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#ifndef lint |
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static const char RCSid[] = "$Id: virtuals.c,v 2.19 2011/08/16 18:09:53 greg Exp $"; |
3 |
#endif |
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/* |
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* Routines for simulating virtual light sources |
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* Thus far, we only support planar mirrors. |
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* |
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* External symbols declared in source.h |
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*/ |
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|
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#include "copyright.h" |
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|
13 |
#include "ray.h" |
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|
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#include "otypes.h" |
16 |
|
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#include "source.h" |
18 |
|
19 |
#include "random.h" |
20 |
|
21 |
#define MINSAMPLES 16 /* minimum number of pretest samples */ |
22 |
#define STESTMAX 32 /* maximum seeks per sample */ |
23 |
|
24 |
#define FEQ(a,b) ((a)-(b)+FTINY >= 0 && (b)-(a)+FTINY >= 0) |
25 |
|
26 |
|
27 |
static OBJECT *vobject; /* virtual source objects */ |
28 |
static int nvobjects = 0; /* number of virtual source objects */ |
29 |
|
30 |
|
31 |
static int |
32 |
isident4(MAT4 m) |
33 |
{ |
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int i, j; |
35 |
|
36 |
for (i = 4; i--; ) |
37 |
for (j = 4; j--; ) |
38 |
if (!FEQ(m[i][j], i==j)) |
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return(0); |
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return(1); |
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} |
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|
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|
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void |
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markvirtuals(void) /* find and mark virtual sources */ |
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{ |
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OBJREC *o; |
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int i; |
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/* check number of direct relays */ |
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if (directrelay <= 0) |
51 |
return; |
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/* find virtual source objects */ |
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for (i = 0; i < nsceneobjs; i++) { |
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o = objptr(i); |
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if (!issurface(o->otype) || o->omod == OVOID) |
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continue; |
57 |
if (!isvlight(vsmaterial(o)->otype)) |
58 |
continue; |
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if (sfun[o->otype].of == NULL || |
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sfun[o->otype].of->getpleq == NULL) { |
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objerror(o,WARNING,"secondary sources not supported"); |
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continue; |
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} |
64 |
if (nvobjects == 0) |
65 |
vobject = (OBJECT *)malloc(sizeof(OBJECT)); |
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else |
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vobject = (OBJECT *)realloc((void *)vobject, |
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(unsigned)(nvobjects+1)*sizeof(OBJECT)); |
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if (vobject == NULL) |
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error(SYSTEM, "out of memory in addvirtuals"); |
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vobject[nvobjects++] = i; |
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} |
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if (nvobjects == 0) |
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return; |
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#ifdef DEBUG |
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fprintf(stderr, "found %d virtual source objects\n", nvobjects); |
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#endif |
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/* append virtual sources */ |
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for (i = nsources; i-- > 0; ) |
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addvirtuals(i, directrelay); |
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/* done with our object list */ |
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free((void *)vobject); |
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nvobjects = 0; |
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} |
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|
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|
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void |
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addvirtuals( /* add virtuals associated with source */ |
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int sn, |
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int nr |
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) |
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{ |
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int i; |
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/* check relay limit first */ |
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if (nr <= 0) |
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return; |
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if (source[sn].sflags & SSKIP) |
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return; |
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/* check each virtual object for projection */ |
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for (i = 0; i < nvobjects; i++) |
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/* vproject() calls us recursively */ |
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vproject(objptr(vobject[i]), sn, nr-1); |
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} |
104 |
|
105 |
|
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void |
107 |
vproject( /* create projected source(s) if they exist */ |
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OBJREC *o, |
109 |
int sn, |
110 |
int n |
111 |
) |
112 |
{ |
113 |
int i; |
114 |
VSMATERIAL *vsmat; |
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MAT4 proj; |
116 |
int ns; |
117 |
|
118 |
if (o == source[sn].so) /* objects cannot project themselves */ |
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return; |
120 |
/* get virtual source material */ |
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vsmat = sfun[vsmaterial(o)->otype].mf; |
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/* project virtual sources */ |
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for (i = 0; i < vsmat->nproj; i++) |
124 |
if ((*vsmat->vproj)(proj, o, &source[sn], i)) |
125 |
if ((ns = makevsrc(o, sn, proj)) >= 0) { |
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source[ns].sa.sv.pn = i; |
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#ifdef DEBUG |
128 |
virtverb(ns, stderr); |
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#endif |
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addvirtuals(ns, n); |
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} |
132 |
} |
133 |
|
134 |
|
135 |
OBJREC * |
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vsmaterial( /* get virtual source material pointer */ |
137 |
OBJREC *o |
138 |
) |
139 |
{ |
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int i; |
141 |
OBJREC *m; |
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|
143 |
i = o->omod; |
144 |
m = findmaterial(objptr(i)); |
145 |
if (m == NULL) |
146 |
return(objptr(i)); |
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if (m->otype != MAT_ILLUM || m->oargs.nsargs < 1 || |
148 |
!strcmp(m->oargs.sarg[0], VOIDID) || |
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(i = lastmod(objndx(m), m->oargs.sarg[0])) == OVOID) |
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return(m); /* direct modifier */ |
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return(objptr(i)); /* illum alternate */ |
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} |
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|
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|
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int |
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makevsrc( /* make virtual source if reasonable */ |
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OBJREC *op, |
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int sn, |
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MAT4 pm |
160 |
) |
161 |
{ |
162 |
FVECT nsloc, nsnorm, ocent, v; |
163 |
double maxrad2, d; |
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int nsflags; |
165 |
SPOT theirspot, ourspot; |
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int i; |
167 |
/* check for no-op */ |
168 |
if (isident4(pm)) |
169 |
return(0); |
170 |
nsflags = source[sn].sflags | (SVIRTUAL|SSPOT|SFOLLOW); |
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/* get object center and max. radius */ |
172 |
maxrad2 = getdisk(ocent, op, sn); |
173 |
if (maxrad2 <= FTINY) /* too small? */ |
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return(-1); |
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/* get location and spot */ |
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if (source[sn].sflags & SDISTANT) { /* distant source */ |
177 |
if (source[sn].sflags & SPROX) |
178 |
return(-1); /* should never get here! */ |
179 |
multv3(nsloc, source[sn].sloc, pm); |
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normalize(nsloc); |
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VCOPY(ourspot.aim, ocent); |
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ourspot.siz = PI*maxrad2; |
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ourspot.flen = -1.; |
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if (source[sn].sflags & SSPOT) { |
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multp3(theirspot.aim, source[sn].sl.s->aim, pm); |
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/* adjust for source size */ |
187 |
d = sqrt(dist2(ourspot.aim, theirspot.aim)); |
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d = sqrt(source[sn].sl.s->siz/PI) + d*source[sn].srad; |
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theirspot.siz = PI*d*d; |
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ourspot.flen = theirspot.flen = source[sn].sl.s->flen; |
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d = ourspot.siz; |
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if (!commonbeam(&ourspot, &theirspot, nsloc)) |
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return(-1); /* no overlap */ |
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if (ourspot.siz < d-FTINY) { /* it shrunk */ |
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d = beamdisk(v, op, &ourspot, nsloc); |
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if (d <= FTINY) |
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return(-1); |
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if (d < maxrad2) { |
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maxrad2 = d; |
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VCOPY(ocent, v); |
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} |
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} |
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} |
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} else { /* local source */ |
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multp3(nsloc, source[sn].sloc, pm); |
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for (i = 0; i < 3; i++) |
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ourspot.aim[i] = ocent[i] - nsloc[i]; |
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if ((d = normalize(ourspot.aim)) == 0.) |
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return(-1); /* at source!! */ |
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if (source[sn].sflags & SPROX && d > source[sn].sl.prox) |
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return(-1); /* too far away */ |
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ourspot.flen = 0.; |
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/* adjust for source size */ |
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d = (sqrt(maxrad2) + source[sn].srad) / d; |
215 |
if (d < 1.-FTINY) |
216 |
ourspot.siz = 2.*PI*(1. - sqrt(1.-d*d)); |
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else |
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nsflags &= ~SSPOT; |
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if (source[sn].sflags & SSPOT) { |
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theirspot = *(source[sn].sl.s); |
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multv3(theirspot.aim, source[sn].sl.s->aim, pm); |
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normalize(theirspot.aim); |
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if (nsflags & SSPOT) { |
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ourspot.flen = theirspot.flen; |
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d = ourspot.siz; |
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if (!commonspot(&ourspot, &theirspot, nsloc)) |
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return(-1); /* no overlap */ |
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} else { |
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nsflags |= SSPOT; |
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ourspot = theirspot; |
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d = 2.*ourspot.siz; |
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} |
233 |
if (ourspot.siz < d-FTINY) { /* it shrunk */ |
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d = spotdisk(v, op, &ourspot, nsloc); |
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if (d <= FTINY) |
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return(-1); |
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if (d < maxrad2) { |
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maxrad2 = d; |
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VCOPY(ocent, v); |
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} |
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} |
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} |
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if (source[sn].sflags & SFLAT) { /* behind source? */ |
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multv3(nsnorm, source[sn].snorm, pm); |
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normalize(nsnorm); |
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if (nsflags & SSPOT && !checkspot(&ourspot, nsnorm)) |
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return(-1); |
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} |
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} |
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/* pretest visibility */ |
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nsflags = vstestvis(nsflags, op, ocent, maxrad2, sn); |
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if (nsflags & SSKIP) |
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return(-1); /* obstructed */ |
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/* it all checks out, so make it */ |
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if ((i = newsource()) < 0) |
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goto memerr; |
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source[i].sflags = nsflags; |
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VCOPY(source[i].sloc, nsloc); |
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multv3(source[i].ss[SU], source[sn].ss[SU], pm); |
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multv3(source[i].ss[SV], source[sn].ss[SV], pm); |
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if (nsflags & SFLAT) |
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VCOPY(source[i].snorm, nsnorm); |
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else |
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multv3(source[i].ss[SW], source[sn].ss[SW], pm); |
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source[i].srad = source[sn].srad; |
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source[i].ss2 = source[sn].ss2; |
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if (nsflags & SSPOT) { |
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if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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goto memerr; |
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*(source[i].sl.s) = ourspot; |
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} |
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if (nsflags & SPROX) |
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source[i].sl.prox = source[sn].sl.prox; |
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source[i].sa.sv.sn = sn; |
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source[i].so = op; |
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return(i); |
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memerr: |
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error(SYSTEM, "out of memory in makevsrc"); |
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return -1; /* pro forma return */ |
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} |
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|
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|
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double |
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getdisk( /* get visible object disk */ |
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FVECT oc, |
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OBJREC *op, |
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int sn |
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) |
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{ |
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double rad2, roffs, offs, d, rd, rdoto; |
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FVECT rnrm, nrm; |
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/* first, use object getdisk function */ |
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rad2 = getmaxdisk(oc, op); |
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if (!(source[sn].sflags & SVIRTUAL)) |
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return(rad2); /* all done for normal source */ |
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/* check for correct side of relay surface */ |
297 |
roffs = getplaneq(rnrm, source[sn].so); |
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rd = DOT(rnrm, source[sn].sloc); /* source projection */ |
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if (!(source[sn].sflags & SDISTANT)) |
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rd -= roffs; |
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d = DOT(rnrm, oc) - roffs; /* disk distance to relay plane */ |
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if ((d > 0.) ^ (rd > 0.)) |
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return(rad2); /* OK if opposite sides */ |
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if (d*d >= rad2) |
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return(0.); /* no relay is possible */ |
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/* we need a closer look */ |
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offs = getplaneq(nrm, op); |
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rdoto = DOT(rnrm, nrm); |
309 |
if (d*d >= rad2*(1.-rdoto*rdoto)) |
310 |
return(0.); /* disk entirely on projection side */ |
311 |
/* should shrink disk but I'm lazy */ |
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return(rad2); |
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} |
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|
315 |
|
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int |
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vstestvis( /* pretest source visibility */ |
318 |
int f, /* virtual source flags */ |
319 |
OBJREC *o, /* relay object */ |
320 |
FVECT oc, /* relay object center */ |
321 |
double or2, /* relay object radius squared */ |
322 |
int sn /* target source number */ |
323 |
) |
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{ |
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RAY sr; |
326 |
FVECT onorm; |
327 |
FVECT offsdir; |
328 |
SRCINDEX si; |
329 |
double or, d, d1; |
330 |
int stestlim, ssn; |
331 |
int nhit, nok; |
332 |
int i, n; |
333 |
/* return if pretesting disabled */ |
334 |
if (vspretest <= 0) |
335 |
return(f); |
336 |
/* get surface normal */ |
337 |
getplaneq(onorm, o); |
338 |
/* set number of rays to sample */ |
339 |
if (source[sn].sflags & SDISTANT) { |
340 |
/* 32. == heuristic constant */ |
341 |
n = 32.*or2/(thescene.cusize*thescene.cusize)*vspretest + .5; |
342 |
} else { |
343 |
for (i = 0; i < 3; i++) |
344 |
offsdir[i] = source[sn].sloc[i] - oc[i]; |
345 |
d = DOT(offsdir,offsdir); |
346 |
if (d <= FTINY) |
347 |
n = 2.*PI * vspretest + .5; |
348 |
else |
349 |
n = 2.*PI * (1.-sqrt(1./(1.+or2/d)))*vspretest + .5; |
350 |
} |
351 |
if (n < MINSAMPLES) n = MINSAMPLES; |
352 |
#ifdef DEBUG |
353 |
fprintf(stderr, "pretesting source %d in object %s with %d rays\n", |
354 |
sn, o->oname, n); |
355 |
#endif |
356 |
/* sample */ |
357 |
or = sqrt(or2); |
358 |
stestlim = n*STESTMAX; |
359 |
ssn = 0; |
360 |
nhit = nok = 0; |
361 |
initsrcindex(&si); |
362 |
while (n-- > 0) { |
363 |
/* get sample point */ |
364 |
do { |
365 |
if (ssn >= stestlim) { |
366 |
#ifdef DEBUG |
367 |
fprintf(stderr, "\ttoo hard to hit\n"); |
368 |
#endif |
369 |
return(f); /* too small a target! */ |
370 |
} |
371 |
multisamp(offsdir, 3, urand(sn*931+5827+ssn)); |
372 |
for (i = 0; i < 3; i++) |
373 |
offsdir[i] = or*(1. - 2.*offsdir[i]); |
374 |
ssn++; |
375 |
d = 1. - DOT(offsdir, onorm); |
376 |
for (i = 0; i < 3; i++) { |
377 |
sr.rorg[i] = oc[i] + offsdir[i] + d*onorm[i]; |
378 |
sr.rdir[i] = -onorm[i]; |
379 |
} |
380 |
rayorigin(&sr, PRIMARY, NULL, NULL); |
381 |
} while (!(*ofun[o->otype].funp)(o, &sr)); |
382 |
/* check against source */ |
383 |
VCOPY(sr.rorg, sr.rop); /* starting from intersection */ |
384 |
samplendx++; |
385 |
if (si.sp >= si.np-1 || |
386 |
!srcray(&sr, NULL, &si) || sr.rsrc != sn) { |
387 |
si.sn = sn-1; /* reset index to our source */ |
388 |
si.np = 0; |
389 |
if (!srcray(&sr, NULL, &si) || sr.rsrc != sn) |
390 |
continue; /* can't get there from here */ |
391 |
} |
392 |
sr.revf = srcvalue; |
393 |
rayvalue(&sr); /* check sample validity */ |
394 |
if ((d = bright(sr.rcol)) <= FTINY) |
395 |
continue; |
396 |
nok++; /* got sample; check obstructions */ |
397 |
rayclear(&sr); |
398 |
sr.revf = raytrace; |
399 |
rayvalue(&sr); |
400 |
if ((d1 = bright(sr.rcol)) > FTINY) { |
401 |
if (d - d1 > FTINY) { |
402 |
#ifdef DEBUG |
403 |
fprintf(stderr, "\tpartially shadowed\n"); |
404 |
#endif |
405 |
return(f); /* intervening transmitter */ |
406 |
} |
407 |
nhit++; |
408 |
} |
409 |
if (nhit > 0 && nhit < nok) { |
410 |
#ifdef DEBUG |
411 |
fprintf(stderr, "\tpartially occluded\n"); |
412 |
#endif |
413 |
return(f); /* need to shadow test */ |
414 |
} |
415 |
} |
416 |
if (nhit == 0) { |
417 |
#ifdef DEBUG |
418 |
fprintf(stderr, "\t0%% hit rate\n"); |
419 |
#endif |
420 |
return(f | SSKIP); /* 0% hit rate: totally occluded */ |
421 |
} |
422 |
#ifdef DEBUG |
423 |
fprintf(stderr, "\t100%% hit rate\n"); |
424 |
#endif |
425 |
return(f & ~SFOLLOW); /* 100% hit rate: no occlusion */ |
426 |
} |
427 |
|
428 |
|
429 |
#ifdef DEBUG |
430 |
void |
431 |
virtverb( /* print verbose description of virtual source */ |
432 |
int sn, |
433 |
FILE *fp |
434 |
) |
435 |
{ |
436 |
fprintf(fp, "%s virtual source %d in %s %s\n", |
437 |
source[sn].sflags & SDISTANT ? "distant" : "local", |
438 |
sn, ofun[source[sn].so->otype].funame, |
439 |
source[sn].so->oname); |
440 |
fprintf(fp, "\tat (%f,%f,%f)\n", |
441 |
source[sn].sloc[0], source[sn].sloc[1], source[sn].sloc[2]); |
442 |
fprintf(fp, "\tlinked to source %d (%s)\n", |
443 |
source[sn].sa.sv.sn, source[source[sn].sa.sv.sn].so->oname); |
444 |
if (source[sn].sflags & SFOLLOW) |
445 |
fprintf(fp, "\talways followed\n"); |
446 |
else |
447 |
fprintf(fp, "\tnever followed\n"); |
448 |
if (!(source[sn].sflags & SSPOT)) |
449 |
return; |
450 |
fprintf(fp, "\twith spot aim (%f,%f,%f) and size %f\n", |
451 |
source[sn].sl.s->aim[0], source[sn].sl.s->aim[1], |
452 |
source[sn].sl.s->aim[2], source[sn].sl.s->siz); |
453 |
} |
454 |
#endif |