Index for Section 3

Alphabetical listing for G

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gluNurbsCurve()
NAME
  gluNurbsCurve - define the shape of a NURBS curve

SYNOPSIS
  void gluNurbsCurve(
	  GLUnurbs* nurb,
	  GLint knotCount,
	  GLfloat *knots,
	  GLint stride,
	  GLfloat *control,
	  GLint order,
	  GLenum type );

PARAMETERS
  nurb
      Specifies the NURBS object (created with gluNewNurbsRenderer()).

  knotCount
      Specifies the number of knots in knots.  knotCount equals the number of
      control points plus the order.

  knots
      Specifies an array of knotCount nondecreasing knot values.

  stride
      Specifies the offset (as a number of single-precision floating-point
      values) between successive curve control points.

  control
      Specifies a pointer to an array of control points. The coordinates must
      agree with type, specified below.

  order
      Specifies the order of the NURBS curve.  order equals degree + 1, hence
      a cubic curve has an order of 4.

  type
      Specifies the type of the curve. If this curve is defined within a
      gluBeginCurve()/gluEndCurve() pair, then the type can be any of the
      valid one-dimensional evaluator types (such as GL_MAP1_VERTEX_3 or
      GL_MAP1_COLOR_4). Between a gluBeginTrim()/gluEndTrim() pair, the only
      valid types are GLU_MAP1_TRIM_2 and GLU_MAP1_TRIM_3.

DESCRIPTION
  Use gluNurbsCurve() to describe a NURBS curve.

  When gluNurbsCurve() appears between a gluBeginCurve()/gluEndCurve() pair,
  it is used to describe a curve to be rendered. Positional, texture, and
  color coordinates are associated by presenting each as a separate
  gluNurbsCurve() between a gluBeginCurve()/gluEndCurve() pair. No more than
  one call to gluNurbsCurve() for each of color, position, and texture data
  can be made within a single gluBeginCurve()/gluEndCurve() pair. Exactly one
  call must be made to describe the position of the curve (a type of
  GL_MAP1_VERTEX_3 or GL_MAP1_VERTEX_4).

  When gluNurbsCurve() appears between a gluBeginTrim()/gluEndTrim() pair, it
  is used to describe a trimming curve on a NURBS surface. If type is
  GLU_MAP1_TRIM_2, then it describes a curve in two-dimensional (u and v)
  parameter space. If it is GLU_MAP1_TRIM_3, then it describes a curve in
  two-dimensional homogeneous (u, v, and w) parameter space. See the
  gluBeginTrim() reference page for more discussion about trimming curves.

NOTES
  To define trim curves which stitch well, use gluPwlCurve().

EXAMPLE
  The following commands render a textured NURBS curve with normals:

       gluBeginCurve(nobj);
	   gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
	   gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
	   gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4);
       gluEndCurve(nobj);

SEE ALSO
  gluBeginCurve(3), gluBeginTrim(3), gluNewNurbsRenderer(3), gluPwlCurve(3),

Index for Section 3

Alphabetical listing for G

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