2.5.4.46 PtgNurbs

The PtgNurbs structure specifies a non-uniform rational B-spline (NURBS).

When found in a formula expression, this structure MUST satisfy the following ABNF.

ABNF:

 Nurbs = "NURBS(" knotLast "," degree "," xType "," yType *("," xN "," yN "," knotN "," weightN) ")"
 knotLast = val
 degree = val
 xType = val
 yType = val
 xN = val
yN = val
 knotN = val
weightN = val

knotLast is a double precision floating-point number that specifies the last knot.

degree is an integer value that specifies the degree of the B-spline.

xType is an unsigned integer value that specifies how to interpret the x-coordinates. If xType is zero, the input xN is interpreted as relative coordinates. Otherwise, the input xN is interpreted in the coordinate system of the shape containing the structure.

yType is an unsigned integer value that specifies how to interpret the y-coordinates. If yType is zero, the input yN is interpreted as relative coordinates. Otherwise, the input yN is interpreted in the coordinate system of the shape containing the structure.

xN is a double precision floating-point number that specifies an x-coordinate.

yN is a double precision floating-point number that specifies a y-coordinate.

knotN is a double precision floating-point number that specifies a knot on the B-spline.

weightN is a double precision floating-point number that specifies a weight on the B-spline.

When stored in a Cell_Type element, this structure has the following attribute values.

Attribute	Value
V	MUST be a value that satisfies the following ABNF.  Nurbs = "NURBS(" knotLast "," degree "," xType "," yType *("," xN "," yN "," knotN "," weightN) ")"    knotLast = double-value  degree = int-value  xType = unsigned-int-value  yType = unsigned-int-value  xN = double-value  yN = double-value  knotN = double-value  weightN = double-value Specific definition is provided earlier.
U	MUST NOT exist.