Glyphs-Handbook-2013

The Adobe FDK feature file
syntax is described in detail at:
www.adobe.com/devnet/
opentype/afdko/topic_
feature_file_syntax.html.
6.4 FEATURES
OpenType features entered in File > Font Info > Features apply
to the whole font. Specific features can be disabled on a perinstance
with the Remove Features parameter.
Glyphs automatically generates most of the common
features. Click the circled arrow in the lower left corner to
initiate the automatic generation of the feature code. The
feature generator is based on certain name conventions
and suxes. E.g., all letters with names ending in ‘.sc’ will
be put in the small caps features. Find a complete list
of recognized suxes in section 12.1, ‘Automatic Feature
Generation’ (p. 84).
To write features, prefixes, and classes manually, uncheck
the ‘Automatic’ checkbox, or create a new item by clicking the
plus button at the bottom left. Edit the name of the feature,
prefix, or class directly in the list. Glyphs uses Adobe FDK
syntax. You can test-run your features with the ‘Compile’
button. The prefix is for all information that needs to stand
outside an actual feature, e.g., lookup definitions you want
to re-use further down in the code. Glyphs will put language
systems into the prefix.
The bottom right area is for notes. In Stylistic Set features
(ss01 through ss20), you can use it to set the name of the
Set. Type ‘Name:’, followed by the intended description.
Alternatively, you can enter the complete featureNames
lookup as described in the Adobe FDK syntax.
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