gluBeginCurve.3G man page

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(3G), gluBeginTrim(3G), gluNewNurbsRenderer(3G),  gluNurbsCurve(3G),  glPopAttrib(3G), glPushAttrib(3G)

Referenced By

gluBeginSurface.3G(3), gluNewNurbsRenderer.3G(3), gluNurbsCurve.3G(3), gluPwlCurve.3G(3).