gluBeginCurve function
The gluBeginCurve and gluEndCurve functions delimit a Non-Uniform Rational B-Spline (NURBS) curve definition.
Syntax
void WINAPI gluBeginCurve(
GLUnurbs *nobj
);
Parameters
-
nobj
-
The NURBS object (created with gluNewNurbsRenderer).
Return value
This function does not return a value.
Remarks
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.
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 glPushAttrib.
Examples
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);
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows 2000 Professional [desktop apps only] |
| Minimum supported server |
Windows 2000 Server [desktop apps only] |
| Header |
|
| Library |
|
| DLL |
|