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root/radiance/ray/src/common/image.c
Revision: 2.46
Committed: Fri Apr 27 05:00:29 2018 UTC (6 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.45: +18 -9 lines
Log Message:
Improved viewloc() return values to include aft clipping test

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: image.c,v 2.45 2018/02/06 02:08:12 greg Exp $";
3 #endif
4 /*
5 * image.c - routines for image generation.
6 *
7 * External symbols declared in view.h
8 */
9
10 #include "copyright.h"
11
12 #include <ctype.h>
13 #include "rtio.h"
14 #include "rtmath.h"
15 #include "paths.h"
16 #include "view.h"
17
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 static gethfunc gethview;
26
27
28 char *
29 setview( /* set hvec and vvec, return message on error */
30 VIEW *v
31 )
32 {
33 static char ill_horiz[] = "illegal horizontal view size";
34 static char ill_vert[] = "illegal vertical view size";
35
36 if ((v->vfore < -FTINY) | (v->vaft < -FTINY) ||
37 (v->vaft > FTINY) & (v->vaft <= v->vfore))
38 return("illegal fore/aft clipping plane");
39
40 if (v->vdist <= FTINY)
41 return("illegal view distance");
42 v->vdist *= normalize(v->vdir); /* normalize direction */
43 if (v->vdist == 0.0)
44 return("zero view direction");
45
46 if (normalize(v->vup) == 0.0) /* normalize view up */
47 return("zero view up vector");
48
49 fcross(v->hvec, v->vdir, v->vup); /* compute horiz dir */
50
51 if (normalize(v->hvec) == 0.0)
52 return("view up parallel to view direction");
53
54 fcross(v->vvec, v->hvec, v->vdir); /* compute vert dir */
55
56 if (v->horiz <= FTINY)
57 return(ill_horiz);
58 if (v->vert <= FTINY)
59 return(ill_vert);
60
61 switch (v->type) {
62 case VT_PAR: /* parallel view */
63 v->hn2 = v->horiz;
64 v->vn2 = v->vert;
65 break;
66 case VT_PER: /* perspective view */
67 if (v->horiz >= 180.0-FTINY)
68 return(ill_horiz);
69 if (v->vert >= 180.0-FTINY)
70 return(ill_vert);
71 v->hn2 = 2.0 * tan(v->horiz*(PI/180.0/2.0));
72 v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
73 break;
74 case VT_CYL: /* cylindrical panorama */
75 if (v->horiz > 360.0+FTINY)
76 return(ill_horiz);
77 if (v->vert >= 180.0-FTINY)
78 return(ill_vert);
79 v->hn2 = v->horiz * (PI/180.0);
80 v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
81 break;
82 case VT_ANG: /* angular fisheye */
83 if (v->horiz > 360.0+FTINY)
84 return(ill_horiz);
85 if (v->vert > 360.0+FTINY)
86 return(ill_vert);
87 v->hn2 = v->horiz * (PI/180.0);
88 v->vn2 = v->vert * (PI/180.0);
89 break;
90 case VT_HEM: /* hemispherical fisheye */
91 if (v->horiz > 180.0+FTINY)
92 return(ill_horiz);
93 if (v->vert > 180.0+FTINY)
94 return(ill_vert);
95 v->hn2 = 2.0 * sin(v->horiz*(PI/180.0/2.0));
96 v->vn2 = 2.0 * sin(v->vert*(PI/180.0/2.0));
97 break;
98 case VT_PLS: /* planispheric fisheye */
99 if (v->horiz >= 360.0-FTINY)
100 return(ill_horiz);
101 if (v->vert >= 360.0-FTINY)
102 return(ill_vert);
103 v->hn2 = 2.*sin(v->horiz*(PI/180.0/2.0)) /
104 (1.0 + cos(v->horiz*(PI/180.0/2.0)));
105 v->vn2 = 2.*sin(v->vert*(PI/180.0/2.0)) /
106 (1.0 + cos(v->vert*(PI/180.0/2.0)));
107 break;
108 default:
109 return("unknown view type");
110 }
111 if (v->type != VT_ANG && v->type != VT_PLS) {
112 if (v->type != VT_CYL) {
113 v->hvec[0] *= v->hn2;
114 v->hvec[1] *= v->hn2;
115 v->hvec[2] *= v->hn2;
116 }
117 v->vvec[0] *= v->vn2;
118 v->vvec[1] *= v->vn2;
119 v->vvec[2] *= v->vn2;
120 }
121 v->hn2 *= v->hn2;
122 v->vn2 *= v->vn2;
123
124 return(NULL);
125 }
126
127
128 void
129 normaspect( /* fix pixel aspect or resolution */
130 double va, /* view aspect ratio */
131 double *ap, /* pixel aspect in (or out if 0) */
132 int *xp,
133 int *yp /* x and y resolution in (or out if *ap!=0) */
134 )
135 {
136 if (*ap <= FTINY)
137 *ap = va * *xp / *yp; /* compute pixel aspect */
138 else if (va * *xp > *ap * *yp)
139 *xp = *yp / va * *ap + .5; /* reduce x resolution */
140 else
141 *yp = *xp * va / *ap + .5; /* reduce y resolution */
142 }
143
144
145 double
146 viewray( /* compute ray origin and direction */
147 FVECT orig,
148 FVECT direc,
149 VIEW *v,
150 double x,
151 double y
152 )
153 {
154 double d, z;
155
156 x += v->hoff - 0.5;
157 y += v->voff - 0.5;
158
159 switch(v->type) {
160 case VT_PAR: /* parallel view */
161 orig[0] = v->vp[0] + v->vfore*v->vdir[0]
162 + x*v->hvec[0] + y*v->vvec[0];
163 orig[1] = v->vp[1] + v->vfore*v->vdir[1]
164 + x*v->hvec[1] + y*v->vvec[1];
165 orig[2] = v->vp[2] + v->vfore*v->vdir[2]
166 + x*v->hvec[2] + y*v->vvec[2];
167 VCOPY(direc, v->vdir);
168 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
169 case VT_PER: /* perspective view */
170 direc[0] = v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
171 direc[1] = v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
172 direc[2] = v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
173 VSUM(orig, v->vp, direc, v->vfore);
174 d = normalize(direc);
175 return(v->vaft > FTINY ? (v->vaft - v->vfore)*d : 0.0);
176 case VT_HEM: /* hemispherical fisheye */
177 z = 1.0 - x*x*v->hn2 - y*y*v->vn2;
178 if (z < 0.0)
179 return(-1.0);
180 z = sqrt(z);
181 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
182 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
183 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
184 VSUM(orig, v->vp, direc, v->vfore);
185 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
186 case VT_CYL: /* cylindrical panorama */
187 d = x * v->horiz * (PI/180.0);
188 z = cos(d);
189 x = sin(d);
190 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
191 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
192 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
193 VSUM(orig, v->vp, direc, v->vfore);
194 d = normalize(direc);
195 return(v->vaft > FTINY ? (v->vaft - v->vfore)*d : 0.0);
196 case VT_ANG: /* angular fisheye */
197 x *= (1.0/180.0)*v->horiz;
198 y *= (1.0/180.0)*v->vert;
199 d = x*x + y*y;
200 if (d > 1.0)
201 return(-1.0);
202 d = sqrt(d);
203 z = cos(PI*d);
204 d = d <= FTINY ? PI : sqrt(1.0 - z*z)/d;
205 x *= d;
206 y *= d;
207 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
208 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
209 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
210 VSUM(orig, v->vp, direc, v->vfore);
211 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
212 case VT_PLS: /* planispheric fisheye */
213 x *= sqrt(v->hn2);
214 y *= sqrt(v->vn2);
215 d = x*x + y*y;
216 z = (1. - d)/(1. + d);
217 x *= (1. + z);
218 y *= (1. + z);
219 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
220 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
221 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
222 VSUM(orig, v->vp, direc, v->vfore);
223 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
224 }
225 return(-1.0);
226 }
227
228
229 int
230 viewloc( /* find image location for point */
231 FVECT ip,
232 VIEW *v,
233 FVECT p
234 ) /* Use VL_* flags to interpret return value */
235 {
236 int rflags = VL_GOOD;
237 double d, d2;
238 FVECT disp;
239
240 VSUB(disp, p, v->vp);
241
242 switch (v->type) {
243 case VT_PAR: /* parallel view */
244 ip[2] = DOT(disp,v->vdir) - v->vfore;
245 break;
246 case VT_PER: /* perspective view */
247 d = DOT(disp,v->vdir);
248 if ((v->vaft > FTINY) & (d > v->vaft))
249 rflags |= VL_BEYOND;
250 ip[2] = VLEN(disp);
251 if (d < -FTINY) { /* fold pyramid */
252 ip[2] = -ip[2];
253 d = -d;
254 } else if (d <= FTINY)
255 return(VL_BAD); /* at infinite edge */
256 d = 1.0/d;
257 disp[0] *= d;
258 disp[1] *= d;
259 disp[2] *= d;
260 if (ip[2] < 0.0) d = -d;
261 ip[2] *= (1.0 - v->vfore*d);
262 break;
263 case VT_HEM: /* hemispherical fisheye */
264 d = normalize(disp);
265 if (DOT(disp,v->vdir) < 0.0)
266 ip[2] = -d;
267 else
268 ip[2] = d;
269 ip[2] -= v->vfore;
270 break;
271 case VT_CYL: /* cylindrical panorama */
272 d = DOT(disp,v->hvec);
273 d2 = DOT(disp,v->vdir);
274 ip[0] = 180.0/PI * atan2(d,d2) / v->horiz + 0.5 - v->hoff;
275 d = d*d + d2*d2;
276 if (d <= FTINY*FTINY)
277 return(VL_BAD); /* at pole */
278 if ((v->vaft > FTINY) & (d > v->vaft*v->vaft))
279 rflags |= VL_BEYOND;
280 d = 1.0/sqrt(d);
281 ip[1] = DOT(disp,v->vvec)*d/v->vn2 + 0.5 - v->voff;
282 ip[2] = VLEN(disp);
283 ip[2] *= (1.0 - v->vfore*d);
284 goto gotall;
285 case VT_ANG: /* angular fisheye */
286 ip[0] = 0.5 - v->hoff;
287 ip[1] = 0.5 - v->voff;
288 ip[2] = normalize(disp) - v->vfore;
289 d = DOT(disp,v->vdir);
290 if (d >= 1.0-FTINY)
291 goto gotall;
292 if (d <= -(1.0-FTINY)) {
293 ip[0] += 180.0/v->horiz;
294 goto gotall;
295 }
296 d = (180.0/PI)*acos(d) / sqrt(1.0 - d*d);
297 ip[0] += DOT(disp,v->hvec)*d/v->horiz;
298 ip[1] += DOT(disp,v->vvec)*d/v->vert;
299 goto gotall;
300 case VT_PLS: /* planispheric fisheye */
301 ip[0] = 0.5 - v->hoff;
302 ip[1] = 0.5 - v->voff;
303 ip[2] = normalize(disp) - v->vfore;
304 d = DOT(disp,v->vdir);
305 if (d >= 1.0-FTINY)
306 goto gotall;
307 if (d <= -(1.0-FTINY))
308 return(VL_BAD);
309 ip[0] += DOT(disp,v->hvec)/((1. + d)*sqrt(v->hn2));
310 ip[1] += DOT(disp,v->vvec)/((1. + d)*sqrt(v->vn2));
311 goto gotall;
312 default:
313 return(VL_BAD);
314 }
315 ip[0] = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
316 ip[1] = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
317 gotall: /* add appropriate return flags */
318 rflags |= VL_BEHIND*(ip[2] <= 0.0);
319 rflags |= VL_OUTSIDE*((0.0 >= ip[0]) | (ip[0] >= 1.0) |
320 (0.0 >= ip[1]) | (ip[1] >= 1.0));
321 if ((v->vaft > FTINY) & !(rflags & (VL_BEHIND|VL_BEYOND)))
322 rflags |= VL_BEYOND*(ip[2] > v->vaft - v->vfore);
323 return(rflags);
324 }
325
326
327 void
328 pix2loc( /* compute image location from pixel pos. */
329 RREAL loc[2],
330 RESOLU *rp,
331 int px,
332 int py
333 )
334 {
335 int x, y;
336
337 if (rp->rt & YMAJOR) {
338 x = px;
339 y = py;
340 } else {
341 x = py;
342 y = px;
343 }
344 if (rp->rt & XDECR)
345 x = rp->xr-1 - x;
346 if (rp->rt & YDECR)
347 y = rp->yr-1 - y;
348 loc[0] = (x+.5)/rp->xr;
349 loc[1] = (y+.5)/rp->yr;
350 }
351
352
353 void
354 loc2pix( /* compute pixel pos. from image location */
355 int pp[2],
356 RESOLU *rp,
357 double lx,
358 double ly
359 )
360 {
361 int x, y;
362
363 x = (int)(lx*rp->xr + .5 - (lx < 0.0));
364 y = (int)(ly*rp->yr + .5 - (ly < 0.0));
365
366 if (rp->rt & XDECR)
367 x = rp->xr-1 - x;
368 if (rp->rt & YDECR)
369 y = rp->yr-1 - y;
370 if (rp->rt & YMAJOR) {
371 pp[0] = x;
372 pp[1] = y;
373 } else {
374 pp[0] = y;
375 pp[1] = x;
376 }
377 }
378
379
380 int
381 getviewopt( /* process view argument */
382 VIEW *v,
383 int ac,
384 char *av[]
385 )
386 {
387 #define check(c,l) if ((av[0][c]&&av[0][c]!=' ') || \
388 badarg(ac-1,av+1,l)) return(-1)
389
390 if (ac <= 0 || av[0][0] != '-' || av[0][1] != 'v')
391 return(-1);
392 switch (av[0][2]) {
393 case 't': /* type */
394 if (!av[0][3] || av[0][3]==' ')
395 return(-1);
396 check(4,"");
397 v->type = av[0][3];
398 return(0);
399 case 'p': /* point */
400 check(3,"fff");
401 v->vp[0] = atof(av[1]);
402 v->vp[1] = atof(av[2]);
403 v->vp[2] = atof(av[3]);
404 return(3);
405 case 'd': /* direction */
406 check(3,"fff");
407 v->vdir[0] = atof(av[1]);
408 v->vdir[1] = atof(av[2]);
409 v->vdir[2] = atof(av[3]);
410 v->vdist = 1.;
411 return(3);
412 case 'u': /* up */
413 check(3,"fff");
414 v->vup[0] = atof(av[1]);
415 v->vup[1] = atof(av[2]);
416 v->vup[2] = atof(av[3]);
417 return(3);
418 case 'h': /* horizontal size */
419 check(3,"f");
420 v->horiz = atof(av[1]);
421 return(1);
422 case 'v': /* vertical size */
423 check(3,"f");
424 v->vert = atof(av[1]);
425 return(1);
426 case 'o': /* fore clipping plane */
427 check(3,"f");
428 v->vfore = atof(av[1]);
429 return(1);
430 case 'a': /* aft clipping plane */
431 check(3,"f");
432 v->vaft = atof(av[1]);
433 return(1);
434 case 's': /* shift */
435 check(3,"f");
436 v->hoff = atof(av[1]);
437 return(1);
438 case 'l': /* lift */
439 check(3,"f");
440 v->voff = atof(av[1]);
441 return(1);
442 default:
443 return(-1);
444 }
445 #undef check
446 }
447
448
449 int
450 sscanview( /* get view parameters from string */
451 VIEW *vp,
452 char *s
453 )
454 {
455 int ac;
456 char *av[4];
457 int na;
458 int nvopts = 0;
459
460 while (isspace(*s))
461 if (!*s++)
462 return(0);
463 while (*s) {
464 ac = 0;
465 do {
466 if (ac || *s == '-')
467 av[ac++] = s;
468 while (*s && !isspace(*s))
469 s++;
470 while (isspace(*s))
471 s++;
472 } while (*s && ac < 4);
473 if ((na = getviewopt(vp, ac, av)) >= 0) {
474 if (na+1 < ac)
475 s = av[na+1];
476 nvopts++;
477 } else if (ac > 1)
478 s = av[1];
479 }
480 return(nvopts);
481 }
482
483
484 void
485 fprintview( /* write out view parameters */
486 VIEW *vp,
487 FILE *fp
488 )
489 {
490 fprintf(fp, " -vt%c", vp->type);
491 fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]);
492 fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0]*vp->vdist,
493 vp->vdir[1]*vp->vdist,
494 vp->vdir[2]*vp->vdist);
495 fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]);
496 fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert);
497 fprintf(fp, " -vo %.6g -va %.6g", vp->vfore, vp->vaft);
498 fprintf(fp, " -vs %.6g -vl %.6g", vp->hoff, vp->voff);
499 }
500
501
502 char *
503 viewopt( /* translate to minimal view string */
504 VIEW *vp
505 )
506 {
507 static char vwstr[128];
508 char *cp = vwstr;
509
510 *cp = '\0';
511 if (vp->type != stdview.type) {
512 sprintf(cp, " -vt%c", vp->type);
513 cp += strlen(cp);
514 }
515 if (!VEQ(vp->vp,stdview.vp)) {
516 sprintf(cp, " -vp %.6g %.6g %.6g",
517 vp->vp[0], vp->vp[1], vp->vp[2]);
518 cp += strlen(cp);
519 }
520 if (!FEQ(vp->vdist,stdview.vdist) || !VEQ(vp->vdir,stdview.vdir)) {
521 sprintf(cp, " -vd %.6g %.6g %.6g",
522 vp->vdir[0]*vp->vdist,
523 vp->vdir[1]*vp->vdist,
524 vp->vdir[2]*vp->vdist);
525 cp += strlen(cp);
526 }
527 if (!VEQ(vp->vup,stdview.vup)) {
528 sprintf(cp, " -vu %.6g %.6g %.6g",
529 vp->vup[0], vp->vup[1], vp->vup[2]);
530 cp += strlen(cp);
531 }
532 if (!FEQ(vp->horiz,stdview.horiz)) {
533 sprintf(cp, " -vh %.6g", vp->horiz);
534 cp += strlen(cp);
535 }
536 if (!FEQ(vp->vert,stdview.vert)) {
537 sprintf(cp, " -vv %.6g", vp->vert);
538 cp += strlen(cp);
539 }
540 if (!FEQ(vp->vfore,stdview.vfore)) {
541 sprintf(cp, " -vo %.6g", vp->vfore);
542 cp += strlen(cp);
543 }
544 if (!FEQ(vp->vaft,stdview.vaft)) {
545 sprintf(cp, " -va %.6g", vp->vaft);
546 cp += strlen(cp);
547 }
548 if (!FEQ(vp->hoff,stdview.hoff)) {
549 sprintf(cp, " -vs %.6g", vp->hoff);
550 cp += strlen(cp);
551 }
552 if (!FEQ(vp->voff,stdview.voff)) {
553 sprintf(cp, " -vl %.6g", vp->voff);
554 cp += strlen(cp);
555 }
556 return(vwstr);
557 }
558
559
560 int
561 isview( /* is this a view string? */
562 char *s
563 )
564 {
565 static char *altname[]={NULL,VIEWSTR,"rpict","rview","rvu","rpiece","pinterp",NULL};
566 extern char *progname;
567 char *cp;
568 char **an;
569 /* add program name to list */
570 if (altname[0] == NULL) {
571 for (cp = progname; *cp; cp++)
572 ;
573 while (cp > progname && !ISDIRSEP(cp[-1]))
574 cp--;
575 altname[0] = cp;
576 }
577 /* skip leading path */
578 cp = s;
579 while (*cp && *cp != ' ')
580 cp++;
581 while (cp > s && !ISDIRSEP(cp[-1]))
582 cp--;
583 for (an = altname; *an != NULL; an++)
584 if (!strncmp(*an, cp, strlen(*an)))
585 return(1);
586 return(0);
587 }
588
589
590 struct myview {
591 VIEW *hv;
592 int ok;
593 };
594
595
596 static int
597 gethview( /* get view from header */
598 char *s,
599 void *v
600 )
601 {
602 if (isview(s) && sscanview(((struct myview*)v)->hv, s) > 0)
603 ((struct myview*)v)->ok++;
604 return(0);
605 }
606
607
608 int
609 viewfile( /* get view from file */
610 char *fname,
611 VIEW *vp,
612 RESOLU *rp
613 )
614 {
615 struct myview mvs;
616 FILE *fp;
617
618 if (fname == NULL || !strcmp(fname, "-"))
619 fp = stdin;
620 else if ((fp = fopen(fname, "r")) == NULL)
621 return(-1);
622
623 mvs.hv = vp;
624 mvs.ok = 0;
625
626 getheader(fp, gethview, &mvs);
627
628 if (rp != NULL && !fgetsresolu(rp, fp))
629 mvs.ok = 0;
630
631 fclose(fp);
632
633 return(mvs.ok);
634 }