NAME fgluNurbsCurve - define the shape of a NURBS curve FORTRAN SPECIFICATION SUBROUTINE fgluNurbsCurve( CHARACTER*8 nurb, INTEGER*4 knotCount, CHARACTER*8 knots, INTEGER*4 stride, CHARACTER*8 control, INTEGER*4 order, INTEGER*4 type ) PARAMETERS nurb Specifies the NURBS object (created with fgluNewNurbsRenderer). knotCount Specifies the number of knots in knots. knotCount equals the number of control points plus the order. knots Specifies an array of knotCount nondecreasing knot values. stride Specifies the offset (as a number of single- precision floating-point values) between successive curve control points. control Specifies a pointer to an array of control points. The coordinates must agree with type, specified below. order Specifies the order of the NURBS curve. order equals degree + 1, hence a cubic curve has an order of 4. type Specifies the type of the curve. If this curve is defined within a fgluBeginCurve/fgluEndCurve pair, then the type can be any of the valid one- dimensional evaluator types (such as GL_MAP1_VERTEX_3 or GL_MAP1_COLOR_4). Between a fgluBeginTrim/fgluEndTrim pair, the only valid types are GLU_MAP1_TRIM_2 and GLU_MAP1_TRIM_3. DESCRIPTION Use fgluNurbsCurve to describe a NURBS curve. When fgluNurbsCurve appears between a fgluBeginCurve/fgluEndCurve pair, it is used to describe a curve to be rendered. Positional, texture, and color coordinates are associated by presenting each as a separate fgluNurbsCurve between a fgluBeginCurve/fgluEndCurve pair. No more than one call to fgluNurbsCurve for each of color, position, and texture data can be made within a single fgluBeginCurve/fgluEndCurve pair. Exactly one call must be made to describe the position of the curve (a type of GL_MAP1_VERTEX_3 or GL_MAP1_VERTEX_4). When fgluNurbsCurve appears between a fgluBeginTrim/fgluEndTrim pair, it is used to describe a trimming curve on a NURBS surface. If type is GLU_MAP1_TRIM_2, then it describes a curve in two- dimensional (u and v) parameter space. If it is GLU_MAP1_TRIM_3, then it describes a curve in two- dimensional homogeneous (u, v, and w) parameter space. See the fgluBeginTrim reference page for more discussion about trimming curves. EXAMPLE The following commands render a textured NURBS curve with normals: gluBeginCurve(nobj); gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2); gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL); gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4); gluEndCurve(nobj); NOTES To define trim curves which stitch well, use fgluPwlCurve. SEE ALSO fgluBeginCurve, fgluBeginTrim, fgluNewNurbsRenderer, fgluPwlCurve