GLUNURBSCURVE() GLUNURBSCURVE() NAME gluNurbsCurve - define the shape of a NURBS curve C SPECIFICATION void gluNurbsCurve( GLUnurbs* nurb, GLint knotCount, GLfloat *knots, GLint stride, GLfloat *control, GLint order, GLenum type ) delim $$ PARAMETERS nurb Specifies the NURBS object (created with gluNewNurbsRenderer). 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 coordi- nates 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 gluBeginCurve/gluEndCurve pair, then the type can be any of the valid one-dimensional evaluator types (such as GL_MAP1_VER- TEX_3 or GL_MAP1_COLOR_4). Between a gluBeginTrim/gluEndTrim pair, the only valid types are GLU_MAP1_TRIM_2 and GLU_MAP1_TRIM_3. DESCRIPTION Use gluNurbsCurve to describe a NURBS curve. When gluNurbsCurve appears between a gluBeginCurve/gluEndCurve pair, it is used to describe a curve to be rendered. Positional, texture, and color coordinates are associated by presenting each as a separate gluNurbsCurve between a gluBeginCurve/gluEndCurve pair. No more than one call to gluNurb- sCurve for each of color, position, and texture data can be made within a single gluBeginCurve/gluEndCurve pair. Exactly one call must be made to de- scribe the position of the curve (a type of GL_MAP1_VERTEX_3 or GL_MAP1_VERTEX_4). When gluNurbsCurve appears between a gluBeginTrim/gluEndTrim 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) pa- rameter 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 gluBe- ginTrim 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 gluPwlCurve. SEE ALSO gluBeginCurve, gluBeginTrim, gluNewNurbsRenderer, gluPwlCurve GLUNURBSCURVE()
NAME | C SPECIFICATION | PARAMETERS | DESCRIPTION | EXAMPLE | NOTES | SEE ALSO
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=gluNurbsCurve&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>