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