2 ** License Applicability. Except to the extent portions of this file are
3 ** made subject to an alternative license as permitted in the SGI Free
4 ** Software License B, Version 1.1 (the "License"), the contents of this
5 ** file are subject only to the provisions of the License. You may not use
6 ** this file except in compliance with the License. You may obtain a copy
7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
10 ** http://oss.sgi.com/projects/FreeB
12 ** Note that, as provided in the License, the Software is distributed on an
13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
21 ** Copyright in any portions created by third parties is as indicated
22 ** elsewhere herein. All Rights Reserved.
24 ** Additional Notice Provisions: The application programming interfaces
25 ** established by SGI in conjunction with the Original Code are The
26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
31 ** published by SGI, but has not been independently verified as being
32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
40 #include "glimports.h"
43 #include "subdivider.h"
44 #include "renderhints.h"
47 #include "curvelist.h"
48 #include "nurbsconsts.h"
50 /*--------------------------------------------------------------------------
51 * drawCurves - main curve rendering entry point
52 *--------------------------------------------------------------------------
56 Subdivider::drawCurves( void )
60 qlist->getRange( from, to, bpts );
65 for( int i=bpts.start; i<bpts.end-1; i++ ) {
70 qlist->downloadAll( &pta, &ptb, backend );
72 Curvelist curvelist( qlist, pta, ptb );
73 samplingSplit( curvelist, renderhints.maxsubdivisions );
79 /*--------------------------------------------------------------------------
80 * samplingSplit - recursively subdivide patch, cull check each subpatch
81 *--------------------------------------------------------------------------
85 Subdivider::samplingSplit( Curvelist& curvelist, int subdivisions )
87 if( curvelist.cullCheck() == CULL_TRIVIAL_REJECT ) return;
89 curvelist.getstepsize();
91 if( curvelist.needsSamplingSubdivision() && (subdivisions > 0) ) {
92 REAL mid = ( curvelist.range[0] + curvelist.range[1] ) * 0.5;
93 Curvelist lowerlist( curvelist, mid );
94 samplingSplit( lowerlist, subdivisions-1 ); // lower
95 samplingSplit( curvelist, subdivisions-1 ); // upper
97 long nu = 1 + ((long) (curvelist.range[2] / curvelist.stepsize));
98 backend.curvgrid( curvelist.range[0], curvelist.range[1], nu );
99 backend.curvmesh( 0, nu );