Geometry performance

Improve `PolylineGeometry`, `EllipseGeometry`, and `EllipseOutlineGeometry` performance.

For 5760 polylines with about 40 points each, `PolylineGeometry.createGeometry` went from ~3.5% to ~1.5%. For 264 ellipses and ellipse outlines whose granularity was ~0.004, `EllipseGeometryLibrary.computeEllipsePositions` went from ~7% to <1%.