[MPEG-OTSPEC] WD for AMD 2 and COLR v1 enhancements

[Laurence Penney]

Agreed. We have a better understanding of the complexity of the issue now – thanks for that, Peter.

In future discussion perhaps it’s helpful to borrow the “z-index” concept from CSS, such that each glyph in a colour glyph can (optionally) position itself explicitly in a vertical stack, instead of its position in the DAG (directed acyclic graph). The font’s z-index would *probably* not be related to the z-index of the general graphic context, though it it’s worth considering expectations when two textboxes, both containing z-index’d colour type in the same font, overlap.

- Laurence

> On 9 Jan 2021, at 05:32, Dave Crossland <dcrossland at google.com> wrote:
> 
> 
> I think handling this, in all its complexity, is clearly needed for some typography to be viable, but it's not a colr v1 or maybe even v2 effort. V3 :)