| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id$"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Gather samples and compute glare sources. |
| 6 |
*/ |
| 7 |
|
| 8 |
#include "glare.h" |
| 9 |
#include "linregr.h" |
| 10 |
|
| 11 |
#define vcont(vd,vu) ((vu)-(vd)<=SEPS) |
| 12 |
#define hcont(s1,s2) ((s1)->r-(s2)->l>=-SEPS&&(s2)->r-(s1)->l>=-SEPS) |
| 13 |
|
| 14 |
struct source *curlist = NULL; /* current source list */ |
| 15 |
struct source *donelist = NULL; /* finished sources */ |
| 16 |
|
| 17 |
|
| 18 |
struct srcspan * |
| 19 |
newspan(l, r, v, sb) /* allocate a new source span */ |
| 20 |
int l, r, v; |
| 21 |
float *sb; |
| 22 |
{ |
| 23 |
register struct srcspan *ss; |
| 24 |
register int i; |
| 25 |
|
| 26 |
ss = (struct srcspan *)malloc(sizeof(struct srcspan)); |
| 27 |
if (ss == NULL) |
| 28 |
memerr("source spans"); |
| 29 |
ss->l = l; |
| 30 |
ss->r = r; |
| 31 |
ss->v = v; |
| 32 |
ss->brsum = 0.0; |
| 33 |
for (i = l; i < r; i++) |
| 34 |
ss->brsum += sb[i+hsize]; |
| 35 |
return(ss); |
| 36 |
} |
| 37 |
|
| 38 |
|
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analyze() /* analyze our scene */ |
| 40 |
{ |
| 41 |
int h, v; |
| 42 |
int left; |
| 43 |
float *spanbr; |
| 44 |
|
| 45 |
spanbr = (float *)malloc((2*hsize+1)*sizeof(float)); |
| 46 |
if (spanbr == NULL) |
| 47 |
memerr("view span brightness buffer"); |
| 48 |
for (v = vsize; v >= -vsize; v--) { |
| 49 |
close_sources(v); |
| 50 |
#ifndef DEBUG |
| 51 |
if (verbose) { |
| 52 |
fprintf(stderr, "%s: analyzing... %3ld%%\r", |
| 53 |
progname, 100L*(vsize-v)/(2*vsize)); |
| 54 |
fflush(stderr); |
| 55 |
} |
| 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) |
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left = h; |
| 70 |
} else { /* out of source */ |
| 71 |
if (left < h) { |
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addsrcspan(newspan(left,h,v,spanbr)); |
| 73 |
left = hsize + 1; |
| 74 |
} |
| 75 |
addindirect(h, v, spanbr[h+hsize]); |
| 76 |
} |
| 77 |
} |
| 78 |
if (left < h) |
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addsrcspan(newspan(left,h,v,spanbr)); |
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} |
| 81 |
free((void *)spanbr); |
| 82 |
close_allsrcs(); |
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} |
| 84 |
|
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|
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addindirect(h, v, br) /* add brightness to indirect illuminances */ |
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int h, v; |
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double br; |
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{ |
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double tanb, d; |
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int hl; |
| 92 |
register int i; |
| 93 |
|
| 94 |
hl = hlim(v); |
| 95 |
if (h <= -hl) { /* left region */ |
| 96 |
d = (double)(-h-hl)/sampdens; |
| 97 |
if (d >= 1.0-FTINY) |
| 98 |
return; |
| 99 |
tanb = d/sqrt(1.0-d*d); |
| 100 |
for (i = 0; i < nglardirs; i++) { |
| 101 |
d = indirect[i].lcos - tanb*indirect[i].lsin; |
| 102 |
if (d > 0.0) { |
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indirect[i].sum += d * br; |
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indirect[i].n += d; |
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} |
| 106 |
} |
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return; |
| 108 |
} |
| 109 |
if (h >= hl) { /* right region */ |
| 110 |
d = (double)(-h+hl)/sampdens; |
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if (d <= -1.0+FTINY) |
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return; |
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tanb = d/sqrt(1.0-d*d); |
| 114 |
for (i = 0; i < nglardirs; i++) { |
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d = indirect[i].rcos - tanb*indirect[i].rsin; |
| 116 |
if (d > 0.0) { |
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indirect[i].sum += d * br; |
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indirect[i].n += d; |
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} |
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} |
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return; |
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} |
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/* central region */ |
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for (i = 0; i < nglardirs; i++) { |
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d = cos(h_theta(h,v) - indirect[i].theta); |
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if (d > 0.0) { |
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indirect[i].sum += d * br; |
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indirect[i].n += d; |
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} |
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} |
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} |
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|
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|
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comp_thresh() /* compute glare threshold */ |
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{ |
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int h, v; |
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int nsamps; |
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double brsum, br; |
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|
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if (verbose) |
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fprintf(stderr, "%s: computing glare threshold...\n", |
| 142 |
progname); |
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brsum = 0.0; |
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nsamps = 0; |
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for (v = vsize; v >= -vsize; v -= TSAMPSTEP) { |
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for (h = -hsize; h <= hsize; h += TSAMPSTEP) { |
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if ((br = getviewpix(h, v)) < 0.0) |
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continue; |
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brsum += br; |
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nsamps++; |
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} |
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} |
| 153 |
if (nsamps == 0) { |
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fprintf(stderr, "%s: no viewable scene!\n", progname); |
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exit(1); |
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} |
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threshold = GLAREBR * brsum / nsamps; |
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if (threshold <= FTINY) { |
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fprintf(stderr, "%s: threshold zero!\n", progname); |
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exit(1); |
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} |
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if (verbose) { |
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#ifdef DEBUG |
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pict_stats(); |
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#endif |
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fprintf(stderr, |
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"%s: threshold set to %f cd/m2 from %d samples\n", |
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progname, threshold, nsamps); |
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} |
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} |
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|
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|
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addsrcspan(nss) /* add new source span to our list */ |
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struct srcspan *nss; |
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{ |
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struct source *last, *cs, *this; |
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register struct srcspan *ss; |
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|
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cs = NULL; |
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for (this = curlist; this != NULL; this = this->next) { |
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for (ss = this->first; ss != NULL; ss = ss->next) { |
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if (!vcont(nss->v, ss->v)) |
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break; |
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if (hcont(ss, nss)) { |
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if (cs == NULL) |
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cs = this; |
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else { |
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last->next = this->next; |
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mergesource(cs, this); |
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this = last; |
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} |
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break; |
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} |
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} |
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last = this; |
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} |
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if (cs == NULL) { |
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cs = (struct source *)malloc(sizeof(struct source)); |
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if (cs == NULL) |
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memerr("source records"); |
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cs->dom = 0.0; |
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cs->first = NULL; |
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cs->next = curlist; |
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curlist = cs; |
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} |
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nss->next = cs->first; |
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cs->first = nss; |
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} |
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|
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|
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mergesource(sp, ap) /* merge source ap into source sp */ |
| 212 |
struct source *sp, *ap; |
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{ |
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struct srcspan head; |
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register struct srcspan *alp, *prev, *tp; |
| 216 |
|
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head.next = sp->first; |
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prev = &head; |
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alp = ap->first; |
| 220 |
while (alp != NULL && prev->next != NULL) { |
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if (prev->next->v > alp->v) { |
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tp = alp->next; |
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alp->next = prev->next; |
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prev->next = alp; |
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alp = tp; |
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} |
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prev = prev->next; |
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} |
| 229 |
if (prev->next == NULL) |
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prev->next = alp; |
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sp->first = head.next; |
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if (ap->dom > 0.0 && sp->dom > 0.0) { /* sources are done */ |
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sp->dir[0] *= sp->dom; |
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sp->dir[1] *= sp->dom; |
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sp->dir[2] *= sp->dom; |
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fvsum(sp->dir, sp->dir, ap->dir, ap->dom); |
| 237 |
normalize(sp->dir); |
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sp->brt = (sp->brt*sp->dom + ap->brt*ap->dom) |
| 239 |
/ (sp->dom + ap->dom); |
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} |
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free((void *)ap); |
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} |
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|
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|
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close_sources(v) /* close sources above v */ |
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int v; |
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{ |
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struct source head; |
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register struct source *last, *this; |
| 250 |
|
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head.next = curlist; |
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last = &head; |
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for (this = curlist; this != NULL; this = this->next) |
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if (!vcont(v, this->first->v)) { |
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last->next = this->next; |
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donesource(this); |
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this = last; |
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} else |
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last = this; |
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curlist = head.next; |
| 261 |
} |
| 262 |
|
| 263 |
|
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close_allsrcs() /* done with everything */ |
| 265 |
{ |
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register struct source *this, *next; |
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|
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this = curlist; |
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while (this != NULL) { |
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next = this->next; |
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donesource(this); |
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this = next; |
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} |
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curlist = NULL; |
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} |
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|
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|
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struct srcspan * |
| 279 |
splitspan(sso, h, v, m) /* divide source span at point */ |
| 280 |
register struct srcspan *sso; |
| 281 |
double h, v, m; |
| 282 |
{ |
| 283 |
register struct srcspan *ssn; |
| 284 |
double d; |
| 285 |
int hs; |
| 286 |
|
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d = h - m*(sso->v - v); |
| 288 |
hs = d < 0. ? d-.5 : d+.5; |
| 289 |
if (sso->l >= hs) |
| 290 |
return(NULL); |
| 291 |
if (sso->r <= hs) |
| 292 |
return(sso); |
| 293 |
/* need to split it */ |
| 294 |
ssn = (struct srcspan *)malloc(sizeof(struct srcspan)); |
| 295 |
if (ssn == NULL) |
| 296 |
memerr("source spans in splitspan"); |
| 297 |
ssn->brsum = (double)(hs - sso->l)/(sso->r - sso->l) * sso->brsum; |
| 298 |
sso->brsum -= ssn->brsum; |
| 299 |
ssn->v = sso->v; |
| 300 |
ssn->l = sso->l; |
| 301 |
ssn->r = sso->l = hs; |
| 302 |
return(ssn); |
| 303 |
} |
| 304 |
|
| 305 |
|
| 306 |
struct source * |
| 307 |
splitsource(so) /* divide source in two if it's big and long */ |
| 308 |
struct source *so; |
| 309 |
{ |
| 310 |
LRSUM lr; |
| 311 |
LRLIN fit; |
| 312 |
register struct srcspan *ss, *ssn; |
| 313 |
struct srcspan *ssl, *ssnl, head; |
| 314 |
int h; |
| 315 |
double mh, mv; |
| 316 |
struct source *sn; |
| 317 |
|
| 318 |
lrclear(&lr); |
| 319 |
for (ss = so->first; ss != NULL; ss = ss->next) |
| 320 |
for (h = ss->l; h < ss->r; h++) |
| 321 |
lrpoint(h, ss->v, &lr); |
| 322 |
if ((double)lr.n/(sampdens*sampdens) < SABIG) |
| 323 |
return(NULL); /* too small */ |
| 324 |
if (lrfit(&fit, &lr) < 0) |
| 325 |
return(NULL); /* can't fit a line */ |
| 326 |
if (fit.correlation < LCORR && fit.correlation > -LCORR) |
| 327 |
return(NULL); |
| 328 |
if (verbose) |
| 329 |
fprintf(stderr, "%s: splitting large source\n", progname); |
| 330 |
mh = lrxavg(&lr); |
| 331 |
mv = lryavg(&lr); |
| 332 |
sn = (struct source *)malloc(sizeof(struct source)); |
| 333 |
if (sn == NULL) |
| 334 |
memerr("source records in splitsource"); |
| 335 |
sn->dom = 0.0; |
| 336 |
sn->first = NULL; |
| 337 |
ssnl = NULL; |
| 338 |
head.next = so->first; |
| 339 |
ssl = &head; |
| 340 |
for (ss = so->first; ss != NULL; ssl = ss, ss = ss->next) |
| 341 |
if ((ssn = splitspan(ss, mh, mv, fit.slope)) != NULL) { |
| 342 |
if (ssn == ss) { /* remove from old */ |
| 343 |
ssl->next = ss->next; |
| 344 |
ss = ssl; |
| 345 |
} |
| 346 |
if (ssnl == NULL) /* add to new */ |
| 347 |
sn->first = ssn; |
| 348 |
else |
| 349 |
ssnl->next = ssn; |
| 350 |
ssn->next = NULL; |
| 351 |
ssnl = ssn; |
| 352 |
} |
| 353 |
so->first = head.next; |
| 354 |
return(sn); |
| 355 |
} |
| 356 |
|
| 357 |
|
| 358 |
donesource(sp) /* finished with this source */ |
| 359 |
register struct source *sp; |
| 360 |
{ |
| 361 |
struct source *newsrc; |
| 362 |
register struct srcspan *ss; |
| 363 |
int h, n; |
| 364 |
double hsum, vsum, d; |
| 365 |
|
| 366 |
while ((newsrc = splitsource(sp)) != NULL) /* split it? */ |
| 367 |
donesource(newsrc); |
| 368 |
sp->dom = 0.0; |
| 369 |
hsum = vsum = 0.0; |
| 370 |
sp->brt = 0.0; |
| 371 |
n = 0; |
| 372 |
for (ss = sp->first; ss != NULL; ss = ss->next) { |
| 373 |
sp->brt += ss->brsum; |
| 374 |
n += ss->r - ss->l; |
| 375 |
for (h = ss->l; h < ss->r; h++) { |
| 376 |
d = pixsize(h, ss->v); |
| 377 |
hsum += d*h; |
| 378 |
vsum += d*ss->v; |
| 379 |
sp->dom += d; |
| 380 |
} |
| 381 |
} |
| 382 |
freespans(sp); |
| 383 |
if (sp->dom <= FTINY) { /* must be right at edge of image */ |
| 384 |
free((void *)sp); |
| 385 |
return; |
| 386 |
} |
| 387 |
sp->brt /= (double)n; |
| 388 |
compdir(sp->dir, (int)(hsum/sp->dom), (int)(vsum/sp->dom)); |
| 389 |
sp->next = donelist; |
| 390 |
donelist = sp; |
| 391 |
if (verbose) |
| 392 |
fprintf(stderr, |
| 393 |
"%s: source at [%.3f,%.3f,%.3f], dw %.5f, br %.1f (%d samps)\n", |
| 394 |
progname, sp->dir[0], sp->dir[1], sp->dir[2], |
| 395 |
sp->dom, sp->brt, n); |
| 396 |
} |
| 397 |
|
| 398 |
|
| 399 |
struct source * |
| 400 |
findbuddy(s, l) /* find close enough source to s in l*/ |
| 401 |
register struct source *s, *l; |
| 402 |
{ |
| 403 |
struct source *bestbuddy = NULL; |
| 404 |
double d, r, mindist = MAXBUDDY; |
| 405 |
|
| 406 |
r = sqrt(s->dom/PI); |
| 407 |
for ( ; l != NULL; l = l->next) { |
| 408 |
d = sqrt(dist2(l->dir, s->dir)) - sqrt(l->dom/PI) - r; |
| 409 |
if (d < mindist) { |
| 410 |
bestbuddy = l; |
| 411 |
mindist = d; |
| 412 |
} |
| 413 |
} |
| 414 |
return(bestbuddy); |
| 415 |
} |
| 416 |
|
| 417 |
|
| 418 |
absorb_specks() /* eliminate too-small sources */ |
| 419 |
{ |
| 420 |
struct source head, *buddy; |
| 421 |
register struct source *last, *this; |
| 422 |
|
| 423 |
if (verbose) |
| 424 |
fprintf(stderr, "%s: absorbing small sources...\n", progname); |
| 425 |
head.next = donelist; |
| 426 |
last = &head; |
| 427 |
for (this = head.next; this != NULL; this = this->next) |
| 428 |
if (TOOSMALL(this)) { |
| 429 |
last->next = this->next; |
| 430 |
buddy = findbuddy(this, head.next); |
| 431 |
if (buddy != NULL) |
| 432 |
mergesource(buddy, this); |
| 433 |
else |
| 434 |
absorb(this); |
| 435 |
this = last; |
| 436 |
} else |
| 437 |
last = this; |
| 438 |
donelist = head.next; |
| 439 |
} |
| 440 |
|
| 441 |
|
| 442 |
absorb(s) /* absorb a source into indirect */ |
| 443 |
register struct source *s; |
| 444 |
{ |
| 445 |
FVECT dir; |
| 446 |
double d; |
| 447 |
register int i; |
| 448 |
|
| 449 |
for (i = 0; i < nglardirs; i++) { |
| 450 |
spinvector(dir, ourview.vdir, ourview.vup, indirect[i].theta); |
| 451 |
d = DOT(dir,s->dir)*s->dom*(sampdens*sampdens); |
| 452 |
if (d <= 0.0) |
| 453 |
continue; |
| 454 |
indirect[i].sum += d * s->brt; |
| 455 |
indirect[i].n += d; |
| 456 |
} |
| 457 |
freespans(s); |
| 458 |
free((void *)s); |
| 459 |
} |
| 460 |
|
| 461 |
|
| 462 |
freespans(sp) /* free spans associated with source */ |
| 463 |
struct source *sp; |
| 464 |
{ |
| 465 |
register struct srcspan *ss; |
| 466 |
|
| 467 |
while ((ss = sp->first) != NULL) { |
| 468 |
sp->first = ss->next; |
| 469 |
free((void *)ss); |
| 470 |
} |
| 471 |
} |
