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/* Copyright (c) 1991 Regents of the University of California */
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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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* Support routines for source objects and materials
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*/
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#include "ray.h"
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#include "otypes.h"
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#include "source.h"
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#include "cone.h"
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#include "face.h"
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SRCREC *source = NULL; /* our list of sources */
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int nsources = 0; /* the number of sources */
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SRCFUNC sfun[NUMOTYPE]; /* source dispatch table */
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initstypes() /* initialize source dispatch table */
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{
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extern VSMATERIAL mirror_vs, direct1_vs, direct2_vs;
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extern int fsetsrc(), ssetsrc(), sphsetsrc(), rsetsrc();
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extern double fgetplaneq(), rgetplaneq();
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extern double fgetmaxdisk(), rgetmaxdisk();
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static SOBJECT fsobj = {fsetsrc, fgetplaneq, fgetmaxdisk};
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static SOBJECT ssobj = {ssetsrc};
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static SOBJECT sphsobj = {sphsetsrc};
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static SOBJECT rsobj = {rsetsrc, rgetplaneq, rgetmaxdisk};
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sfun[MAT_MIRROR].mf = &mirror_vs;
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sfun[MAT_DIRECT1].mf = &direct1_vs;
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sfun[MAT_DIRECT2].mf = &direct2_vs;
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sfun[OBJ_FACE].of = &fsobj;
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sfun[OBJ_SOURCE].of = &ssobj;
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sfun[OBJ_SPHERE].of = &sphsobj;
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sfun[OBJ_RING].of = &rsobj;
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}
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int
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newsource() /* allocate new source in our array */
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{
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if (nsources == 0)
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source = (SRCREC *)malloc(sizeof(SRCREC));
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else
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source = (SRCREC *)realloc((char *)source,
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(unsigned)(nsources+1)*sizeof(SRCREC));
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if (source == NULL)
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return(-1);
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source[nsources].sflags = 0;
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source[nsources].nhits = 1;
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source[nsources].ntests = 2; /* initial hit probability = 1/2 */
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return(nsources++);
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}
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fsetsrc(src, so) /* set a face as a source */
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register SRCREC *src;
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OBJREC *so;
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{
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register FACE *f;
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register int i, j;
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
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src->so = so;
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/* get the face */
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f = getface(so);
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/* find the center */
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for (j = 0; j < 3; j++) {
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src->sloc[j] = 0.0;
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for (i = 0; i < f->nv; i++)
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src->sloc[j] += VERTEX(f,i)[j];
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src->sloc[j] /= (double)f->nv;
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}
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if (!inface(src->sloc, f))
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objerror(so, USER, "cannot hit center");
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src->sflags |= SFLAT;
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VCOPY(src->snorm, f->norm);
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src->ss = sqrt(f->area / PI);
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src->ss2 = f->area;
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}
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ssetsrc(src, so) /* set a source as a source */
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register SRCREC *src;
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register OBJREC *so;
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{
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double theta;
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
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src->so = so;
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if (so->oargs.nfargs != 4)
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objerror(so, USER, "bad arguments");
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src->sflags |= SDISTANT;
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VCOPY(src->sloc, so->oargs.farg);
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if (normalize(src->sloc) == 0.0)
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objerror(so, USER, "zero direction");
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theta = PI/180.0/2.0 * so->oargs.farg[3];
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if (theta <= FTINY)
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objerror(so, USER, "zero size");
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src->ss = theta >= PI/4.0 ? 1.0 : tan(theta);
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src->ss2 = 2.0*PI * (1.0 - cos(theta));
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}
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sphsetsrc(src, so) /* set a sphere as a source */
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register SRCREC *src;
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register OBJREC *so;
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{
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
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src->so = so;
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if (so->oargs.nfargs != 4)
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objerror(so, USER, "bad # arguments");
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if (so->oargs.farg[3] <= FTINY)
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objerror(so, USER, "illegal radius");
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VCOPY(src->sloc, so->oargs.farg);
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src->ss = so->oargs.farg[3];
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src->ss2 = PI * src->ss * src->ss;
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}
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rsetsrc(src, so) /* set a ring (disk) as a source */
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register SRCREC *src;
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OBJREC *so;
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{
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register CONE *co;
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src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
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src->so = so;
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/* get the ring */
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co = getcone(so, 0);
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VCOPY(src->sloc, CO_P0(co));
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if (CO_R0(co) > 0.0)
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objerror(so, USER, "cannot hit center");
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src->sflags |= SFLAT;
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VCOPY(src->snorm, co->ad);
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src->ss = CO_R1(co);
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src->ss2 = PI * src->ss * src->ss;
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}
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SPOT *
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makespot(m) /* make a spotlight */
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register OBJREC *m;
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{
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register SPOT *ns;
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if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
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return(NULL);
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ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3]));
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VCOPY(ns->aim, m->oargs.farg+4);
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if ((ns->flen = normalize(ns->aim)) == 0.0)
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objerror(m, USER, "zero focus vector");
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return(ns);
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}
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double
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fgetmaxdisk(ocent, op) /* get center and squared radius of face */
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FVECT ocent;
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OBJREC *op;
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{
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double maxrad2;
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double d;
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register int i, j;
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register FACE *f;
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f = getface(op);
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if (f->area == 0.)
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return(0.);
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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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d = DOT(ocent,f->norm);
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for (i = 0; i < 3; i++)
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ocent[i] += (f->offset - d)*f->norm[i];
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maxrad2 = 0.;
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for (j = 0; j < f->nv; j++) {
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d = dist2(VERTEX(f,j), ocent);
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if (d > maxrad2)
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maxrad2 = d;
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}
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return(maxrad2);
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}
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double
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rgetmaxdisk(ocent, op) /* get center and squared radius of ring */
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FVECT ocent;
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OBJREC *op;
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{
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register CONE *co;
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co = getcone(op, 0);
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VCOPY(ocent, CO_P0(co));
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return(CO_R1(co)*CO_R1(co));
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}
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double
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fgetplaneq(nvec, op) /* get plane equation for face */
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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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fo = getface(op);
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VCOPY(nvec, fo->norm);
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return(fo->offset);
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}
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double
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rgetplaneq(nvec, op) /* get plane equation for ring */
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FVECT nvec;
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OBJREC *op;
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{
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register CONE *co;
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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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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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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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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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checkspot(sp, nrm) /* check spotlight for behind source */
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register SPOT *sp; /* spotlight */
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FVECT nrm; /* source surface normal */
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{
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double d, d1;
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d = DOT(sp->aim, nrm);
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if (d > FTINY) /* center in front? */
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return(1);
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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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double
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spotdisk(oc, op, sp, pos) /* intersect spot with object op */
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FVECT oc;
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OBJREC *op;
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register SPOT *sp;
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FVECT pos;
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{
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FVECT onorm;
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double offs, d, dist;
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register int i;
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offs = getplaneq(onorm, op);
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d = -DOT(onorm, sp->aim);
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if (d >= -FTINY && d <= FTINY)
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return(0.);
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dist = (DOT(pos, onorm) - offs)/d;
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if (dist < 0.)
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return(0.);
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for (i = 0; i < 3; i++)
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oc[i] = pos[i] + dist*sp->aim[i];
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return(sp->siz*dist*dist/PI/(d*d));
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}
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double
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beamdisk(oc, op, sp, dir) /* intersect beam with object op */
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FVECT oc;
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OBJREC *op;
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register SPOT *sp;
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FVECT dir;
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{
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FVECT onorm;
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double offs, d, dist;
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register int i;
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offs = getplaneq(onorm, op);
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d = -DOT(onorm, dir);
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if (d >= -FTINY && d <= FTINY)
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return(0.);
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dist = (DOT(sp->aim, onorm) - offs)/d;
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for (i = 0; i < 3; i++)
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oc[i] = sp->aim[i] + dist*dir[i];
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return(sp->siz/PI/(d*d));
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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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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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| 372 |
/* no overlap? */
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| 373 |
if (a2 <= 0.)
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return(0.);
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/* overlap, compute center */
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| 376 |
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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| 380 |
}
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| 382 |
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sourcehit(r) /* check to see if ray hit distant source */
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| 384 |
register RAY *r;
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| 385 |
{
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| 386 |
int first, last;
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| 387 |
register int i;
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| 388 |
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| 389 |
if (r->rsrc >= 0) { /* check only one if aimed */
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first = last = r->rsrc;
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} else { /* otherwise check all */
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| 392 |
first = 0; last = nsources-1;
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}
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| 394 |
for (i = first; i <= last; i++)
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| 395 |
if (source[i].sflags & SDISTANT)
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| 396 |
/*
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| 397 |
* Check to see if ray is within
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| 398 |
* solid angle of source.
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| 399 |
*/
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| 400 |
if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir))
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| 401 |
<= source[i].ss2) {
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| 402 |
r->ro = source[i].so;
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| 403 |
if (!(source[i].sflags & SSKIP))
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| 404 |
break;
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| 405 |
}
|
| 406 |
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| 407 |
if (r->ro != NULL) {
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| 408 |
for (i = 0; i < 3; i++)
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| 409 |
r->ron[i] = -r->rdir[i];
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| 410 |
r->rod = 1.0;
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| 411 |
r->rox = NULL;
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| 412 |
return(1);
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| 413 |
}
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| 414 |
return(0);
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| 415 |
}
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| 416 |
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| 417 |
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| 418 |
#define wrongsource(m, r) (r->rsrc>=0 && \
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| 419 |
source[r->rsrc].so!=r->ro && \
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(m->otype!=MAT_ILLUM || \
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objptr(source[r->rsrc].so->omod)->otype==MAT_ILLUM))
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| 422 |
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| 423 |
#define distglow(m, r) (m->otype==MAT_GLOW && \
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r->rot > m->oargs.farg[3])
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#define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \
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!distglow(m, r))
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| 429 |
#define passillum(m, r) (m->otype==MAT_ILLUM && \
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| 430 |
!(r->rsrc>=0&&source[r->rsrc].so==r->ro))
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| 432 |
#define srcignore(m, r) (directinvis && !(r->crtype&SHADOW) && \
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| 433 |
!distglow(m, r))
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| 434 |
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| 435 |
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| 436 |
m_light(m, r) /* ray hit a light source */
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| 437 |
register OBJREC *m;
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| 438 |
register RAY *r;
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| 439 |
{
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| 440 |
/* check for over-counting */
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| 441 |
if (wrongsource(m, r) || badambient(m, r))
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| 442 |
return;
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| 443 |
/* check for passed illum */
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| 444 |
if (passillum(m, r)) {
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| 445 |
if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID))
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| 446 |
raytrans(r);
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| 447 |
else
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| 448 |
rayshade(r, modifier(m->oargs.sarg[0]));
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| 449 |
return;
|
| 450 |
}
|
| 451 |
/* otherwise treat as source */
|
| 452 |
/* check for behind */
|
| 453 |
if (r->rod < 0.0)
|
| 454 |
return;
|
| 455 |
/* check for invisibility */
|
| 456 |
if (srcignore(m, r))
|
| 457 |
return;
|
| 458 |
/* get distribution pattern */
|
| 459 |
raytexture(r, m->omod);
|
| 460 |
/* get source color */
|
| 461 |
setcolor(r->rcol, m->oargs.farg[0],
|
| 462 |
m->oargs.farg[1],
|
| 463 |
m->oargs.farg[2]);
|
| 464 |
/* modify value */
|
| 465 |
multcolor(r->rcol, r->pcol);
|
| 466 |
}
|
