OTWG stalled : post-linebreaking layout

[tiroj]

This is a stalled item from the ad hoc OpenType Working Group (the closed group working on OT layout that emerged from the April 2014 meeting).

This is a topic to which the OTWG and private discussions have returned multiple times, without resolution. The idea is to provide a framework within which some kinds of OpenType Layout—or OTL-like behaviour—could be applied or re-applied after linebreaking has occurred. Examples of use would be cross-script or cross-directional kerning or other positioning refinements without the earlier run itemisation restrictions, and making substitution and positioning lookups, including contextual lookups, available to justification algorithms, which could enable e.g. Arabic elongated or compressed forms.