i_l l.
The ordering of my substitution rules for i_l and l_l doesn't make a difference and nothing else I can think of or find online helps either.
Thanks in advance.
Tagged:
0
Comments
-
set the first line of your feature to:
sub i l' l' by l_l;
The order of the substution rules does matter, and you need to define the longest substitutions first.2 -
Try putting the l_l substitution in a separate lookup before the i_l lookup.
4 -
1
-
and you need to define the longest substitutions first.Actually, this is not strictly true for features in Adobe syntax which are being compiled by AFDKO. From http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html#5.d :
“A contiguous set of ligature rules does not need to be ordered in any particular way by the font editor; the implementation software must do the appropriate sorting.”
The compiler is supposed to be responsible for ordering the longest substitutions first.
2 -
In this case, though, the substitutions are of equal length:
i l -> i_l
l l -> l_l
Paul has suggested a way to handle this by making the substitution for the sequence <i l l> to /i l_l/ contextual. That's certainly one solution.1
Categories
- All Categories
- 46 Introductions
- 3.8K Typeface Design
- 476 Type Design Critiques
- 555 Type Design Software
- 1.1K Type Design Technique & Theory
- 640 Type Business
- 831 Font Technology
- 29 Punchcutting
- 508 Typography
- 120 Type Education
- 313 Type History
- 75 Type Resources
- 109 Lettering and Calligraphy
- 30 Lettering Critiques
- 79 Lettering Technique & Theory
- 533 Announcements
- 86 Events
- 110 Job Postings
- 167 Type Releases
- 169 Miscellaneous News
- 274 About TypeDrawers
- 53 TypeDrawers Announcements
- 119 Suggestions and Bug Reports