editor

ADR-0001 — Geometric scope: segments and circular arcs ​

Status: Accepted — scope narrowed to symbols by ADR-0018

Context ​

Synoptic symbols are schematic. The Product Owner asked for shapes described by numbers rather than drawn by hand, with a corner radius that behaves as in Figma.

Decision ​

  • Primitives: line segment and circular arc.
  • An arc only appears as the fillet of a vertex (corner radius).
  • No Bézier curve (quadratic or cubic).

Consequences ​

  • Closed-form intersections: segment/segment, segment/arc, arc/arc.
  • Exact offset (the offset of an arc is a concentric arc) → strokes computed exactly.
  • Exact lengths → exact dash patterns.
  • No Bend tool, no handle mirroring, no corner smoothing.
  • No ellipse without elliptical arcs (open question Q4).

References ​

REF-GG-FILLET, REF-SVG2-PATHS