x86 normalizes with a bare _mm_rsqrt_ps, so normal lengths are only good
to about 3.7e-4 there and the 1e-4 check failed on every x86 CI job.
Compare direction after normalizing instead.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
With animated control points the pole is only nearly degenerate, so the
vanishing derivative is rounding noise rather than exactly zero, and the
absolute threshold missed it. The resulting random normals still showed
as dark patches on Pac-Man Arrangement's ghosts (#12354).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Compares the software tessellator's positions, normals, UVs and colors
against a longhand double-precision reference (Bernstein polynomials,
Cox-de Boor with clamped knots, finite-difference normals), across
Bezier and spline surfaces, edge types, poles and patch facing, so it
can be optimized with something independent to be wrong against. Also
reports vertices per second.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
