The lens + perspective warp classified source-edge pixels in f32 on the GPU.
A position 0.000035 px outside the edge rounded inside, so the GPU sampled
photo pixels where the CPU reference draws blank canvas (geometry_variants,
"embedded lens + perspective", max 91 LSB). The CPU now evaluates the f64
framing decision into a one-bit-per-pixel mask; sampling and colour stay on
the GPU. The embedded-lens cases move to their own test,
embedded_lens_perspective_edges_match, with the same tolerances.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>