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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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#include "cone.h" |
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|
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#include "face.h" |
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|
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|
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double intercircle(); |
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SRCREC *makevsrc(); |
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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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/* 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(&source[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(sr, nr) /* add virtual sources associated with sr */ |
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SRCREC *sr; |
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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(i), sr, nr-1); |
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} |
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|
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|
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vproject(o, s, n) /* create projected source(s) if they exist */ |
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OBJREC *o; |
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SRCREC *s; |
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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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SRCREC *ns; |
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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, s, i)) |
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if ((ns = makevsrc(o, s, proj)) != NULL) |
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addvirtuals(ns, n); |
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} |
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|
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|
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SRCREC * |
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makevsrc(op, sp, pm) /* make virtual source if reasonable */ |
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OBJREC *op; |
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register SRCREC *sp; |
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MAT4 pm; |
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{ |
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register SRCREC *newsrc; |
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FVECT nsloc, ocent, nsnorm; |
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int nsflags; |
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double maxrad2; |
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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 = (sp->sflags|(SVIRTUAL|SFOLLOW)) & ~SSPOT; |
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/* get object center and max. radius */ |
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if (sfun[op->otype].of->getdisk != NULL) { |
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maxrad2 = (*sfun[op->otype].of->getdisk)(ocent, op); |
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if (maxrad2 <= FTINY) /* too small? */ |
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return(NULL); |
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nsflags |= SSPOT; |
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} |
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/* get location and spot */ |
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if (sp->sflags & SDISTANT) { /* distant source */ |
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if (sp->sflags & SPROX) |
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return(NULL); /* should never get here! */ |
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multv3(nsloc, sp->sloc, pm); |
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if (nsflags & SSPOT) { |
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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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} |
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if (sp->sflags & SSPOT) { |
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copystruct(&theirspot, sp->sl.s); |
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multp3(theirspot.aim, sp->sl.s->aim, pm); |
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if (nsflags & SSPOT && |
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!commonbeam(&ourspot, &theirspot, nsloc)) |
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return(NULL); /* no overlap */ |
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} |
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} else { /* local source */ |
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multp3(nsloc, sp->sloc, pm); |
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if (nsflags & SSPOT) { |
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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(NULL); /* at source!! */ |
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if (sp->sflags & SPROX && d1 > sp->sl.prox) |
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return(NULL); /* 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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} else if (sp->sflags & SPROX) { |
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FVECT norm; |
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double offs; |
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/* use distance from plane */ |
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offs = (*sfun[op->otype].of->getpleq)(norm, op); |
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d1 = DOT(norm, nsloc) - offs; |
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if (d1 > sp->sl.prox || d1 < -sp->sl.prox) |
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return(NULL); /* too far away */ |
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} |
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if (sp->sflags & SSPOT) { |
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copystruct(&theirspot, sp->sl.s); |
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multv3(theirspot.aim, sp->sl.s->aim, pm); |
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if (nsflags & SSPOT) { |
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if (!commonspot(&ourspot, &theirspot, nsloc)) |
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return(NULL); /* no overlap */ |
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ourspot.flen = theirspot.flen; |
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} |
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} |
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if (sp->sflags & SFLAT) { /* check for behind source */ |
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multv3(nsnorm, sp->snorm, pm); |
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if (nsflags & SSPOT && checkspot(&ourspot, nsnorm) < 0) |
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return(NULL); |
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} |
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} |
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/* everything is OK, make source */ |
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if ((newsrc = newsource()) == NULL) |
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goto memerr; |
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newsrc->sflags = nsflags; |
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VCOPY(newsrc->sloc, nsloc); |
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if (nsflags & SFLAT) |
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VCOPY(newsrc->snorm, nsnorm); |
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newsrc->ss = sp->ss; newsrc->ss2 = sp->ss2; |
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if ((nsflags | sp->sflags) & SSPOT) { |
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if ((newsrc->sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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goto memerr; |
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if (nsflags & SSPOT) |
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copystruct(newsrc->sl.s, &ourspot); |
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else |
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copystruct(newsrc->sl.s, &theirspot); |
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newsrc->sflags |= SSPOT; |
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} |
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if (nsflags & SPROX) |
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newsrc->sl.prox = sp->sl.prox; |
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newsrc->sa.svnext = sp - source; |
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return(newsrc); |
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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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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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} |
