Type Alias: HalfDiscPreset

HalfDiscPreset = "deep" | "shallow"

Which half-disc proportion to trace. Both are flat-on-one-edge, bulging half-discs whose arc reaches the opposite edge near mid-height; they differ only in how far the arc reaches.

• 'deep' — the arc spans about 32% of the box width, symmetric about mid-height (the default).
• 'shallow' — the arc spans about 13%, slightly asymmetric, with its apex just below mid-height.