gluBeginCurve, gluEndCurve

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 gluNewNurbsRenderer).

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.

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); 
 

QuickInfo

  Windows NT: Use version 3.5 and later.
  Windows: Use Windows 95 and later.
  Windows CE: Unsupported.
  Header: Declared in glu.h.
  Import Library: Link with glu32.lib.

See Also

glPopAttrib, glPushAttrib, gluBeginSurface, gluBeginTrim, gluNewNurbsRenderer, gluNurbsCurve