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 
244