pub fn chart_grid_divisions(radius: f64, chord_tolerance: f64) -> usizeExpand description
Divisions across a chart square (90°) at chord_tolerance.
Sized against the CELL DIAGONAL, not the cell side: a Delaunay triangle over a square grid has the diagonal as its longest edge, and it is that chord whose sag the tolerance is about. Sizing by the side leaves every triangle a factor of two over tolerance, so the refinement pass fires on all of them and rebuilds the grid it was meant to correct — three times the triangles and a crop of slivers for the same accuracy.