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#ifndef lint |
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static const char RCSid[] = "$Id$"; |
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#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" |
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#include "linregr.h" |
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|
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#define vcont(vd,vu) ((vu)-(vd)<=SEPS) |
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#define hcont(s1,s2) ((s1)->r-(s2)->l>=-SEPS&&(s2)->r-(s1)->l>=-SEPS) |
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|
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struct source *curlist = NULL; /* current source list */ |
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struct source *donelist = NULL; /* finished sources */ |
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|
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|
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struct srcspan * |
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newspan(l, r, v, sb) /* allocate a new source span */ |
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int l, r, v; |
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float *sb; |
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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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analyze() /* 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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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; |
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register int i; |
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|
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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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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", |
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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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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 */ |
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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; |
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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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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; |
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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) |
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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; |
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} |
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|
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|
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close_allsrcs() /* done with everything */ |
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{ |
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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 * |
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splitspan(sso, h, v, m) /* divide source span at point */ |
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register struct srcspan *sso; |
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double h, v, m; |
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{ |
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register struct srcspan *ssn; |
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double d; |
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int hs; |
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|
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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); |
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if (sso->r <= hs) |
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return(sso); |
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/* need to split it */ |
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ssn = (struct srcspan *)malloc(sizeof(struct srcspan)); |
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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; |
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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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} |
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|
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|
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struct source * |
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splitsource(so) /* divide source in two if it's big and long */ |
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struct source *so; |
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{ |
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LRSUM lr; |
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LRLIN fit; |
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register struct srcspan *ss, *ssn; |
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struct srcspan *ssl, *ssnl, head; |
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int h; |
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double mh, mv; |
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struct source *sn; |
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|
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lrclear(&lr); |
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for (ss = so->first; ss != NULL; ss = ss->next) |
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for (h = ss->l; h < ss->r; h++) |
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lrpoint(h, ss->v, &lr); |
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if ((double)lr.n/(sampdens*sampdens) < SABIG) |
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return(NULL); /* too small */ |
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if (lrfit(&fit, &lr) < 0) |
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return(NULL); /* can't fit a line */ |
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if (fit.correlation < LCORR && fit.correlation > -LCORR) |
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return(NULL); |
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if (verbose) |
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fprintf(stderr, "%s: splitting large source\n", progname); |
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mh = lrxavg(&lr); |
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mv = lryavg(&lr); |
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sn = (struct source *)malloc(sizeof(struct source)); |
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if (sn == NULL) |
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memerr("source records in splitsource"); |
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sn->dom = 0.0; |
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sn->first = NULL; |
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ssnl = NULL; |
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head.next = so->first; |
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ssl = &head; |
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for (ss = so->first; ss != NULL; ssl = ss, ss = ss->next) |
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if ((ssn = splitspan(ss, mh, mv, fit.slope)) != NULL) { |
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if (ssn == ss) { /* remove from old */ |
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ssl->next = ss->next; |
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ss = ssl; |
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} |
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if (ssnl == NULL) /* add to new */ |
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sn->first = ssn; |
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else |
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ssnl->next = ssn; |
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ssn->next = NULL; |
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ssnl = ssn; |
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} |
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so->first = head.next; |
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return(sn); |
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} |
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|
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|
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donesource(sp) /* finished with this source */ |
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register struct source *sp; |
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{ |
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struct source *newsrc; |
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register struct srcspan *ss; |
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int h, n; |
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double hsum, vsum, d; |
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|
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while ((newsrc = splitsource(sp)) != NULL) /* split it? */ |
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donesource(newsrc); |
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sp->dom = 0.0; |
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hsum = vsum = 0.0; |
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sp->brt = 0.0; |
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n = 0; |
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for (ss = sp->first; ss != NULL; ss = ss->next) { |
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sp->brt += ss->brsum; |
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n += ss->r - ss->l; |
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for (h = ss->l; h < ss->r; h++) { |
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d = pixsize(h, ss->v); |
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hsum += d*h; |
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vsum += d*ss->v; |
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sp->dom += d; |
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} |
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} |
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freespans(sp); |
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if (sp->dom <= FTINY) { /* must be right at edge of image */ |
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free((void *)sp); |
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return; |
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} |
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sp->brt /= (double)n; |
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compdir(sp->dir, (int)(hsum/sp->dom), (int)(vsum/sp->dom)); |
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sp->next = donelist; |
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donelist = sp; |
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if (verbose) |
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fprintf(stderr, |
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"%s: source at [%.3f,%.3f,%.3f], dw %.5f, br %.1f (%d samps)\n", |
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progname, sp->dir[0], sp->dir[1], sp->dir[2], |
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sp->dom, sp->brt, n); |
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} |
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|
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|
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struct source * |
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findbuddy(s, l) /* find close enough source to s in l*/ |
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register struct source *s, *l; |
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{ |
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struct source *bestbuddy = NULL; |
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double d, r, mindist = MAXBUDDY; |
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|
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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) { |
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bestbuddy = l; |
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mindist = d; |
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} |
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} |
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return(bestbuddy); |
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} |
416 |
|
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|
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absorb_specks() /* eliminate too-small sources */ |
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{ |
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struct source head, *buddy; |
421 |
register struct source *last, *this; |
422 |
|
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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 |
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absorb(this); |
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this = last; |
436 |
} else |
437 |
last = this; |
438 |
donelist = head.next; |
439 |
} |
440 |
|
441 |
|
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absorb(s) /* absorb a source into indirect */ |
443 |
register struct source *s; |
444 |
{ |
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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 |
} |