--- ray/src/rt/source.c	1996/04/17 14:02:18	2.24
+++ ray/src/rt/source.c	2003/02/25 02:47:23	2.30
@@ -1,19 +1,16 @@
-/* Copyright (c) 1995 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: source.c,v 2.30 2003/02/25 02:47:23 greg Exp $";
 #endif
-
 /*
  *  source.c - routines dealing with illumination sources.
  *
- *     8/20/85
+ *  External symbols declared in source.h
  */
 
+#include "copyright.h"
+
 #include  "ray.h"
 
-#include  "octree.h"
-
 #include  "otypes.h"
 
 #include  "source.h"
@@ -47,6 +44,7 @@ static CNTPTR  *cntord;			/* source ordering in direct
 static int  maxcntr = 0;		/* size of contribution arrays */
 
 
+void
 marksources()			/* find and mark source objects */
 {
 	int  foundsource = 0;
@@ -125,6 +123,25 @@ memerr:
 }
 
 
+void
+freesources()			/* free all source structures */
+{
+	if (nsources > 0) {
+		free((void *)source);
+		source = NULL;
+		nsources = 0;
+	}
+	if (maxcntr <= 0)
+		return;
+	free((void *)srccnt);
+	srccnt = NULL;
+	free((void *)cntord);
+	cntord = NULL;
+	maxcntr = 0;
+}
+
+
+int
 srcray(sr, r, si)		/* send a ray to a source, return domega */
 register RAY  *sr;		/* returned source ray */
 RAY  *r;			/* ray which hit object */
@@ -162,6 +179,7 @@ SRCINDEX  *si;			/* source sample index */
 }
 
 
+void
 srcvalue(r)			/* punch ray to source and compute value */
 register RAY  *r;
 {
@@ -202,6 +220,7 @@ nomat:
 }
 
 
+int
 sourcehit(r)			/* check to see if ray hit distant source */
 register RAY  *r;
 {
@@ -227,6 +246,7 @@ register RAY  *r;
 			}
 
 	if (r->ro != NULL) {
+		r->robj = objndx(r->ro);
 		for (i = 0; i < 3; i++)
 			r->ron[i] = -r->rdir[i];
 		r->rod = 1.0;
@@ -249,12 +269,13 @@ register CNTPTR  *sc1, *sc2;
 }
 
 
+void
 direct(r, f, p)				/* add direct component */
 RAY  *r;			/* ray that hit surface */
-int  (*f)();			/* direct component coefficient function */
+void  (*f)();			/* direct component coefficient function */
 char  *p;			/* data for f */
 {
-	extern int  (*trace)();
+	extern void  (*trace)();
 	register int  sn;
 	register CONTRIB  *scp;
 	SRCINDEX  si;
@@ -374,6 +395,7 @@ char  *p;			/* data for f */
 }
 
 
+void
 srcscatter(r)			/* compute source scattering into ray */
 register RAY  *r;
 {
@@ -381,8 +403,9 @@ register RAY  *r;
 	int  nsamps;
 	RAY  sr;
 	SRCINDEX  si;
-	double  t, lastt, d;
-	COLOR  cumval, ctmp;
+	double  t, d;
+	double  re, ge, be;
+	COLOR  cvext;
 	int  i, j;
 
 	if (r->slights == NULL || r->slights[0] == 0
@@ -397,11 +420,18 @@ register RAY  *r;
 	oldsampndx = samplendx;
 	samplendx = random()&0x7fff;		/* randomize */
 	for (i = r->slights[0]; i > 0; i--) {	/* for each source */
-		setcolor(cumval, 0., 0., 0.);
-		lastt = r->rot;
-		for (j = nsamps; j-- > 0; ) {	/* for each sample position */
+		for (j = 0; j < nsamps; j++) {	/* for each sample position */
 			samplendx++;
 			t = r->rot * (j+frandom())/nsamps;
+							/* extinction */
+			re = t*colval(r->cext,RED);
+			ge = t*colval(r->cext,GRN);
+			be = t*colval(r->cext,BLU);
+			setcolor(cvext,	re > 92. ? 0. : exp(-re),
+					ge > 92. ? 0. : exp(-ge),
+					be > 92. ? 0. : exp(-be));
+			if (intens(cvext) <= FTINY)
+				break;			/* too far away */
 			sr.rorg[0] = r->rorg[0] + r->rdir[0]*t;
 			sr.rorg[1] = r->rorg[1] + r->rdir[1]*t;
 			sr.rorg[2] = r->rorg[2] + r->rdir[2]*t;
@@ -415,36 +445,25 @@ register RAY  *r;
 			copycolor(sr.cext, r->cext);
 			copycolor(sr.albedo, r->albedo);
 			sr.gecc = r->gecc;
+			sr.slights = r->slights;
 			rayvalue(&sr);			/* eval. source ray */
 			if (bright(sr.rcol) <= FTINY)
 				continue;
-							/* compute fall-off */
-			d = lastt - t;
-			setcolor(ctmp,	1.-d*colval(r->cext,RED),
-					1.-d*colval(r->cext,GRN),
-					1.-d*colval(r->cext,BLU));
-			multcolor(cumval, ctmp);
-			lastt = t;
 			if (r->gecc <= FTINY)		/* compute P(theta) */
 				d = 1.;
 			else {
 				d = DOT(r->rdir, sr.rdir);
-				d = sqrt(1. + r->gecc*r->gecc - 2.*r->gecc*d);
-				d = (1. - r->gecc*r->gecc) / (d*d*d);
+				d = 1. + r->gecc*r->gecc - 2.*r->gecc*d;
+				d = (1. - r->gecc*r->gecc) / (d*sqrt(d));
 			}
 							/* other factors */
 			d *= si.dom * r->rot / (4.*PI*nsamps);
 			multcolor(sr.rcol, r->cext);
 			multcolor(sr.rcol, r->albedo);
 			scalecolor(sr.rcol, d);
-			addcolor(cumval, sr.rcol);
+			multcolor(sr.rcol, cvext);
+			addcolor(r->rcol, sr.rcol);	/* add it in */
 		}
-						/* final fall-off */
-		setcolor(ctmp,	1.-lastt*colval(r->cext,RED),
-				1.-lastt*colval(r->cext,GRN),
-				1.-lastt*colval(r->cext,BLU));
-		multcolor(cumval, ctmp);
-		addcolor(r->rcol, cumval);	/* sum into ray result */
 	}
 	samplendx = oldsampndx;
 }
@@ -528,6 +547,7 @@ return(o->otype==MAT_ILLUM|o->otype==MAT_GLOW);}
 				distglow(m, r, raydist(r,PRIMARY)))
 
 
+int
 m_light(m, r)			/* ray hit a light source */
 register OBJREC  *m;
 register RAY  *r;
@@ -540,7 +560,7 @@ register RAY  *r;
 						/* check for passed illum */
 	if (passillum(m, r)) {
 		if (m->oargs.nsargs && strcmp(m->oargs.sarg[0], VOIDID))
-			return(rayshade(r, modifier(m->oargs.sarg[0])));
+			return(rayshade(r,lastmod(objndx(m),m->oargs.sarg[0])));
 		raytrans(r);
 		return(1);
 	}