GLUBEGINCURVE(3G) |
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GLUBEGINCURVE(3G) |
NAME
gluBeginCurve, gluEndCurve - delimit a NURBS curve definition
C SPECIFICATION
void
gluBeginCurve( GLUnurbs*
nurb )
void
gluEndCurve( GLUnurbs*
nurb )
delim$$
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(3G),
gluBeginTrim(3G),
gluNewNurbsRenderer(3G),
gluNurbsCurve(3G),
glPopAttrib(3G),
glPushAttrib(3G)