--- ray/src/hd/rholo2.c	1997/12/12 18:33:50	3.6
+++ ray/src/hd/rholo2.c	1998/12/07 16:56:08	3.21
@@ -1,4 +1,4 @@
-/* Copyright (c) 1997 Silicon Graphics, Inc. */
+/* Copyright (c) 1998 Silicon Graphics, Inc. */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ SGI";
@@ -13,29 +13,234 @@ static char SCCSid[] = "$SunId$ SGI";
 #include "random.h"
 
 
+VIEWPOINT	myeye;		/* target view position */
+
+struct gclim {
+	HOLO	*hp;			/* holodeck pointer */
+	GCOORD	gc;			/* grid cell */
+	FVECT	egp;			/* eye grid point */
+	double	erg2;			/* mean square eye grid range */
+	double	gmin[2], gmax[2];	/* grid coordinate limits */
+};				/* a grid coordinate range */
+
+
+static
+initeyelim(gcl, hp, gc)		/* initialize grid coordinate limits */
+register struct gclim	*gcl;
+register HOLO	*hp;
+GCOORD	*gc;
+{
+	register FLOAT	*v;
+	register int	i;
+
+	if (hp != NULL) {
+		hdgrid(gcl->egp, gcl->hp = hp, myeye.vpt);
+		gcl->erg2 = 0;
+		for (i = 0, v = hp->wg[0]; i < 3; i++, v += 3)
+			gcl->erg2 += DOT(v,v);
+		gcl->erg2 *= (1./3.) * myeye.rng*myeye.rng;
+	}
+	if (gc != NULL)
+		copystruct(&gcl->gc, gc);
+	gcl->gmin[0] = gcl->gmin[1] = FHUGE;
+	gcl->gmax[0] = gcl->gmax[1] = -FHUGE;
+}
+
+
+static
+groweyelim(gcl, gc, r0, r1, tight)	/* grow grid limits about eye point */
+register struct gclim	*gcl;
+GCOORD	*gc;
+double	r0, r1;
+int	tight;
+{
+	FVECT	gp, ab;
+	double	ab2, od, cfact;
+	double	sqcoef[3], ctcoef[3], licoef[3], cnst;
+	int	gw, gi[2];
+	double	wallpos, a, b, c, d, e, f;
+	double	root[2], yex;
+	int	n, i, j, nex;
+						/* point/view cone */
+	i = gc->w>>1;
+	gp[i] = gc->w&1 ? gcl->hp->grid[i] : 0;
+	gp[hdwg0[gc->w]] = gc->i[0] + r0;
+	gp[hdwg1[gc->w]] = gc->i[1] + r1;
+	VSUB(ab, gcl->egp, gp);
+	ab2 = DOT(ab, ab);
+	gw = gcl->gc.w>>1;
+	if ((i==gw ? ab[gw]*ab[gw] : ab2)  <= gcl->erg2 + FTINY) {
+		gcl->gmin[0] = gcl->gmin[1] = -FHUGE;
+		gcl->gmax[0] = gcl->gmax[1] = FHUGE;
+		return;			/* too close (to wall) */
+	}
+	ab2 = 1./ab2;				/* 1/norm2(ab) */
+	od = DOT(gp, ab);			/* origin dot direction */
+	cfact = 1./(1. - ab2*gcl->erg2);	/* tan^2 + 1 of cone angle */
+	for (i = 0; i < 3; i++) {		/* compute cone equation */
+		sqcoef[i] = ab[i]*ab[i]*cfact*ab2 - 1.;
+		ctcoef[i] = 2.*ab[i]*ab[(i+1)%3]*cfact*ab2;
+		licoef[i] = 2.*(gp[i] - ab[i]*cfact*od*ab2);
+	}
+	cnst = cfact*od*od*ab2 - DOT(gp,gp);
+	/*
+	 * CONE:	sqcoef[0]*x*x + sqcoef[1]*y*y + sqcoef[2]*z*z
+	 *		+ ctcoef[0]*x*y + ctcoef[1]*y*z + ctcoef[2]*z*x
+	 *		+ licoef[0]*x + licoef[1]*y + licoef[2]*z + cnst == 0
+	 */
+				/* equation for conic section in plane */
+	gi[0] = hdwg0[gcl->gc.w];
+	gi[1] = hdwg1[gcl->gc.w];
+	wallpos = gcl->gc.w&1 ? gcl->hp->grid[gw] : 0;
+	a = sqcoef[gi[0]];					/* x2 */
+	b = ctcoef[gi[0]];					/* xy */
+	c = sqcoef[gi[1]];					/* y2 */
+	d = ctcoef[gw]*wallpos + licoef[gi[0]];			/* x */
+	e = ctcoef[gi[1]]*wallpos + licoef[gi[1]];		/* y */
+	f = wallpos*(wallpos*sqcoef[gw] + licoef[gw]) + cnst;
+	for (i = 0; i < 2; i++) {
+		if (i) {		/* swap x and y coefficients */
+			register double	t;
+			t = a; a = c; c = t;
+			t = d; d = e; e = t;
+		}
+		nex = 0;		/* check global extrema */
+		n = quadratic(root, a*(4.*a*c-b*b), 2.*a*(2.*c*d-b*e),
+				d*(c*d-b*e) + f*b*b);
+		while (n-- > 0) {
+			if (gc->w>>1 == gi[i] &&
+					(gc->w&1) ^ root[n] < gp[gc->w>>1]) {
+				if (gc->w&1)
+					gcl->gmin[i] = -FHUGE;
+				else
+					gcl->gmax[i] = FHUGE;
+				nex++;
+				continue;		/* hyperbolic */
+			}
+			if (tight) {
+				yex = (-2.*a*root[n] - d)/b;
+				if (yex < gcl->gc.i[1-i] ||
+						yex > gcl->gc.i[1-i]+1)
+					continue;	/* outside cell */
+			}
+			if (root[n] < gcl->gmin[i])
+				gcl->gmin[i] = root[n];
+			if (root[n] > gcl->gmax[i])
+				gcl->gmax[i] = root[n];
+			nex++;
+		}
+					/* check local extrema */
+		for (j = nex < 2 ? 2 : 0; j--; ) {
+			yex = gcl->gc.i[1-i] + j;
+			n = quadratic(root, a, b*yex+d, yex*(yex*c+e)+f);
+			while (n-- > 0) {
+				if (gc->w>>1 == gi[i] &&
+					(gc->w&1) ^ root[n] < gp[gc->w>>1])
+					continue;
+				if (root[n] < gcl->gmin[i])
+					gcl->gmin[i] = root[n];
+				if (root[n] > gcl->gmax[i])
+					gcl->gmax[i] = root[n];
+			}
+		}
+	}
+}
+
+
+static int
+clipeyelim(rrng, gcl)		/* clip eye limits to grid cell */
+register short	rrng[2][2];
+register struct gclim	*gcl;
+{
+	int	incell = 1;
+	register int	i;
+
+	for (i = 0; i < 2; i++) {
+		if (gcl->gmin[i] < gcl->gc.i[i])
+			gcl->gmin[i] = gcl->gc.i[i];
+		if (gcl->gmax[i] > gcl->gc.i[i]+1)
+			gcl->gmax[i] = gcl->gc.i[i]+1;
+		if (gcl->gmax[i] > gcl->gmin[i]) {
+			rrng[i][0] = 256.*(gcl->gmin[i] - gcl->gc.i[i]) +
+					(1.-FTINY);
+			rrng[i][1] = 256.*(gcl->gmax[i] - gcl->gc.i[i]) +
+					(1.-FTINY) - rrng[i][0];
+		} else
+			rrng[i][0] = rrng[i][1] = 0;
+		incell &= rrng[i][1] > 0;
+	}
+	return(incell);
+}
+
+
 packrays(rod, p)		/* pack ray origins and directions */
 register float	*rod;
 register PACKET	*p;
 {
-	static FVECT	ro, rd;
+#if 0
+	double	dist2sum = 0.;
+	FVECT	vt;
+#endif
+	int	nretries = p->nr + 2;
+	struct gclim	eyelim;
+	short	rrng0[2][2], rrng1[2][2];
+	int	useyelim;
 	GCOORD	gc[2];
-	int	ila[2], hsh;
-	double	d, sl[4];
+	FVECT	ro, rd;
+	double	d;
 	register int	i;
 
 	if (!hdbcoord(gc, hdlist[p->hd], p->bi))
 		error(CONSISTENCY, "bad beam index in packrays");
-	ila[0] = p->hd; ila[1] = p->bi;
-	hsh = ilhash(ila,2) + p->nc;
+	if ((useyelim = myeye.rng > FTINY)) {
+		initeyelim(&eyelim, hdlist[p->hd], gc);
+		groweyelim(&eyelim, gc+1, 0., 0., 0);
+		groweyelim(&eyelim, gc+1, 1., 1., 0);
+		useyelim = clipeyelim(rrng0, &eyelim);
+#ifdef DEBUG
+		if (!useyelim)
+			error(WARNING, "no eye overlap in packrays");
+#endif
+	}
 	for (i = 0; i < p->nr; i++) {
-		multisamp(sl, 4, urand(hsh+i));
-		p->ra[i].r[0][0] = sl[0] * 256.;
-		p->ra[i].r[0][1] = sl[1] * 256.;
-		p->ra[i].r[1][0] = sl[2] * 256.;
-		p->ra[i].r[1][1] = sl[3] * 256.;
+	retry:
+		if (useyelim) {
+			initeyelim(&eyelim, NULL, gc+1);
+			p->ra[i].r[0][0] = (int)(frandom()*rrng0[0][1])
+						+ rrng0[0][0];
+			p->ra[i].r[0][1] = (int)(frandom()*rrng0[1][1])
+						+ rrng0[1][0];
+			groweyelim(&eyelim, gc,
+					(1./256.)*(p->ra[i].r[0][0]+.5),
+					(1./256.)*(p->ra[i].r[0][1]+.5), 1);
+			if (!clipeyelim(rrng1, &eyelim)) {
+				useyelim = nretries-- > 0;
+#ifdef DEBUG
+				if (!useyelim)
+					error(WARNING,
+					"exceeded retry limit in packrays");
+#endif
+				goto retry;
+			}
+			p->ra[i].r[1][0] = (int)(frandom()*rrng1[0][1])
+						+ rrng1[0][0];
+			p->ra[i].r[1][1] = (int)(frandom()*rrng1[1][1])
+						+ rrng1[1][0];
+		} else {
+			p->ra[i].r[0][0] = frandom() * 256.;
+			p->ra[i].r[0][1] = frandom() * 256.;
+			p->ra[i].r[1][0] = frandom() * 256.;
+			p->ra[i].r[1][1] = frandom() * 256.;
+		}
 		d = hdray(ro, rd, hdlist[p->hd], gc, p->ra[i].r);
+#if 0
+		VSUM(vt, ro, rd, d);
+		dist2sum += dist2line(myeye.vpt, ro, vt);
+#endif
 		if (p->offset != NULL) {
-			VSUM(ro, ro, rd, d);		/* exterior only */
+			if (!vdef(OBSTRUCTIONS))
+				d *= frandom();		/* random offset */
+			VSUM(ro, ro, rd, d);		/* advance ray */
 			p->offset[i] = d;
 		}
 		VCOPY(rod, ro);
@@ -43,6 +248,10 @@ register PACKET	*p;
 		VCOPY(rod, rd);
 		rod += 3;
 	}
+#if 0
+	fprintf(stderr, "%f RMS (%d retries)\t", sqrt(dist2sum/p->nr),
+			p->nr + 2 - nretries);
+#endif
 }
 
 
@@ -72,14 +281,17 @@ done_rtrace()			/* clean up and close rtrace calculati
 					/* already closed? */
 	if (!nprocs)
 		return;
-	wputs("closing rtrace process...\n");
 					/* flush beam queue */
 	done_packets(flush_queue());
+					/* sync holodeck */
+	hdsync(NULL, 1);
 					/* close rtrace */
 	if ((status = end_rtrace()))
 		error(WARNING, "bad exit status from rtrace");
-	if (vdef(REPORT))		/* report time */
+	if (vdef(REPORT)) {		/* report time */
+		eputs("rtrace process closed\n");
 		report(0);
+	}
 	return(status);			/* return status */
 }
 
@@ -90,7 +302,6 @@ new_rtrace()			/* restart rtrace calculation */
 
 	if (nprocs > 0)			/* already running? */
 		return;
-	wputs("restarting rtrace process...\n");
 	starttime = time(NULL);		/* reset start time and counts */
 	npacksdone = nraysdone = 0L;
 	if (vdef(TIME))			/* reset end time */
@@ -102,14 +313,16 @@ new_rtrace()			/* restart rtrace calculation */
 	}
 	if (start_rtrace() < 1)		/* start rtrace */
 		error(WARNING, "cannot restart rtrace");
-	else if (vdef(REPORT))
+	else if (vdef(REPORT)) {
+		eputs("rtrace process restarted\n");
 		report(0);
+	}
 }
 
 
 getradfile()			/* run rad and get needed variables */
 {
-	static short	mvar[] = {OCTREE,-1};
+	static short	mvar[] = {OCTREE,EYESEP,-1};
 	static char	tf1[] = TEMPLATE;
 	char	tf2[64];
 	char	combuf[256];
@@ -118,7 +331,7 @@ getradfile()			/* run rad and get needed variables */
 	register char	*cp;
 					/* check if rad file specified */
 	if (!vdef(RIF))
-		return;
+		return(0);
 					/* create rad command */
 	mktemp(tf1);
 	sprintf(tf2, "%s.rif", tf1);
@@ -141,17 +354,17 @@ getradfile()			/* run rad and get needed variables */
 		strcpy(pippt, "> /dev/null");	/* nothing to match */
 	else
 		sprintf(cp, ")[ \t]*=' > %s", tf2);
-	if (system(combuf)) {
-		unlink(tf2);			/* clean up */
-		unlink(tf1);
-		error(SYSTEM, "cannot execute rad command");
-	}
+#ifdef DEBUG
+	wputs(combuf); wputs("\n");
+#endif
+	system(combuf);				/* ignore exit code */
 	if (pippt == NULL) {
 		loadvars(tf2);			/* load variables */
 		unlink(tf2);
 	}
 	rtargc += wordfile(rtargv+rtargc, tf1);	/* get rtrace options */
 	unlink(tf1);			/* clean up */
+	return(1);
 }