gluBeginCurve()gluBeginCurve()NAME
gluBeginCurve, gluEndCurve - delimit a NURBS curve definition
SYNOPSIS
void gluBeginCurve(
GLUnurbs* nurb ); void gluEndCurve(
GLUnurbs* nurb );
PARAMETERS
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 gluNurb‐
sCurve() 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 glPushAt‐
trib()(GL_EVAL_BIT) and glPopAttrib(). See the glPushAttrib() refer‐
ence 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: gluBe‐
ginCurve(nobj);
gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4); gluEndCurve(nobj);
SEE ALSOgluBeginSurface(3), gluBeginTrim(3), gluNewNurbsRenderer(3), gluNurb‐
sCurve(3), glPopAttrib(3), glPushAttrib(3)gluBeginCurve()