[FIXED] Destructing font in new font creator

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faisal.quadirey
Posts: 33
Joined: Wed Apr 07, 2021 6:50 am

[FIXED] Destructing font in new font creator

Post by faisal.quadirey »

On importing font in font creator 14, it may breaks the kerning tables.
For reference files has been attached.
Attachments
Nastaliq Lahore.ttf
(178.46 KiB) Downloaded 202 times
Nastaliq Lahore (Project_FontCreator14).fcp
(209.19 KiB) Downloaded 204 times
Nastaleeq Lahore.jpg
Nastaleeq Lahore.jpg (2.03 MiB) Viewed 1940 times
Erwin Denissen
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Re: Destructing font in new font creator

Post by Erwin Denissen »

The font contains several Chained Contexts Substitution lookups (ChainingContext40-ChainingContext47) that replace a space for another glyph. Then single adjustment is applied to that glyph. See the two screenshots below.

For some unknown reason those lookups are not applied by other shaping engines. It would be great to know why they ignore them. Within the original font all lookups are extensions, which is awkward and needless. Maybe there is a limit (50!) on the number of such extension lookups? You could try to post an issue at harfbuzz or post at typedrawers...
NastaliqLahore.png
NastaliqLahore.png (160.97 KiB) Viewed 1929 times
NastaliqLahore2.png
NastaliqLahore2.png (278.19 KiB) Viewed 1929 times
Erwin Denissen
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Proven Font Technology
Erwin Denissen
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Re: Destructing font in new font creator

Post by Erwin Denissen »

I have exported the font with all lookups as extensions, and it also fails, so it is most likely not related to the extensions.
Erwin Denissen
High-Logic
Proven Font Technology
Erwin Denissen
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Posts: 11107
Joined: Fri Oct 04, 2002 12:41 am
Location: Bilthoven, The Netherlands
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Re: Destructing font in new font creator

Post by Erwin Denissen »

After some more digging I located the cause of the problem. The font contains chained contexts substitution lookups with empty classes. We ignored the empty classes, but we should actually skip such lookup rules. The problem is solved with the update we just released!

Thank you for reporting these rare but nasty issues, as it makes our software more robust.
Erwin Denissen
High-Logic
Proven Font Technology
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