gluBeginCurve(3G)

NAME
     gluBeginCurve, gluEndCurve - delimit a NURBS curve definition


C SPECIFICATION
     void gluBeginCurve( GLUnurbs* nurb )

     void gluEndCurve( GLUnurbs* nurb )


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
     reference page for details on exactly what state these calls preserve.

EXAMPLE
     The following commands render a textured NURBS curve with normals;
     texture 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, gluBeginTrim, gluNewNurbsRenderer, gluNurbsCurve,
     glPopAttrib, glPushAttrib