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/* Copyright (c) 1991 Regents of the University of California */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ LBL"; |
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#endif |
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|
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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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|
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#include "ray.h" |
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|
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#include "otypes.h" |
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|
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#include "source.h" |
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|
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|
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double intercircle(), getdisk(); |
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|
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static OBJECT *vobject; /* virtual source objects */ |
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static int nvobjects = 0; /* number of virtual source objects */ |
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|
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|
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markvirtuals() /* find and mark virtual sources */ |
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{ |
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register OBJREC *o; |
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register int i; |
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/* check number of direct relays */ |
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if (directrelay <= 0) |
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return; |
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/* find virtual source objects */ |
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for (i = 0; i < nobjects; i++) { |
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o = objptr(i); |
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if (!issurface(o->otype) || o->omod == OVOID) |
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continue; |
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if (!isvlight(objptr(o->omod)->otype)) |
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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, USER, "illegal material"); |
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if (nvobjects == 0) |
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vobject = (OBJECT *)malloc(sizeof(OBJECT)); |
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else |
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vobject = (OBJECT *)realloc((char *)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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if (!(source[i].sflags & SSKIP)) |
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addvirtuals(i, directrelay); |
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/* done with our object list */ |
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free((char *)vobject); |
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nvobjects = 0; |
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} |
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|
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|
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addvirtuals(sn, nr) /* 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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register 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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/* 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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} |
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|
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|
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vproject(o, sn, n) /* create projected source(s) if they exist */ |
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OBJREC *o; |
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int sn; |
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int n; |
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{ |
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register int i; |
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register VSMATERIAL *vsmat; |
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MAT4 proj; |
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int ns; |
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|
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if (o == source[sn].so) /* objects cannot project themselves */ |
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return; |
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/* get virtual source material */ |
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vsmat = sfun[objptr(o->omod)->otype].mf; |
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/* project virtual sources */ |
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for (i = 0; i < vsmat->nproj; i++) |
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if ((*vsmat->vproj)(proj, o, &source[sn], i)) |
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if ((ns = makevsrc(o, sn, proj)) >= 0) { |
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#ifdef DEBUG |
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virtverb(ns, stderr); |
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#endif |
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addvirtuals(ns, n); |
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} |
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} |
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|
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|
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int |
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makevsrc(op, sn, pm) /* make virtual source if reasonable */ |
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OBJREC *op; |
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register int sn; |
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MAT4 pm; |
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{ |
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FVECT nsloc, nsnorm, ocent; |
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double maxrad2; |
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int nsflags; |
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double d1; |
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SPOT theirspot, ourspot; |
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register int i; |
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|
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nsflags = source[sn].sflags | (SVIRTUAL|SSPOT|SFOLLOW); |
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/* get object center and max. radius */ |
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maxrad2 = getdisk(ocent, op, sn); |
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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 */ |
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if (source[sn].sflags & SPROX) |
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return(-1); /* should never get here! */ |
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multv3(nsloc, source[sn].sloc, pm); |
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VCOPY(ourspot.aim, ocent); |
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ourspot.siz = PI*maxrad2; |
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ourspot.flen = 0.; |
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if (source[sn].sflags & SSPOT) { |
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copystruct(&theirspot, source[sn].sl.s); |
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multp3(theirspot.aim, source[sn].sl.s->aim, pm); |
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if (!commonbeam(&ourspot, &theirspot, nsloc)) |
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return(-1); /* no overlap */ |
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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 ((d1 = normalize(ourspot.aim)) == 0.) |
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return(-1); /* at source!! */ |
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if (source[sn].sflags & SPROX && d1 > source[sn].sl.prox) |
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return(-1); /* too far away */ |
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ourspot.siz = 2.*PI*(1. - d1/sqrt(d1*d1+maxrad2)); |
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ourspot.flen = 0.; |
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if (source[sn].sflags & SSPOT) { |
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copystruct(&theirspot, source[sn].sl.s); |
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multv3(theirspot.aim, source[sn].sl.s->aim, pm); |
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if (!commonspot(&ourspot, &theirspot, nsloc)) |
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return(-1); /* no overlap */ |
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ourspot.flen = theirspot.flen; |
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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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if (checkspot(&ourspot, nsnorm) < 0) |
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return(-1); |
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} |
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} |
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/* everything is OK, make source */ |
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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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if (nsflags & SFLAT) |
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VCOPY(source[i].snorm, nsnorm); |
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source[i].ss = source[sn].ss; source[i].ss2 = source[sn].ss2; |
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if ((source[i].sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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goto memerr; |
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copystruct(source[i].sl.s, &ourspot); |
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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.svnext = 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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} |
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|
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|
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double |
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getdisk(oc, op, sn) /* get visible object disk */ |
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FVECT oc; |
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OBJREC *op; |
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register int sn; |
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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 = (*sfun[op->otype].of->getdisk)(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 */ |
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roffs = (*sfun[source[sn].so->otype].of->getpleq)(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 = (*sfun[op->otype].of->getpleq)(nrm, op); |
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rdoto = DOT(rnrm, nrm); |
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if (d*d >= rad2*(1.-rdoto*rdoto)) |
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return(0.); /* disk entirely on projection side */ |
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/* should shrink disk but I'm lazy */ |
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return(rad2); |
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} |
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|
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|
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commonspot(sp1, sp2, org) /* set sp1 to intersection of sp1 and sp2 */ |
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register SPOT *sp1, *sp2; |
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FVECT org; |
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{ |
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FVECT cent; |
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double rad2, cos1, cos2; |
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|
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cos1 = 1. - sp1->siz/(2.*PI); |
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cos2 = 1. - sp2->siz/(2.*PI); |
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if (sp2->siz >= 2.*PI-FTINY) /* BIG, just check overlap */ |
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return(DOT(sp1->aim,sp2->aim) >= cos1*cos2 - |
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sqrt((1.-cos1*cos1)*(1.-cos2*cos2))); |
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/* compute and check disks */ |
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rad2 = intercircle(cent, sp1->aim, sp2->aim, |
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1./(cos1*cos1) - 1., 1./(cos2*cos2) - 1.); |
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if (rad2 <= FTINY || normalize(cent) == 0.) |
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return(0); |
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VCOPY(sp1->aim, cent); |
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sp1->siz = 2.*PI*(1. - 1./sqrt(1.+rad2)); |
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return(1); |
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} |
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|
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|
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commonbeam(sp1, sp2, dir) /* set sp1 to intersection of sp1 and sp2 */ |
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register SPOT *sp1, *sp2; |
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FVECT dir; |
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{ |
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FVECT cent, c1, c2; |
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double rad2, d; |
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register int i; |
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/* move centers to common plane */ |
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d = DOT(sp1->aim, dir); |
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for (i = 0; i < 3; i++) |
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c1[i] = sp1->aim[i] - d*dir[i]; |
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d = DOT(sp2->aim, dir); |
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for (i = 0; i < 3; i++) |
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c2[i] = sp2->aim[i] - d*dir[i]; |
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/* compute overlap */ |
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rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI); |
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if (rad2 <= FTINY) |
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return(0); |
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VCOPY(sp1->aim, cent); |
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sp1->siz = PI*rad2; |
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return(1); |
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} |
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|
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|
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checkspot(sp, nrm) /* check spotlight for behind source */ |
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register SPOT *sp; |
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FVECT nrm; |
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{ |
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double d, d1; |
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|
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d = DOT(sp->aim, nrm); |
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if (d > FTINY) /* center in front? */ |
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return(0); |
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/* else check horizon */ |
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d1 = 1. - sp->siz/(2.*PI); |
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return(1.-FTINY-d*d > d1*d1); |
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} |
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|
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|
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double |
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intercircle(cc, c1, c2, r1s, r2s) /* intersect two circles */ |
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FVECT cc; /* midpoint (return value) */ |
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FVECT c1, c2; /* circle centers */ |
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double r1s, r2s; /* radii squared */ |
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{ |
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double a2, d2, l; |
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FVECT disp; |
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register int i; |
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|
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for (i = 0; i < 3; i++) |
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disp[i] = c2[i] - c1[i]; |
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d2 = DOT(disp,disp); |
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/* circle within overlap? */ |
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if (r1s < r2s) { |
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if (r2s >= r1s + d2) { |
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VCOPY(cc, c1); |
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return(r1s); |
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} |
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} else { |
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if (r1s >= r2s + d2) { |
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VCOPY(cc, c2); |
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return(r2s); |
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} |
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} |
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a2 = .25*(2.*(r1s+r2s) - d2 - (r2s-r1s)*(r2s-r1s)/d2); |
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/* no overlap? */ |
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if (a2 <= 0.) |
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return(0.); |
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/* overlap, compute center */ |
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l = sqrt((r1s - a2)/d2); |
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for (i = 0; i < 3; i++) |
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cc[i] = c1[i] + l*disp[i]; |
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return(a2); |
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} |
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|
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|
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#ifdef DEBUG |
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virtverb(sn, fp) /* print verbose description of virtual source */ |
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register int sn; |
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FILE *fp; |
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{ |
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register int i; |
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|
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fprintf(fp, "%s virtual source %d in %s %s\n", |
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source[sn].sflags & SDISTANT ? "distant" : "local", |
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sn, ofun[source[sn].so->otype].funame, |
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source[sn].so->oname); |
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fprintf(fp, "\tat (%f,%f,%f)\n", |
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source[sn].sloc[0], source[sn].sloc[1], source[sn].sloc[2]); |
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fprintf(fp, "\tlinked to source %d (%s)\n", |
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source[sn].sa.svnext, source[source[sn].sa.svnext].so->oname); |
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if (source[sn].sflags & SFOLLOW) |
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fprintf(fp, "\talways followed\n"); |
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else |
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fprintf(fp, "\tnever followed\n"); |
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if (!(source[sn].sflags & SSPOT)) |
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return; |
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fprintf(fp, "\twith spot aim (%f,%f,%f) and size %f\n", |
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source[sn].sl.s->aim[0], source[sn].sl.s->aim[1], |
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source[sn].sl.s->aim[2], source[sn].sl.s->siz); |
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} |
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#endif |
