FreeWRL/FreeX3D  3.0.0
mapdescv.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  * mapdescv.c++
37  *
38  */
39 
40 #include "glimports.h"
41 #include "mystdio.h"
42 #include "myassert.h"
43 #include "mystring.h"
44 #include "mymath.h"
45 #include "nurbsconsts.h"
46 #include "mapdesc.h"
47 
48 /*--------------------------------------------------------------------------
49  * calcPartialVelocity - calculate maximum magnitude of a given partial
50  * derivative
51  *--------------------------------------------------------------------------
52  */
53 REAL
54 Mapdesc::calcPartialVelocity (
55  REAL *p,
56  int stride,
57  int ncols,
58  int partial,
59  REAL range )
60 {
61  REAL tmp[MAXORDER][MAXCOORDS];
62  REAL mag[MAXORDER];
63 
64  assert( ncols <= MAXORDER );
65 
66  int j, k, t;
67  // copy inhomogeneous control points into temporary array
68  for( j=0; j != ncols; j++ )
69  for( k=0; k != inhcoords; k++ )
70  tmp[j][k] = p[j*stride + k];
71 
72  for( t=0; t != partial; t++ )
73  for( j=0; j != ncols-t-1; j++ )
74  for( k=0; k != inhcoords; k++ )
75  tmp[j][k] = tmp[j+1][k] - tmp[j][k];
76 
77  // compute magnitude and store in mag array
78  for( j=0; j != ncols-partial; j++ ) {
79  mag[j] = 0.0;
80  for( k=0; k != inhcoords; k++ )
81  mag[j] += tmp[j][k] * tmp[j][k];
82  }
83 
84  // compute scale factor
85  REAL fac = 1;
86  REAL invt = 1.0 / range;
87  for( t = ncols-1; t != ncols-1-partial; t-- )
88  fac *= t * invt;
89 
90  // compute max magnitude of all entries in array
91  REAL max = 0.0;
92  for( j=0; j != ncols-partial; j++ )
93  if( mag[j] > max ) max = mag[j];
94  max = fac * sqrtf( (float) max );
95 
96  return max;
97 }
98 
99 /*--------------------------------------------------------------------------
100  * calcPartialVelocity - calculate maximum magnitude of a given partial
101  * derivative
102  *--------------------------------------------------------------------------
103  */
104 REAL
105 Mapdesc::calcPartialVelocity (
106  REAL *dist,
107  REAL *p,
108  int rstride,
109  int cstride,
110  int nrows,
111  int ncols,
112  int spartial,
113  int tpartial,
114  REAL srange,
115  REAL trange,
116  int side )
117 {
118  REAL tmp[MAXORDER][MAXORDER][MAXCOORDS];
119  REAL mag[MAXORDER][MAXORDER];
120 
121  assert( nrows <= MAXORDER );
122  assert( ncols <= MAXORDER );
123 
124  REAL *tp = &tmp[0][0][0];
125  REAL *mp = &mag[0][0];
126  const int istride = sizeof( tmp[0]) / sizeof( tmp[0][0][0] );
127  const int jstride = sizeof( tmp[0][0]) / sizeof( tmp[0][0][0] );
128  /*
129  const int kstride = sizeof( tmp[0][0][0]) / sizeof( tmp[0][0][0] );
130  */
131  const int mistride = sizeof( mag[0]) / sizeof( mag[0][0] );
132  const int mjstride = sizeof( mag[0][0]) / sizeof( mag[0][0] );
133  const int idist = nrows * istride;
134  const int jdist = ncols * jstride;
135  /*
136  const int kdist = inhcoords * kstride;
137  */
138  const int id = idist - spartial * istride;
139  const int jd = jdist - tpartial * jstride;
140 
141  {
142  // copy control points
143  REAL *ti = tp;
144  REAL *qi = p;
145  REAL *til = tp + idist;
146  for( ; ti != til; ) {
147  REAL *tj = ti;
148  REAL *qj = qi;
149  REAL *tjl = ti + jdist;
150  for( ; tj != tjl; ) {
151  for( int k=0; k != inhcoords; k++ ) {
152  tj[k] = qj[k];
153  }
154  tj += jstride;
155  qj += cstride;
156  }
157  ti += istride;
158  qi += rstride;
159  }
160  }
161 
162  {
163  // compute (s)-partial derivative control points
164  REAL *til = tp + idist - istride;
165  const REAL *till = til - ( spartial * istride );
166  for( ; til != till; til -= istride )
167  for( REAL *ti = tp; ti != til; ti += istride )
168  for( REAL *tj = ti, *tjl = tj + jdist; tj != tjl; tj += jstride )
169  for( int k=0; k != inhcoords; k++ )
170  tj[k] = tj[k+istride] - tj[k];
171  }
172 
173  {
174  // compute (s,t)-partial derivative control points
175  REAL *tjl = tp + jdist - jstride;
176  const REAL *tjll = tjl - ( tpartial * jstride );
177  for( ; tjl != tjll; tjl -= jstride )
178  for( REAL *tj = tp; tj != tjl; tj += jstride )
179  for( REAL *ti = tj, *til = ti + id; ti != til; ti += istride )
180  for( int k=0; k != inhcoords; k++ )
181  ti[k] = ti[k+jstride] - ti[k];
182 
183  }
184 
185  REAL max = 0.0;
186  {
187  // compute magnitude and store in mag array
188  memset( (void *) mp, 0, sizeof( mag ) );
189  for( REAL *ti = tp, *mi = mp, *til = tp + id; ti != til; ti += istride, mi += mistride )
190  for( REAL *tj = ti, *mj = mi, *tjl = ti + jd; tj != tjl; tj += jstride, mj += mjstride ) {
191  for( int k=0; k != inhcoords; k++ )
192  *mj += tj[k] * tj[k];
193  if( *mj > max ) max = *mj;
194  }
195 
196  }
197 
198  int i, j;
199 
200  // compute scale factor
201  REAL fac = 1.0;
202  {
203  REAL invs = 1.0 / srange;
204  REAL invt = 1.0 / trange;
205  for( int s = nrows-1, slast = s-spartial; s != slast; s-- )
206  fac *= s * invs;
207  for( int t = ncols-1, tlast = t-tpartial; t != tlast; t-- )
208  fac *= t * invt;
209  }
210 
211  if( side == 0 ) {
212  // compute max magnitude of first and last column
213  dist[0] = 0.0;
214  dist[1] = 0.0;
215  for( i=0; i != nrows-spartial; i++ ) {
216  j = 0;
217  if( mag[i][j] > dist[0] ) dist[0] = mag[i][j];
218 
219  j = ncols-tpartial-1;
220  if( mag[i][j] > dist[1] ) dist[1] = mag[i][j];
221  }
222  dist[0] = fac * sqrtf( dist[0] );
223  dist[1] = fac * sqrtf( dist[1] );
224  } else if( side == 1 ) {
225  // compute max magnitude of first and last row
226  dist[0] = 0.0;
227  dist[1] = 0.0;
228  for( j=0; j != ncols-tpartial; j++ ) {
229  i = 0;
230  if( mag[i][j] > dist[0] ) dist[0] = mag[i][j];
231 
232  i = nrows-spartial-1;
233  if( mag[i][j] > dist[1] ) dist[1] = mag[i][j];
234  }
235  dist[0] = fac * sqrtf( dist[0] );
236  dist[1] = fac * sqrtf( dist[1] );
237  }
238 
239  max = fac * sqrtf( (float) max );
240 
241  return max;
242 }
243