--- ray/src/hd/holo.c	1997/11/11 17:03:28	3.6
+++ ray/src/hd/holo.c	1998/01/03 15:55:55	3.12
@@ -199,16 +199,13 @@ register GCOORD	*gc;
 }
 
 
-hdlseg(lseg, hp, i)			/* compute line segment for beam */
+hdlseg(lseg, hp, gc)			/* compute line segment for beam */
 register int	lseg[2][3];
 register HOLO	*hp;
-int	i;
+GCOORD	gc[2];
 {
-	GCOORD	gc[2];
 	register int	k;
 
-	if (!hdbcoord(gc, hp, i))		/* compute grid coordinates */
-		return(0);
 	for (k = 0; k < 2; k++) {		/* compute end points */
 		lseg[k][gc[k].w>>1] = gc[k].w&1	? hp->grid[gc[k].w>>1]-1 : 0 ;
 		lseg[k][wg0[gc[k].w]] = gc[k].i[0];
@@ -224,7 +221,7 @@ HOLO	*hp;
 double	d;
 {
 	double	tl = hp->tlin;
-	register unsigned	c;
+	register long	c;
 
 	if (d <= 0.)
 		return(0);
@@ -232,8 +229,8 @@ double	d;
 		return(DCINF);
 	if (d < tl)
 		return((unsigned)(d*DCLIN/tl));
-	c = (unsigned)(log(d/tl)/logstep) + DCLIN;
-	return(c > DCINF ? DCINF : c);
+	c = (long)(log(d/tl)/logstep) + DCLIN;
+	return(c > DCINF ? (unsigned)DCINF : (unsigned)c);
 }
 
 
@@ -253,6 +250,24 @@ FVECT	wp;
 }
 
 
+hdworld(wp, hp, gp)		/* compute world coordinates */
+register FVECT	wp;
+register HOLO	*hp;
+FVECT	gp;
+{
+	register double	d;
+
+	d = gp[0]/hp->grid[0];
+	VSUM(wp, hp->orig, hp->xv[0], d);
+
+	d = gp[1]/hp->grid[1];
+	VSUM(wp, wp, hp->xv[1], d);
+
+	d = gp[2]/hp->grid[2];
+	VSUM(wp, wp, hp->xv[2], d);
+}
+
+
 double
 hdray(ro, rd, hp, gc, r)	/* compute ray within a beam */
 FVECT	ro, rd;		/* returned */
@@ -281,11 +296,12 @@ BYTE	r[2][2];
 
 
 double
-hdinter(gc, r, hp, ro, rd)	/* compute ray intersection with section */
+hdinter(gc, r, ed, hp, ro, rd)	/* compute ray intersection with section */
 register GCOORD	gc[2];	/* returned */
-BYTE	r[2][2];	/* returned */
+BYTE	r[2][2];	/* returned (optional) */
+double	*ed;		/* returned (optional) */
 register HOLO	*hp;
-FVECT	ro, rd;		/* rd should be normalized */
+FVECT	ro, rd;		/* normalization of rd affects distances */
 {
 	FVECT	p[2], vt;
 	double	d, t0, t1, d0, d1;
@@ -337,16 +353,16 @@ FVECT	ro, rd;		/* rd should be normalized */
 		d = DOT(vt, v) * hp->wg[wg0[gc[i].w]];
 		if (d < 0. || (gc[i].i[0] = d) >= hp->grid[wg0[gc[i].w]])
 			return(FHUGE);		/* outside wall */
-		r[i][0] = 256. * (d - gc[i].i[0]);
+		if (r != NULL)
+			r[i][0] = 256. * (d - gc[i].i[0]);
 		v = hp->wn[wg1[gc[i].w]];
 		d = DOT(vt, v) * hp->wg[wg1[gc[i].w]];
 		if (d < 0. || (gc[i].i[1] = d) >= hp->grid[wg1[gc[i].w]])
 			return(FHUGE);		/* outside wall */
-		r[i][1] = 256. * (d - gc[i].i[1]);
+		if (r != NULL)
+			r[i][1] = 256. * (d - gc[i].i[1]);
 	}
-					/* return distance from entry point */
-	vt[0] = ro[0] - p[0][0];
-	vt[1] = ro[1] - p[0][1];
-	vt[2] = ro[2] - p[0][2];
-	return(DOT(vt,rd));
+	if (ed != NULL)			/* assign distance to exit point */
+		*ed = t1;
+	return(t0);			/* return distance to entry point */
 }