Sets our main struct and passes it to the parent class.
Converts a #hb_feature_t into a %NULL-terminated string in the format understood by hb_feature_from_string(). The client in responsible for allocating big enough size for @buf, 128 bytes is more than enough.
the main Gtk struct as a void*
Get the main Gtk struct
the cluster to end applying this feature setting (exclusive).
the cluster to start applying this feature setting (inclusive).
The #hb_tag_t tag of the feature
The value of the feature. 0 disables the feature, non-zero (usually 1) enables the feature. For features implemented as lookup type 3 (like 'salt') the @value is a one based index into the alternates.
the main Gtk struct
The #hb_feature_t is the structure that holds information about requested feature application. The feature will be applied with the given value to all glyphs which are in clusters between @start (inclusive) and @end (exclusive). Setting start to #HB_FEATURE_GLOBAL_START and end to #HB_FEATURE_GLOBAL_END specifies that the feature always applies to the entire buffer.