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_C_ License Applicability. Except to the extent portions of this file are
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_C_ made subject to an alternative license as permitted in the SGI Free
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_C_ Software License B, Version 1.1 (the "License"), the contents of this
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_C_ file are subject only to the provisions of the License. You may not use
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_C_ this file except in compliance with the License. You may obtain a copy
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_C_ of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
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_C_ Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
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_C_ http://oss.sgi.com/projects/FreeB
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_C_ Note that, as provided in the License, the Software is distributed on an
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_C_ "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
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_C_ DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
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_C_ CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
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_C_ PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
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_C_ Original Code. The Original Code is: OpenGL Sample Implementation,
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_C_ Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
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_C_ Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
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_C_ Copyright in any portions created by third parties is as indicated
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_C_ elsewhere herein. All Rights Reserved.
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_C_ Additional Notice Provisions: The application programming interfaces
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_C_ established by SGI in conjunction with the Original Code are The
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_C_ OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
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_C_ April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
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_C_ 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
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_C_ Window System(R) (Version 1.3), released October 19, 1998. This software
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_C_ was created using the OpenGL(R) version 1.2.1 Sample Implementation
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_C_ published by SGI, but has not been independently verified as being
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_C_ compliant with the OpenGL(R) version 1.2.1 Specification.
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_C_ The first character in this file must be an '_'!
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_C_ Anything on a line after _C_ is ignored
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_define(_filters,eqn)_C_
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_C_ eqn is automatically replaced with neqn for nroff
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_header(NurbsCurve, define the shape of a NURBS curve)
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Specifies the NURBS object (created with _cmnd(NewNurbsRenderer)).
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Specifies the number of knots in _param3.
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_param2 equals the number of control points plus the order.
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Specifies an array of _param2 nondecreasing knot values.
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Specifies the offset (as a number of single-precision floating-point values)
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between successive curve control points.
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Specifies a pointer to an array of control points. The coordinates must
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agree with _param7, specified below.
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Specifies the order of the NURBS curve. _param6 equals degree + 1, hence
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a cubic curve has an order of 4.
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Specifies the type of the curve. If this curve is defined within a
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_cmnd(BeginCurve)/_cmnd(EndCurve) pair, then
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the type can be any of the valid
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one-dimensional evaluator types (such as _const(MAP1_VERTEX_3) or
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_const(MAP1_COLOR_4)). Between a _cmnd(BeginTrim)/_cmnd(EndTrim) pair,
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the only valid types are _gluconst(MAP1_TRIM_2) and _gluconst(MAP1_TRIM_3).
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Use _cmnd to describe a NURBS curve.
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When _cmnd appears between a _cmnd(BeginCurve)/_cmnd(EndCurve) pair, it is
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used to describe a curve to be rendered.
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Positional, texture, and color coordinates are associated
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by presenting each as a separate _cmnd between a
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_cmnd(BeginCurve)/_cmnd(EndCurve) pair. No more than
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one call to _cmnd for each of color, position, and texture
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data can be made within a single _cmnd(BeginCurve)/_cmnd(EndCurve)
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pair. Exactly one call must be made to describe the position of the
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curve (a _param7 of _const(MAP1_VERTEX_3) or _const(MAP1_VERTEX_4)).
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When _cmnd appears between a _cmnd(BeginTrim)/_cmnd(EndTrim) pair, it is
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used to describe a trimming curve on a NURBS surface. If _param7 is
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_gluconst(MAP1_TRIM_2), then it describes a curve in two-dimensional (\f2u\fP
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parameter space. If it is _gluconst(MAP1_TRIM_3), then it describes a
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curve in two-dimensional homogeneous (\f2u\fP, \f2v\fP, and \f2w\fP)
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See the _cmnd(BeginTrim) reference page for more discussion about trimming
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The following commands render a textured NURBS curve with normals:
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gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
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gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
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gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4);
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To define trim curves which stitch well, use _cmnd(PwlCurve).
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_cmnd(BeginCurve), _cmnd(BeginTrim), _cmnd(NewNurbsRenderer), _cmnd(PwlCurve)