GLUBEGINCURVE(3G) OpenGL Manual GLUBEGINCURVE(3G)
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 (C) 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/.
AUTHORS
opengl.org
opengl.org 06/10/2014 GLUBEGINCURVE(3G)
