MORX-20: Contextual Glyph Substitution at End of Text
The font for this test case has
an AAT Extended Glyph Metamorphosis Table
with a single Contextual Glyph Substitution Subtable. Its finite-state machine
contains a single state with the following transitions:
For glyph A, B, and C,
the transition carries the SetMark flag.
For End of Text, the transition sets MarkIndex to 0,
and CurrentIndex to 1.
The glyph substitution table has two entries. Index 0 replaces
letters A to E by circled black-on-white forms;
index 1 replaces A to E by circled white-on-black
forms.
If your rendering system correctly implements Apple Advanced
Typography, the renderings should look as expected.
See also Fontkit bug 151.