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root/radiance/ray/src/common/image.c
Revision: 2.13
Committed: Tue Dec 9 16:41:03 1997 UTC (26 years, 4 months ago) by gregl
Content type: text/plain
Branch: MAIN
Changes since 2.12: +8 -9 lines
Log Message:
fixed computation for VT_CYL in viewloc() -- at last!

File Contents

# Content
1 /* Copyright (c) 1996 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * image.c - routines for image generation.
9 */
10
11 #include "standard.h"
12
13 #include "view.h"
14
15 #include "resolu.h"
16
17 #include "paths.h"
18
19 #define FEQ(x,y) (fabs((x)-(y)) <= FTINY)
20 #define VEQ(v,w) (FEQ((v)[0],(w)[0]) && FEQ((v)[1],(w)[1]) \
21 && FEQ((v)[2],(w)[2]))
22
23 VIEW stdview = STDVIEW; /* default view parameters */
24
25
26 char *
27 setview(v) /* set hvec and vvec, return message on error */
28 register VIEW *v;
29 {
30 static char ill_horiz[] = "illegal horizontal view size";
31 static char ill_vert[] = "illegal vertical view size";
32
33 if (v->vfore < -FTINY || v->vaft < -FTINY ||
34 (v->vaft > FTINY && v->vaft <= v->vfore))
35 return("illegal fore/aft clipping plane");
36
37 if (normalize(v->vdir) == 0.0) /* normalize direction */
38 return("zero view direction");
39
40 if (normalize(v->vup) == 0.0) /* normalize view up */
41 return("zero view up vector");
42
43 fcross(v->hvec, v->vdir, v->vup); /* compute horiz dir */
44
45 if (normalize(v->hvec) == 0.0)
46 return("view up parallel to view direction");
47
48 fcross(v->vvec, v->hvec, v->vdir); /* compute vert dir */
49
50 if (v->horiz <= FTINY)
51 return(ill_horiz);
52 if (v->vert <= FTINY)
53 return(ill_vert);
54
55 switch (v->type) {
56 case VT_PAR: /* parallel view */
57 v->hn2 = v->horiz;
58 v->vn2 = v->vert;
59 break;
60 case VT_PER: /* perspective view */
61 if (v->horiz >= 180.0-FTINY)
62 return(ill_horiz);
63 if (v->vert >= 180.0-FTINY)
64 return(ill_vert);
65 v->hn2 = 2.0 * tan(v->horiz*(PI/180.0/2.0));
66 v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
67 break;
68 case VT_CYL: /* cylindrical panorama */
69 if (v->horiz > 360.0+FTINY)
70 return(ill_horiz);
71 if (v->vert >= 180.0-FTINY)
72 return(ill_vert);
73 v->hn2 = v->horiz * (PI/180.0);
74 v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
75 break;
76 case VT_ANG: /* angular fisheye */
77 if (v->horiz > 360.0+FTINY)
78 return(ill_horiz);
79 if (v->vert > 360.0+FTINY)
80 return(ill_vert);
81 v->hn2 = v->horiz * (PI/180.0);
82 v->vn2 = v->vert * (PI/180.0);
83 break;
84 case VT_HEM: /* hemispherical fisheye */
85 if (v->horiz > 180.0+FTINY)
86 return(ill_horiz);
87 if (v->vert > 180.0+FTINY)
88 return(ill_vert);
89 v->hn2 = 2.0 * sin(v->horiz*(PI/180.0/2.0));
90 v->vn2 = 2.0 * sin(v->vert*(PI/180.0/2.0));
91 break;
92 default:
93 return("unknown view type");
94 }
95 if (v->type != VT_ANG) {
96 if (v->type != VT_CYL) {
97 v->hvec[0] *= v->hn2;
98 v->hvec[1] *= v->hn2;
99 v->hvec[2] *= v->hn2;
100 }
101 v->vvec[0] *= v->vn2;
102 v->vvec[1] *= v->vn2;
103 v->vvec[2] *= v->vn2;
104 }
105 v->hn2 *= v->hn2;
106 v->vn2 *= v->vn2;
107
108 return(NULL);
109 }
110
111
112 normaspect(va, ap, xp, yp) /* fix pixel aspect or resolution */
113 double va; /* view aspect ratio */
114 double *ap; /* pixel aspect in (or out if 0) */
115 int *xp, *yp; /* x and y resolution in (or out if *ap!=0) */
116 {
117 if (*ap <= FTINY)
118 *ap = va * *xp / *yp; /* compute pixel aspect */
119 else if (va * *xp > *ap * *yp)
120 *xp = *yp / va * *ap + .5; /* reduce x resolution */
121 else
122 *yp = *xp * va / *ap + .5; /* reduce y resolution */
123 }
124
125
126 double
127 viewray(orig, direc, v, x, y) /* compute ray origin and direction */
128 FVECT orig, direc;
129 register VIEW *v;
130 double x, y;
131 {
132 double d, z;
133
134 x += v->hoff - 0.5;
135 y += v->voff - 0.5;
136
137 switch(v->type) {
138 case VT_PAR: /* parallel view */
139 orig[0] = v->vp[0] + v->vfore*v->vdir[0]
140 + x*v->hvec[0] + y*v->vvec[0];
141 orig[1] = v->vp[1] + v->vfore*v->vdir[1]
142 + x*v->hvec[1] + y*v->vvec[1];
143 orig[2] = v->vp[2] + v->vfore*v->vdir[2]
144 + x*v->hvec[2] + y*v->vvec[2];
145 VCOPY(direc, v->vdir);
146 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
147 case VT_PER: /* perspective view */
148 direc[0] = v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
149 direc[1] = v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
150 direc[2] = v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
151 orig[0] = v->vp[0] + v->vfore*direc[0];
152 orig[1] = v->vp[1] + v->vfore*direc[1];
153 orig[2] = v->vp[2] + v->vfore*direc[2];
154 d = normalize(direc);
155 return(v->vaft > FTINY ? (v->vaft - v->vfore)*d : 0.0);
156 case VT_HEM: /* hemispherical fisheye */
157 z = 1.0 - x*x*v->hn2 - y*y*v->vn2;
158 if (z < 0.0)
159 return(-1.0);
160 z = sqrt(z);
161 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
162 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
163 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
164 orig[0] = v->vp[0] + v->vfore*direc[0];
165 orig[1] = v->vp[1] + v->vfore*direc[1];
166 orig[2] = v->vp[2] + v->vfore*direc[2];
167 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
168 case VT_CYL: /* cylindrical panorama */
169 d = x * v->horiz * (PI/180.0);
170 z = cos(d);
171 x = sin(d);
172 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
173 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
174 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
175 orig[0] = v->vp[0] + v->vfore*direc[0];
176 orig[1] = v->vp[1] + v->vfore*direc[1];
177 orig[2] = v->vp[2] + v->vfore*direc[2];
178 d = normalize(direc);
179 return(v->vaft > FTINY ? (v->vaft - v->vfore)*d : 0.0);
180 case VT_ANG: /* angular fisheye */
181 x *= v->horiz/180.0;
182 y *= v->vert/180.0;
183 d = x*x + y*y;
184 if (d > 1.0)
185 return(-1.0);
186 d = sqrt(d);
187 z = cos(PI*d);
188 d = d <= FTINY ? PI : sqrt(1 - z*z)/d;
189 x *= d;
190 y *= d;
191 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
192 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
193 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
194 orig[0] = v->vp[0] + v->vfore*direc[0];
195 orig[1] = v->vp[1] + v->vfore*direc[1];
196 orig[2] = v->vp[2] + v->vfore*direc[2];
197 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
198 }
199 return(-1.0);
200 }
201
202
203 viewloc(ip, v, p) /* find image location for point */
204 FVECT ip;
205 register VIEW *v;
206 FVECT p;
207 {
208 double d, d2;
209 FVECT disp;
210
211 disp[0] = p[0] - v->vp[0];
212 disp[1] = p[1] - v->vp[1];
213 disp[2] = p[2] - v->vp[2];
214
215 switch (v->type) {
216 case VT_PAR: /* parallel view */
217 ip[2] = DOT(disp,v->vdir) - v->vfore;
218 break;
219 case VT_PER: /* perspective view */
220 d = DOT(disp,v->vdir);
221 ip[2] = VLEN(disp);
222 if (d < 0.0) { /* fold pyramid */
223 ip[2] = -ip[2];
224 d = -d;
225 }
226 if (d > FTINY) {
227 d = 1.0/d;
228 disp[0] *= d;
229 disp[1] *= d;
230 disp[2] *= d;
231 }
232 ip[2] *= (1.0 - v->vfore*d);
233 break;
234 case VT_HEM: /* hemispherical fisheye */
235 d = normalize(disp);
236 if (DOT(disp,v->vdir) < 0.0)
237 ip[2] = -d;
238 else
239 ip[2] = d;
240 ip[2] -= v->vfore;
241 break;
242 case VT_CYL: /* cylindrical panorama */
243 d = DOT(disp,v->hvec);
244 d2 = DOT(disp,v->vdir);
245 ip[0] = 180.0/PI * atan2(d,d2) / v->horiz + 0.5 - v->hoff;
246 d = 1.0/sqrt(d*d + d2*d2);
247 ip[1] = DOT(disp,v->vvec)*d/v->vn2 + 0.5 - v->voff;
248 ip[2] = VLEN(disp);
249 if (v->vfore > FTINY)
250 ip[2] *= (1.0 - v->vfore*d);
251 return;
252 case VT_ANG: /* angular fisheye */
253 ip[0] = 0.5 - v->hoff;
254 ip[1] = 0.5 - v->voff;
255 ip[2] = normalize(disp) - v->vfore;
256 d = DOT(disp,v->vdir);
257 if (d >= 1.0-FTINY)
258 return;
259 if (d <= -(1.0-FTINY)) {
260 ip[0] += 180.0/v->horiz;
261 return;
262 }
263 d = acos(d)/PI / sqrt(1.0 - d*d);
264 ip[0] += DOT(disp,v->hvec)*d*180.0/v->horiz;
265 ip[1] += DOT(disp,v->vvec)*d*180.0/v->vert;
266 return;
267 }
268 ip[0] = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
269 ip[1] = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
270 }
271
272
273 pix2loc(loc, rp, px, py) /* compute image location from pixel pos. */
274 FLOAT loc[2];
275 register RESOLU *rp;
276 int px, py;
277 {
278 register int x, y;
279
280 if (rp->or & YMAJOR) {
281 x = px;
282 y = py;
283 } else {
284 x = py;
285 y = px;
286 }
287 if (rp->or & XDECR)
288 x = rp->xr-1 - x;
289 if (rp->or & YDECR)
290 y = rp->yr-1 - y;
291 loc[0] = (x+.5)/rp->xr;
292 loc[1] = (y+.5)/rp->yr;
293 }
294
295
296 loc2pix(pp, rp, lx, ly) /* compute pixel pos. from image location */
297 int pp[2];
298 register RESOLU *rp;
299 double lx, ly;
300 {
301 register int x, y;
302
303 x = lx * rp->xr;
304 y = ly * rp->yr;
305 if (rp->or & XDECR)
306 x = rp->xr-1 - x;
307 if (rp->or & YDECR)
308 y = rp->yr-1 - y;
309 if (rp->or & YMAJOR) {
310 pp[0] = x;
311 pp[1] = y;
312 } else {
313 pp[0] = y;
314 pp[1] = x;
315 }
316 }
317
318
319 int
320 getviewopt(v, ac, av) /* process view argument */
321 register VIEW *v;
322 int ac;
323 register char *av[];
324 {
325 #define check(c,l) if ((av[0][c]&&av[0][c]!=' ') || \
326 badarg(ac-1,av+1,l)) return(-1)
327
328 if (ac <= 0 || av[0][0] != '-' || av[0][1] != 'v')
329 return(-1);
330 switch (av[0][2]) {
331 case 't': /* type */
332 if (!av[0][3] || av[0][3]==' ')
333 return(-1);
334 check(4,"");
335 v->type = av[0][3];
336 return(0);
337 case 'p': /* point */
338 check(3,"fff");
339 v->vp[0] = atof(av[1]);
340 v->vp[1] = atof(av[2]);
341 v->vp[2] = atof(av[3]);
342 return(3);
343 case 'd': /* direction */
344 check(3,"fff");
345 v->vdir[0] = atof(av[1]);
346 v->vdir[1] = atof(av[2]);
347 v->vdir[2] = atof(av[3]);
348 return(3);
349 case 'u': /* up */
350 check(3,"fff");
351 v->vup[0] = atof(av[1]);
352 v->vup[1] = atof(av[2]);
353 v->vup[2] = atof(av[3]);
354 return(3);
355 case 'h': /* horizontal size */
356 check(3,"f");
357 v->horiz = atof(av[1]);
358 return(1);
359 case 'v': /* vertical size */
360 check(3,"f");
361 v->vert = atof(av[1]);
362 return(1);
363 case 'o': /* fore clipping plane */
364 check(3,"f");
365 v->vfore = atof(av[1]);
366 return(1);
367 case 'a': /* aft clipping plane */
368 check(3,"f");
369 v->vaft = atof(av[1]);
370 return(1);
371 case 's': /* shift */
372 check(3,"f");
373 v->hoff = atof(av[1]);
374 return(1);
375 case 'l': /* lift */
376 check(3,"f");
377 v->voff = atof(av[1]);
378 return(1);
379 default:
380 return(-1);
381 }
382 #undef check
383 }
384
385
386 int
387 sscanview(vp, s) /* get view parameters from string */
388 VIEW *vp;
389 register char *s;
390 {
391 int ac;
392 char *av[4];
393 int na;
394 int nvopts = 0;
395
396 if (*s != '-')
397 s = sskip2(s,1);
398 while (*s) {
399 ac = 0;
400 do {
401 av[ac++] = s;
402 while (*s && *s != ' ')
403 s++;
404 while (*s == ' ')
405 s++;
406 } while (*s && ac < 4);
407 if ((na = getviewopt(vp, ac, av)) >= 0) {
408 if (na+1 < ac)
409 s = av[na+1];
410 nvopts++;
411 } else if (ac > 1)
412 s = av[1];
413 }
414 return(nvopts);
415 }
416
417
418 fprintview(vp, fp) /* write out view parameters */
419 register VIEW *vp;
420 FILE *fp;
421 {
422 fprintf(fp, " -vt%c", vp->type);
423 fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]);
424 fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0], vp->vdir[1], vp->vdir[2]);
425 fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]);
426 fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert);
427 fprintf(fp, " -vo %.6g -va %.6g", vp->vfore, vp->vaft);
428 fprintf(fp, " -vs %.6g -vl %.6g", vp->hoff, vp->voff);
429 }
430
431
432 char *
433 viewopt(vp) /* translate to minimal view string */
434 register VIEW *vp;
435 {
436 static char vwstr[128];
437 register char *cp = vwstr;
438
439 if (vp->type != stdview.type) {
440 sprintf(cp, " -vt%c", vp->type);
441 cp += strlen(cp);
442 }
443 if (!VEQ(vp->vp,stdview.vp)) {
444 sprintf(cp, " -vp %.6g %.6g %.6g",
445 vp->vp[0], vp->vp[1], vp->vp[2]);
446 cp += strlen(cp);
447 }
448 if (!VEQ(vp->vdir,stdview.vdir)) {
449 sprintf(cp, " -vd %.6g %.6g %.6g",
450 vp->vdir[0], vp->vdir[1], vp->vdir[2]);
451 cp += strlen(cp);
452 }
453 if (!VEQ(vp->vup,stdview.vup)) {
454 sprintf(cp, " -vu %.6g %.6g %.6g",
455 vp->vup[0], vp->vup[1], vp->vup[2]);
456 cp += strlen(cp);
457 }
458 if (!FEQ(vp->horiz,stdview.horiz)) {
459 sprintf(cp, " -vh %.6g", vp->horiz);
460 cp += strlen(cp);
461 }
462 if (!FEQ(vp->vert,stdview.vert)) {
463 sprintf(cp, " -vv %.6g", vp->vert);
464 cp += strlen(cp);
465 }
466 if (!FEQ(vp->vfore,stdview.vfore)) {
467 sprintf(cp, " -vo %.6g", vp->vfore);
468 cp += strlen(cp);
469 }
470 if (!FEQ(vp->vaft,stdview.vaft)) {
471 sprintf(cp, " -va %.6g", vp->vaft);
472 cp += strlen(cp);
473 }
474 if (!FEQ(vp->hoff,stdview.hoff)) {
475 sprintf(cp, " -vs %.6g", vp->hoff);
476 cp += strlen(cp);
477 }
478 if (!FEQ(vp->voff,stdview.voff)) {
479 sprintf(cp, " -vl %.6g", vp->voff);
480 cp += strlen(cp);
481 }
482 return(vwstr);
483 }
484
485
486 int
487 isview(s) /* is this a view string? */
488 char *s;
489 {
490 static char *altname[]={NULL,VIEWSTR,"rpict","rview","pinterp",NULL};
491 extern char *progname;
492 register char *cp;
493 register char **an;
494 /* add program name to list */
495 if (altname[0] == NULL) {
496 for (cp = progname; *cp; cp++)
497 ;
498 while (cp > progname && !ISDIRSEP(cp[-1]))
499 cp--;
500 altname[0] = cp;
501 }
502 /* skip leading path */
503 cp = s;
504 while (*cp && *cp != ' ')
505 cp++;
506 while (cp > s && !ISDIRSEP(cp[-1]))
507 cp--;
508 for (an = altname; *an != NULL; an++)
509 if (!strncmp(*an, cp, strlen(*an)))
510 return(1);
511 return(0);
512 }
513
514
515 struct myview {
516 VIEW *hv;
517 int ok;
518 };
519
520
521 static
522 gethview(s, v) /* get view from header */
523 char *s;
524 register struct myview *v;
525 {
526 if (isview(s) && sscanview(v->hv, s) > 0)
527 v->ok++;
528 }
529
530
531 int
532 viewfile(fname, vp, rp) /* get view from file */
533 char *fname;
534 VIEW *vp;
535 RESOLU *rp;
536 {
537 struct myview mvs;
538 FILE *fp;
539
540 if ((fp = fopen(fname, "r")) == NULL)
541 return(-1);
542
543 mvs.hv = vp;
544 mvs.ok = 0;
545
546 getheader(fp, gethview, &mvs);
547
548 if (rp != NULL && !fgetsresolu(rp, fp))
549 mvs.ok = 0;
550
551 fclose(fp);
552
553 return(mvs.ok);
554 }