Name

gluBeginCurve — delimit a NURBS curve definition

C Specification

void gluBeginCurve(GLUnurbs* nurb);
 

C Specification

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 GLU_MAP1_VERTEX_3 or GLU_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(GLU_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

Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.