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root/radiance/ray/src/util/glaresrc.c
Revision: 1.9
Committed: Thu Mar 21 14:53:56 1991 UTC (33 years ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.8: +4 -4 lines
Log Message:
fixed bug in addindirect -- forgot to update after reorienting theta

File Contents

# Content
1 /* Copyright (c) 1991 Regents of the University of California */
2
3 #ifndef lint
4 static char SCCSid[] = "$SunId$ LBL";
5 #endif
6
7 /*
8 * Gather samples and compute glare sources.
9 */
10
11 #include "glare.h"
12
13 #define vcont(vd,vu) ((vu)-(vd)<=SEPS)
14 #define hcont(s1,s2) ((s1)->r-(s2)->l>=-SEPS&&(s2)->r-(s1)->l>=-SEPS)
15
16 struct source *curlist = NULL; /* current source list */
17 struct source *donelist = NULL; /* finished sources */
18
19
20 struct srcspan *
21 newspan(l, r, v, sb) /* allocate a new source span */
22 int l, r, v;
23 float *sb;
24 {
25 register struct srcspan *ss;
26 register int i;
27
28 ss = (struct srcspan *)malloc(sizeof(struct srcspan));
29 if (ss == NULL)
30 memerr("source spans");
31 ss->l = l;
32 ss->r = r;
33 ss->v = v;
34 ss->brsum = 0.0;
35 for (i = l; i < r; i++)
36 ss->brsum += sb[i+hsize];
37 return(ss);
38 }
39
40
41 analyze() /* analyze our scene */
42 {
43 int h, v;
44 int left;
45 float *spanbr;
46
47 spanbr = (float *)malloc((2*hsize+1)*sizeof(float));
48 if (spanbr == NULL)
49 memerr("view span brightness buffer");
50 for (v = vsize; v >= -vsize; v--) {
51 close_sources(v);
52 #ifndef DEBUG
53 if (verbose)
54 fprintf(stderr, "%s: analyzing... %3ld%%\r",
55 progname, 100L*(vsize-v)/(2*vsize));
56 #endif
57 getviewspan(v, spanbr);
58 left = hsize + 1;
59 for (h = -hsize; h <= hsize; h++) {
60 if (spanbr[h+hsize] < 0.0) { /* off view */
61 if (left < h) {
62 addsrcspan(newspan(left,h,v,spanbr));
63 left = hsize + 1;
64 }
65 continue;
66 }
67 if (spanbr[h+hsize] > threshold) { /* in source */
68 if (left > h)
69 left = h;
70 } else { /* out of source */
71 if (left < h) {
72 addsrcspan(newspan(left,h,v,spanbr));
73 left = hsize + 1;
74 }
75 addindirect(h, spanbr[h+hsize]);
76 }
77 }
78 if (left < h)
79 addsrcspan(newspan(left,h,v,spanbr));
80 }
81 free((char *)spanbr);
82 close_allsrcs();
83 absorb_specks();
84 }
85
86
87 addindirect(h, br) /* add brightness to indirect illuminances */
88 int h;
89 double br;
90 {
91 double tanb, d;
92 register int i;
93
94 if (h <= -hlim) { /* left region */
95 d = (double)(-h-hlim)/sampdens;
96 if (d >= 1.0-FTINY)
97 return;
98 tanb = d/sqrt(1.0-d*d);
99 for (i = 0; i < nglardirs; i++) {
100 d = indirect[i].lcos - tanb*indirect[i].lsin;
101 if (d > 0.0) {
102 indirect[i].sum += d * br;
103 indirect[i].n++;
104 }
105 }
106 return;
107 }
108 if (h >= hlim) { /* right region */
109 d = (double)(-h+hlim)/sampdens;
110 if (d <= -1.0+FTINY)
111 return;
112 tanb = d/sqrt(1.0-d*d);
113 for (i = 0; i < nglardirs; i++) {
114 d = indirect[i].rcos - tanb*indirect[i].rsin;
115 if (d > 0.0) {
116 indirect[i].sum += d * br;
117 indirect[i].n++;
118 }
119 }
120 return;
121 }
122 /* central region */
123 for (i = 0; i < nglardirs; i++) {
124 d = cos(h_theta(h) - indirect[i].theta);
125 if (d > 0.0) {
126 indirect[i].sum += d * br;
127 indirect[i].n++;
128 }
129 }
130 }
131
132
133 comp_thresh() /* compute glare threshold */
134 {
135 int h, v;
136 int nsamps;
137 double brsum, br;
138
139 if (verbose)
140 fprintf(stderr, "%s: computing glare threshold...\n",
141 progname);
142 brsum = 0.0;
143 nsamps = 0;
144 for (v = vsize; v >= -vsize; v -= TSAMPSTEP)
145 for (h = -hsize; h <= hsize; h += TSAMPSTEP) {
146 if ((br = getviewpix(h, v)) < 0.0)
147 continue;
148 brsum += br;
149 nsamps++;
150 }
151 if (nsamps == 0) {
152 fprintf(stderr, "%s: no viewable scene!\n", progname);
153 exit(1);
154 }
155 threshold = GLAREBR * brsum / nsamps;
156 if (threshold <= FTINY) {
157 fprintf(stderr, "%s: threshold zero!\n", progname);
158 exit(1);
159 }
160 if (verbose) {
161 #ifdef DEBUG
162 pict_stats();
163 #endif
164 fprintf(stderr,
165 "%s: threshold set to %f cd/m2 from %d samples\n",
166 progname, threshold, nsamps);
167 }
168 }
169
170
171 addsrcspan(nss) /* add new source span to our list */
172 struct srcspan *nss;
173 {
174 struct source *last, *cs, *this;
175 register struct srcspan *ss;
176
177 cs = NULL;
178 for (this = curlist; this != NULL; this = this->next) {
179 for (ss = this->first; ss != NULL; ss = ss->next) {
180 if (!vcont(nss->v, ss->v))
181 break;
182 if (hcont(ss, nss)) {
183 if (cs == NULL)
184 cs = this;
185 else {
186 last->next = this->next;
187 mergesource(cs, this);
188 this = last;
189 }
190 break;
191 }
192 }
193 last = this;
194 }
195 if (cs == NULL) {
196 cs = (struct source *)malloc(sizeof(struct source));
197 if (cs == NULL)
198 memerr("source records");
199 cs->dom = 0.0;
200 cs->first = NULL;
201 cs->next = curlist;
202 curlist = cs;
203 }
204 nss->next = cs->first;
205 cs->first = nss;
206 }
207
208
209 mergesource(sp, ap) /* merge source ap into source sp */
210 struct source *sp, *ap;
211 {
212 struct srcspan head;
213 register struct srcspan *alp, *prev, *tp;
214
215 head.next = sp->first;
216 prev = &head;
217 alp = ap->first;
218 while (alp != NULL && prev->next != NULL) {
219 if (prev->next->v > alp->v) {
220 tp = alp->next;
221 alp->next = prev->next;
222 prev->next = alp;
223 alp = tp;
224 }
225 prev = prev->next;
226 }
227 if (prev->next == NULL)
228 prev->next = alp;
229 sp->first = head.next;
230 if (ap->dom > 0.0 && sp->dom > 0.0) { /* sources are done */
231 sp->dir[0] *= sp->dom;
232 sp->dir[1] *= sp->dom;
233 sp->dir[2] *= sp->dom;
234 fvsum(sp->dir, sp->dir, ap->dir, ap->dom);
235 normalize(sp->dir);
236 sp->brt = (sp->brt*sp->dom + ap->brt*ap->dom)
237 / (sp->dom + ap->dom);
238 }
239 free((char *)ap);
240 }
241
242
243 close_sources(v) /* close sources above v */
244 int v;
245 {
246 struct source head;
247 register struct source *last, *this;
248
249 head.next = curlist;
250 last = &head;
251 for (this = curlist; this != NULL; this = this->next)
252 if (!vcont(v, this->first->v)) {
253 last->next = this->next;
254 donesource(this);
255 this = last;
256 } else
257 last = this;
258 curlist = head.next;
259 }
260
261
262 close_allsrcs() /* done with everything */
263 {
264 register struct source *this, *next;
265
266 this = curlist;
267 while (this != NULL) {
268 next = this->next;
269 donesource(this);
270 this = next;
271 }
272 curlist = NULL;
273 }
274
275
276 donesource(sp) /* finished with this source */
277 register struct source *sp;
278 {
279 FVECT dthis, dright;
280 register struct srcspan *ss;
281 int h, n;
282 double d;
283
284 sp->dom = 0.0;
285 sp->dir[0] = sp->dir[1] = sp->dir[2] = 0.0;
286 sp->brt = 0.0;
287 n = 0;
288 for (ss = sp->first; ss != NULL; ss = ss->next) {
289 sp->brt += ss->brsum;
290 n += ss->r - ss->l;
291 if (compdir(dright, ss->r, ss->v) < 0)
292 compdir(dright, ss->r-2, ss->v);
293 for (h = ss->r-1; h >= ss->l; h--)
294 if (compdir(dthis, h, ss->v) == 0) {
295 d = dist2(dthis, dright);
296 fvsum(sp->dir, sp->dir, dthis, d);
297 sp->dom += d;
298 VCOPY(dright, dthis);
299 }
300 free((char *)ss);
301 }
302 sp->first = NULL;
303 sp->brt /= (double)n;
304 normalize(sp->dir);
305 sp->next = donelist;
306 donelist = sp;
307 if (verbose)
308 fprintf(stderr,
309 "%s: found source at (%.3f,%.3f,%.3f), dw %.5f, br %.1f (%d samps)\n",
310 progname, sp->dir[0], sp->dir[1], sp->dir[2],
311 sp->dom, sp->brt, n);
312 }
313
314
315 struct source *
316 findbuddy(s, l) /* find close enough source to s in l*/
317 register struct source *s, *l;
318 {
319 struct source *bestbuddy = NULL;
320 double d, r, mindist = MAXBUDDY;
321
322 r = sqrt(s->dom/PI);
323 for ( ; l != NULL; l = l->next) {
324 d = sqrt(dist2(l->dir, s->dir)) - sqrt(l->dom/PI) - r;
325 if (d < mindist) {
326 bestbuddy = l;
327 mindist = d;
328 }
329 }
330 return(bestbuddy);
331 }
332
333
334 absorb_specks() /* eliminate too-small sources */
335 {
336 struct source head, *buddy;
337 register struct source *last, *this;
338
339 if (verbose)
340 fprintf(stderr, "%s: absorbing small sources...\n", progname);
341 head.next = donelist;
342 last = &head;
343 for (this = donelist; this != NULL; this = this->next)
344 if (TOOSMALL(this)) {
345 last->next = this->next;
346 buddy = findbuddy(this, donelist);
347 if (buddy != NULL)
348 mergesource(buddy, this);
349 else
350 absorb(this);
351 this = last;
352 } else
353 last = this;
354 donelist = head.next;
355 }
356
357
358 absorb(s) /* absorb a source into indirect */
359 register struct source *s;
360 {
361 FVECT dir;
362 register int i, n;
363
364 for (i = 0; i < nglardirs; i++) {
365 spinvector(dir, ourview.vdir, ourview.vup, indirect[i].theta);
366 n = DOT(dir,s->dir)*s->dom*(sampdens*sampdens) + 0.5;
367 if (n == 0)
368 continue;
369 indirect[i].sum += n * s->brt;
370 indirect[i].n += n;
371 }
372 for ( ; s->first != NULL; s->first = s->first->next)
373 free((char *)s->first);
374 free((char *)s);
375 }