| 1 |
#ifndef lint |
| 2 |
static char SCCSid[] = "$SunId$ LBL"; |
| 3 |
#endif |
| 4 |
|
| 5 |
/* Copyright (c) 1989 Regents of the University of California */ |
| 6 |
|
| 7 |
/* |
| 8 |
* gensurf.c - program to generate functional surfaces |
| 9 |
* |
| 10 |
* Parametric functions x(s,t), y(s,t) and z(s,t) |
| 11 |
* specify the surface, which is tesselated into an m by n |
| 12 |
* array of paired triangles. |
| 13 |
* The surface normal is defined by the right hand |
| 14 |
* rule applied to (s,t). |
| 15 |
* |
| 16 |
* 4/3/87 |
| 17 |
*/ |
| 18 |
|
| 19 |
#include "standard.h" |
| 20 |
|
| 21 |
char XNAME[] = "X`SYS`"; /* x function name */ |
| 22 |
char YNAME[] = "Y`SYS`"; /* y function name */ |
| 23 |
char ZNAME[] = "Z`SYS`"; /* z function name */ |
| 24 |
|
| 25 |
#define ABS(x) ((x)>=0 ? (x) : -(x)) |
| 26 |
|
| 27 |
#define pvect(p) printf(vformat, (p)[0], (p)[1], (p)[2]) |
| 28 |
|
| 29 |
char vformat[] = "%15.9g %15.9g %15.9g\n"; |
| 30 |
char tsargs[] = "4 surf_dx surf_dy surf_dz surf.cal\n"; |
| 31 |
char texname[] = "Phong"; |
| 32 |
|
| 33 |
int smooth = 0; /* apply smoothing? */ |
| 34 |
|
| 35 |
char *modname, *surfname; |
| 36 |
|
| 37 |
/* recorded data flags */ |
| 38 |
#define HASBORDER 01 |
| 39 |
#define TRIPLETS 02 |
| 40 |
/* a data structure */ |
| 41 |
struct { |
| 42 |
int flags; /* data type */ |
| 43 |
short m, n; /* number of s and t values */ |
| 44 |
FLOAT *data; /* the data itself, s major sort */ |
| 45 |
} datarec; /* our recorded data */ |
| 46 |
|
| 47 |
double l_hermite(), l_bezier(), l_bspline(), l_dataval(); |
| 48 |
extern double funvalue(), argument(); |
| 49 |
|
| 50 |
typedef struct { |
| 51 |
FVECT p; /* vertex position */ |
| 52 |
FVECT n; /* average normal */ |
| 53 |
} POINT; |
| 54 |
|
| 55 |
|
| 56 |
main(argc, argv) |
| 57 |
int argc; |
| 58 |
char *argv[]; |
| 59 |
{ |
| 60 |
extern long eclock; |
| 61 |
POINT *row0, *row1, *row2, *rp; |
| 62 |
int i, j, m, n; |
| 63 |
char stmp[256]; |
| 64 |
|
| 65 |
varset("PI", ':', PI); |
| 66 |
funset("hermite", 5, ':', l_hermite); |
| 67 |
funset("bezier", 5, ':', l_bezier); |
| 68 |
funset("bspline", 5, ':', l_bspline); |
| 69 |
|
| 70 |
if (argc < 8) |
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goto userror; |
| 72 |
|
| 73 |
for (i = 8; i < argc; i++) |
| 74 |
if (!strcmp(argv[i], "-e")) |
| 75 |
scompile(argv[++i], NULL, 0); |
| 76 |
else if (!strcmp(argv[i], "-f")) |
| 77 |
fcompile(argv[++i]); |
| 78 |
else if (!strcmp(argv[i], "-s")) |
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smooth++; |
| 80 |
else |
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goto userror; |
| 82 |
|
| 83 |
modname = argv[1]; |
| 84 |
surfname = argv[2]; |
| 85 |
m = atoi(argv[6]); |
| 86 |
n = atoi(argv[7]); |
| 87 |
if (m <= 0 || n <= 0) |
| 88 |
goto userror; |
| 89 |
if (!strcmp(argv[5], "-") || access(argv[5], 4) == 0) { /* file? */ |
| 90 |
funset(ZNAME, 2, ':', l_dataval); |
| 91 |
if (!strcmp(argv[5],argv[3]) && !strcmp(argv[5],argv[4])) { |
| 92 |
loaddata(argv[5], m, n, 3); |
| 93 |
funset(XNAME, 2, ':', l_dataval); |
| 94 |
funset(YNAME, 2, ':', l_dataval); |
| 95 |
} else { |
| 96 |
loaddata(argv[5], m, n, 1); |
| 97 |
sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]); |
| 98 |
scompile(stmp, NULL, 0); |
| 99 |
sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]); |
| 100 |
scompile(stmp, NULL, 0); |
| 101 |
} |
| 102 |
} else { |
| 103 |
sprintf(stmp, "%s(s,t)=%s;", XNAME, argv[3]); |
| 104 |
scompile(stmp, NULL, 0); |
| 105 |
sprintf(stmp, "%s(s,t)=%s;", YNAME, argv[4]); |
| 106 |
scompile(stmp, NULL, 0); |
| 107 |
sprintf(stmp, "%s(s,t)=%s;", ZNAME, argv[5]); |
| 108 |
scompile(stmp, NULL, 0); |
| 109 |
} |
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row0 = (POINT *)malloc((n+3)*sizeof(POINT)); |
| 111 |
row1 = (POINT *)malloc((n+3)*sizeof(POINT)); |
| 112 |
row2 = (POINT *)malloc((n+3)*sizeof(POINT)); |
| 113 |
if (row0 == NULL || row1 == NULL || row2 == NULL) { |
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fprintf(stderr, "%s: out of memory\n", argv[0]); |
| 115 |
quit(1); |
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} |
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row0++; row1++; row2++; |
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/* print header */ |
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printhead(argc, argv); |
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eclock = 0; |
| 121 |
/* initialize */ |
| 122 |
comprow(-1.0/m, row0, n); |
| 123 |
comprow(0.0, row1, n); |
| 124 |
comprow(1.0/m, row2, n); |
| 125 |
compnorms(row0, row1, row2, n); |
| 126 |
/* for each row */ |
| 127 |
for (i = 0; i < m; i++) { |
| 128 |
/* compute next row */ |
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rp = row0; |
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row0 = row1; |
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row1 = row2; |
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row2 = rp; |
| 133 |
comprow((double)(i+2)/m, row2, n); |
| 134 |
compnorms(row0, row1, row2, n); |
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|
| 136 |
for (j = 0; j < n; j++) { |
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/* put polygons */ |
| 138 |
if ((i+j) & 1) |
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putsquare(&row0[j], &row1[j], |
| 140 |
&row0[j+1], &row1[j+1]); |
| 141 |
else |
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putsquare(&row1[j], &row1[j+1], |
| 143 |
&row0[j], &row0[j+1]); |
| 144 |
} |
| 145 |
} |
| 146 |
|
| 147 |
quit(0); |
| 148 |
|
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userror: |
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fprintf(stderr, "Usage: %s material name ", argv[0]); |
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fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n"); |
| 152 |
quit(1); |
| 153 |
} |
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|
| 155 |
|
| 156 |
loaddata(file, m, n, pointsize) /* load point data from file */ |
| 157 |
char *file; |
| 158 |
int m, n; |
| 159 |
int pointsize; |
| 160 |
{ |
| 161 |
extern char *fgetword(); |
| 162 |
FILE *fp; |
| 163 |
char word[64]; |
| 164 |
register int size; |
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register FLOAT *dp; |
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|
| 167 |
datarec.flags = HASBORDER; /* assume border values */ |
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size = (m+1)*(n+1)*pointsize; |
| 169 |
if (pointsize == 3) |
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datarec.flags |= TRIPLETS; |
| 171 |
dp = (FLOAT *)malloc(size*sizeof(FLOAT)); |
| 172 |
if ((datarec.data = dp) == NULL) { |
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fputs("Out of memory\n", stderr); |
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exit(1); |
| 175 |
} |
| 176 |
if (!strcmp(file, "-")) { |
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file = "<stdin>"; |
| 178 |
fp = stdin; |
| 179 |
} else if ((fp = fopen(file, "r")) == NULL) { |
| 180 |
fputs(file, stderr); |
| 181 |
fputs(": cannot open\n", stderr); |
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exit(1); |
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} |
| 184 |
while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) { |
| 185 |
if (!isflt(word)) { |
| 186 |
fprintf(stderr, "%s: garbled data value: %s\n", |
| 187 |
file, word); |
| 188 |
exit(1); |
| 189 |
} |
| 190 |
*dp++ = atof(word); |
| 191 |
size--; |
| 192 |
} |
| 193 |
if (size == (m+n+1)*pointsize) { /* no border after all */ |
| 194 |
dp = (FLOAT *)realloc((char *)datarec.data, |
| 195 |
m*n*pointsize*sizeof(FLOAT)); |
| 196 |
if (dp != NULL) |
| 197 |
datarec.data = dp; |
| 198 |
datarec.flags &= ~HASBORDER; |
| 199 |
size = 0; |
| 200 |
} |
| 201 |
if (size || fgetword(word, sizeof(word), fp) != NULL) { |
| 202 |
fputs(file, stderr); |
| 203 |
fputs(": bad number of data points\n", stderr); |
| 204 |
exit(1); |
| 205 |
} |
| 206 |
fclose(fp); |
| 207 |
} |
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|
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|
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double |
| 211 |
l_dataval(nam) /* return recorded data value */ |
| 212 |
char *nam; |
| 213 |
{ |
| 214 |
double u, v; |
| 215 |
register int i, j; |
| 216 |
register FLOAT *dp; |
| 217 |
double d00, d01, d10, d11; |
| 218 |
/* compute coordinates */ |
| 219 |
u = argument(1); v = argument(2); |
| 220 |
if (datarec.flags & HASBORDER) { |
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i = u *= datarec.m; |
| 222 |
j = v *= datarec.n; |
| 223 |
} else { |
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i = u = u*(datarec.m+1) - .5; |
| 225 |
j = v = v*(datarec.n+1) - .5; |
| 226 |
} |
| 227 |
if (i < 0) i = 0; |
| 228 |
else if (i > datarec.m-2) i = datarec.m-2; |
| 229 |
if (j < 0) j = 0; |
| 230 |
else if (j > datarec.n-2) j = datarec.n-2; |
| 231 |
/* compute value */ |
| 232 |
if (datarec.flags & TRIPLETS) { |
| 233 |
dp = datarec.data + 3*(j*datarec.n + i); |
| 234 |
if (nam == YNAME) |
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dp++; |
| 236 |
else if (nam == ZNAME) |
| 237 |
dp += 2; |
| 238 |
d00 = dp[0]; d01 = dp[3]; |
| 239 |
dp += 3*datarec.n; |
| 240 |
d10 = dp[0]; d11 = dp[3]; |
| 241 |
} else { |
| 242 |
dp = datarec.data + j*datarec.n + i; |
| 243 |
d00 = dp[0]; d01 = dp[1]; |
| 244 |
dp += datarec.n; |
| 245 |
d10 = dp[0]; d11 = dp[1]; |
| 246 |
} |
| 247 |
/* bilinear interpolation */ |
| 248 |
return((j+1-v)*((i+1-u)*d00+(u-i)*d01)+(v-j)*((i+1-u)*d10+(u-i)*d11)); |
| 249 |
} |
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|
| 251 |
|
| 252 |
putsquare(p0, p1, p2, p3) /* put out a square */ |
| 253 |
POINT *p0, *p1, *p2, *p3; |
| 254 |
{ |
| 255 |
static int nout = 0; |
| 256 |
FVECT norm[4]; |
| 257 |
int axis; |
| 258 |
FVECT v1, v2, vc1, vc2; |
| 259 |
int ok1, ok2; |
| 260 |
/* compute exact normals */ |
| 261 |
fvsum(v1, p1->p, p0->p, -1.0); |
| 262 |
fvsum(v2, p2->p, p0->p, -1.0); |
| 263 |
fcross(vc1, v1, v2); |
| 264 |
ok1 = normalize(vc1) != 0.0; |
| 265 |
fvsum(v1, p2->p, p3->p, -1.0); |
| 266 |
fvsum(v2, p1->p, p3->p, -1.0); |
| 267 |
fcross(vc2, v1, v2); |
| 268 |
ok2 = normalize(vc2) != 0.0; |
| 269 |
if (!(ok1 | ok2)) |
| 270 |
return; |
| 271 |
/* compute normal interpolation */ |
| 272 |
axis = norminterp(norm, p0, p1, p2, p3); |
| 273 |
|
| 274 |
/* put out quadrilateral? */ |
| 275 |
if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) { |
| 276 |
printf("\n%s ", modname); |
| 277 |
if (axis != -1) { |
| 278 |
printf("texfunc %s\n", texname); |
| 279 |
printf(tsargs); |
| 280 |
printf("0\n13\t%d\n", axis); |
| 281 |
pvect(norm[0]); |
| 282 |
pvect(norm[1]); |
| 283 |
pvect(norm[2]); |
| 284 |
fvsum(v1, norm[3], vc1, -0.5); |
| 285 |
fvsum(v1, v1, vc2, -0.5); |
| 286 |
pvect(v1); |
| 287 |
printf("\n%s ", texname); |
| 288 |
} |
| 289 |
printf("polygon %s.%d\n", surfname, ++nout); |
| 290 |
printf("0\n0\n12\n"); |
| 291 |
pvect(p0->p); |
| 292 |
pvect(p1->p); |
| 293 |
pvect(p3->p); |
| 294 |
pvect(p2->p); |
| 295 |
return; |
| 296 |
} |
| 297 |
/* put out triangles? */ |
| 298 |
if (ok1) { |
| 299 |
printf("\n%s ", modname); |
| 300 |
if (axis != -1) { |
| 301 |
printf("texfunc %s\n", texname); |
| 302 |
printf(tsargs); |
| 303 |
printf("0\n13\t%d\n", axis); |
| 304 |
pvect(norm[0]); |
| 305 |
pvect(norm[1]); |
| 306 |
pvect(norm[2]); |
| 307 |
fvsum(v1, norm[3], vc1, -1.0); |
| 308 |
pvect(v1); |
| 309 |
printf("\n%s ", texname); |
| 310 |
} |
| 311 |
printf("polygon %s.%d\n", surfname, ++nout); |
| 312 |
printf("0\n0\n9\n"); |
| 313 |
pvect(p0->p); |
| 314 |
pvect(p1->p); |
| 315 |
pvect(p2->p); |
| 316 |
} |
| 317 |
if (ok2) { |
| 318 |
printf("\n%s ", modname); |
| 319 |
if (axis != -1) { |
| 320 |
printf("texfunc %s\n", texname); |
| 321 |
printf(tsargs); |
| 322 |
printf("0\n13\t%d\n", axis); |
| 323 |
pvect(norm[0]); |
| 324 |
pvect(norm[1]); |
| 325 |
pvect(norm[2]); |
| 326 |
fvsum(v2, norm[3], vc2, -1.0); |
| 327 |
pvect(v2); |
| 328 |
printf("\n%s ", texname); |
| 329 |
} |
| 330 |
printf("polygon %s.%d\n", surfname, ++nout); |
| 331 |
printf("0\n0\n9\n"); |
| 332 |
pvect(p2->p); |
| 333 |
pvect(p1->p); |
| 334 |
pvect(p3->p); |
| 335 |
} |
| 336 |
} |
| 337 |
|
| 338 |
|
| 339 |
comprow(s, row, siz) /* compute row of values */ |
| 340 |
double s; |
| 341 |
register POINT *row; |
| 342 |
int siz; |
| 343 |
{ |
| 344 |
double st[2]; |
| 345 |
int end; |
| 346 |
register int i; |
| 347 |
|
| 348 |
if (smooth) { |
| 349 |
i = -1; /* compute one past each end */ |
| 350 |
end = siz+1; |
| 351 |
} else { |
| 352 |
if (s < -FTINY || s > 1.0+FTINY) |
| 353 |
return; |
| 354 |
i = 0; |
| 355 |
end = siz; |
| 356 |
} |
| 357 |
st[0] = s; |
| 358 |
while (i <= end) { |
| 359 |
st[1] = (double)i/siz; |
| 360 |
row[i].p[0] = funvalue(XNAME, 2, st); |
| 361 |
row[i].p[1] = funvalue(YNAME, 2, st); |
| 362 |
row[i].p[2] = funvalue(ZNAME, 2, st); |
| 363 |
i++; |
| 364 |
} |
| 365 |
} |
| 366 |
|
| 367 |
|
| 368 |
compnorms(r0, r1, r2, siz) /* compute row of averaged normals */ |
| 369 |
register POINT *r0, *r1, *r2; |
| 370 |
int siz; |
| 371 |
{ |
| 372 |
FVECT v1, v2; |
| 373 |
register int i; |
| 374 |
|
| 375 |
if (!smooth) /* not needed if no smoothing */ |
| 376 |
return; |
| 377 |
/* compute middle points */ |
| 378 |
while (siz-- >= 0) { |
| 379 |
fvsum(v1, r2[0].p, r0[0].p, -1.0); |
| 380 |
fvsum(v2, r1[1].p, r1[-1].p, -1.0); |
| 381 |
fcross(r1[0].n, v1, v2); |
| 382 |
normalize(r1[0].n); |
| 383 |
r0++; r1++; r2++; |
| 384 |
} |
| 385 |
} |
| 386 |
|
| 387 |
|
| 388 |
int |
| 389 |
norminterp(resmat, p0, p1, p2, p3) /* compute normal interpolation */ |
| 390 |
register FVECT resmat[4]; |
| 391 |
POINT *p0, *p1, *p2, *p3; |
| 392 |
{ |
| 393 |
#define u ((ax+1)%3) |
| 394 |
#define v ((ax+2)%3) |
| 395 |
|
| 396 |
register int ax; |
| 397 |
MAT4 eqnmat; |
| 398 |
FVECT v1; |
| 399 |
register int i, j; |
| 400 |
|
| 401 |
if (!smooth) /* no interpolation if no smoothing */ |
| 402 |
return(-1); |
| 403 |
/* find dominant axis */ |
| 404 |
VCOPY(v1, p0->n); |
| 405 |
fvsum(v1, v1, p1->n, 1.0); |
| 406 |
fvsum(v1, v1, p2->n, 1.0); |
| 407 |
fvsum(v1, v1, p3->n, 1.0); |
| 408 |
ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1; |
| 409 |
ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2; |
| 410 |
/* assign equation matrix */ |
| 411 |
eqnmat[0][0] = p0->p[u]*p0->p[v]; |
| 412 |
eqnmat[0][1] = p0->p[u]; |
| 413 |
eqnmat[0][2] = p0->p[v]; |
| 414 |
eqnmat[0][3] = 1.0; |
| 415 |
eqnmat[1][0] = p1->p[u]*p1->p[v]; |
| 416 |
eqnmat[1][1] = p1->p[u]; |
| 417 |
eqnmat[1][2] = p1->p[v]; |
| 418 |
eqnmat[1][3] = 1.0; |
| 419 |
eqnmat[2][0] = p2->p[u]*p2->p[v]; |
| 420 |
eqnmat[2][1] = p2->p[u]; |
| 421 |
eqnmat[2][2] = p2->p[v]; |
| 422 |
eqnmat[2][3] = 1.0; |
| 423 |
eqnmat[3][0] = p3->p[u]*p3->p[v]; |
| 424 |
eqnmat[3][1] = p3->p[u]; |
| 425 |
eqnmat[3][2] = p3->p[v]; |
| 426 |
eqnmat[3][3] = 1.0; |
| 427 |
/* invert matrix (solve system) */ |
| 428 |
if (!invmat(eqnmat, eqnmat)) |
| 429 |
return(-1); /* no solution */ |
| 430 |
/* compute result matrix */ |
| 431 |
for (j = 0; j < 4; j++) |
| 432 |
for (i = 0; i < 3; i++) |
| 433 |
resmat[j][i] = eqnmat[j][0]*p0->n[i] + |
| 434 |
eqnmat[j][1]*p1->n[i] + |
| 435 |
eqnmat[j][2]*p2->n[i] + |
| 436 |
eqnmat[j][3]*p3->n[i]; |
| 437 |
return(ax); |
| 438 |
|
| 439 |
#undef u |
| 440 |
#undef v |
| 441 |
} |
| 442 |
|
| 443 |
|
| 444 |
/* |
| 445 |
* invmat - computes the inverse of mat into inverse. Returns 1 |
| 446 |
* if there exists an inverse, 0 otherwise. It uses Gaussian Elimination |
| 447 |
* method. |
| 448 |
*/ |
| 449 |
|
| 450 |
invmat(inverse,mat) |
| 451 |
MAT4 inverse, mat; |
| 452 |
{ |
| 453 |
#define SWAP(a,b,t) (t=a,a=b,b=t) |
| 454 |
|
| 455 |
MAT4 m4tmp; |
| 456 |
register int i,j,k; |
| 457 |
register double temp; |
| 458 |
|
| 459 |
copymat4(m4tmp, mat); |
| 460 |
/* set inverse to identity */ |
| 461 |
for (i = 0; i < 4; i++) |
| 462 |
for (j = 0; j < 4; j++) |
| 463 |
inverse[i][j] = i==j ? 1.0 : 0.0; |
| 464 |
|
| 465 |
for(i = 0; i < 4; i++) { |
| 466 |
/* Look for row with largest pivot and swap rows */ |
| 467 |
temp = FTINY; j = -1; |
| 468 |
for(k = i; k < 4; k++) |
| 469 |
if(ABS(m4tmp[k][i]) > temp) { |
| 470 |
temp = ABS(m4tmp[k][i]); |
| 471 |
j = k; |
| 472 |
} |
| 473 |
if(j == -1) /* No replacing row -> no inverse */ |
| 474 |
return(0); |
| 475 |
if (j != i) |
| 476 |
for(k = 0; k < 4; k++) { |
| 477 |
SWAP(m4tmp[i][k],m4tmp[j][k],temp); |
| 478 |
SWAP(inverse[i][k],inverse[j][k],temp); |
| 479 |
} |
| 480 |
|
| 481 |
temp = m4tmp[i][i]; |
| 482 |
for(k = 0; k < 4; k++) { |
| 483 |
m4tmp[i][k] /= temp; |
| 484 |
inverse[i][k] /= temp; |
| 485 |
} |
| 486 |
for(j = 0; j < 4; j++) { |
| 487 |
if(j != i) { |
| 488 |
temp = m4tmp[j][i]; |
| 489 |
for(k = 0; k < 4; k++) { |
| 490 |
m4tmp[j][k] -= m4tmp[i][k]*temp; |
| 491 |
inverse[j][k] -= inverse[i][k]*temp; |
| 492 |
} |
| 493 |
} |
| 494 |
} |
| 495 |
} |
| 496 |
return(1); |
| 497 |
|
| 498 |
#undef SWAP |
| 499 |
} |
| 500 |
|
| 501 |
|
| 502 |
eputs(msg) |
| 503 |
char *msg; |
| 504 |
{ |
| 505 |
fputs(msg, stderr); |
| 506 |
} |
| 507 |
|
| 508 |
|
| 509 |
wputs(msg) |
| 510 |
char *msg; |
| 511 |
{ |
| 512 |
eputs(msg); |
| 513 |
} |
| 514 |
|
| 515 |
|
| 516 |
quit(code) |
| 517 |
{ |
| 518 |
exit(code); |
| 519 |
} |
| 520 |
|
| 521 |
|
| 522 |
printhead(ac, av) /* print command header */ |
| 523 |
register int ac; |
| 524 |
register char **av; |
| 525 |
{ |
| 526 |
putchar('#'); |
| 527 |
while (ac--) { |
| 528 |
putchar(' '); |
| 529 |
fputs(*av++, stdout); |
| 530 |
} |
| 531 |
putchar('\n'); |
| 532 |
} |
| 533 |
|
| 534 |
|
| 535 |
double |
| 536 |
l_hermite() |
| 537 |
{ |
| 538 |
double t; |
| 539 |
|
| 540 |
t = argument(5); |
| 541 |
return( argument(1)*((2.0*t-3.0)*t*t+1.0) + |
| 542 |
argument(2)*(-2.0*t+3.0)*t*t + |
| 543 |
argument(3)*((t-2.0)*t+1.0)*t + |
| 544 |
argument(4)*(t-1.0)*t*t ); |
| 545 |
} |
| 546 |
|
| 547 |
|
| 548 |
double |
| 549 |
l_bezier() |
| 550 |
{ |
| 551 |
double t; |
| 552 |
|
| 553 |
t = argument(5); |
| 554 |
return( argument(1) * (1.+t*(-3.+t*(3.-t))) + |
| 555 |
argument(2) * 3.*t*(1.+t*(-2.+t)) + |
| 556 |
argument(3) * 3.*t*t*(1.-t) + |
| 557 |
argument(4) * t*t*t ); |
| 558 |
} |
| 559 |
|
| 560 |
|
| 561 |
double |
| 562 |
l_bspline() |
| 563 |
{ |
| 564 |
double t; |
| 565 |
|
| 566 |
t = argument(5); |
| 567 |
return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) + |
| 568 |
argument(2) * (2./3.+t*t*(-1.+1./2.*t)) + |
| 569 |
argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) + |
| 570 |
argument(4) * (1./6.*t*t*t) ); |
| 571 |
} |
