JP Journal · bounded offline evidence studio

Clothoid SVG motion studio

Integrate a linear-curvature path, approximate it with deterministic cubic Bézier segments, inspect handles and a curvature comb, then export SVG beside a validated geometry receipt.

Geometry contract

Initial heading (degrees)Initial curvatureCurvature slopeLengthScale (px/unit)Integration samplesCubic segmentsResidual tolerance (px)

Work is capped at 131,072 integration/probe operations. Inputs are finite and bounded.

Motion ribbon

Proof contract

Heading follows θ(s)=θ₀+κ₀s+cs²/2 and position is numerically integrated.
A separately implemented finer RK4 position oracle checks endpoints and interior residuals.
Adjacent cubic segments share anchors and analytic tangent directions.
Actual sample and probe counts, scale, path data, executable mutant evidence, and tolerances enter the canonical hash.