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) |
71 |
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")) |
79 |
smooth++; |
80 |
else |
81 |
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); |
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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 |
} |
110 |
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); |
116 |
} |
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row0++; row1++; row2++; |
118 |
/* print header */ |
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printhead(argc, argv); |
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eclock = 0; |
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/* initialize */ |
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comprow(-1.0/m, row0, n); |
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comprow(0.0, row1, n); |
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comprow(1.0/m, row2, n); |
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compnorms(row0, row1, row2, n); |
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/* for each row */ |
127 |
for (i = 0; i < m; i++) { |
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/* compute next row */ |
129 |
rp = row0; |
130 |
row0 = row1; |
131 |
row1 = row2; |
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row2 = rp; |
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comprow((double)(i+2)/m, row2, n); |
134 |
compnorms(row0, row1, row2, n); |
135 |
|
136 |
for (j = 0; j < n; j++) { |
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/* put polygons */ |
138 |
if ((i+j) & 1) |
139 |
putsquare(&row0[j], &row1[j], |
140 |
&row0[j+1], &row1[j+1]); |
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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: |
150 |
fprintf(stderr, "Usage: %s material name ", argv[0]); |
151 |
fprintf(stderr, "x(s,t) y(s,t) z(s,t) m n [-s][-e expr][-f file]\n"); |
152 |
quit(1); |
153 |
} |
154 |
|
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|
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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; |
165 |
register FLOAT *dp; |
166 |
|
167 |
datarec.flags = HASBORDER; /* assume border values */ |
168 |
datarec.m = m+1; |
169 |
datarec.n = n+1; |
170 |
size = datarec.m*datarec.n*pointsize; |
171 |
if (pointsize == 3) |
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datarec.flags |= TRIPLETS; |
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dp = (FLOAT *)malloc(size*sizeof(FLOAT)); |
174 |
if ((datarec.data = dp) == NULL) { |
175 |
fputs("Out of memory\n", stderr); |
176 |
exit(1); |
177 |
} |
178 |
if (!strcmp(file, "-")) { |
179 |
file = "<stdin>"; |
180 |
fp = stdin; |
181 |
} else if ((fp = fopen(file, "r")) == NULL) { |
182 |
fputs(file, stderr); |
183 |
fputs(": cannot open\n", stderr); |
184 |
exit(1); |
185 |
} |
186 |
while (size > 0 && fgetword(word, sizeof(word), fp) != NULL) { |
187 |
if (!isflt(word)) { |
188 |
fprintf(stderr, "%s: garbled data value: %s\n", |
189 |
file, word); |
190 |
exit(1); |
191 |
} |
192 |
*dp++ = atof(word); |
193 |
size--; |
194 |
} |
195 |
if (size == (m+n+1)*pointsize) { /* no border after all */ |
196 |
dp = (FLOAT *)realloc((char *)datarec.data, |
197 |
m*n*pointsize*sizeof(FLOAT)); |
198 |
if (dp != NULL) |
199 |
datarec.data = dp; |
200 |
datarec.flags &= ~HASBORDER; |
201 |
datarec.m = m; |
202 |
datarec.n = n; |
203 |
size = 0; |
204 |
} |
205 |
if (datarec.m < 2 || datarec.n < 2 || size != 0 || |
206 |
fgetword(word, sizeof(word), fp) != NULL) { |
207 |
fputs(file, stderr); |
208 |
fputs(": bad number of data points\n", stderr); |
209 |
exit(1); |
210 |
} |
211 |
fclose(fp); |
212 |
} |
213 |
|
214 |
|
215 |
double |
216 |
l_dataval(nam) /* return recorded data value */ |
217 |
char *nam; |
218 |
{ |
219 |
double u, v; |
220 |
register int i, j; |
221 |
register FLOAT *dp; |
222 |
double d00, d01, d10, d11; |
223 |
/* compute coordinates */ |
224 |
u = argument(1); v = argument(2); |
225 |
if (datarec.flags & HASBORDER) { |
226 |
i = u *= datarec.m-1; |
227 |
j = v *= datarec.n-1; |
228 |
} else { |
229 |
i = u = u*datarec.m - .5; |
230 |
j = v = v*datarec.n - .5; |
231 |
} |
232 |
if (i < 0) i = 0; |
233 |
else if (i > datarec.m-2) i = datarec.m-2; |
234 |
if (j < 0) j = 0; |
235 |
else if (j > datarec.n-2) j = datarec.n-2; |
236 |
/* compute value */ |
237 |
if (datarec.flags & TRIPLETS) { |
238 |
dp = datarec.data + 3*(j*datarec.m + i); |
239 |
if (nam == ZNAME) |
240 |
dp += 2; |
241 |
else if (nam == YNAME) |
242 |
dp++; |
243 |
d00 = dp[0]; d01 = dp[3]; |
244 |
dp += 3*datarec.m; |
245 |
d10 = dp[0]; d11 = dp[3]; |
246 |
} else { |
247 |
dp = datarec.data + j*datarec.m + i; |
248 |
d00 = dp[0]; d01 = dp[1]; |
249 |
dp += datarec.m; |
250 |
d10 = dp[0]; d11 = dp[1]; |
251 |
} |
252 |
/* bilinear interpolation */ |
253 |
return((j+1-v)*((i+1-u)*d00+(u-i)*d01)+(v-j)*((i+1-u)*d10+(u-i)*d11)); |
254 |
} |
255 |
|
256 |
|
257 |
putsquare(p0, p1, p2, p3) /* put out a square */ |
258 |
POINT *p0, *p1, *p2, *p3; |
259 |
{ |
260 |
static int nout = 0; |
261 |
FVECT norm[4]; |
262 |
int axis; |
263 |
FVECT v1, v2, vc1, vc2; |
264 |
int ok1, ok2; |
265 |
/* compute exact normals */ |
266 |
fvsum(v1, p1->p, p0->p, -1.0); |
267 |
fvsum(v2, p2->p, p0->p, -1.0); |
268 |
fcross(vc1, v1, v2); |
269 |
ok1 = normalize(vc1) != 0.0; |
270 |
fvsum(v1, p2->p, p3->p, -1.0); |
271 |
fvsum(v2, p1->p, p3->p, -1.0); |
272 |
fcross(vc2, v1, v2); |
273 |
ok2 = normalize(vc2) != 0.0; |
274 |
if (!(ok1 | ok2)) |
275 |
return; |
276 |
/* compute normal interpolation */ |
277 |
axis = norminterp(norm, p0, p1, p2, p3); |
278 |
|
279 |
/* put out quadrilateral? */ |
280 |
if (ok1 & ok2 && fdot(vc1,vc2) >= 1.0-FTINY*FTINY) { |
281 |
printf("\n%s ", modname); |
282 |
if (axis != -1) { |
283 |
printf("texfunc %s\n", texname); |
284 |
printf(tsargs); |
285 |
printf("0\n13\t%d\n", axis); |
286 |
pvect(norm[0]); |
287 |
pvect(norm[1]); |
288 |
pvect(norm[2]); |
289 |
fvsum(v1, norm[3], vc1, -0.5); |
290 |
fvsum(v1, v1, vc2, -0.5); |
291 |
pvect(v1); |
292 |
printf("\n%s ", texname); |
293 |
} |
294 |
printf("polygon %s.%d\n", surfname, ++nout); |
295 |
printf("0\n0\n12\n"); |
296 |
pvect(p0->p); |
297 |
pvect(p1->p); |
298 |
pvect(p3->p); |
299 |
pvect(p2->p); |
300 |
return; |
301 |
} |
302 |
/* put out triangles? */ |
303 |
if (ok1) { |
304 |
printf("\n%s ", modname); |
305 |
if (axis != -1) { |
306 |
printf("texfunc %s\n", texname); |
307 |
printf(tsargs); |
308 |
printf("0\n13\t%d\n", axis); |
309 |
pvect(norm[0]); |
310 |
pvect(norm[1]); |
311 |
pvect(norm[2]); |
312 |
fvsum(v1, norm[3], vc1, -1.0); |
313 |
pvect(v1); |
314 |
printf("\n%s ", texname); |
315 |
} |
316 |
printf("polygon %s.%d\n", surfname, ++nout); |
317 |
printf("0\n0\n9\n"); |
318 |
pvect(p0->p); |
319 |
pvect(p1->p); |
320 |
pvect(p2->p); |
321 |
} |
322 |
if (ok2) { |
323 |
printf("\n%s ", modname); |
324 |
if (axis != -1) { |
325 |
printf("texfunc %s\n", texname); |
326 |
printf(tsargs); |
327 |
printf("0\n13\t%d\n", axis); |
328 |
pvect(norm[0]); |
329 |
pvect(norm[1]); |
330 |
pvect(norm[2]); |
331 |
fvsum(v2, norm[3], vc2, -1.0); |
332 |
pvect(v2); |
333 |
printf("\n%s ", texname); |
334 |
} |
335 |
printf("polygon %s.%d\n", surfname, ++nout); |
336 |
printf("0\n0\n9\n"); |
337 |
pvect(p2->p); |
338 |
pvect(p1->p); |
339 |
pvect(p3->p); |
340 |
} |
341 |
} |
342 |
|
343 |
|
344 |
comprow(s, row, siz) /* compute row of values */ |
345 |
double s; |
346 |
register POINT *row; |
347 |
int siz; |
348 |
{ |
349 |
double st[2]; |
350 |
int end; |
351 |
register int i; |
352 |
|
353 |
if (smooth) { |
354 |
i = -1; /* compute one past each end */ |
355 |
end = siz+1; |
356 |
} else { |
357 |
if (s < -FTINY || s > 1.0+FTINY) |
358 |
return; |
359 |
i = 0; |
360 |
end = siz; |
361 |
} |
362 |
st[0] = s; |
363 |
while (i <= end) { |
364 |
st[1] = (double)i/siz; |
365 |
row[i].p[0] = funvalue(XNAME, 2, st); |
366 |
row[i].p[1] = funvalue(YNAME, 2, st); |
367 |
row[i].p[2] = funvalue(ZNAME, 2, st); |
368 |
i++; |
369 |
} |
370 |
} |
371 |
|
372 |
|
373 |
compnorms(r0, r1, r2, siz) /* compute row of averaged normals */ |
374 |
register POINT *r0, *r1, *r2; |
375 |
int siz; |
376 |
{ |
377 |
FVECT v1, v2; |
378 |
|
379 |
if (!smooth) /* not needed if no smoothing */ |
380 |
return; |
381 |
/* compute middle points */ |
382 |
while (siz-- >= 0) { |
383 |
fvsum(v1, r2[0].p, r0[0].p, -1.0); |
384 |
fvsum(v2, r1[1].p, r1[-1].p, -1.0); |
385 |
fcross(r1[0].n, v1, v2); |
386 |
normalize(r1[0].n); |
387 |
r0++; r1++; r2++; |
388 |
} |
389 |
} |
390 |
|
391 |
|
392 |
int |
393 |
norminterp(resmat, p0, p1, p2, p3) /* compute normal interpolation */ |
394 |
register FVECT resmat[4]; |
395 |
POINT *p0, *p1, *p2, *p3; |
396 |
{ |
397 |
#define u ((ax+1)%3) |
398 |
#define v ((ax+2)%3) |
399 |
|
400 |
register int ax; |
401 |
MAT4 eqnmat; |
402 |
FVECT v1; |
403 |
register int i, j; |
404 |
|
405 |
if (!smooth) /* no interpolation if no smoothing */ |
406 |
return(-1); |
407 |
/* find dominant axis */ |
408 |
VCOPY(v1, p0->n); |
409 |
fvsum(v1, v1, p1->n, 1.0); |
410 |
fvsum(v1, v1, p2->n, 1.0); |
411 |
fvsum(v1, v1, p3->n, 1.0); |
412 |
ax = ABS(v1[0]) > ABS(v1[1]) ? 0 : 1; |
413 |
ax = ABS(v1[ax]) > ABS(v1[2]) ? ax : 2; |
414 |
/* assign equation matrix */ |
415 |
eqnmat[0][0] = p0->p[u]*p0->p[v]; |
416 |
eqnmat[0][1] = p0->p[u]; |
417 |
eqnmat[0][2] = p0->p[v]; |
418 |
eqnmat[0][3] = 1.0; |
419 |
eqnmat[1][0] = p1->p[u]*p1->p[v]; |
420 |
eqnmat[1][1] = p1->p[u]; |
421 |
eqnmat[1][2] = p1->p[v]; |
422 |
eqnmat[1][3] = 1.0; |
423 |
eqnmat[2][0] = p2->p[u]*p2->p[v]; |
424 |
eqnmat[2][1] = p2->p[u]; |
425 |
eqnmat[2][2] = p2->p[v]; |
426 |
eqnmat[2][3] = 1.0; |
427 |
eqnmat[3][0] = p3->p[u]*p3->p[v]; |
428 |
eqnmat[3][1] = p3->p[u]; |
429 |
eqnmat[3][2] = p3->p[v]; |
430 |
eqnmat[3][3] = 1.0; |
431 |
/* invert matrix (solve system) */ |
432 |
if (!invmat(eqnmat, eqnmat)) |
433 |
return(-1); /* no solution */ |
434 |
/* compute result matrix */ |
435 |
for (j = 0; j < 4; j++) |
436 |
for (i = 0; i < 3; i++) |
437 |
resmat[j][i] = eqnmat[j][0]*p0->n[i] + |
438 |
eqnmat[j][1]*p1->n[i] + |
439 |
eqnmat[j][2]*p2->n[i] + |
440 |
eqnmat[j][3]*p3->n[i]; |
441 |
return(ax); |
442 |
|
443 |
#undef u |
444 |
#undef v |
445 |
} |
446 |
|
447 |
|
448 |
/* |
449 |
* invmat - computes the inverse of mat into inverse. Returns 1 |
450 |
* if there exists an inverse, 0 otherwise. It uses Gaussian Elimination |
451 |
* method. |
452 |
*/ |
453 |
|
454 |
invmat(inverse,mat) |
455 |
MAT4 inverse, mat; |
456 |
{ |
457 |
#define SWAP(a,b,t) (t=a,a=b,b=t) |
458 |
|
459 |
MAT4 m4tmp; |
460 |
register int i,j,k; |
461 |
register double temp; |
462 |
|
463 |
copymat4(m4tmp, mat); |
464 |
/* set inverse to identity */ |
465 |
for (i = 0; i < 4; i++) |
466 |
for (j = 0; j < 4; j++) |
467 |
inverse[i][j] = i==j ? 1.0 : 0.0; |
468 |
|
469 |
for(i = 0; i < 4; i++) { |
470 |
/* Look for row with largest pivot and swap rows */ |
471 |
temp = FTINY; j = -1; |
472 |
for(k = i; k < 4; k++) |
473 |
if(ABS(m4tmp[k][i]) > temp) { |
474 |
temp = ABS(m4tmp[k][i]); |
475 |
j = k; |
476 |
} |
477 |
if(j == -1) /* No replacing row -> no inverse */ |
478 |
return(0); |
479 |
if (j != i) |
480 |
for(k = 0; k < 4; k++) { |
481 |
SWAP(m4tmp[i][k],m4tmp[j][k],temp); |
482 |
SWAP(inverse[i][k],inverse[j][k],temp); |
483 |
} |
484 |
|
485 |
temp = m4tmp[i][i]; |
486 |
for(k = 0; k < 4; k++) { |
487 |
m4tmp[i][k] /= temp; |
488 |
inverse[i][k] /= temp; |
489 |
} |
490 |
for(j = 0; j < 4; j++) { |
491 |
if(j != i) { |
492 |
temp = m4tmp[j][i]; |
493 |
for(k = 0; k < 4; k++) { |
494 |
m4tmp[j][k] -= m4tmp[i][k]*temp; |
495 |
inverse[j][k] -= inverse[i][k]*temp; |
496 |
} |
497 |
} |
498 |
} |
499 |
} |
500 |
return(1); |
501 |
|
502 |
#undef SWAP |
503 |
} |
504 |
|
505 |
|
506 |
eputs(msg) |
507 |
char *msg; |
508 |
{ |
509 |
fputs(msg, stderr); |
510 |
} |
511 |
|
512 |
|
513 |
wputs(msg) |
514 |
char *msg; |
515 |
{ |
516 |
eputs(msg); |
517 |
} |
518 |
|
519 |
|
520 |
quit(code) |
521 |
int code; |
522 |
{ |
523 |
exit(code); |
524 |
} |
525 |
|
526 |
|
527 |
printhead(ac, av) /* print command header */ |
528 |
register int ac; |
529 |
register char **av; |
530 |
{ |
531 |
putchar('#'); |
532 |
while (ac--) { |
533 |
putchar(' '); |
534 |
fputs(*av++, stdout); |
535 |
} |
536 |
putchar('\n'); |
537 |
} |
538 |
|
539 |
|
540 |
double |
541 |
l_hermite() |
542 |
{ |
543 |
double t; |
544 |
|
545 |
t = argument(5); |
546 |
return( argument(1)*((2.0*t-3.0)*t*t+1.0) + |
547 |
argument(2)*(-2.0*t+3.0)*t*t + |
548 |
argument(3)*((t-2.0)*t+1.0)*t + |
549 |
argument(4)*(t-1.0)*t*t ); |
550 |
} |
551 |
|
552 |
|
553 |
double |
554 |
l_bezier() |
555 |
{ |
556 |
double t; |
557 |
|
558 |
t = argument(5); |
559 |
return( argument(1) * (1.+t*(-3.+t*(3.-t))) + |
560 |
argument(2) * 3.*t*(1.+t*(-2.+t)) + |
561 |
argument(3) * 3.*t*t*(1.-t) + |
562 |
argument(4) * t*t*t ); |
563 |
} |
564 |
|
565 |
|
566 |
double |
567 |
l_bspline() |
568 |
{ |
569 |
double t; |
570 |
|
571 |
t = argument(5); |
572 |
return( argument(1) * (1./6.+t*(-1./2.+t*(1./2.-1./6.*t))) + |
573 |
argument(2) * (2./3.+t*t*(-1.+1./2.*t)) + |
574 |
argument(3) * (1./6.+t*(1./2.+t*(1./2.-1./2.*t))) + |
575 |
argument(4) * (1./6.*t*t*t) ); |
576 |
} |