gluBeginCurve, gluEndCurve

[New - Windows 95, OEM Service Release 2]

The gluBeginCurve and gluEndCurve functions delimit a NURBS curve definition.

void gluBeginCurve(

GLUnurbsObj * nobj
);

void gluEndCurve(

GLUnurbsObj * nobj
);

Parameters

nobj

The NURBS object (created with gluNewNurbsRenderer1Y9AJ3Z).

Remarks

Use gluBeginCurve to mark the beginning of a NURBS curve definition. After calling gluBeginCurve, make one or more calls to gluNurbsCurve5N1M_IB 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.

OpenGL 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. For information on exactly what state these calls preserve, see glPushAttrib2Z6IY_.

Example

The following functions 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);