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Diffstat (limited to 'mesalib/src/glu/sgi/libnurbs/internals/knotvector.cc')
| -rw-r--r-- | mesalib/src/glu/sgi/libnurbs/internals/knotvector.cc | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/mesalib/src/glu/sgi/libnurbs/internals/knotvector.cc b/mesalib/src/glu/sgi/libnurbs/internals/knotvector.cc new file mode 100644 index 000000000..9eb5cbace --- /dev/null +++ b/mesalib/src/glu/sgi/libnurbs/internals/knotvector.cc @@ -0,0 +1,139 @@ +/* +** 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. +*/ + +/* + * knotvector.c++ + * + */ + +#include "glimports.h" +#include "mystdio.h" +#include "myassert.h" +#include "knotvector.h" +#include "defines.h" + +#ifdef __WATCOMC__ +#pragma warning 726 10 +#endif + +void Knotvector::init( long _knotcount, long _stride, long _order, INREAL *_knotlist ) +{ + knotcount = _knotcount; + stride = _stride; + order = _order; + knotlist = new Knot[_knotcount]; + assert( knotlist != 0 ); + + for( int i = 0; i != _knotcount; i++ ) + knotlist[i] = (Knot) _knotlist[i]; +} + +Knotvector::Knotvector( void ) +{ + knotlist = 0; +} + +Knotvector::~Knotvector( void ) +{ + if( knotlist ) delete[] knotlist; +} + +int Knotvector::validate( void ) +{ + /* kindex is used as an array index so subtract one first, + * this propagates throughout the code so study carefully */ + long kindex = knotcount-1; + + if( order < 1 || order > MAXORDER ) { + // spline order un-supported + return( 1 ); + } + + if( knotcount < (2 * order) ) { + // too few knots + return( 2 ); + } + + if( identical( knotlist[kindex-(order-1)], knotlist[order-1]) ) { + // valid knot range is empty + return( 3 ); + } + + for( long i = 0; i < kindex; i++) + if( knotlist[i] > knotlist[i+1] ) { + // decreasing knot sequence + return( 4 ); + } + + /* check for valid multiplicity */ + + /* kindex is currently the index of the last knot. + * In the next loop it is decremented to ignore the last knot + * and the loop stops when kindex is 2 so as to ignore the first + * knot as well. These knots are not used in computing + * knot multiplicities. + */ + + long multi = 1; + for( ; kindex >= 1; kindex-- ) { + if( knotlist[kindex] - knotlist[kindex-1] < TOLERANCE ) { + multi++; + continue; + } + if ( multi > order ) { + // knot multiplicity greater than order of spline + return( 5 ); + } + multi = 1; + } + + if ( multi > order ) { + // knot multiplicity greater than order of spline + return( 5 ); + } + + return 0; +} + +void Knotvector::show( const char *msg ) +{ +#ifndef NDEBUG + _glu_dprintf( "%s\n", msg ); + _glu_dprintf( "order = %ld, count = %ld\n", order, knotcount ); + + for( int i=0; i<knotcount; i++ ) + _glu_dprintf( "knot[%d] = %g\n", i, knotlist[i] ); +#endif +} + |