3 people 13a3ebc0d1 AREA: an ellipse's perimeter is its exact length, not a closed-form estimate (#1471) ...

AREA's Object option reported a full ellipse's perimeter with
Ramanujan's closed-form estimate, which falls short as the ellipse
flattens: 46.0256 for a 10 x 4 ellipse (exactly 46.0262), 39.8741 for a
10 x 0.1 one (exactly 40.0110, 0.34% short). It now integrates the
perimeter with the geometry crate's ellipse arc length, the one LENGTHEN
measures with, so both report the same length for the same ellipse.

Ellipse::arc_length_from halves a panel where it needs it (the same
adaptive Gauss-Legendre as spline arc lengths): with fixed panels a
100:1 ellipse came out 4e-8 long, as it turns sharply at its ends.

Tests check four ellipses (round to 100:1) against the
arithmetic-geometric mean to 1e-9, and the printed AREA line.

Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

2026-10-19 02:57:04 -04:00

..

src

AREA: an ellipse's perimeter is its exact length, not a closed-form estimate (#1471)

2026-10-19 02:57:04 -04:00

Cargo.toml

M0: CADCraft skeleton and vertical slice

2026-10-05 23:22:25 -04:00