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RadiancePmap/srcsupp.c
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srcsupp.c
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#ifndef lint
static const char RCSid[] = "$Id: srcsupp.c,v 2.23 2016/04/21 00:40:35 greg Exp $";
#endif
/*
* Support routines for source objects and materials
*
* External symbols declared in source.h
*/
#include "copyright.h"
#include "ray.h"
#include "otypes.h"
#include "source.h"
#include "cone.h"
#include "face.h"
#define SRCINC 32 /* realloc increment for array */
SRCREC *source = NULL; /* our list of sources */
int nsources = 0; /* the number of sources */
SRCFUNC sfun[NUMOTYPE]; /* source dispatch table */
void
initstypes(void) /* initialize source dispatch table */
{
extern VSMATERIAL mirror_vs, direct1_vs, direct2_vs;
static SOBJECT fsobj = {fsetsrc, flatpart, fgetplaneq, fgetmaxdisk};
static SOBJECT ssobj = {ssetsrc, nopart};
static SOBJECT sphsobj = {sphsetsrc, nopart};
static SOBJECT cylsobj = {cylsetsrc, cylpart};
static SOBJECT rsobj = {rsetsrc, flatpart, rgetplaneq, rgetmaxdisk};
sfun[MAT_MIRROR].mf = &mirror_vs;
sfun[MAT_DIRECT1].mf = &direct1_vs;
sfun[MAT_DIRECT2].mf = &direct2_vs;
sfun[OBJ_FACE].of = &fsobj;
sfun[OBJ_SOURCE].of = &ssobj;
sfun[OBJ_SPHERE].of = &sphsobj;
sfun[OBJ_CYLINDER].of = &cylsobj;
sfun[OBJ_RING].of = &rsobj;
}
int
newsource(void) /* allocate new source in our array */
{
if (nsources == 0)
source = (SRCREC *)malloc(SRCINC*sizeof(SRCREC));
else if (nsources%SRCINC == 0)
source = (SRCREC *)realloc((void *)source,
(unsigned)(nsources+SRCINC)*sizeof(SRCREC));
if (source == NULL)
return(-1);
source[nsources].sflags = 0;
source[nsources].nhits = 1;
source[nsources].ntests = 2; /* initial hit probability = 50% */
#if SHADCACHE
source[nsources].obscache = NULL;
#endif
return(nsources++);
}
void
setflatss( /* set sampling for a flat source */
SRCREC *src
)
{
double mult;
int i;
getperpendicular(src->ss[SU], src->snorm, rand_samp);
mult = .5 * sqrt( src->ss2 );
for (i = 0; i < 3; i++)
src->ss[SU][i] *= mult;
fcross(src->ss[SV], src->snorm, src->ss[SU]);
}
void
fsetsrc( /* set a face as a source */
SRCREC *src,
OBJREC *so
)
{
FACE *f;
int i, j;
double d;
src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
src->so = so;
/* get the face */
f = getface(so);
if (f->area == 0.)
objerror(so, USER, "zero source area");
/* find the center */
for (j = 0; j < 3; j++) {
src->sloc[j] = 0.0;
for (i = 0; i < f->nv; i++)
src->sloc[j] += VERTEX(f,i)[j];
src->sloc[j] /= (double)f->nv;
}
if (!inface(src->sloc, f))
objerror(so, USER, "cannot hit source center");
src->sflags |= SFLAT;
VCOPY(src->snorm, f->norm);
src->ss2 = f->area;
/* find maximum radius */
src->srad = 0.;
for (i = 0; i < f->nv; i++) {
d = dist2(VERTEX(f,i), src->sloc);
if (d > src->srad)
src->srad = d;
}
src->srad = sqrt(src->srad);
/* compute size vectors */
if (f->nv == 4) /* parallelogram case */
for (j = 0; j < 3; j++) {
src->ss[SU][j] = .5*(VERTEX(f,1)[j]-VERTEX(f,0)[j]);
src->ss[SV][j] = .5*(VERTEX(f,3)[j]-VERTEX(f,0)[j]);
}
else
setflatss(src);
}
void
ssetsrc( /* set a source as a source */
SRCREC *src,
OBJREC *so
)
{
double theta;
src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
src->so = so;
if (so->oargs.nfargs != 4)
objerror(so, USER, "bad arguments");
src->sflags |= (SDISTANT|SCIR);
VCOPY(src->sloc, so->oargs.farg);
if (normalize(src->sloc) == 0.0)
objerror(so, USER, "zero direction");
theta = PI/180.0/2.0 * so->oargs.farg[3];
if (theta <= FTINY)
objerror(so, USER, "zero size");
src->ss2 = 2.0*PI * (1.0 - cos(theta));
/* the following is approximate */
src->srad = sqrt(src->ss2/PI);
VCOPY(src->snorm, src->sloc);
setflatss(src); /* hey, whatever works */
src->ss[SW][0] = src->ss[SW][1] = src->ss[SW][2] = 0.0;
}
void
sphsetsrc( /* set a sphere as a source */
SRCREC *src,
OBJREC *so
)
{
int i;
src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
src->so = so;
if (so->oargs.nfargs != 4)
objerror(so, USER, "bad # arguments");
if (so->oargs.farg[3] <= FTINY)
objerror(so, USER, "illegal source radius");
src->sflags |= SCIR;
VCOPY(src->sloc, so->oargs.farg);
src->srad = so->oargs.farg[3];
src->ss2 = PI * src->srad * src->srad;
for (i = 0; i < 3; i++)
src->ss[SU][i] = src->ss[SV][i] = src->ss[SW][i] = 0.0;
for (i = 0; i < 3; i++)
src->ss[i][i] = 0.7236 * so->oargs.farg[3];
}
void
rsetsrc( /* set a ring (disk) as a source */
SRCREC *src,
OBJREC *so
)
{
CONE *co;
src->sa.success = 2*AIMREQT-1; /* bitch on second failure */
src->so = so;
/* get the ring */
co = getcone(so, 0);
if (co == NULL)
objerror(so, USER, "illegal source");
if (CO_R1(co) <= FTINY)
objerror(so, USER, "illegal source radius");
VCOPY(src->sloc, CO_P0(co));
if (CO_R0(co) > 0.0)
objerror(so, USER, "cannot hit source center");
src->sflags |= (SFLAT|SCIR);
VCOPY(src->snorm, co->ad);
src->srad = CO_R1(co);
src->ss2 = PI * src->srad * src->srad;
setflatss(src);
}
void
cylsetsrc( /* set a cylinder as a source */
SRCREC *src,
OBJREC *so
)
{
CONE *co;
int i;
src->sa.success = 4*AIMREQT-1; /* bitch on fourth failure */
src->so = so;
/* get the cylinder */
co = getcone(so, 0);
if (co == NULL)
objerror(so, USER, "illegal source");
if (CO_R0(co) <= FTINY)
objerror(so, USER, "illegal source radius");
if (CO_R0(co) > .2*co->al) /* heuristic constraint */
objerror(so, WARNING, "source aspect too small");
src->sflags |= SCYL;
for (i = 0; i < 3; i++)
src->sloc[i] = .5 * (CO_P1(co)[i] + CO_P0(co)[i]);
src->srad = .5*co->al;
src->ss2 = 2.*CO_R0(co)*co->al;
/* set sampling vectors */
for (i = 0; i < 3; i++)
src->ss[SU][i] = .5 * co->al * co->ad[i];
getperpendicular(src->ss[SW], co->ad, rand_samp);
for (i = 0; i < 3; i++)
src->ss[SW][i] *= .8559 * CO_R0(co);
fcross(src->ss[SV], src->ss[SW], co->ad);
}
SPOT *
makespot( /* make a spotlight */
OBJREC *m
)
{
SPOT *ns;
if ((ns = (SPOT *)m->os) != NULL)
return(ns);
if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL)
return(NULL);
if (m->oargs.farg[3] <= FTINY)
objerror(m, USER, "zero angle");
ns->siz = 2.0*PI * (1.0 - cos(PI/180.0/2.0 * m->oargs.farg[3]));
VCOPY(ns->aim, m->oargs.farg+4);
if ((ns->flen = normalize(ns->aim)) == 0.0)
objerror(m, USER, "zero focus vector");
m->os = (char *)ns;
return(ns);
}
int
spotout( /* check if we're outside spot region */
RAY *r,
SPOT *s
)
{
double d;
FVECT vd;
if (s == NULL)
return(0);
if (s->flen < -FTINY) { /* distant source */
vd[0] = s->aim[0] - r->rorg[0];
vd[1] = s->aim[1] - r->rorg[1];
vd[2] = s->aim[2] - r->rorg[2];
d = DOT(r->rdir,vd);
/* wrong side?
if (d <= FTINY)
return(1); */
d = DOT(vd,vd) - d*d;
if (PI*d > s->siz)
return(1); /* out */
return(0); /* OK */
}
/* local source */
if (s->siz < 2.0*PI * (1.0 + DOT(s->aim,r->rdir)))
return(1); /* out */
return(0); /* OK */
}
double
fgetmaxdisk( /* get center and squared radius of face */
FVECT ocent,
OBJREC *op
)
{
double maxrad2;
double d;
int i, j;
FACE *f;
f = getface(op);
if (f->area == 0.)
return(0.);
for (i = 0; i < 3; i++) {
ocent[i] = 0.;
for (j = 0; j < f->nv; j++)
ocent[i] += VERTEX(f,j)[i];
ocent[i] /= (double)f->nv;
}
d = DOT(ocent,f->norm);
for (i = 0; i < 3; i++)
ocent[i] += (f->offset - d)*f->norm[i];
maxrad2 = 0.;
for (j = 0; j < f->nv; j++) {
d = dist2(VERTEX(f,j), ocent);
if (d > maxrad2)
maxrad2 = d;
}
return(maxrad2);
}
double
rgetmaxdisk( /* get center and squared radius of ring */
FVECT ocent,
OBJREC *op
)
{
CONE *co;
co = getcone(op, 0);
if (co == NULL)
return(0.);
VCOPY(ocent, CO_P0(co));
return(CO_R1(co)*CO_R1(co));
}
double
fgetplaneq( /* get plane equation for face */
FVECT nvec,
OBJREC *op
)
{
FACE *fo;
fo = getface(op);
VCOPY(nvec, fo->norm);
return(fo->offset);
}
double
rgetplaneq( /* get plane equation for ring */
FVECT nvec,
OBJREC *op
)
{
CONE *co;
co = getcone(op, 0);
if (co == NULL) {
memset(nvec, 0, sizeof(FVECT));
return(0.);
}
VCOPY(nvec, co->ad);
return(DOT(nvec, CO_P0(co)));
}
int
commonspot( /* set sp1 to intersection of sp1 and sp2 */
SPOT *sp1,
SPOT *sp2,
FVECT org
)
{
FVECT cent;
double rad2, cos1, cos2;
cos1 = 1. - sp1->siz/(2.*PI);
cos2 = 1. - sp2->siz/(2.*PI);
if (sp2->siz >= 2.*PI-FTINY) /* BIG, just check overlap */
return(DOT(sp1->aim,sp2->aim) >= cos1*cos2 -
sqrt((1.-cos1*cos1)*(1.-cos2*cos2)));
/* compute and check disks */
rad2 = intercircle(cent, sp1->aim, sp2->aim,
1./(cos1*cos1) - 1., 1./(cos2*cos2) - 1.);
if (rad2 <= FTINY || normalize(cent) == 0.)
return(0);
VCOPY(sp1->aim, cent);
sp1->siz = 2.*PI*(1. - 1./sqrt(1.+rad2));
return(1);
}
int
commonbeam( /* set sp1 to intersection of sp1 and sp2 */
SPOT *sp1,
SPOT *sp2,
FVECT dir
)
{
FVECT cent, c1, c2;
double rad2, d;
/* move centers to common plane */
d = DOT(sp1->aim, dir);
VSUM(c1, sp1->aim, dir, -d);
d = DOT(sp2->aim, dir);
VSUM(c2, sp2->aim, dir, -d);
/* compute overlap */
rad2 = intercircle(cent, c1, c2, sp1->siz/PI, sp2->siz/PI);
if (rad2 <= FTINY)
return(0);
VCOPY(sp1->aim, cent);
sp1->siz = PI*rad2;
return(1);
}
int
checkspot( /* check spotlight for behind source */
SPOT *sp, /* spotlight */
FVECT nrm /* source surface normal */
)
{
double d, d1;
d = DOT(sp->aim, nrm);
if (d > FTINY) /* center in front? */
return(1);
/* else check horizon */
d1 = 1. - sp->siz/(2.*PI);
return(1.-FTINY-d*d < d1*d1);
}
double
spotdisk( /* intersect spot with object op */
FVECT oc,
OBJREC *op,
SPOT *sp,
FVECT pos
)
{
FVECT onorm;
double offs, d, dist;
offs = getplaneq(onorm, op);
d = -DOT(onorm, sp->aim);
if (d >= -FTINY && d <= FTINY)
return(0.);
dist = (DOT(pos, onorm) - offs)/d;
if (dist < 0.)
return(0.);
VSUM(oc, pos, sp->aim, dist);
return(sp->siz*dist*dist/PI/(d*d));
}
double
beamdisk( /* intersect beam with object op */
FVECT oc,
OBJREC *op,
SPOT *sp,
FVECT dir
)
{
FVECT onorm;
double offs, d, dist;
offs = getplaneq(onorm, op);
d = -DOT(onorm, dir);
if (d >= -FTINY && d <= FTINY)
return(0.);
dist = (DOT(sp->aim, onorm) - offs)/d;
VSUM(oc, sp->aim, dir, dist);
return(sp->siz/PI/(d*d));
}
double
intercircle( /* intersect two circles */
FVECT cc, /* midpoint (return value) */
FVECT c1, /* circle centers */
FVECT c2,
double r1s, /* radii squared */
double r2s
)
{
double a2, d2, l;
FVECT disp;
VSUB(disp, c2, c1);
d2 = DOT(disp,disp);
/* circle within overlap? */
if (r1s < r2s) {
if (r2s >= r1s + d2) {
VCOPY(cc, c1);
return(r1s);
}
} else {
if (r1s >= r2s + d2) {
VCOPY(cc, c2);
return(r2s);
}
}
a2 = .25*(2.*(r1s+r2s) - d2 - (r2s-r1s)*(r2s-r1s)/d2);
/* no overlap? */
if (a2 <= 0.)
return(0.);
/* overlap, compute center */
l = sqrt((r1s - a2)/d2);
VSUM(cc, c1, disp, l);
return(a2);
}
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