Entities

entities/spline

#include "dxfio/entities/spline.hpp"

In DxfIO::Entities

struct Curve

The AcDbSpline subclass a SPLINE and a HELIX share: a NURBS curve, by its knots and control points or by the points it fits.

Field	Type and default	Meaning
`Normal`	`std::optional<Vector>`	The normal of the plane of a planar spline; none for one that is not planar. Groups 210, 220, 230.
`Flags`	`int`	1 closed, 2 periodic, 4 rational, 8 planar, 16 linear, which is planar too. Group 70.
`Degree`	`int{3}`	The degree of the curve, 3 for a new one. Group 71.
`Knotted`	`double{Knotting}`	The knot tolerance. Group 42.
`Framed`	`double{Framing}`	The control point tolerance. Group 43.
`Fitted`	`std::optional<double>`	The fit tolerance, when the spline is given by fit points. Group 44.
`Start`	`std::optional<Vector>`	The tangent at the start, when one is given. Groups 12, 22, 32.
`End`	`std::optional<Vector>`	The tangent at the end, when one is given. Groups 13, 23, 33.
`Knots`	`std::vector<double>`	The knot values; group 72 counts them. Group 40.
`Poles`	`std::vector<Vector>`	The control points, in world coordinates; group 73 counts them. Groups 10, 20, 30.
`Weights`	`std::vector<double>`	The weight of each control point, when the spline is rational. Group 41.
`Fits`	`std::vector<Vector>`	The points the curve passes through, in world coordinates; group 74 counts them. Groups 11, 21, 31.

A SPLINE: a smooth curve through or near a set of points.

Field	Type	Meaning
`Record`	`Entities::Record`	The layer, linetype, color and the rest every entity carries.
`Curve`	`Boxed<Entities::Curve>`	The knots, control points and fit points, from the AcDbSpline subclass.

`Knotting`	`double = 1e-9`	The knot tolerance a new spline takes.
`Framing`	`double = 1e-10`	The control point tolerance a new spline takes.