📦 WP-055 — feat(data): rotated geometry primitives¶
Research log · Phase 8 — Oriented detection, v0.3.0
WP-055 — rotated geometry primitives¶
Canonicalization is exactly idempotent rather than idempotent to tolerance, and the angle range is a guarantee rather than a near-certainty. The edge case that forces the final clamp: for an angle within an ulp of a range bound, shifting by multiples of pi cannot rescue it — the remainder rounds to pi and the shift returns its own input. A similarity round trip of a box at exactly −45° reaches this in practice, so a clamp closes it at a cost of one ulp.
The square tie-break keys on exact w == h, which means a quad reconstructed from DOTA's eight coordinates can return either pi/2-separated representative of the same rectangle. WP-060's angle loss, aimed precisely at near-square objects, must therefore not assume which — and that is why it is tested for bit-identical scoring of both representatives rather than agreement to seven digits.