Synchronize with trunk's revision r57629.
[reactos.git] / dll / opengl / glu32 / src / libnurbs / internals / curve.cc
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 * curve.c++
37 *
38 */
39
40 #include "glimports.h"
41 #include "myassert.h"
42 #include "mystdio.h"
43 #include "mymath.h"
44 #include "curve.h"
45 #include "mapdesc.h"
46 #include "types.h"
47 #include "quilt.h"
48 #include "nurbsconsts.h"
49
50 /*--------------------------------------------------------------------------
51 * Curve::Curve - copy curve from quilt and transform control points
52 *--------------------------------------------------------------------------
53 */
54
55 Curve::Curve( Quilt_ptr geo, REAL pta, REAL ptb, Curve *c )
56 {
57 mapdesc = geo->mapdesc;
58 next = c;
59 needsSampling = mapdesc->isRangeSampling() ? 1 : 0;
60 cullval = mapdesc->isCulling() ? CULL_ACCEPT : CULL_TRIVIAL_ACCEPT;
61 order = geo->qspec[0].order;
62 stride = MAXCOORDS;
63 for( int i = 0; i < MAXORDER * MAXCOORDS; i++ ) {
64 cpts[i] = 0;
65 spts[i] = 0;
66 }
67 stepsize = 0;
68 minstepsize = 0;
69
70 REAL *ps = geo->cpts;
71 Quiltspec_ptr qs = geo->qspec;
72 ps += qs->offset;
73 ps += qs->index * qs->order * qs->stride;
74
75 if( needsSampling )
76 mapdesc->xformSampling( ps, qs->order, qs->stride, spts, stride );
77
78 if( cullval == CULL_ACCEPT )
79 mapdesc->xformCulling( ps, qs->order, qs->stride, cpts, stride );
80
81 /* set untrimmed curve range */
82 range[0] = qs->breakpoints[qs->index];
83 range[1] = qs->breakpoints[qs->index+1];
84 range[2] = range[1] - range[0];
85
86 if( range[0] != pta ) {
87 Curve lower( *this, pta, 0 );
88 lower.next = next;
89 *this = lower;
90 }
91 if( range[1] != ptb ) {
92 Curve lower( *this, ptb, 0 );
93 }
94 }
95
96 /*--------------------------------------------------------------------------
97 * Curve::Curve - subdivide a curve along an isoparametric line
98 *--------------------------------------------------------------------------
99 */
100
101 Curve::Curve( Curve& upper, REAL value, Curve *c )
102 {
103 Curve &lower = *this;
104
105 lower.next = c;
106 lower.mapdesc = upper.mapdesc;
107 lower.needsSampling = upper.needsSampling;
108 lower.order = upper.order;
109 lower.stride = upper.stride;
110 lower.cullval = upper.cullval;
111
112 REAL d = (value - upper.range[0]) / upper.range[2];
113
114 if( needsSampling )
115 mapdesc->subdivide( upper.spts, lower.spts, d, upper.stride, upper.order );
116
117 if( cullval == CULL_ACCEPT )
118 mapdesc->subdivide( upper.cpts, lower.cpts, d, upper.stride, upper.order );
119
120 lower.range[0] = upper.range[0];
121 lower.range[1] = value;
122 lower.range[2] = value - upper.range[0];
123 upper.range[0] = value;
124 upper.range[2] = upper.range[1] - value;
125 }
126
127
128 /*--------------------------------------------------------------------------
129 * Curve::clamp - clamp the sampling rate to a given maximum
130 *--------------------------------------------------------------------------
131 */
132
133 void
134 Curve::clamp( void )
135 {
136 if( stepsize < minstepsize )
137 stepsize = mapdesc->clampfactor * minstepsize;
138 }
139
140 void
141 Curve::setstepsize( REAL max )
142 {
143 stepsize = ( max >= 1.0 ) ? (range[2] / max) : range[2];
144 minstepsize = stepsize;
145 }
146
147 void
148 Curve::getstepsize( void )
149 {
150 minstepsize= 0;
151
152 if( mapdesc->isConstantSampling() ) {
153 // fixed number of samples per patch in each direction
154 // maxrate is number of s samples per patch
155 setstepsize( mapdesc->maxrate );
156 } else if( mapdesc->isDomainSampling() ) {
157 // maxrate is number of s samples per unit s length of domain
158 setstepsize( mapdesc->maxrate * range[2] );
159 } else {
160 // upper bound on path length between sample points
161
162 assert( order <= MAXORDER );
163
164 /* points have been transformed, therefore they are homogeneous */
165 REAL tmp[MAXORDER][MAXCOORDS];
166 const int tstride = sizeof(tmp[0]) / sizeof(REAL);
167 int val = mapdesc->project( spts, stride, &tmp[0][0], tstride, order );
168
169 if( val == 0 ) {
170 // control points cross infinity, therefore derivatives are undefined
171 setstepsize( mapdesc->maxrate );
172 } else {
173 REAL t = mapdesc->getProperty( N_PIXEL_TOLERANCE );
174 if( mapdesc->isParametricDistanceSampling() ) {
175 REAL d = mapdesc->calcPartialVelocity( &tmp[0][0], tstride, order, 2, range[2] );
176 stepsize = (d > 0.0) ? sqrtf( 8.0 * t / d ) : range[2];
177 minstepsize = ( mapdesc->maxrate > 0.0 ) ? (range[2] / mapdesc->maxrate) : 0.0;
178 } else if( mapdesc->isPathLengthSampling() ) {
179 // t is upper bound on path (arc) length
180 REAL d = mapdesc->calcPartialVelocity( &tmp[0][0], tstride, order, 1, range[2] );
181 stepsize = ( d > 0.0 ) ? (t / d) : range[2];
182 minstepsize = ( mapdesc->maxrate > 0.0 ) ? (range[2] / mapdesc->maxrate) : 0.0;
183 } else {
184 // control points cross infinity, therefore partials are undefined
185 setstepsize( mapdesc->maxrate );
186 }
187 }
188 }
189 }
190
191 int
192 Curve::needsSamplingSubdivision( void )
193 {
194 return ( stepsize < minstepsize ) ? 1 : 0;
195 }
196
197 int
198 Curve::cullCheck( void )
199 {
200 if( cullval == CULL_ACCEPT )
201 cullval = mapdesc->cullCheck( cpts, order, stride );
202 return cullval;
203 }
204