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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 |
| 6 |
|
| 7 |
/* |
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* Routines for simulating virtual light sources |
| 9 |
* Thus far, we only support planar mirrors. |
| 10 |
*/ |
| 11 |
|
| 12 |
#include "ray.h" |
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|
| 14 |
#include "source.h" |
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|
| 16 |
#include "otypes.h" |
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|
| 18 |
#include "cone.h" |
| 19 |
|
| 20 |
#include "face.h" |
| 21 |
|
| 22 |
extern int directrelay; /* maximum number of source relays */ |
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|
| 24 |
double getplaneq(); |
| 25 |
double getmaxdisk(); |
| 26 |
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 (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 (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(objptr(i), sr, nr-1); /* calls us recursively */ |
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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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double maxrad2; |
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double d1, d2; |
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SPOT theirspot, ourspot; |
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register int i; |
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/* get object center and max. radius */ |
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maxrad2 = getmaxdisk(ocent, op); |
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if (maxrad2 <= FTINY) /* too small? */ |
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return(NULL); |
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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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VCOPY(ourspot.aim, ocent); |
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ourspot.siz = PI*maxrad2; |
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ourspot.flen = 0.; |
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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 (!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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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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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 (!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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if (sp->sflags & SFLAT) { /* check for behind source */ |
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multv3(nsnorm, sp->snorm, pm); |
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if (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 = sp->sflags | (SVIRTUAL|SSPOT|SFOLLOW); |
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VCOPY(newsrc->sloc, nsloc); |
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if (newsrc->sflags & 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 ((newsrc->sl.s = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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goto memerr; |
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copystruct(newsrc->sl.s, &ourspot); |
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if (newsrc->sflags & 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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mirrorproj(m, nv, offs) /* get mirror projection for surface */ |
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register MAT4 m; |
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FVECT nv; |
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double offs; |
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{ |
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register int i, j; |
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/* assign matrix */ |
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setident4(m); |
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for (i = 0; i < 3; i++) |
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for (j = 0; j < 3; j++) |
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m[i][j] -= 2.*nv[i]*nv[j]; |
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for (j = 0; j < 3; j++) |
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m[3][j] = 2.*offs*nv[j]; |
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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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/* |
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* The following routines depend on the supported OBJECTS: |
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*/ |
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|
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|
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double |
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getmaxdisk(ocent, op) /* get object center and squared radius */ |
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FVECT ocent; |
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register OBJREC *op; |
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{ |
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double maxrad2; |
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|
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switch (op->otype) { |
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case OBJ_FACE: |
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{ |
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double d2; |
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register int i, j; |
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register FACE *f = getface(op); |
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|
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for (i = 0; i < 3; i++) { |
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ocent[i] = 0.; |
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for (j = 0; j < f->nv; j++) |
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ocent[i] += VERTEX(f,j)[i]; |
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ocent[i] /= (double)f->nv; |
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} |
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maxrad2 = 0.; |
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for (j = 0; j < f->nv; j++) { |
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d2 = dist2(VERTEX(f,j), ocent); |
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if (d2 > maxrad2) |
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maxrad2 = d2; |
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} |
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} |
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return(maxrad2); |
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case OBJ_RING: |
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{ |
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register CONE *co = getcone(op, 0); |
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|
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VCOPY(ocent, CO_P0(co)); |
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maxrad2 = CO_R1(co); |
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maxrad2 *= maxrad2; |
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} |
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return(maxrad2); |
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} |
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objerror(op, USER, "illegal material"); |
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} |
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|
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|
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double |
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getplaneq(nvec, op) /* get plane equation for object */ |
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FVECT nvec; |
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OBJREC *op; |
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{ |
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register FACE *fo; |
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register CONE *co; |
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|
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switch (op->otype) { |
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case OBJ_FACE: |
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fo = getface(op); |
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VCOPY(nvec, fo->norm); |
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return(fo->offset); |
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case OBJ_RING: |
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co = getcone(op, 0); |
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VCOPY(nvec, co->ad); |
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return(DOT(nvec, CO_P0(co))); |
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} |
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objerror(op, USER, "illegal material"); |
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} |
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|
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|
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/* |
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* The following routines depend on the supported MATERIALS: |
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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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SRCREC *ns; |
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FVECT norm; |
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double offset; |
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MAT4 proj; |
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/* get surface normal and offset */ |
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offset = getplaneq(norm, o); |
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switch (objptr(o->omod)->otype) { |
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case MAT_MIRROR: /* mirror source */ |
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if (DOT(s->sloc, norm) <= (s->sflags & SDISTANT ? |
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FTINY : offset+FTINY)) |
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return; /* behind mirror */ |
| 360 |
mirrorproj(proj, norm, offset); |
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if ((ns = makevsrc(o, s, proj)) != NULL) |
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addvirtuals(ns, n); |
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break; |
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} |
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} |
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|
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|
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vsrcrelay(rn, rv) /* relay virtual source ray */ |
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register RAY *rn, *rv; |
| 370 |
{ |
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int snext; |
| 372 |
register int i; |
| 373 |
/* source we're aiming for here */ |
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snext = source[rv->rsrc].sa.svnext; |
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/* compute relayed ray direction */ |
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switch (objptr(rv->ro->omod)->otype) { |
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case MAT_MIRROR: /* mirror: singular reflection */ |
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rayorigin(rn, rv, REFLECTED, 1.); |
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/* ignore textures */ |
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for (i = 0; i < 3; i++) |
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rn->rdir[i] = rv->rdir[i] + 2.*rv->rod*rv->ron[i]; |
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break; |
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#ifdef DEBUG |
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default: |
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error(CONSISTENCY, "inappropriate material in vsrcrelay"); |
| 386 |
#endif |
| 387 |
} |
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rn->rsrc = snext; |
| 389 |
} |
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|
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|
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m_mirror(m, r) /* shade mirrored ray */ |
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register OBJREC *m; |
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register RAY *r; |
| 395 |
{ |
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COLOR mcolor; |
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RAY nr; |
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register int i; |
| 399 |
|
| 400 |
if (m->oargs.nfargs != 3 || m->oargs.nsargs > 1) |
| 401 |
objerror(m, USER, "bad number of arguments"); |
| 402 |
if (r->rsrc >= 0) { /* aiming for somebody */ |
| 403 |
if (source[r->rsrc].so != r->ro) |
| 404 |
return; /* but not us */ |
| 405 |
} else if (m->oargs.nsargs > 0) { /* else call substitute? */ |
| 406 |
rayshade(r, modifier(m->oargs.sarg[0])); |
| 407 |
return; |
| 408 |
} |
| 409 |
if (r->rod < 0.) /* back is black */ |
| 410 |
return; |
| 411 |
/* get modifiers */ |
| 412 |
raytexture(r, m->omod); |
| 413 |
/* assign material color */ |
| 414 |
setcolor(mcolor, m->oargs.farg[0], |
| 415 |
m->oargs.farg[1], |
| 416 |
m->oargs.farg[2]); |
| 417 |
multcolor(mcolor, r->pcol); |
| 418 |
/* compute reflected ray */ |
| 419 |
if (r->rsrc >= 0) /* relayed light source */ |
| 420 |
vsrcrelay(&nr, r); |
| 421 |
else { /* ordinary reflection */ |
| 422 |
FVECT pnorm; |
| 423 |
double pdot; |
| 424 |
|
| 425 |
if (rayorigin(&nr, r, REFLECTED, bright(mcolor)) < 0) |
| 426 |
return; |
| 427 |
pdot = raynormal(pnorm, r); /* use textures */ |
| 428 |
for (i = 0; i < 3; i++) |
| 429 |
nr.rdir[i] = r->rdir[i] + 2.*pdot*pnorm[i]; |
| 430 |
} |
| 431 |
rayvalue(&nr); |
| 432 |
multcolor(nr.rcol, mcolor); |
| 433 |
addcolor(r->rcol, nr.rcol); |
| 434 |
} |
