Like z, a primitive whose vertices are all beyond the same x or y plane
(|x| > w) isn't drawn, for every primitive type and with clipping on or off;
a vertex on the plane is inside (gpu/probe exp176, gpu/clipping/xycull).
Immediate-mode vertices carry screen coordinates in their clip position, so
only z culls them.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Measured with gpu/probe exp43-47, bit exact:
- New vertices are interpolated from the inside vertex, t = d_in / (d_in -
d_out) with d = z + w through the GE adder, using the GE's reciprocal;
out - in is truncated to float24 before the multiply by t, and t and each
coordinate use float24 products and adds.
- With one vertex outside, the quad is split from the vertex before it in the
GE's order: (p, a, b) and (p, b, n). The GE takes odd strip triangles in
reverse and fan triangles in order, so SendTriangle now says when the
vertices it gets are reversed from that.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
