--- ray/src/rt/raytrace.c	1991/02/12 12:57:07	1.14
+++ ray/src/rt/raytrace.c	1991/05/10 08:51:06	1.17
@@ -1,4 +1,4 @@
-/* Copyright (c) 1990 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -16,12 +16,21 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include  "otypes.h"
 
+#include  "otspecial.h"
+
 extern CUBE  thescene;			/* our scene */
 extern int  maxdepth;			/* maximum recursion depth */
 extern double  minweight;		/* minimum ray weight */
+extern int  do_irrad;			/* compute irradiance? */
 
 long  nrays = 0L;			/* number of rays traced */
 
+static double  Lambfa[5] = {PI, PI, PI, 0.0, 0.0};
+OBJREC  Lamb = {
+	OVOID, MAT_PLASTIC, "Lambertian",
+	{0, 5, NULL, Lambfa}, NULL, -1,
+};					/* a Lambertian surface */
+
 #define  MAXLOOP	128		/* modifier loop detection */
 
 #define  RAYHIT		(-1)		/* return value for intercepted ray */
@@ -69,8 +78,10 @@ RAY  *r;
 {
 	extern int  (*trace)();
 
-	if (localhit(r, &thescene) || sourcehit(r))
+	if (localhit(r, &thescene))
 		raycont(r);
+	else if (sourcehit(r))
+		rayshade(r, r->ro->omod);
 
 	if (trace != NULL)
 		(*trace)(r);		/* trace execution */
@@ -118,6 +129,16 @@ int  mod;
 			error(USER, errmsg);
 		}
 		******/
+					/* hack for irradiance calculation */
+		if (do_irrad && !(r->crtype & ~(PRIMARY|TRANS))) {
+			if (irr_ignore(m->otype)) {
+				depth--;
+				raytrans(r);
+				return;
+			}
+			if (m->otype != MAT_ILLUM)
+				m = &Lamb;
+		}
 		(*ofun[m->otype].funp)(m, r);	/* execute function */
 		m->lastrno = r->rno;
 		if (ismaterial(m->otype)) {	/* materials call raytexture */
@@ -301,6 +322,8 @@ register CUBE  *scene;
 		else if (r->rdir[i] < -FTINY)
 			sflags |= 0x10 << i;
 	}
+	if (sflags == 0)
+		error(CONSISTENCY, "zero ray direction in localhit");
 	t = 0.0;
 	if (!incube(scene, curpos)) {
 					/* find distance to entry */