It turns out the slice pipeline is compatible with the glyph pipeline in
that its vertex attribute data is a superset (just the addition of the
offset attributes). While the queues have yet to be merged, this will
eventually get glyphs, sliced sprites, and general (static) quads into
the one pipeline. Although this is slightly slower for glyph rendering
(due to the need to pass an extra 8 bytes per glyph), this should be
faster for quad rendering (when done) as it will be 24 bytes per quad
instead of 32 bytes per vertex (ie, 128 bytes per quad), but this does
serve as a proof of concept for doing quads, glyphs and sprites in the
one pipeline.
With an eye towards merging the 2d pipelines as much as possible, I
found that the glyph and basic 2d quad texture descriptors were in
different slots for no reason I can think of. Having them in the same
slot would mean I could use the same fragment shader for all 2d
pipelines (though the plan is to get it down to two: (sliced) quads and
lines).
There's no API yet as I need to look into the handling of qpic_t before
I can get any of this into the other renderers (or even vulkan, for that
matter).
However, the current design for slice rendering is based on glyphs (ie,
using instances and vertex pulling), with 3 strips of 3 quads, 16 verts,
and 26 indices (2 reset). Hacky testing seems to work, but real tests
need the API.