--- ray/src/rt/source.c	2018/06/11 15:10:49	2.68
+++ ray/src/rt/source.c	2020/12/17 03:30:37	2.74
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: source.c,v 2.68 2018/06/11 15:10:49 greg Exp $";
+static const char RCSid[] = "$Id: source.c,v 2.74 2020/12/17 03:30:37 greg Exp $";
 #endif
 /*
  *  source.c - routines dealing with illumination sources.
@@ -9,6 +9,7 @@ static const char RCSid[] = "$Id: source.c,v 2.68 2018
 
 #include  "ray.h"
 #include  "otypes.h"
+#include  "otspecial.h"
 #include  "rtotypes.h"
 #include  "source.h"
 #include  "random.h"
@@ -42,32 +43,6 @@ static int  maxcntr = 0;		/* size of contribution arra
 static int cntcmp(const void *p1, const void *p2);
 
 
-OBJREC *			/* find an object's actual material */
-findmaterial(OBJREC *o)
-{
-	while (!ismaterial(o->otype)) {
-		if (o->otype == MOD_ALIAS && o->oargs.nsargs) {
-			OBJECT  aobj;
-			OBJREC  *ao;
-			aobj = lastmod(objndx(o), o->oargs.sarg[0]);
-			if (aobj < 0)
-				objerror(o, USER, "bad reference");
-			ao = objptr(aobj);
-			if (ismaterial(ao->otype))
-				return(ao);
-			if (ao->otype == MOD_ALIAS) {
-				o = ao;
-				continue;
-			}
-		}
-		if (o->omod == OVOID)
-			return(NULL);
-		o = objptr(o->omod);
-	}
-	return(o);		/* mixtures will return NULL */
-}
-
-
 void
 marksources(void)			/* find and mark source objects */
 {
@@ -99,8 +74,8 @@ marksources(void)			/* find and mark source objects */
 				m->otype == MAT_SPOT ? 7 : 3))
 			objerror(m, USER, "bad # arguments");
 
-		if (m->oargs.farg[0] <= FTINY && m->oargs.farg[1] <= FTINY &&
-				m->oargs.farg[2] <= FTINY)
+		if (m->oargs.farg[0] <= FTINY && (m->oargs.farg[1] <= FTINY) &
+				(m->oargs.farg[2] <= FTINY))
 			continue;			/* don't bother */
 		if (m->otype == MAT_GLOW &&
 				o->otype != OBJ_SOURCE &&
@@ -125,6 +100,9 @@ marksources(void)			/* find and mark source objects */
 				foundsource += (ambounce > 0);
 			}
 		} else if (m->otype == MAT_SPOT) {
+			if (source[ns].sflags & SDISTANT)
+				objerror(o, WARNING,
+					"distant source is a spotlight");
 			source[ns].sflags |= SSPOT;
 			if ((source[ns].sl.s = makespot(m)) == NULL)
 				goto memerr;
@@ -153,15 +131,61 @@ marksources(void)			/* find and mark source objects */
 	maxcntr = nsources + MAXSPART;	/* start with this many */
 	srccnt = (CONTRIB *)malloc(maxcntr*sizeof(CONTRIB));
 	cntord = (CNTPTR *)malloc(maxcntr*sizeof(CNTPTR));
-	if ((srccnt == NULL) | (cntord == NULL))
-		goto memerr;
-	return;
+	if ((srccnt != NULL) & (cntord != NULL))
+		return;
 memerr:
 	error(SYSTEM, "out of memory in marksources");
 }
 
 
 void
+distantsources(void)			/* only mark distant sources */
+{
+	int  i;
+	OBJREC  *o, *m;
+	int  ns;
+					/* initialize dispatch table */
+	initstypes();
+					/* sources needed for sourcehit() */
+	for (i = 0; i < nsceneobjs; i++) {
+	
+		o = objptr(i);
+
+		if ((o->otype != OBJ_SOURCE) | (o->omod == OVOID))
+			continue;
+					/* find material */
+		m = findmaterial(objptr(o->omod));
+		if (m == NULL)
+			continue;
+		if (!islight(m->otype))
+			continue;	/* not source modifier */
+	
+		if (m->oargs.nfargs != (m->otype == MAT_GLOW ? 4 :
+				m->otype == MAT_SPOT ? 7 : 3))
+			objerror(m, USER, "bad # arguments");
+
+		if (m->oargs.farg[0] <= FTINY && (m->oargs.farg[1] <= FTINY) &
+				(m->oargs.farg[2] <= FTINY))
+			continue;			/* don't bother */
+		if (sfun[o->otype].of == NULL ||
+				sfun[o->otype].of->setsrc == NULL)
+			objerror(o, USER, "illegal material");
+
+		if ((ns = newsource()) < 0)
+			error(SYSTEM, "out of memory in distantsources");
+
+		setsource(&source[ns], o);
+
+		if (m->otype == MAT_GLOW) {
+			source[ns].sflags |= SPROX|SSKIP;
+			source[ns].sl.prox = m->oargs.farg[3];
+		} else if (m->otype == MAT_SPOT)
+			objerror(o, WARNING, "distant source is a spotlight");
+	}
+}
+
+
+void
 freesources(void)			/* free all source structures */
 {
 	if (nsources > 0) {
@@ -410,18 +434,17 @@ direct(					/* add direct component */
 		cntord[sn].sndx = sn;
 		scp = srccnt + sn;
 		scp->sno = sr.rsrc;
-						/* compute coefficient */
-		(*f)(scp->coef, p, sr.rdir, si.dom);
-		cntord[sn].brt = intens(scp->coef);
-		if (cntord[sn].brt <= 0.0)
-			continue;
-#if SHADCACHE
-						/* check shadow cache */
+#if SHADCACHE					/* check shadow cache */
 		if (si.np == 1 && srcblocked(&sr)) {
 			cntord[sn].brt = 0.0;
 			continue;
 		}
 #endif
+						/* compute coefficient */
+		(*f)(scp->coef, p, sr.rdir, si.dom);
+		cntord[sn].brt = intens(scp->coef);
+		if (cntord[sn].brt <= 0.0)
+			continue;
 		VCOPY(scp->dir, sr.rdir);
 		copycolor(sr.rcoef, scp->coef);
 						/* compute potential */
@@ -454,19 +477,17 @@ direct(					/* add direct component */
 						/* compute number to check */
 	nshadcheck = pow((double)ncnts, shadcert) + .5;
 						/* modify threshold */
-	if (ncnts > MINSHADCNT)
-		ourthresh = shadthresh / r->rweight;
-	else
-		ourthresh = 0;
+	ourthresh = shadthresh / r->rweight;
 						/* test for shadows */
 	for (nhits = 0, hwt = 0.0, sn = 0; sn < ncnts;
 			hwt += (double)source[scp->sno].nhits /
 				(double)source[scp->sno].ntests,
 			sn++) {
 						/* check threshold */
-		if ((sn+nshadcheck>=ncnts ? cntord[sn].brt :
+		if (sn >= MINSHADCNT &&
+			    (sn+nshadcheck>=ncnts ? cntord[sn].brt :
 				cntord[sn].brt-cntord[sn+nshadcheck].brt)
-				< ourthresh*bright(r->rcol))
+					< ourthresh*bright(r->rcol))
 			break;
 		scp = srccnt + cntord[sn].sndx;
 						/* test for hit */
@@ -546,7 +567,7 @@ srcscatter(			/* compute source scattering into ray */
 	COLOR  cvext;
 	int  i, j;
 
-	if (r->rot >= FHUGE || r->gecc >= 1.-FTINY)
+	if (r->rot >= FHUGE*.99 || r->gecc >= 1.-FTINY)
 		return;		/* this can never work */
 	/* PMAP: do unconditional inscattering for volume photons */
 	if (!volumePhotonMapping && (r->slights == NULL || r->slights[0] == 0))