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greg |
1.1 |
/* Copyright (c) 1986 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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* source.c - routines dealing with illumination sources. |
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* |
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* 8/20/85 |
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*/ |
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#include "ray.h" |
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greg |
1.4 |
#include "octree.h" |
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greg |
1.1 |
#include "source.h" |
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#include "otypes.h" |
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#include "cone.h" |
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#include "face.h" |
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#include "random.h" |
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extern double dstrsrc; /* source distribution amount */ |
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greg |
1.4 |
extern double shadthresh; /* relative shadow threshold */ |
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greg |
1.1 |
|
31 |
greg |
1.4 |
SRCREC *source = NULL; /* our list of sources */ |
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greg |
1.1 |
int nsources = 0; /* the number of sources */ |
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marksources() /* find and mark source objects */ |
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{ |
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register OBJREC *o, *m; |
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register int i; |
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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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m = objptr(o->omod); |
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if (m->otype != MAT_LIGHT && |
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m->otype != MAT_ILLUM && |
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greg |
1.6 |
m->otype != MAT_GLOW && |
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m->otype != MAT_SPOT) |
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greg |
1.1 |
continue; |
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greg |
1.6 |
if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 : |
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m->otype == MAT_SPOT ? 7 : 3)) |
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greg |
1.1 |
objerror(m, USER, "bad # arguments"); |
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greg |
1.6 |
if (m->otype == MAT_GLOW && |
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o->otype != OBJ_SOURCE && |
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m->oargs.farg[3] <= FTINY) |
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greg |
1.1 |
continue; /* don't bother */ |
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greg |
1.4 |
if (source == NULL) |
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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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error(SYSTEM, "out of memory in marksources"); |
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greg |
1.1 |
|
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greg |
1.4 |
newsource(&source[nsources], o); |
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greg |
1.1 |
|
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greg |
1.6 |
if (m->otype == MAT_GLOW) { |
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source[nsources].sflags |= SPROX; |
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source[nsources].sl.prox = m->oargs.farg[3]; |
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if (o->otype == OBJ_SOURCE) |
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source[nsources].sflags |= SSKIP; |
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} else if (m->otype == MAT_SPOT) { |
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source[nsources].sflags |= SSPOT; |
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source[nsources].sl.s = makespot(m); |
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} |
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greg |
1.1 |
nsources++; |
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} |
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} |
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newsource(src, so) /* add a source to the array */ |
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greg |
1.4 |
register SRCREC *src; |
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greg |
1.1 |
register OBJREC *so; |
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{ |
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double cos(), tan(), sqrt(); |
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double theta; |
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FACE *f; |
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CONE *co; |
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int j; |
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register int i; |
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src->sflags = 0; |
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greg |
1.6 |
src->nhits = 1; src->ntests = 2; /* start probability = 1/2 */ |
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greg |
1.1 |
src->so = so; |
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switch (so->otype) { |
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case OBJ_SOURCE: |
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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 ? 1.0 : tan(theta); |
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src->ss2 = 2.0*PI * (1.0 - cos(theta)); |
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break; |
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case OBJ_SPHERE: |
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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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break; |
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case OBJ_FACE: |
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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] /= 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->ss = sqrt(f->area / PI); |
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src->ss2 = f->area; |
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break; |
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case OBJ_RING: |
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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->ss = CO_R1(co); |
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src->ss2 = PI * src->ss * src->ss; |
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break; |
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default: |
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objerror(so, USER, "illegal material"); |
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} |
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} |
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151 |
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152 |
greg |
1.6 |
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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extern double cos(); |
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register SPOT *ns; |
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if ((ns = (SPOT *)malloc(sizeof(SPOT))) == NULL) |
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error(SYSTEM, "out of memory in makespot"); |
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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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greg |
1.1 |
double |
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srcray(sr, r, sn) /* send a ray to a source, return domega */ |
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register RAY *sr; /* returned source ray */ |
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RAY *r; /* ray which hit object */ |
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register int sn; /* source number */ |
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{ |
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register double *norm = NULL; /* plane normal */ |
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double ddot; /* (distance times) cosine */ |
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FVECT vd; |
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double d; |
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register int i; |
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greg |
1.4 |
if (source[sn].sflags & SSKIP) |
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greg |
1.1 |
return(0.0); /* skip this source */ |
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rayorigin(sr, r, SHADOW, 1.0); /* ignore limits */ |
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sr->rsrc = sn; /* remember source */ |
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/* get source direction */ |
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greg |
1.4 |
if (source[sn].sflags & SDISTANT) |
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greg |
1.1 |
/* constant direction */ |
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greg |
1.4 |
VCOPY(sr->rdir, source[sn].sloc); |
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greg |
1.1 |
else { /* compute direction */ |
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for (i = 0; i < 3; i++) |
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greg |
1.4 |
sr->rdir[i] = source[sn].sloc[i] - sr->rorg[i]; |
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greg |
1.1 |
|
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greg |
1.4 |
if (source[sn].so->otype == OBJ_FACE) |
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norm = getface(source[sn].so)->norm; |
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else if (source[sn].so->otype == OBJ_RING) |
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norm = getcone(source[sn].so,0)->ad; |
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greg |
1.1 |
|
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greg |
1.2 |
if (norm != NULL && (ddot = -DOT(sr->rdir, norm)) <= FTINY) |
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greg |
1.1 |
return(0.0); /* behind surface! */ |
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} |
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if (dstrsrc > FTINY) { |
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/* distribute source direction */ |
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for (i = 0; i < 3; i++) |
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greg |
1.4 |
vd[i] = dstrsrc * source[sn].ss * (1.0 - 2.0*frandom()); |
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greg |
1.1 |
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if (norm != NULL) { /* project offset */ |
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d = DOT(vd, norm); |
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for (i = 0; i < 3; i++) |
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vd[i] -= d * norm[i]; |
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} |
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for (i = 0; i < 3; i++) /* offset source direction */ |
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sr->rdir[i] += vd[i]; |
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greg |
1.4 |
} else if (source[sn].sflags & SDISTANT) |
217 |
greg |
1.1 |
/* already normalized */ |
218 |
greg |
1.4 |
return(source[sn].ss2); |
219 |
greg |
1.1 |
|
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if ((d = normalize(sr->rdir)) == 0.0) |
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/* at source! */ |
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return(0.0); |
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greg |
1.4 |
if (source[sn].sflags & SDISTANT) |
225 |
greg |
1.1 |
/* domega constant */ |
226 |
greg |
1.4 |
return(source[sn].ss2); |
227 |
greg |
1.1 |
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else { |
229 |
greg |
1.6 |
/* check proximity */ |
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if (source[sn].sflags & SPROX && |
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d > source[sn].sl.prox) |
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return(0.0); |
233 |
greg |
1.1 |
|
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if (norm != NULL) |
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ddot /= d; |
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else |
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ddot = 1.0; |
238 |
greg |
1.6 |
/* check angle */ |
239 |
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if (source[sn].sflags & SSPOT) { |
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if (source[sn].sl.s->siz < 2.0*PI * |
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(1.0 + DOT(source[sn].sl.s->aim,sr->rdir))) |
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return(0.0); |
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d += source[sn].sl.s->flen; |
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} |
245 |
greg |
1.1 |
/* return domega */ |
246 |
greg |
1.4 |
return(ddot*source[sn].ss2/(d*d)); |
247 |
greg |
1.1 |
} |
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} |
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251 |
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sourcehit(r) /* check to see if ray hit distant source */ |
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register RAY *r; |
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{ |
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int first, last; |
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register int i; |
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257 |
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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 */ |
260 |
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first = 0; last = nsources-1; |
261 |
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} |
262 |
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for (i = first; i <= last; i++) |
263 |
greg |
1.4 |
if (source[i].sflags & SDISTANT) |
264 |
greg |
1.1 |
/* |
265 |
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* Check to see if ray is within |
266 |
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* solid angle of source. |
267 |
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*/ |
268 |
greg |
1.4 |
if (2.0*PI * (1.0 - DOT(source[i].sloc,r->rdir)) |
269 |
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<= source[i].ss2) { |
270 |
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r->ro = source[i].so; |
271 |
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if (!(source[i].sflags & SSKIP)) |
272 |
greg |
1.1 |
break; |
273 |
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} |
274 |
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275 |
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if (r->ro != NULL) { |
276 |
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for (i = 0; i < 3; i++) |
277 |
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r->ron[i] = -r->rdir[i]; |
278 |
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r->rod = 1.0; |
279 |
greg |
1.3 |
r->rofs = 1.0; setident4(r->rofx); |
280 |
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r->robs = 1.0; setident4(r->robx); |
281 |
greg |
1.1 |
return(1); |
282 |
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} |
283 |
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return(0); |
284 |
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} |
285 |
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286 |
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287 |
greg |
1.4 |
static int |
288 |
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cntcmp(sc1, sc2) /* contribution compare (descending) */ |
289 |
greg |
1.9 |
register CNTPTR *sc1, *sc2; |
290 |
greg |
1.4 |
{ |
291 |
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if (sc1->brt > sc2->brt) |
292 |
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return(-1); |
293 |
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if (sc1->brt < sc2->brt) |
294 |
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return(1); |
295 |
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return(0); |
296 |
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} |
297 |
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298 |
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299 |
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direct(r, f, p) /* add direct component */ |
300 |
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RAY *r; /* ray that hit surface */ |
301 |
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int (*f)(); /* direct component coefficient function */ |
302 |
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char *p; /* data for f */ |
303 |
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{ |
304 |
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register int sn; |
305 |
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register CONTRIB *srccnt; |
306 |
greg |
1.9 |
register CNTPTR *cntord; |
307 |
greg |
1.10 |
double prob, ourthresh, hwt, test2, hit2; |
308 |
greg |
1.4 |
RAY sr; |
309 |
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310 |
greg |
1.9 |
srccnt = (CONTRIB *)malloc(nsources*sizeof(CONTRIB)); |
311 |
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cntord = (CNTPTR *)malloc(nsources*sizeof(CNTPTR)); |
312 |
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if (srccnt == NULL || cntord == NULL) |
313 |
greg |
1.4 |
error(SYSTEM, "out of memory in direct"); |
314 |
greg |
1.8 |
/* modify threshold */ |
315 |
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ourthresh = shadthresh / r->rweight; |
316 |
greg |
1.4 |
/* potential contributions */ |
317 |
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for (sn = 0; sn < nsources; sn++) { |
318 |
greg |
1.9 |
cntord[sn].sno = sn; |
319 |
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cntord[sn].brt = 0.0; |
320 |
greg |
1.4 |
/* get source ray */ |
321 |
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if ((srccnt[sn].dom = srcray(&sr, r, sn)) == 0.0) |
322 |
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continue; |
323 |
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VCOPY(srccnt[sn].dir, sr.rdir); |
324 |
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/* compute coefficient */ |
325 |
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(*f)(srccnt[sn].val, p, srccnt[sn].dir, srccnt[sn].dom); |
326 |
greg |
1.9 |
cntord[sn].brt = bright(srccnt[sn].val); |
327 |
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if (cntord[sn].brt <= FTINY) |
328 |
greg |
1.4 |
continue; |
329 |
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/* compute intersection */ |
330 |
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if (!( source[sn].sflags & SDISTANT ? |
331 |
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sourcehit(&sr) : |
332 |
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(*ofun[source[sn].so->otype].funp) |
333 |
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(source[sn].so, &sr) )) |
334 |
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continue; |
335 |
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/* compute contribution */ |
336 |
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rayshade(&sr, sr.ro->omod); |
337 |
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multcolor(srccnt[sn].val, sr.rcol); |
338 |
greg |
1.9 |
cntord[sn].brt = bright(srccnt[sn].val); |
339 |
greg |
1.4 |
} |
340 |
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/* sort contributions */ |
341 |
greg |
1.9 |
qsort(cntord, nsources, sizeof(CNTPTR), cntcmp); |
342 |
greg |
1.11 |
hit2 = 0.5; test2 = 1.0; /* start with prob=.5 */ |
343 |
greg |
1.10 |
/* test for shadows */ |
344 |
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for (sn = 0; sn < nsources; sn++) { |
345 |
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/* check threshold */ |
346 |
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if (cntord[sn].brt <= ourthresh*bright(r->rcol)) |
347 |
greg |
1.4 |
break; |
348 |
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/* get statistics */ |
349 |
greg |
1.9 |
hwt = (double)source[cntord[sn].sno].nhits / |
350 |
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(double)source[cntord[sn].sno].ntests; |
351 |
greg |
1.4 |
test2 += hwt; |
352 |
greg |
1.9 |
source[cntord[sn].sno].ntests++; |
353 |
greg |
1.4 |
/* test for hit */ |
354 |
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rayorigin(&sr, r, SHADOW, 1.0); |
355 |
greg |
1.9 |
VCOPY(sr.rdir, srccnt[cntord[sn].sno].dir); |
356 |
greg |
1.4 |
if (localhit(&sr, &thescene) && |
357 |
greg |
1.9 |
sr.ro != source[cntord[sn].sno].so) { |
358 |
greg |
1.4 |
/* check for transmission */ |
359 |
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if (sr.clipset != NULL && inset(sr.clipset,sr.ro->omod)) |
360 |
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raytrans(&sr); /* object is clipped */ |
361 |
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else |
362 |
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rayshade(&sr, sr.ro->omod); |
363 |
greg |
1.5 |
if (bright(sr.rcol) <= FTINY) |
364 |
greg |
1.4 |
continue; /* missed! */ |
365 |
greg |
1.9 |
(*f)(srccnt[cntord[sn].sno].val, p, |
366 |
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srccnt[cntord[sn].sno].dir, |
367 |
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srccnt[cntord[sn].sno].dom); |
368 |
|
|
multcolor(srccnt[cntord[sn].sno].val, sr.rcol); |
369 |
greg |
1.4 |
} |
370 |
|
|
/* add contribution if hit */ |
371 |
greg |
1.9 |
addcolor(r->rcol, srccnt[cntord[sn].sno].val); |
372 |
greg |
1.4 |
hit2 += hwt; |
373 |
greg |
1.9 |
source[cntord[sn].sno].nhits++; |
374 |
greg |
1.4 |
} |
375 |
greg |
1.7 |
/* weighted hit rate */ |
376 |
|
|
hwt = hit2 / test2; |
377 |
greg |
1.4 |
#ifdef DEBUG |
378 |
greg |
1.10 |
{ |
379 |
|
|
int ntested = sn; |
380 |
greg |
1.4 |
#endif |
381 |
|
|
/* add in untested sources */ |
382 |
greg |
1.10 |
for ( ; sn < nsources; sn++) { |
383 |
|
|
if (cntord[sn].brt <= 0.0) |
384 |
|
|
break; |
385 |
greg |
1.9 |
prob = hwt * (double)source[cntord[sn].sno].nhits / |
386 |
|
|
(double)source[cntord[sn].sno].ntests; |
387 |
|
|
scalecolor(srccnt[cntord[sn].sno].val, prob); |
388 |
|
|
addcolor(r->rcol, srccnt[cntord[sn].sno].val); |
389 |
greg |
1.4 |
} |
390 |
greg |
1.10 |
#ifdef DEBUG |
391 |
|
|
fprintf(stderr, "%d tested, %d untested, %f hit rate\n", |
392 |
|
|
ntested, sn-ntested, hwt); |
393 |
|
|
} |
394 |
|
|
#endif |
395 |
|
|
|
396 |
greg |
1.4 |
free(srccnt); |
397 |
greg |
1.9 |
free(cntord); |
398 |
greg |
1.4 |
} |
399 |
|
|
|
400 |
|
|
|
401 |
greg |
1.1 |
#define wrongsource(m, r) (m->otype!=MAT_ILLUM && \ |
402 |
|
|
r->rsrc>=0 && \ |
403 |
greg |
1.4 |
source[r->rsrc].so!=r->ro) |
404 |
greg |
1.1 |
|
405 |
|
|
#define badambient(m, r) ((r->crtype&(AMBIENT|SHADOW))==AMBIENT && \ |
406 |
greg |
1.6 |
!(r->rtype&REFLECTED) && /* hack! */\ |
407 |
|
|
!(m->otype==MAT_GLOW&&r->rot>m->oargs.farg[3])) |
408 |
greg |
1.1 |
|
409 |
|
|
#define passillum(m, r) (m->otype==MAT_ILLUM && \ |
410 |
greg |
1.4 |
!(r->rsrc>=0&&source[r->rsrc].so==r->ro)) |
411 |
greg |
1.1 |
|
412 |
|
|
|
413 |
|
|
m_light(m, r) /* ray hit a light source */ |
414 |
|
|
register OBJREC *m; |
415 |
|
|
register RAY *r; |
416 |
|
|
{ |
417 |
|
|
/* check for behind */ |
418 |
|
|
if (r->rod < 0.0) |
419 |
|
|
return; |
420 |
|
|
/* check for over-counting */ |
421 |
|
|
if (wrongsource(m, r) || badambient(m, r)) |
422 |
|
|
return; |
423 |
|
|
/* check for passed illum */ |
424 |
|
|
if (passillum(m, r)) { |
425 |
|
|
|
426 |
|
|
if (m->oargs.nsargs < 1 || !strcmp(m->oargs.sarg[0], VOIDID)) |
427 |
|
|
raytrans(r); |
428 |
|
|
else |
429 |
|
|
rayshade(r, modifier(m->oargs.sarg[0])); |
430 |
|
|
|
431 |
|
|
/* otherwise treat as source */ |
432 |
|
|
} else { |
433 |
|
|
/* get distribution pattern */ |
434 |
|
|
raytexture(r, m->omod); |
435 |
|
|
/* get source color */ |
436 |
|
|
setcolor(r->rcol, m->oargs.farg[0], |
437 |
|
|
m->oargs.farg[1], |
438 |
|
|
m->oargs.farg[2]); |
439 |
|
|
/* modify value */ |
440 |
|
|
multcolor(r->rcol, r->pcol); |
441 |
|
|
} |
442 |
|
|
} |
443 |
|
|
|
444 |
|
|
|
445 |
|
|
o_source() {} /* intersection with a source is done elsewhere */ |