gluBeginCurve.3gl

Name

  gluBeginCurve, gluEndCurve - delimit a NURBS curve definition

C Specification

  void gluBeginCurve( GLUnurbsObj *nobj	)

  void gluEndCurve( GLUnurbsObj	*nobj )

Parameters

  nobj	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.

  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(). 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, gluBeginTrim, gluNewNurbsRenderer, gluNurbsCurve,
  glPopAttrib, glPushAttrib

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Last Edited: Fri Dec 6 11:18:03 EST 1996 by AFV
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