gluBeginCurve(3)

NAME

       gluBeginCurve, gluEndCurve - delimit a NURBS curve definition

C SPECIFICATION

       void gluBeginCurve( GLUnurbs* nurb )

       void gluEndCurve( GLUnurbs* nurb )

       delim $$

PARAMETERS

       nurb  Specifies the NURBS object (created with gluNewNurbsRenderer).

DESCRIPTION

       Use  gluBeginCurve  to  mark the beginning of a NURBS curve definition.
       After calling gluBeginCurve, make one or more calls to gluNurbsCurve to
       define  the  attributes  of  the  curve.   Exactly  one of the calls to
       gluNurbsCurve  must  have  a  curve   type   of   GL_MAP1_VERTEX_3   or
       GL_MAP1_VERTEX_4.   To mark the end of the NURBS curve definition, call
       gluEndCurve.

       GL evaluators are used to render the NURBS curve as a  series  of  line
       segments.    Evaluator   state   is  preserved  during  rendering  with
       glPushAttrib(GL_EVAL_BIT) and glPopAttrib().  See the glPushAttrib ref-
       erence page for details on exactly what state these calls preserve.

EXAMPLE

       The following commands render a textured NURBS curve with normals; tex-
       ture coordinates and normals are also specified as NURBS curves:

       gluBeginCurve(nobj);
          gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
          gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
          gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4); gluEndCurve(nobj);

SEE ALSO

       gluBeginSurface(3G),     gluBeginTrim(3G),     gluNewNurbsRenderer(3G),
       gluNurbsCurve(3G), glPopAttrib(3G), glPushAttrib(3G)

                                                             GLUBEGINCURVE(3G)