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diff --git a/nx-X11/extras/ogl-sample/main/doc/man/manglu/standard/begintrim.gl b/nx-X11/extras/ogl-sample/main/doc/man/manglu/standard/begintrim.gl new file mode 100644 index 000000000..a9df90666 --- /dev/null +++ b/nx-X11/extras/ogl-sample/main/doc/man/manglu/standard/begintrim.gl @@ -0,0 +1,120 @@ +_C_ License Applicability. Except to the extent portions of this file are +_C_ made subject to an alternative license as permitted in the SGI Free +_C_ Software License B, Version 1.1 (the "License"), the contents of this +_C_ file are subject only to the provisions of the License. You may not use +_C_ this file except in compliance with the License. You may obtain a copy +_C_ of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 +_C_ Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: +_C_ +_C_ http://oss.sgi.com/projects/FreeB +_C_ +_C_ Note that, as provided in the License, the Software is distributed on an +_C_ "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS +_C_ DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND +_C_ CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A +_C_ PARTICULAR PURPOSE, AND NON-INFRINGEMENT. +_C_ +_C_ Original Code. The Original Code is: OpenGL Sample Implementation, +_C_ Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, +_C_ Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. +_C_ Copyright in any portions created by third parties is as indicated +_C_ elsewhere herein. All Rights Reserved. +_C_ +_C_ Additional Notice Provisions: The application programming interfaces +_C_ established by SGI in conjunction with the Original Code are The +_C_ OpenGL(R) Graphics System: A Specification (Version 1.2.1), released +_C_ April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version +_C_ 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X +_C_ Window System(R) (Version 1.3), released October 19, 1998. This software +_C_ was created using the OpenGL(R) version 1.2.1 Sample Implementation +_C_ published by SGI, but has not been independently verified as being +_C_ compliant with the OpenGL(R) version 1.2.1 Specification. +_C_ +_C_ $Date: 2004/03/14 08:29:09 $ $Revision: 1.1.1.4 $ +_C_ The first character in this file must be an '_'! +_C_ Anything on a line after _C_ is ignored +_define(_filters,eqn)_C_ +_C_ eqn is automatically replaced with neqn for nroff +_header(BeginTrim, delimit a NURBS trimming loop definition) +_names(BeginTrim) +_names(EndTrim,,noheader) +.EQ +delim $$ +.EN +.SH PARAMETERS +_phead(_param1) +Specifies the NURBS object (created with _cmnd(NewNurbsRenderer)). +.SH DESCRIPTION +Use _cmnd(BeginTrim) to mark the beginning of a +trimming loop, and _cmnd(EndTrim) to mark the end +of a trimming loop. A trimming loop is +a set of oriented curve segments (forming a closed curve) that +define boundaries of a NURBS surface. You include these +trimming loops in the definition of a NURBS +surface, between calls to _cmnd(BeginSurface) and _cmnd(EndSurface). +.P +The definition for a NURBS surface can contain many +trimming loops. For example, if you wrote a definition +for a NURBS surface that resembled a rectangle with +a hole punched out, the definition would contain two +trimming loops. One loop would define the outer edge +of the rectangle; the other would define +the hole punched out of the rectangle. The definitions +of each of these trimming loops would be bracketed by a +_cmnd(BeginTrim)/_cmnd(EndTrim) pair. +.P +The definition of a single closed trimming loop can consist +of multiple curve segments, each described as a piecewise +linear curve (see _cmnd(PwlCurve)) or as a single NURBS +curve (see _cmnd(NurbsCurve)), or as a combination of +both in any order. The only library calls that can +appear in a trimming loop definition (between the calls +to _cmnd(BeginTrim) and _cmnd(EndTrim)) are +_cmnd(PwlCurve) and _cmnd(NurbsCurve). +.P +The area of the NURBS surface that is displayed is the +region in the domain to the left of the trimming curve +as the curve parameter increases. Thus, the retained +region of the NURBS surface is inside a +counterclockwise trimming loop and outside a clockwise +trimming loop. For the rectangle mentioned earlier, +the trimming loop for the outer edge of the rectangle runs +counterclockwise, while the trimming loop for the punched-out hole +runs clockwise. +.P +If you use more than one curve to define a single trimming +loop, the curve segments must form a closed loop (that is, +the endpoint of each curve must be the starting point of the +next curve, and the endpoint of the final curve must +be the starting point of the first curve). If the +endpoints of the curve are sufficiently close together +but not exactly coincident, they will be coerced to match. +If the endpoints are not sufficiently close, an error results +(see _cmnd(NurbsCallback)). +.P +If a trimming loop definition contains multiple curves, +the direction of the curves must be consistent (that is, the +inside must be to the left of all of the curves). Nested +trimming loops are legal as long as the curve orientations +alternate correctly. +If trimming curves are self-intersecting, +or intersect one another, an error results. +.P +If no trimming information is given +for a NURBS surface, the entire surface is drawn. +.SH EXAMPLE +This code fragment defines a trimming loop that consists of one +piecewise linear curve, and two NURBS curves: +.sp +.Ex +gluBeginTrim(nobj); + gluPwlCurve(..., GLU_MAP1_TRIM_2); + gluNurbsCurve(..., GLU_MAP1_TRIM_2); + gluNurbsCurve(..., GLU_MAP1_TRIM_3); +gluEndTrim(nobj); +.Ee +.SH SEE ALSO +_cmnd(BeginSurface), _cmnd(NewNurbsRenderer), _cmnd(NurbsCallback), +_cmnd(NurbsCurve), _cmnd(PwlCurve) + + |