Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 1 | /* |
| 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: |
| 9 | ** |
| 10 | ** http://oss.sgi.com/projects/FreeB |
| 11 | ** |
| 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. |
| 17 | ** |
| 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. |
| 23 | ** |
| 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. |
| 33 | */ |
| 34 | |
| 35 | /* |
| 36 | * knotvector.c++ |
| 37 | * |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 38 | */ |
| 39 | |
| 40 | #include "glimports.h" |
| 41 | #include "mystdio.h" |
| 42 | #include "myassert.h" |
| 43 | #include "knotvector.h" |
| 44 | #include "defines.h" |
| 45 | |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 46 | #ifdef __WATCOMC__ |
| 47 | #pragma warning 726 10 |
| 48 | #endif |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 49 | |
| 50 | void Knotvector::init( long _knotcount, long _stride, long _order, INREAL *_knotlist ) |
| 51 | { |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 52 | knotcount = _knotcount; |
| 53 | stride = _stride; |
| 54 | order = _order; |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 55 | knotlist = new Knot[_knotcount]; |
| 56 | assert( knotlist != 0 ); |
| 57 | |
| 58 | for( int i = 0; i != _knotcount; i++ ) |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 59 | knotlist[i] = (Knot) _knotlist[i]; |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 60 | } |
| 61 | |
| 62 | Knotvector::Knotvector( void ) |
| 63 | { |
| 64 | knotlist = 0; |
| 65 | } |
| 66 | |
| 67 | Knotvector::~Knotvector( void ) |
| 68 | { |
| 69 | if( knotlist ) delete[] knotlist; |
| 70 | } |
| 71 | |
| 72 | int Knotvector::validate( void ) |
| 73 | { |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 74 | /* kindex is used as an array index so subtract one first, |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 75 | * this propagates throughout the code so study carefully */ |
| 76 | long kindex = knotcount-1; |
| 77 | |
| 78 | if( order < 1 || order > MAXORDER ) { |
| 79 | // spline order un-supported |
| 80 | return( 1 ); |
| 81 | } |
| 82 | |
| 83 | if( knotcount < (2 * order) ) { |
| 84 | // too few knots |
| 85 | return( 2 ); |
| 86 | } |
| 87 | |
| 88 | if( identical( knotlist[kindex-(order-1)], knotlist[order-1]) ) { |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 89 | // valid knot range is empty |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 90 | return( 3 ); |
| 91 | } |
| 92 | |
| 93 | for( long i = 0; i < kindex; i++) |
| 94 | if( knotlist[i] > knotlist[i+1] ) { |
| 95 | // decreasing knot sequence |
| 96 | return( 4 ); |
| 97 | } |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 98 | |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 99 | /* check for valid multiplicity */ |
| 100 | |
| 101 | /* kindex is currently the index of the last knot. |
| 102 | * In the next loop it is decremented to ignore the last knot |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 103 | * and the loop stops when kindex is 2 so as to ignore the first |
| 104 | * knot as well. These knots are not used in computing |
| 105 | * knot multiplicities. |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 106 | */ |
| 107 | |
| 108 | long multi = 1; |
| 109 | for( ; kindex >= 1; kindex-- ) { |
| 110 | if( knotlist[kindex] - knotlist[kindex-1] < TOLERANCE ) { |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 111 | multi++; |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 112 | continue; |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 113 | } |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 114 | if ( multi > order ) { |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 115 | // knot multiplicity greater than order of spline |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 116 | return( 5 ); |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 117 | } |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 118 | multi = 1; |
| 119 | } |
| 120 | |
| 121 | if ( multi > order ) { |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 122 | // knot multiplicity greater than order of spline |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 123 | return( 5 ); |
Kendall Bennett | 596d57c | 2003-10-14 23:48:57 +0000 | [diff] [blame] | 124 | } |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 125 | |
| 126 | return 0; |
| 127 | } |
| 128 | |
Guillaume Melquiond | 6e51feb | 2008-09-13 14:20:14 -0600 | [diff] [blame] | 129 | void Knotvector::show( const char *msg ) |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 130 | { |
| 131 | #ifndef NDEBUG |
Brian Paul | 15e74a6 | 2006-03-14 15:08:52 +0000 | [diff] [blame] | 132 | _glu_dprintf( "%s\n", msg ); |
| 133 | _glu_dprintf( "order = %ld, count = %ld\n", order, knotcount ); |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 134 | |
| 135 | for( int i=0; i<knotcount; i++ ) |
Brian Paul | 15e74a6 | 2006-03-14 15:08:52 +0000 | [diff] [blame] | 136 | _glu_dprintf( "knot[%d] = %g\n", i, knotlist[i] ); |
Brian Paul | 77cc447 | 2001-03-17 00:25:40 +0000 | [diff] [blame] | 137 | #endif |
| 138 | } |
| 139 | |