Extrude & Bevel, Inflate and Rotate sampled every curve at sixteen points and
refused a shape past 1,024 points, about 64 curves: outlined words reached
that quickly, and Rotate refused them although it only turns the outline.
- Each curve takes as many straight pieces as keep it within 1/2000 of the
shape's size (at least 0.05 pt), by Wang's bound: 1 to 32.
- Extrude & Bevel and Inflate take up to 2,048 points, Rotate 65,536.
- Inflate's distance and crossing tests use a bucketed edge index, and
cells no edge crosses skip clipping: about 80 ms at 2,000 points (it was
over 600 ms with the old search; 95 ms at the old 1,024-point limit).
Revolve's own sampling is unchanged.