1GLUNURBSCURVE(3G)                OpenGL Manual               GLUNURBSCURVE(3G)
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NAME

6       gluNurbsCurve - define the shape of a NURBS curve
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C SPECIFICATION

9       void gluNurbsCurve(GLUnurbs* nurb, GLint knotCount, GLfloat * knots,
10                          GLint stride, GLfloat * control, GLint order,
11                          GLenum type);
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PARAMETERS

14       nurb
15           Specifies the NURBS object (created with gluNewNurbsRenderer()).
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17       knotCount
18           Specifies the number of knots in knots.  knotCount equals the
19           number of control points plus the order.
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21       knots
22           Specifies an array of knotCount nondecreasing knot values.
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24       stride
25           Specifies the offset (as a number of single-precision
26           floating-point values) between successive curve control points.
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28       control
29           Specifies a pointer to an array of control points. The coordinates
30           must agree with type, specified below.
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32       order
33           Specifies the order of the NURBS curve.  order equals degree + 1,
34           hence a cubic curve has an order of 4.
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36       type
37           Specifies the type of the curve. If this curve is defined within a
38           gluBeginCurve()/gluEndCurve() pair, then the type can be any of the
39           valid one-dimensional evaluator types (such as GLU_MAP1_VERTEX_3 or
40           GLU_MAP1_COLOR_4). Between a gluBeginTrim()/gluEndTrim() pair, the
41           only valid types are GLU_MAP1_TRIM_2 and GLU_MAP1_TRIM_3.
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DESCRIPTION

44       Use gluNurbsCurve to describe a NURBS curve.
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46       When gluNurbsCurve appears between a gluBeginCurve()/gluEndCurve()
47       pair, it is used to describe a curve to be rendered. Positional,
48       texture, and color coordinates are associated by presenting each as a
49       separate gluNurbsCurve between a gluBeginCurve()/gluEndCurve() pair. No
50       more than one call to gluNurbsCurve for each of color, position, and
51       texture data can be made within a single gluBeginCurve()/gluEndCurve()
52       pair. Exactly one call must be made to describe the position of the
53       curve (a type of GLU_MAP1_VERTEX_3 or GLU_MAP1_VERTEX_4).
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55       When gluNurbsCurve appears between a gluBeginTrim()/gluEndTrim() pair,
56       it is used to describe a trimming curve on a NURBS surface. If type is
57       GLU_MAP1_TRIM_2, then it describes a curve in two-dimensional (u and v)
58       parameter space. If it is GLU_MAP1_TRIM_3, then it describes a curve in
59       two-dimensional homogeneous (u, v, and w) parameter space. See the
60       gluBeginTrim() reference page for more discussion about trimming
61       curves.
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EXAMPLE

64       The following commands render a textured NURBS curve with normals:
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66           gluBeginCurve(nobj);
67              gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
68              gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
69              gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4);
70           gluEndCurve(nobj);
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NOTES

75       To define trim curves that stitch well, use gluPwlCurve().
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SEE ALSO

78       gluBeginCurve(), gluBeginTrim(), gluNewNurbsRenderer(), gluPwlCurve()
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81       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
82       under the SGI Free Software B License. For details, see
83       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

86       opengl.org
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90opengl.org                        07/13/2018                 GLUNURBSCURVE(3G)
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