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/*
** License Applicability. Except to the extent portions of this file are
** made subject to an alternative license as permitted in the SGI Free
** Software License B, Version 1.1 (the "License"), the contents of this
** file are subject only to the provisions of the License. You may not use
** this file except in compliance with the License. You may obtain a copy
** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
**
** http://oss.sgi.com/projects/FreeB
**
** Note that, as provided in the License, the Software is distributed on an
** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
**
** Original Code. The Original Code is: OpenGL Sample Implementation,
** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
** Copyright in any portions created by third parties is as indicated
** elsewhere herein. All Rights Reserved.
**
** Additional Notice Provisions: The application programming interfaces
** established by SGI in conjunction with the Original Code are The
** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
** Window System(R) (Version 1.3), released October 19, 1998. This software
** was created using the OpenGL(R) version 1.2.1 Sample Implementation
** published by SGI, but has not been independently verified as being
** compliant with the OpenGL(R) version 1.2.1 Specification.
*/
/*
* curvesub.c++
*
*/
#include "glimports.h"
#include "myassert.h"
#include "mystdio.h"
#include "subdivider.h"
#include "renderhints.h"
#include "backend.h"
#include "quilt.h"
#include "curvelist.h"
#include "curve.h"
#include "nurbsconsts.h"
/*--------------------------------------------------------------------------
* drawCurves - main curve rendering entry point
*--------------------------------------------------------------------------
*/
void
Subdivider::drawCurves( void )
{
REAL from[1], to[1];
Flist bpts;
qlist->getRange( from, to, bpts );
renderhints.init( );
backend.bgncurv();
for( int i=bpts.start; i<bpts.end-1; i++ ) {
REAL pta, ptb;
pta = bpts.pts[i];
ptb = bpts.pts[i+1];
qlist->downloadAll( &pta, &ptb, backend );
Curvelist curvelist( qlist, pta, ptb );
samplingSplit( curvelist, renderhints.maxsubdivisions );
}
backend.endcurv();
}
/*--------------------------------------------------------------------------
* samplingSplit - recursively subdivide patch, cull check each subpatch
*--------------------------------------------------------------------------
*/
void
Subdivider::samplingSplit( Curvelist& curvelist, int subdivisions )
{
if( curvelist.cullCheck() == CULL_TRIVIAL_REJECT ) return;
curvelist.getstepsize();
if( curvelist.needsSamplingSubdivision() && (subdivisions > 0) ) {
REAL mid = ( curvelist.range[0] + curvelist.range[1] ) * 0.5;
Curvelist lowerlist( curvelist, mid );
samplingSplit( lowerlist, subdivisions-1 ); // lower
samplingSplit( curvelist, subdivisions-1 ); // upper
} else {
long nu = 1 + ((long) (curvelist.range[2] / curvelist.stepsize));
backend.curvgrid( curvelist.range[0], curvelist.range[1], nu );
backend.curvmesh( 0, nu );
}
}
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