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#ifndef lint |
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static const char RCSid[] = "$Id: glaresrc.c,v 2.4 2003/02/22 02:07:30 greg Exp $"; |
3 |
#endif |
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/* |
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* Gather samples and compute glare sources. |
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*/ |
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|
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#include "glare.h" |
9 |
#include "linregr.h" |
10 |
|
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#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 |
static struct srcspan * newspan(int l, int r, int v, float *sb); |
18 |
static struct srcspan * newspan(int l, int r, int v, float *sb); |
19 |
static void addindirect(int h, int v, double br); |
20 |
static void addsrcspan(struct srcspan *nss); |
21 |
static void mergesource(struct source *sp, struct source *ap); |
22 |
static void close_sources(int v); |
23 |
static void close_allsrcs(void); |
24 |
static struct srcspan * splitspan(register struct srcspan *sso, double h, double v, double m); |
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static struct source * splitsource(struct source *so); |
26 |
static void donesource(register struct source *sp); |
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static struct source * findbuddy(register struct source *s, register struct source *l); |
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static void absorb(register struct source *s); |
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static void freespans(struct source *sp); |
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|
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|
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static struct srcspan * |
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newspan( /* allocate a new source span */ |
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int l, |
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int r, |
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int v, |
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float *sb |
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) |
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{ |
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register struct srcspan *ss; |
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register int i; |
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|
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ss = (struct srcspan *)malloc(sizeof(struct srcspan)); |
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if (ss == NULL) |
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memerr("source spans"); |
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ss->l = l; |
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ss->r = r; |
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ss->v = v; |
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ss->brsum = 0.0; |
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for (i = l; i < r; i++) |
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ss->brsum += sb[i+hsize]; |
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return(ss); |
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} |
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|
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|
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extern void |
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analyze(void) /* analyze our scene */ |
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{ |
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int h, v; |
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int left; |
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float *spanbr; |
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|
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spanbr = (float *)malloc((2*hsize+1)*sizeof(float)); |
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if (spanbr == NULL) |
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memerr("view span brightness buffer"); |
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for (v = vsize; v >= -vsize; v--) { |
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close_sources(v); |
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#ifndef DEBUG |
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if (verbose) { |
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fprintf(stderr, "%s: analyzing... %3ld%%\r", |
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progname, 100L*(vsize-v)/(2*vsize)); |
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fflush(stderr); |
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} |
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#endif |
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getviewspan(v, spanbr); |
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left = hsize + 1; |
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for (h = -hsize; h <= hsize; h++) { |
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if (spanbr[h+hsize] < 0.0) { /* off view */ |
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if (left < h) { |
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addsrcspan(newspan(left,h,v,spanbr)); |
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left = hsize + 1; |
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} |
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continue; |
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} |
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if (spanbr[h+hsize] > threshold) { /* in source */ |
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if (left > h) |
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left = h; |
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} else { /* out of source */ |
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if (left < h) { |
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addsrcspan(newspan(left,h,v,spanbr)); |
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left = hsize + 1; |
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} |
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addindirect(h, v, spanbr[h+hsize]); |
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} |
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} |
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if (left < h) |
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addsrcspan(newspan(left,h,v,spanbr)); |
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} |
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free((void *)spanbr); |
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close_allsrcs(); |
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} |
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|
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|
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static void |
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addindirect( /* add brightness to indirect illuminances */ |
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int h, |
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int v, |
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double br |
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) |
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{ |
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double tanb, d; |
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int hl; |
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register int i; |
114 |
|
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hl = hlim(v); |
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if (h <= -hl) { /* left region */ |
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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); |
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for (i = 0; i < nglardirs; i++) { |
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d = indirect[i].lcos - tanb*indirect[i].lsin; |
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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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return; |
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} |
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if (h >= hl) { /* right region */ |
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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); |
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for (i = 0; i < nglardirs; i++) { |
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d = indirect[i].rcos - tanb*indirect[i].rsin; |
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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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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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extern void |
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comp_thresh(void) /* 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", |
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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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} |
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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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static void |
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addsrcspan( /* add new source span to our list */ |
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struct srcspan *nss |
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) |
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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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static void |
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mergesource( /* merge source ap into source sp */ |
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struct source *sp, |
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struct source *ap |
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) |
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{ |
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struct srcspan head; |
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register struct srcspan *alp, *prev, *tp; |
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|
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head.next = sp->first; |
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prev = &head; |
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alp = ap->first; |
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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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} |
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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); |
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normalize(sp->dir); |
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sp->brt = (sp->brt*sp->dom + ap->brt*ap->dom) |
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/ (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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static void |
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close_sources( /* close sources above v */ |
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int v |
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) |
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{ |
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struct source head; |
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register struct source *last, *this; |
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|
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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) |
283 |
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; |
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} |
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|
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|
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static void |
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close_allsrcs(void) /* done with everything */ |
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{ |
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register struct source *this, *next; |
297 |
|
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this = curlist; |
299 |
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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} |
304 |
curlist = NULL; |
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} |
306 |
|
307 |
|
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static struct srcspan * |
309 |
splitspan( /* divide source span at point */ |
310 |
register struct srcspan *sso, |
311 |
double h, |
312 |
double v, |
313 |
double m |
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) |
315 |
{ |
316 |
register struct srcspan *ssn; |
317 |
double d; |
318 |
int hs; |
319 |
|
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d = h - m*(sso->v - v); |
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hs = d < 0. ? d-.5 : d+.5; |
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if (sso->l >= hs) |
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return(NULL); |
324 |
if (sso->r <= hs) |
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return(sso); |
326 |
/* need to split it */ |
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ssn = (struct srcspan *)malloc(sizeof(struct srcspan)); |
328 |
if (ssn == NULL) |
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memerr("source spans in splitspan"); |
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ssn->brsum = (double)(hs - sso->l)/(sso->r - sso->l) * sso->brsum; |
331 |
sso->brsum -= ssn->brsum; |
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ssn->v = sso->v; |
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ssn->l = sso->l; |
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ssn->r = sso->l = hs; |
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return(ssn); |
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} |
337 |
|
338 |
|
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static struct source * |
340 |
splitsource( /* divide source in two if it's big and long */ |
341 |
struct source *so |
342 |
) |
343 |
{ |
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LRSUM lr; |
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LRLIN fit; |
346 |
register struct srcspan *ss, *ssn; |
347 |
struct srcspan *ssl, *ssnl, head; |
348 |
int h; |
349 |
double mh, mv; |
350 |
struct source *sn; |
351 |
|
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lrclear(&lr); |
353 |
for (ss = so->first; ss != NULL; ss = ss->next) |
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for (h = ss->l; h < ss->r; h++) |
355 |
lrpoint(h, ss->v, &lr); |
356 |
if ((double)lr.n/(sampdens*sampdens) < SABIG) |
357 |
return(NULL); /* too small */ |
358 |
if (lrfit(&fit, &lr) < 0) |
359 |
return(NULL); /* can't fit a line */ |
360 |
if (fit.correlation < LCORR && fit.correlation > -LCORR) |
361 |
return(NULL); |
362 |
if (verbose) |
363 |
fprintf(stderr, "%s: splitting large source\n", progname); |
364 |
mh = lrxavg(&lr); |
365 |
mv = lryavg(&lr); |
366 |
sn = (struct source *)malloc(sizeof(struct source)); |
367 |
if (sn == NULL) |
368 |
memerr("source records in splitsource"); |
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sn->dom = 0.0; |
370 |
sn->first = NULL; |
371 |
ssnl = NULL; |
372 |
head.next = so->first; |
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ssl = &head; |
374 |
for (ss = so->first; ss != NULL; ssl = ss, ss = ss->next) |
375 |
if ((ssn = splitspan(ss, mh, mv, fit.slope)) != NULL) { |
376 |
if (ssn == ss) { /* remove from old */ |
377 |
ssl->next = ss->next; |
378 |
ss = ssl; |
379 |
} |
380 |
if (ssnl == NULL) /* add to new */ |
381 |
sn->first = ssn; |
382 |
else |
383 |
ssnl->next = ssn; |
384 |
ssn->next = NULL; |
385 |
ssnl = ssn; |
386 |
} |
387 |
so->first = head.next; |
388 |
return(sn); |
389 |
} |
390 |
|
391 |
|
392 |
static void |
393 |
donesource( /* finished with this source */ |
394 |
register struct source *sp |
395 |
) |
396 |
{ |
397 |
struct source *newsrc; |
398 |
register struct srcspan *ss; |
399 |
int h, n; |
400 |
double hsum, vsum, d; |
401 |
|
402 |
while ((newsrc = splitsource(sp)) != NULL) /* split it? */ |
403 |
donesource(newsrc); |
404 |
sp->dom = 0.0; |
405 |
hsum = vsum = 0.0; |
406 |
sp->brt = 0.0; |
407 |
n = 0; |
408 |
for (ss = sp->first; ss != NULL; ss = ss->next) { |
409 |
sp->brt += ss->brsum; |
410 |
n += ss->r - ss->l; |
411 |
for (h = ss->l; h < ss->r; h++) { |
412 |
d = pixsize(h, ss->v); |
413 |
hsum += d*h; |
414 |
vsum += d*ss->v; |
415 |
sp->dom += d; |
416 |
} |
417 |
} |
418 |
freespans(sp); |
419 |
if (sp->dom <= FTINY) { /* must be right at edge of image */ |
420 |
free((void *)sp); |
421 |
return; |
422 |
} |
423 |
sp->brt /= (double)n; |
424 |
compdir(sp->dir, (int)(hsum/sp->dom), (int)(vsum/sp->dom)); |
425 |
sp->next = donelist; |
426 |
donelist = sp; |
427 |
if (verbose) |
428 |
fprintf(stderr, |
429 |
"%s: source at [%.3f,%.3f,%.3f], dw %.5f, br %.1f (%d samps)\n", |
430 |
progname, sp->dir[0], sp->dir[1], sp->dir[2], |
431 |
sp->dom, sp->brt, n); |
432 |
} |
433 |
|
434 |
|
435 |
static struct source * |
436 |
findbuddy( /* find close enough source to s in l*/ |
437 |
register struct source *s, |
438 |
register struct source *l |
439 |
) |
440 |
{ |
441 |
struct source *bestbuddy = NULL; |
442 |
double d, r, mindist = MAXBUDDY; |
443 |
|
444 |
r = sqrt(s->dom/PI); |
445 |
for ( ; l != NULL; l = l->next) { |
446 |
d = sqrt(dist2(l->dir, s->dir)) - sqrt(l->dom/PI) - r; |
447 |
if (d < mindist) { |
448 |
bestbuddy = l; |
449 |
mindist = d; |
450 |
} |
451 |
} |
452 |
return(bestbuddy); |
453 |
} |
454 |
|
455 |
|
456 |
extern void |
457 |
absorb_specks(void) /* eliminate too-small sources */ |
458 |
{ |
459 |
struct source head, *buddy; |
460 |
register struct source *last, *this; |
461 |
|
462 |
if (verbose) |
463 |
fprintf(stderr, "%s: absorbing small sources...\n", progname); |
464 |
head.next = donelist; |
465 |
last = &head; |
466 |
for (this = head.next; this != NULL; this = this->next) |
467 |
if (TOOSMALL(this)) { |
468 |
last->next = this->next; |
469 |
buddy = findbuddy(this, head.next); |
470 |
if (buddy != NULL) |
471 |
mergesource(buddy, this); |
472 |
else |
473 |
absorb(this); |
474 |
this = last; |
475 |
} else |
476 |
last = this; |
477 |
donelist = head.next; |
478 |
} |
479 |
|
480 |
|
481 |
static void |
482 |
absorb( /* absorb a source into indirect */ |
483 |
register struct source *s |
484 |
) |
485 |
{ |
486 |
FVECT dir; |
487 |
double d; |
488 |
register int i; |
489 |
|
490 |
for (i = 0; i < nglardirs; i++) { |
491 |
spinvector(dir, ourview.vdir, ourview.vup, indirect[i].theta); |
492 |
d = DOT(dir,s->dir)*s->dom*(sampdens*sampdens); |
493 |
if (d <= 0.0) |
494 |
continue; |
495 |
indirect[i].sum += d * s->brt; |
496 |
indirect[i].n += d; |
497 |
} |
498 |
freespans(s); |
499 |
free((void *)s); |
500 |
} |
501 |
|
502 |
|
503 |
static void |
504 |
freespans( /* free spans associated with source */ |
505 |
struct source *sp |
506 |
) |
507 |
{ |
508 |
register struct srcspan *ss; |
509 |
|
510 |
while ((ss = sp->first) != NULL) { |
511 |
sp->first = ss->next; |
512 |
free((void *)ss); |
513 |
} |
514 |
} |