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root/radiance/ray/src/common/image.c
Revision: 2.15
Committed: Fri Feb 26 12:24:07 1999 UTC (25 years, 2 months ago) by gwlarson
Content type: text/plain
Branch: MAIN
Changes since 2.14: +2 -4 lines
Log Message:
allowed negative fore clipping plane for holographic rendering

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