ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/radiance/ray/src/rt/source.c
Revision: 1.9
Committed: Thu Jun 8 09:35:43 1989 UTC (34 years, 10 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.8: +30 -25 lines
Log Message:
Changed sorting array to reduce memory exchange time in qsort

File Contents

# User Rev Content
1 greg 1.1 /* Copyright (c) 1986 Regents of the University of California */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6    
7     /*
8     * source.c - routines dealing with illumination sources.
9     *
10     * 8/20/85
11     */
12    
13     #include "ray.h"
14    
15 greg 1.4 #include "octree.h"
16    
17 greg 1.1 #include "source.h"
18    
19     #include "otypes.h"
20    
21     #include "cone.h"
22    
23     #include "face.h"
24    
25     #include "random.h"
26    
27    
28     extern double dstrsrc; /* source distribution amount */
29 greg 1.4 extern double shadthresh; /* relative shadow threshold */
30 greg 1.1
31 greg 1.4 SRCREC *source = NULL; /* our list of sources */
32 greg 1.1 int nsources = 0; /* the number of sources */
33    
34    
35     marksources() /* find and mark source objects */
36     {
37     register OBJREC *o, *m;
38     register int i;
39    
40     for (i = 0; i < nobjects; i++) {
41    
42     o = objptr(i);
43    
44     if (o->omod == OVOID)
45     continue;
46    
47     m = objptr(o->omod);
48    
49     if (m->otype != MAT_LIGHT &&
50     m->otype != MAT_ILLUM &&
51 greg 1.6 m->otype != MAT_GLOW &&
52     m->otype != MAT_SPOT)
53 greg 1.1 continue;
54    
55 greg 1.6 if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
56     m->otype == MAT_SPOT ? 7 : 3))
57 greg 1.1 objerror(m, USER, "bad # arguments");
58    
59 greg 1.6 if (m->otype == MAT_GLOW &&
60     o->otype != OBJ_SOURCE &&
61     m->oargs.farg[3] <= FTINY)
62 greg 1.1 continue; /* don't bother */
63    
64 greg 1.4 if (source == NULL)
65     source = (SRCREC *)malloc(sizeof(SRCREC));
66     else
67     source = (SRCREC *)realloc((char *)source,
68     (unsigned)(nsources+1)*sizeof(SRCREC));
69     if (source == NULL)
70     error(SYSTEM, "out of memory in marksources");
71 greg 1.1
72 greg 1.4 newsource(&source[nsources], o);
73 greg 1.1
74 greg 1.6 if (m->otype == MAT_GLOW) {
75     source[nsources].sflags |= SPROX;
76     source[nsources].sl.prox = m->oargs.farg[3];
77     if (o->otype == OBJ_SOURCE)
78     source[nsources].sflags |= SSKIP;
79     } else if (m->otype == MAT_SPOT) {
80     source[nsources].sflags |= SSPOT;
81     source[nsources].sl.s = makespot(m);
82     }
83 greg 1.1 nsources++;
84     }
85     }
86    
87    
88     newsource(src, so) /* add a source to the array */
89 greg 1.4 register SRCREC *src;
90 greg 1.1 register OBJREC *so;
91     {
92     double cos(), tan(), sqrt();
93     double theta;
94     FACE *f;
95     CONE *co;
96     int j;
97     register int i;
98    
99     src->sflags = 0;
100 greg 1.6 src->nhits = 1; src->ntests = 2; /* start probability = 1/2 */
101 greg 1.1 src->so = so;
102    
103     switch (so->otype) {
104     case OBJ_SOURCE:
105     if (so->oargs.nfargs != 4)
106     objerror(so, USER, "bad arguments");
107     src->sflags |= SDISTANT;
108     VCOPY(src->sloc, so->oargs.farg);
109     if (normalize(src->sloc) == 0.0)
110     objerror(so, USER, "zero direction");
111     theta = PI/180.0/2.0 * so->oargs.farg[3];
112     if (theta <= FTINY)
113     objerror(so, USER, "zero size");
114     src->ss = theta >= PI/4 ? 1.0 : tan(theta);
115     src->ss2 = 2.0*PI * (1.0 - cos(theta));
116     break;
117     case OBJ_SPHERE:
118     VCOPY(src->sloc, so->oargs.farg);
119     src->ss = so->oargs.farg[3];
120     src->ss2 = PI * src->ss * src->ss;
121     break;
122     case OBJ_FACE:
123     /* get the face */
124     f = getface(so);
125     /* find the center */
126     for (j = 0; j < 3; j++) {
127     src->sloc[j] = 0.0;
128     for (i = 0; i < f->nv; i++)
129     src->sloc[j] += VERTEX(f,i)[j];
130     src->sloc[j] /= f->nv;
131     }
132     if (!inface(src->sloc, f))
133     objerror(so, USER, "cannot hit center");
134     src->ss = sqrt(f->area / PI);
135     src->ss2 = f->area;
136     break;
137     case OBJ_RING:
138     /* get the ring */
139     co = getcone(so, 0);
140     VCOPY(src->sloc, CO_P0(co));
141     if (CO_R0(co) > 0.0)
142     objerror(so, USER, "cannot hit center");
143     src->ss = CO_R1(co);
144     src->ss2 = PI * src->ss * src->ss;
145     break;
146     default:
147     objerror(so, USER, "illegal material");
148     }
149     }
150    
151    
152 greg 1.6 SPOT *
153     makespot(m) /* make a spotlight */
154     register OBJREC *m;
155     {
156     extern double cos();
157     register SPOT *ns;
158    
159     if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
160     error(SYSTEM, "out of memory in makespot");
161     ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3]));
162     VCOPY(ns->aim, m->oargs.farg+4);
163     if ((ns->flen = normalize(ns->aim)) == 0.0)
164     objerror(m, USER, "zero focus vector");
165     return(ns);
166     }
167    
168    
169 greg 1.1 double
170     srcray(sr, r, sn) /* send a ray to a source, return domega */
171     register RAY *sr; /* returned source ray */
172     RAY *r; /* ray which hit object */
173     register int sn; /* source number */
174     {
175     register double *norm = NULL; /* plane normal */
176     double ddot; /* (distance times) cosine */
177     FVECT vd;
178     double d;
179     register int i;
180    
181 greg 1.4 if (source[sn].sflags & SSKIP)
182 greg 1.1 return(0.0); /* skip this source */
183    
184     rayorigin(sr, r, SHADOW, 1.0); /* ignore limits */
185    
186     sr->rsrc = sn; /* remember source */
187     /* get source direction */
188 greg 1.4 if (source[sn].sflags & SDISTANT)
189 greg 1.1 /* constant direction */
190 greg 1.4 VCOPY(sr->rdir, source[sn].sloc);
191 greg 1.1 else { /* compute direction */
192     for (i = 0; i < 3; i++)
193 greg 1.4 sr->rdir[i] = source[sn].sloc[i] - sr->rorg[i];
194 greg 1.1
195 greg 1.4 if (source[sn].so->otype == OBJ_FACE)
196     norm = getface(source[sn].so)->norm;
197     else if (source[sn].so->otype == OBJ_RING)
198     norm = getcone(source[sn].so,0)->ad;
199 greg 1.1
200 greg 1.2 if (norm != NULL && (ddot = -DOT(sr->rdir, norm)) <= FTINY)
201 greg 1.1 return(0.0); /* behind surface! */
202     }
203     if (dstrsrc > FTINY) {
204     /* distribute source direction */
205     for (i = 0; i < 3; i++)
206 greg 1.4 vd[i] = dstrsrc * source[sn].ss * (1.0 - 2.0*frandom());
207 greg 1.1
208     if (norm != NULL) { /* project offset */
209     d = DOT(vd, norm);
210     for (i = 0; i < 3; i++)
211     vd[i] -= d * norm[i];
212     }
213     for (i = 0; i < 3; i++) /* offset source direction */
214     sr->rdir[i] += vd[i];
215    
216 greg 1.4 } else if (source[sn].sflags & SDISTANT)
217 greg 1.1 /* already normalized */
218 greg 1.4 return(source[sn].ss2);
219 greg 1.1
220     if ((d = normalize(sr->rdir)) == 0.0)
221     /* at source! */
222     return(0.0);
223    
224 greg 1.4 if (source[sn].sflags & SDISTANT)
225 greg 1.1 /* domega constant */
226 greg 1.4 return(source[sn].ss2);
227 greg 1.1
228     else {
229 greg 1.6 /* check proximity */
230     if (source[sn].sflags & SPROX &&
231     d > source[sn].sl.prox)
232     return(0.0);
233 greg 1.1
234     if (norm != NULL)
235     ddot /= d;
236     else
237     ddot = 1.0;
238 greg 1.6 /* check angle */
239     if (source[sn].sflags & SSPOT) {
240     if (source[sn].sl.s->siz < 2.0*PI *
241     (1.0 + DOT(source[sn].sl.s->aim,sr->rdir)))
242     return(0.0);
243     d += source[sn].sl.s->flen;
244     }
245 greg 1.1 /* return domega */
246 greg 1.4 return(ddot*source[sn].ss2/(d*d));
247 greg 1.1 }
248     }
249    
250    
251     sourcehit(r) /* check to see if ray hit distant source */
252     register RAY *r;
253     {
254     int first, last;
255     register int i;
256    
257     if (r->rsrc >= 0) { /* check only one if aimed */
258     first = last = r->rsrc;
259     } else { /* otherwise check all */
260     first = 0; last = nsources-1;
261     }
262     for (i = first; i <= last; i++)
263 greg 1.4 if (source[i].sflags & SDISTANT)
264 greg 1.1 /*
265     * Check to see if ray is within
266     * solid angle of source.
267     */
268 greg 1.4 if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir))
269     <= source[i].ss2) {
270     r->ro = source[i].so;
271     if (!(source[i].sflags & SSKIP))
272 greg 1.1 break;
273     }
274    
275     if (r->ro != NULL) {
276     for (i = 0; i < 3; i++)
277     r->ron[i] = -r->rdir[i];
278     r->rod = 1.0;
279 greg 1.3 r->rofs = 1.0; setident4(r->rofx);
280     r->robs = 1.0; setident4(r->robx);
281 greg 1.1 return(1);
282     }
283     return(0);
284     }
285    
286    
287 greg 1.4 static int
288     cntcmp(sc1, sc2) /* contribution compare (descending) */
289 greg 1.9 register CNTPTR *sc1, *sc2;
290 greg 1.4 {
291     if (sc1->brt > sc2->brt)
292     return(-1);
293     if (sc1->brt < sc2->brt)
294     return(1);
295     return(0);
296     }
297    
298    
299     direct(r, f, p) /* add direct component */
300     RAY *r; /* ray that hit surface */
301     int (*f)(); /* direct component coefficient function */
302     char *p; /* data for f */
303     {
304     register int sn;
305     register CONTRIB *srccnt;
306 greg 1.9 register CNTPTR *cntord;
307 greg 1.8 int ncnts;
308     double ourthresh, prob, hwt, test2, hit2;
309 greg 1.4 RAY sr;
310    
311 greg 1.9 srccnt = (CONTRIB *)malloc(nsources*sizeof(CONTRIB));
312     cntord = (CNTPTR *)malloc(nsources*sizeof(CNTPTR));
313     if (srccnt == NULL || cntord == NULL)
314 greg 1.4 error(SYSTEM, "out of memory in direct");
315 greg 1.8 /* modify threshold */
316     ourthresh = shadthresh / r->rweight;
317 greg 1.4 /* potential contributions */
318     for (sn = 0; sn < nsources; sn++) {
319 greg 1.9 cntord[sn].sno = sn;
320     cntord[sn].brt = 0.0;
321 greg 1.4 /* get source ray */
322     if ((srccnt[sn].dom = srcray(&sr, r, sn)) == 0.0)
323     continue;
324     VCOPY(srccnt[sn].dir, sr.rdir);
325     /* compute coefficient */
326     (*f)(srccnt[sn].val, p, srccnt[sn].dir, srccnt[sn].dom);
327 greg 1.9 cntord[sn].brt = bright(srccnt[sn].val);
328     if (cntord[sn].brt <= FTINY)
329 greg 1.4 continue;
330     /* compute intersection */
331     if (!( source[sn].sflags & SDISTANT ?
332     sourcehit(&sr) :
333     (*ofun[source[sn].so->otype].funp)
334     (source[sn].so, &sr) ))
335     continue;
336     /* compute contribution */
337     rayshade(&sr, sr.ro->omod);
338     multcolor(srccnt[sn].val, sr.rcol);
339 greg 1.9 cntord[sn].brt = bright(srccnt[sn].val);
340 greg 1.4 }
341     /* sort contributions */
342 greg 1.9 qsort(cntord, nsources, sizeof(CNTPTR), cntcmp);
343 greg 1.7 hit2 = 0.0; test2 = FTINY;
344 greg 1.8 /* find last */
345     sn = 0; ncnts = nsources;
346     while (sn < ncnts-1) {
347     register int m;
348     m = (sn + ncnts) >> 1;
349 greg 1.9 if (cntord[m].brt > 0.0)
350 greg 1.8 sn = m;
351     else
352     ncnts = m;
353     }
354     /* accumulate tail */
355     for (sn = ncnts-1; sn > 0; sn--)
356 greg 1.9 cntord[sn-1].brt += cntord[sn].brt;
357 greg 1.8 /* shadow testing */
358     for (sn = 0; sn < ncnts; sn++) {
359     /* tail below threshold? */
360 greg 1.9 if (cntord[sn].brt < ourthresh*bright(r->rcol))
361 greg 1.4 break;
362     /* get statistics */
363 greg 1.9 hwt = (double)source[cntord[sn].sno].nhits /
364     (double)source[cntord[sn].sno].ntests;
365 greg 1.4 test2 += hwt;
366 greg 1.9 source[cntord[sn].sno].ntests++;
367 greg 1.4 /* test for hit */
368     rayorigin(&sr, r, SHADOW, 1.0);
369 greg 1.9 VCOPY(sr.rdir, srccnt[cntord[sn].sno].dir);
370 greg 1.4 if (localhit(&sr, &thescene) &&
371 greg 1.9 sr.ro != source[cntord[sn].sno].so) {
372 greg 1.4 /* check for transmission */
373     if (sr.clipset != NULL && inset(sr.clipset,sr.ro->omod))
374     raytrans(&sr); /* object is clipped */
375     else
376     rayshade(&sr, sr.ro->omod);
377 greg 1.5 if (bright(sr.rcol) <= FTINY)
378 greg 1.4 continue; /* missed! */
379 greg 1.9 (*f)(srccnt[cntord[sn].sno].val, p,
380     srccnt[cntord[sn].sno].dir,
381     srccnt[cntord[sn].sno].dom);
382     multcolor(srccnt[cntord[sn].sno].val, sr.rcol);
383 greg 1.4 }
384     /* add contribution if hit */
385 greg 1.9 addcolor(r->rcol, srccnt[cntord[sn].sno].val);
386 greg 1.4 hit2 += hwt;
387 greg 1.9 source[cntord[sn].sno].nhits++;
388 greg 1.4 }
389 greg 1.7 /* weighted hit rate */
390     hwt = hit2 / test2;
391 greg 1.4 #ifdef DEBUG
392 greg 1.8 fprintf(stderr, "%d tested, %d untested, %f hit rate\n",
393     sn, ncnts-sn, hwt);
394 greg 1.4 #endif
395     /* add in untested sources */
396 greg 1.8 for ( ; sn < ncnts; sn++) {
397 greg 1.9 prob = hwt * (double)source[cntord[sn].sno].nhits /
398     (double)source[cntord[sn].sno].ntests;
399     scalecolor(srccnt[cntord[sn].sno].val, prob);
400     addcolor(r->rcol, srccnt[cntord[sn].sno].val);
401 greg 1.4 }
402     free(srccnt);
403 greg 1.9 free(cntord);
404 greg 1.4 }
405    
406    
407 greg 1.1 #define wrongsource(m, r) (m->otype!=MAT_ILLUM && \
408     r->rsrc>=0 && \
409 greg 1.4 source[r->rsrc].so!=r->ro)
410 greg 1.1
411     #define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \
412 greg 1.6 !(r->rtype&REFLECTED) && /* hack! */\
413     !(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3]))
414 greg 1.1
415     #define passillum(m, r) (m->otype==MAT_ILLUM && \
416 greg 1.4 !(r->rsrc>=0&&source[r->rsrc].so==r->ro))
417 greg 1.1
418    
419     m_light(m, r) /* ray hit a light source */
420     register OBJREC *m;
421     register RAY *r;
422     {
423     /* check for behind */
424     if (r->rod < 0.0)
425     return;
426     /* check for over-counting */
427     if (wrongsource(m, r) || badambient(m, r))
428     return;
429     /* check for passed illum */
430     if (passillum(m, r)) {
431    
432     if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID))
433     raytrans(r);
434     else
435     rayshade(r, modifier(m->oargs.sarg[0]));
436    
437     /* otherwise treat as source */
438     } else {
439     /* get distribution pattern */
440     raytexture(r, m->omod);
441     /* get source color */
442     setcolor(r->rcol, m->oargs.farg[0],
443     m->oargs.farg[1],
444     m->oargs.farg[2]);
445     /* modify value */
446     multcolor(r->rcol, r->pcol);
447     }
448     }
449    
450    
451     o_source() {} /* intersection with a source is done elsewhere */