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root/radiance/ray/src/common/image.c
Revision: 2.52
Committed: Fri Feb 12 00:47:08 2021 UTC (3 years, 3 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.51: +10 -15 lines
Log Message:
refactor: added macros for RREAL comparisons

File Contents

# Content
1 #ifndef lint
2 static const char RCSid[] = "$Id: image.c,v 2.51 2020/05/14 20:49:57 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 VIEW stdview = STDVIEW; /* default view parameters */
19
20 static gethfunc gethview;
21
22
23 char *
24 setview( /* set hvec and vvec, return message on error */
25 VIEW *v
26 )
27 {
28 static char ill_horiz[] = "illegal horizontal view size";
29 static char ill_vert[] = "illegal vertical view size";
30
31 if ((v->vfore < -FTINY) | (v->vaft < -FTINY) ||
32 (v->vaft > FTINY) & (v->vaft <= v->vfore))
33 return("illegal fore/aft clipping plane");
34
35 if (v->vdist <= FTINY)
36 return("illegal view distance");
37 v->vdist *= normalize(v->vdir); /* normalize direction */
38 if (v->vdist == 0.0)
39 return("zero view direction");
40
41 if (normalize(v->vup) == 0.0) /* normalize view up */
42 return("zero view up vector");
43
44 fcross(v->hvec, v->vdir, v->vup); /* compute horiz dir */
45
46 if (normalize(v->hvec) == 0.0)
47 return("view up parallel to view direction");
48
49 fcross(v->vvec, v->hvec, v->vdir); /* compute vert dir */
50
51 if (v->horiz <= FTINY)
52 return(ill_horiz);
53 if (v->vert <= FTINY)
54 return(ill_vert);
55
56 switch (v->type) {
57 case VT_PAR: /* parallel view */
58 v->hn2 = v->horiz;
59 v->vn2 = v->vert;
60 break;
61 case VT_PER: /* perspective view */
62 if (v->horiz >= 180.0-FTINY)
63 return(ill_horiz);
64 if (v->vert >= 180.0-FTINY)
65 return(ill_vert);
66 v->hn2 = 2.0 * tan(v->horiz*(PI/180.0/2.0));
67 v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
68 break;
69 case VT_CYL: /* cylindrical panorama */
70 if (v->horiz > 360.0+FTINY)
71 return(ill_horiz);
72 if (v->vert >= 180.0-FTINY)
73 return(ill_vert);
74 v->hn2 = v->horiz * (PI/180.0);
75 v->vn2 = 2.0 * tan(v->vert*(PI/180.0/2.0));
76 break;
77 case VT_ANG: /* angular fisheye */
78 if (v->horiz > 360.0+FTINY)
79 return(ill_horiz);
80 if (v->vert > 360.0+FTINY)
81 return(ill_vert);
82 v->hn2 = v->horiz * (PI/180.0);
83 v->vn2 = v->vert * (PI/180.0);
84 break;
85 case VT_HEM: /* hemispherical fisheye */
86 if (v->horiz > 180.0+FTINY)
87 return(ill_horiz);
88 if (v->vert > 180.0+FTINY)
89 return(ill_vert);
90 v->hn2 = 2.0 * sin(v->horiz*(PI/180.0/2.0));
91 v->vn2 = 2.0 * sin(v->vert*(PI/180.0/2.0));
92 break;
93 case VT_PLS: /* planispheric fisheye */
94 if (v->horiz >= 360.0-FTINY)
95 return(ill_horiz);
96 if (v->vert >= 360.0-FTINY)
97 return(ill_vert);
98 v->hn2 = 2.*sin(v->horiz*(PI/180.0/2.0)) /
99 (1.0 + cos(v->horiz*(PI/180.0/2.0)));
100 v->vn2 = 2.*sin(v->vert*(PI/180.0/2.0)) /
101 (1.0 + cos(v->vert*(PI/180.0/2.0)));
102 break;
103 default:
104 return("unknown view type");
105 }
106 if (v->type != VT_ANG && v->type != VT_PLS) {
107 if (v->type != VT_CYL) {
108 v->hvec[0] *= v->hn2;
109 v->hvec[1] *= v->hn2;
110 v->hvec[2] *= v->hn2;
111 }
112 v->vvec[0] *= v->vn2;
113 v->vvec[1] *= v->vn2;
114 v->vvec[2] *= v->vn2;
115 }
116 v->hn2 *= v->hn2;
117 v->vn2 *= v->vn2;
118
119 return(NULL);
120 }
121
122
123 void
124 normaspect( /* fix pixel aspect or resolution */
125 double va, /* view aspect ratio */
126 double *ap, /* pixel aspect in (or out if 0) */
127 int *xp,
128 int *yp /* x and y resolution in (or out if *ap!=0) */
129 )
130 {
131 if (*ap <= FTINY)
132 *ap = va * *xp / *yp; /* compute pixel aspect */
133 else if (va * *xp > *ap * *yp)
134 *xp = *yp / va * *ap + .5; /* reduce x resolution */
135 else
136 *yp = *xp * va / *ap + .5; /* reduce y resolution */
137 }
138
139
140 double
141 viewray( /* compute ray origin and direction */
142 FVECT orig,
143 FVECT direc,
144 VIEW *v,
145 double x,
146 double y
147 )
148 {
149 double d, z;
150
151 x += v->hoff - 0.5;
152 y += v->voff - 0.5;
153
154 switch(v->type) {
155 case VT_PAR: /* parallel view */
156 orig[0] = v->vp[0] + v->vfore*v->vdir[0]
157 + x*v->hvec[0] + y*v->vvec[0];
158 orig[1] = v->vp[1] + v->vfore*v->vdir[1]
159 + x*v->hvec[1] + y*v->vvec[1];
160 orig[2] = v->vp[2] + v->vfore*v->vdir[2]
161 + x*v->hvec[2] + y*v->vvec[2];
162 VCOPY(direc, v->vdir);
163 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
164 case VT_PER: /* perspective view */
165 direc[0] = v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
166 direc[1] = v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
167 direc[2] = v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
168 VSUM(orig, v->vp, direc, v->vfore);
169 d = normalize(direc);
170 return(v->vaft > FTINY ? (v->vaft - v->vfore)*d : 0.0);
171 case VT_HEM: /* hemispherical fisheye */
172 z = 1.0 - x*x*v->hn2 - y*y*v->vn2;
173 if (z < 0.0)
174 return(-1.0);
175 z = sqrt(z);
176 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
177 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
178 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
179 VSUM(orig, v->vp, direc, v->vfore);
180 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
181 case VT_CYL: /* cylindrical panorama */
182 d = x * v->horiz * (PI/180.0);
183 z = cos(d);
184 x = sin(d);
185 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
186 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
187 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
188 VSUM(orig, v->vp, direc, v->vfore);
189 d = normalize(direc);
190 return(v->vaft > FTINY ? (v->vaft - v->vfore)*d : 0.0);
191 case VT_ANG: /* angular fisheye */
192 x *= (1.0/180.0)*v->horiz;
193 y *= (1.0/180.0)*v->vert;
194 d = x*x + y*y;
195 if (d > 1.0)
196 return(-1.0);
197 d = sqrt(d);
198 z = cos(PI*d);
199 d = d <= FTINY ? PI : sqrt(1.0 - z*z)/d;
200 x *= d;
201 y *= d;
202 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
203 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
204 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
205 VSUM(orig, v->vp, direc, v->vfore);
206 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
207 case VT_PLS: /* planispheric fisheye */
208 x *= sqrt(v->hn2);
209 y *= sqrt(v->vn2);
210 d = x*x + y*y;
211 z = (1. - d)/(1. + d);
212 x *= (1. + z);
213 y *= (1. + z);
214 direc[0] = z*v->vdir[0] + x*v->hvec[0] + y*v->vvec[0];
215 direc[1] = z*v->vdir[1] + x*v->hvec[1] + y*v->vvec[1];
216 direc[2] = z*v->vdir[2] + x*v->hvec[2] + y*v->vvec[2];
217 VSUM(orig, v->vp, direc, v->vfore);
218 return(v->vaft > FTINY ? v->vaft - v->vfore : 0.0);
219 }
220 return(-1.0);
221 }
222
223
224 int
225 viewloc( /* find image location for point */
226 FVECT ip,
227 VIEW *v,
228 FVECT p
229 ) /* Use VL_* flags to interpret return value */
230 {
231 int rflags = VL_GOOD;
232 double d, d2;
233 FVECT disp;
234
235 VSUB(disp, p, v->vp);
236
237 switch (v->type) {
238 case VT_PAR: /* parallel view */
239 ip[2] = DOT(disp,v->vdir) - v->vfore;
240 break;
241 case VT_PER: /* perspective view */
242 d = DOT(disp,v->vdir);
243 if ((v->vaft > FTINY) & (d >= v->vaft))
244 rflags |= VL_BEYOND;
245 ip[2] = VLEN(disp);
246 if (d < -FTINY) { /* fold pyramid */
247 ip[2] = -ip[2];
248 d = -d;
249 } else if (d <= FTINY)
250 return(VL_BAD); /* at infinite edge */
251 d = 1.0/d;
252 disp[0] *= d;
253 disp[1] *= d;
254 disp[2] *= d;
255 if (ip[2] < 0.0) d = -d;
256 ip[2] *= (1.0 - v->vfore*d);
257 break;
258 case VT_HEM: /* hemispherical fisheye */
259 d = normalize(disp);
260 if (DOT(disp,v->vdir) < 0.0)
261 ip[2] = -d;
262 else
263 ip[2] = d;
264 ip[2] -= v->vfore;
265 break;
266 case VT_CYL: /* cylindrical panorama */
267 d = DOT(disp,v->hvec);
268 d2 = DOT(disp,v->vdir);
269 ip[0] = 180.0/PI * atan2(d,d2) / v->horiz + 0.5 - v->hoff;
270 d2 = d*d + d2*d2;
271 if (d2 <= FTINY*FTINY)
272 return(VL_BAD); /* at pole */
273 if ((v->vaft > FTINY) & (d2 >= v->vaft*v->vaft))
274 rflags |= VL_BEYOND;
275 d = 1.0/sqrt(d2);
276 ip[1] = DOT(disp,v->vvec)*d/v->vn2 + 0.5 - v->voff;
277 ip[2] = VLEN(disp);
278 ip[2] *= (1.0 - v->vfore*d);
279 goto gotall;
280 case VT_ANG: /* angular fisheye */
281 ip[0] = 0.5 - v->hoff;
282 ip[1] = 0.5 - v->voff;
283 ip[2] = normalize(disp) - v->vfore;
284 d = DOT(disp,v->vdir);
285 if (d >= 1.0-FTINY)
286 goto gotall;
287 if (d <= -(1.0-FTINY)) {
288 ip[0] += 180.0/v->horiz;
289 goto gotall;
290 }
291 d = (180.0/PI)*acos(d) / sqrt(1.0 - d*d);
292 ip[0] += DOT(disp,v->hvec)*d/v->horiz;
293 ip[1] += DOT(disp,v->vvec)*d/v->vert;
294 goto gotall;
295 case VT_PLS: /* planispheric fisheye */
296 ip[0] = 0.5 - v->hoff;
297 ip[1] = 0.5 - v->voff;
298 ip[2] = normalize(disp) - v->vfore;
299 d = DOT(disp,v->vdir);
300 if (d >= 1.0-FTINY)
301 goto gotall;
302 if (d <= -(1.0-FTINY))
303 return(VL_BAD);
304 ip[0] += DOT(disp,v->hvec)/((1. + d)*sqrt(v->hn2));
305 ip[1] += DOT(disp,v->vvec)/((1. + d)*sqrt(v->vn2));
306 goto gotall;
307 default:
308 return(VL_BAD);
309 }
310 ip[0] = DOT(disp,v->hvec)/v->hn2 + 0.5 - v->hoff;
311 ip[1] = DOT(disp,v->vvec)/v->vn2 + 0.5 - v->voff;
312 gotall: /* add appropriate return flags */
313 if (ip[2] <= 0.0)
314 rflags |= VL_BEHIND;
315 else if ((v->type != VT_PER) & (v->type != VT_CYL))
316 rflags |= VL_BEYOND*((v->vaft > FTINY) &
317 (ip[2] >= v->vaft - v->vfore));
318 rflags |= VL_OUTSIDE*((0.0 >= ip[0]) | (ip[0] >= 1.0) |
319 (0.0 >= ip[1]) | (ip[1] >= 1.0));
320 return(rflags);
321 }
322
323
324 void
325 pix2loc( /* compute image location from pixel pos. */
326 RREAL loc[2],
327 RESOLU *rp,
328 int px,
329 int py
330 )
331 {
332 int x, y;
333
334 if (rp->rt & YMAJOR) {
335 x = px;
336 y = py;
337 } else {
338 x = py;
339 y = px;
340 }
341 if (rp->rt & XDECR)
342 x = rp->xr-1 - x;
343 if (rp->rt & YDECR)
344 y = rp->yr-1 - y;
345 loc[0] = (x+.5)/rp->xr;
346 loc[1] = (y+.5)/rp->yr;
347 }
348
349
350 void
351 loc2pix( /* compute pixel pos. from image location */
352 int pp[2],
353 RESOLU *rp,
354 double lx,
355 double ly
356 )
357 {
358 int x, y;
359
360 x = (int)(lx*rp->xr + .5 - (lx < 0.0));
361 y = (int)(ly*rp->yr + .5 - (ly < 0.0));
362
363 if (rp->rt & XDECR)
364 x = rp->xr-1 - x;
365 if (rp->rt & YDECR)
366 y = rp->yr-1 - y;
367 if (rp->rt & YMAJOR) {
368 pp[0] = x;
369 pp[1] = y;
370 } else {
371 pp[0] = y;
372 pp[1] = x;
373 }
374 }
375
376
377 int
378 getviewopt( /* process view argument */
379 VIEW *v,
380 int ac,
381 char *av[]
382 )
383 {
384 #define check(c,l) if ((av[0][c]&&!isspace(av[0][c])) || \
385 badarg(ac-1,av+1,l)) return(-1)
386
387 if (ac <= 0 || av[0][0] != '-' || av[0][1] != 'v')
388 return(-1);
389 switch (av[0][2]) {
390 case 't': /* type */
391 if (!av[0][3] || isspace(av[0][3]))
392 return(-1);
393 check(4,"");
394 v->type = av[0][3];
395 return(0);
396 case 'p': /* point */
397 check(3,"fff");
398 v->vp[0] = atof(av[1]);
399 v->vp[1] = atof(av[2]);
400 v->vp[2] = atof(av[3]);
401 return(3);
402 case 'd': /* direction */
403 check(3,"fff");
404 v->vdir[0] = atof(av[1]);
405 v->vdir[1] = atof(av[2]);
406 v->vdir[2] = atof(av[3]);
407 v->vdist = 1.;
408 return(3);
409 case 'u': /* up */
410 check(3,"fff");
411 v->vup[0] = atof(av[1]);
412 v->vup[1] = atof(av[2]);
413 v->vup[2] = atof(av[3]);
414 return(3);
415 case 'h': /* horizontal size */
416 check(3,"f");
417 v->horiz = atof(av[1]);
418 return(1);
419 case 'v': /* vertical size */
420 check(3,"f");
421 v->vert = atof(av[1]);
422 return(1);
423 case 'o': /* fore clipping plane */
424 check(3,"f");
425 v->vfore = atof(av[1]);
426 return(1);
427 case 'a': /* aft clipping plane */
428 check(3,"f");
429 v->vaft = atof(av[1]);
430 return(1);
431 case 's': /* shift */
432 check(3,"f");
433 v->hoff = atof(av[1]);
434 return(1);
435 case 'l': /* lift */
436 check(3,"f");
437 v->voff = atof(av[1]);
438 return(1);
439 default:
440 return(-1);
441 }
442 #undef check
443 }
444
445
446 int
447 sscanview( /* get view parameters from string */
448 VIEW *vp,
449 char *s
450 )
451 {
452 int ac;
453 char *av[4];
454 int na;
455 int nvopts = 0;
456
457 while (isspace(*s))
458 if (!*s++)
459 return(0);
460 while (*s) {
461 ac = 0;
462 do {
463 if (ac || *s == '-')
464 av[ac++] = s;
465 while (*s && !isspace(*s))
466 s++;
467 while (isspace(*s))
468 s++;
469 } while (*s && ac < 4);
470 if ((na = getviewopt(vp, ac, av)) >= 0) {
471 if (na+1 < ac)
472 s = av[na+1];
473 nvopts++;
474 } else if (ac > 1)
475 s = av[1];
476 }
477 return(nvopts);
478 }
479
480
481 void
482 fprintview( /* write out view parameters */
483 VIEW *vp,
484 FILE *fp
485 )
486 {
487 fprintf(fp, " -vt%c", vp->type);
488 fprintf(fp, " -vp %.6g %.6g %.6g", vp->vp[0], vp->vp[1], vp->vp[2]);
489 fprintf(fp, " -vd %.6g %.6g %.6g", vp->vdir[0]*vp->vdist,
490 vp->vdir[1]*vp->vdist,
491 vp->vdir[2]*vp->vdist);
492 fprintf(fp, " -vu %.6g %.6g %.6g", vp->vup[0], vp->vup[1], vp->vup[2]);
493 fprintf(fp, " -vh %.6g -vv %.6g", vp->horiz, vp->vert);
494 fprintf(fp, " -vo %.6g -va %.6g", vp->vfore, vp->vaft);
495 fprintf(fp, " -vs %.6g -vl %.6g", vp->hoff, vp->voff);
496 }
497
498
499 char *
500 viewopt( /* translate to minimal view string */
501 VIEW *vp
502 )
503 {
504 static char vwstr[128];
505 char *cp = vwstr;
506
507 *cp = '\0';
508 if (vp->type != stdview.type) {
509 sprintf(cp, " -vt%c", vp->type);
510 cp += strlen(cp);
511 }
512 if (!VABSEQ(vp->vp,stdview.vp)) {
513 sprintf(cp, " -vp %.6g %.6g %.6g",
514 vp->vp[0], vp->vp[1], vp->vp[2]);
515 cp += strlen(cp);
516 }
517 if (!FABSEQ(vp->vdist,stdview.vdist) || !VABSEQ(vp->vdir,stdview.vdir)) {
518 sprintf(cp, " -vd %.6g %.6g %.6g",
519 vp->vdir[0]*vp->vdist,
520 vp->vdir[1]*vp->vdist,
521 vp->vdir[2]*vp->vdist);
522 cp += strlen(cp);
523 }
524 if (!VABSEQ(vp->vup,stdview.vup)) {
525 sprintf(cp, " -vu %.6g %.6g %.6g",
526 vp->vup[0], vp->vup[1], vp->vup[2]);
527 cp += strlen(cp);
528 }
529 if (!FABSEQ(vp->horiz,stdview.horiz)) {
530 sprintf(cp, " -vh %.6g", vp->horiz);
531 cp += strlen(cp);
532 }
533 if (!FABSEQ(vp->vert,stdview.vert)) {
534 sprintf(cp, " -vv %.6g", vp->vert);
535 cp += strlen(cp);
536 }
537 if (!FABSEQ(vp->vfore,stdview.vfore)) {
538 sprintf(cp, " -vo %.6g", vp->vfore);
539 cp += strlen(cp);
540 }
541 if (!FABSEQ(vp->vaft,stdview.vaft)) {
542 sprintf(cp, " -va %.6g", vp->vaft);
543 cp += strlen(cp);
544 }
545 if (!FABSEQ(vp->hoff,stdview.hoff)) {
546 sprintf(cp, " -vs %.6g", vp->hoff);
547 cp += strlen(cp);
548 }
549 if (!FABSEQ(vp->voff,stdview.voff)) {
550 sprintf(cp, " -vl %.6g", vp->voff);
551 cp += strlen(cp);
552 }
553 return(vwstr);
554 }
555
556
557 int
558 isview( /* is this a view string? */
559 char *s
560 )
561 {
562 static char *altname[]={NULL,VIEWSTR,"rpict","rview","rvu","rpiece","pinterp",NULL};
563 extern char *progname;
564 char *cp;
565 char **an;
566 /* add program name to list */
567 if (altname[0] == NULL) {
568 for (cp = progname; *cp; cp++)
569 ;
570 while (cp > progname && !ISDIRSEP(cp[-1]))
571 cp--;
572 altname[0] = cp;
573 }
574 /* skip leading path */
575 cp = s;
576 while (*cp && !isspace(*cp))
577 cp++;
578 while (cp > s && !ISDIRSEP(cp[-1]))
579 cp--;
580 for (an = altname; *an != NULL; an++)
581 if (!strncmp(*an, cp, strlen(*an)))
582 return(1);
583 return(0);
584 }
585
586
587 struct myview {
588 VIEW *hv;
589 int ok;
590 };
591
592
593 static int
594 gethview( /* get view from header */
595 char *s,
596 void *v
597 )
598 {
599 if (isview(s) && sscanview(((struct myview*)v)->hv, s) > 0)
600 ((struct myview*)v)->ok++;
601 return(0);
602 }
603
604
605 int
606 viewfile( /* get view from file */
607 char *fname,
608 VIEW *vp,
609 RESOLU *rp
610 )
611 {
612 struct myview mvs;
613 FILE *fp;
614
615 if (fname == NULL || !strcmp(fname, "-"))
616 fp = stdin;
617 else if ((fp = fopen(fname, "r")) == NULL)
618 return(-1);
619
620 mvs.hv = vp;
621 mvs.ok = 0;
622
623 getheader(fp, gethview, &mvs);
624
625 if (rp != NULL && !fgetsresolu(rp, fp))
626 mvs.ok = 0;
627
628 if (fp != stdin)
629 fclose(fp);
630
631 return(mvs.ok);
632 }