--- ray/src/px/pinterp.c	1990/01/18 23:58:29	1.23
+++ ray/src/px/pinterp.c	1998/10/27 09:08:26	2.31
@@ -1,3 +1,5 @@
+/* Copyright (c) 1995 Regents of the University of California */
+
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
 #endif
@@ -10,30 +12,44 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include "standard.h"
 
-#include <sys/fcntl.h>
+#include <ctype.h>
 
 #include "view.h"
 
 #include "color.h"
 
-#ifndef BSD
-#define vfork		fork
-#endif
+#include "resolu.h"
 
+#define LOG2		0.69314718055994530942
+
 #define pscan(y)	(ourpict+(y)*hresolu)
+#define sscan(y)	(ourspict+(y)*hresolu)
+#define wscan(y)	(ourweigh+(y)*hresolu)
 #define zscan(y)	(ourzbuf+(y)*hresolu)
+#define bscan(y)	(ourbpict+(y)*hresolu)
+#define averaging	(ourweigh != NULL)
+#define blurring	(ourbpict != NULL)
+#define usematrix	(hasmatrix & !averaging)
+#define zisnorm		(!usematrix | ourview.type != VT_PER)
 
+#define MAXWT		1000.		/* maximum pixel weight (averaging) */
+
 #define F_FORE		1		/* fill foreground */
 #define F_BACK		2		/* fill background */
 
-#define PACKSIZ		42		/* calculation packet size */
+#define PACKSIZ		256		/* max. calculation packet size */
 
-#define RTCOM		"rtrace -h -ovl -fff -x %d %s"
+#define RTCOM		"rtrace -h- -ovl -fff -ld- -i- -I- "
 
 #define ABS(x)		((x)>0?(x):-(x))
 
 struct position {int x,y; float z;};
 
+#define NSTEPS		64		/* number steps in overlap prescan */
+#define MINSTEP		4		/* minimum worthwhile preview step */
+
+struct bound {int min,max;};
+
 VIEW	ourview = STDVIEW;		/* desired view */
 int	hresolu = 512;			/* horizontal resolution */
 int	vresolu = 512;			/* vertical resolution */
@@ -41,171 +57,261 @@ double	pixaspect = 1.0;		/* pixel aspect ratio */
 
 double	zeps = .02;			/* allowed z epsilon */
 
-COLR	*ourpict;			/* output picture */
+COLR	*ourpict;			/* output picture (COLR's) */
+COLOR	*ourspict;			/* output pixel sums (averaging) */
+float	*ourweigh = NULL;		/* output pixel weights (averaging) */
 float	*ourzbuf;			/* corresponding z-buffer */
+COLOR	*ourbpict = NULL;		/* blurred picture (view averaging) */
 
+VIEW	avgview;			/* average view for -B option */
+int	nvavg;				/* number of views averaged */
+
 char	*progname;
 
-int	fill = F_FORE|F_BACK;		/* selected fill algorithm */
+int	fillo = F_FORE|F_BACK;		/* selected fill options */
+int	fillsamp = 0;			/* sample separation (0 == inf) */
 extern int	backfill(), rcalfill();	/* fill functions */
-int	(*deffill)() = backfill;	/* selected fill function */
+int	(*fillfunc)() = backfill;	/* selected fill function */
 COLR	backcolr = BLKCOLR;		/* background color */
+COLOR	backcolor = BLKCOLOR;		/* background color (float) */
 double	backz = 0.0;			/* background z value */
-int	normdist = 1;			/* normalized distance? */
-double	ourexp = -1;			/* output picture exposure */
+int	normdist = 1;			/* i/o normalized distance? */
+char	ourfmt[LPICFMT+1] = PICFMT;	/* original picture format */
+double	ourexp = -1;			/* original picture exposure */
+int	expadj = 0;			/* exposure adjustment (f-stops) */
+double	rexpadj = 1;			/* real exposure adjustment */
 
-VIEW	theirview = STDVIEW;		/* input view */
+VIEW	theirview;			/* input view */
 int	gotview;			/* got input view? */
-int	thresolu, tvresolu;		/* input resolution */
+int	wrongformat = 0;		/* input in another format? */
+RESOLU	tresolu;			/* input resolution */
 double	theirexp;			/* input picture exposure */
-double	theirs2ours[4][4];		/* transformation matrix */
+MAT4	theirs2ours;			/* transformation matrix */
+int	hasmatrix = 0;			/* has transformation matrix */
 
-int	childpid = -1;			/* id of fill process */
-FILE	*psend, *precv;			/* pipes to/from fill calculation */
-int	queue[PACKSIZ][2];		/* pending pixels */
-int	queuesiz;			/* number of pixels pending */
+int	PDesc[3] = {-1,-1,-1};		/* rtrace process descriptor */
+#define childpid	(PDesc[2])
+unsigned short	queue[PACKSIZ][2];	/* pending pixels */
+int	packsiz;			/* actual packet size */
+int	queuesiz = 0;			/* number of pixels pending */
 
+extern double	movepixel();
 
+
 main(argc, argv)			/* interpolate pictures */
 int	argc;
 char	*argv[];
 {
-#define check(olen,narg)	if (argv[i][olen] || narg >= argc-i) goto badopt
-	extern double	atof();
+#define  check(ol,al)		if (argv[an][ol] || \
+				badarg(argc-an-1,argv+an+1,al)) \
+				goto badopt
 	int	gotvfile = 0;
+	int	doavg = -1;
+	int	doblur = 0;
 	char	*zfile = NULL;
-	char	*err;
-	int	i, rval;
+	char	*expcomp = NULL;
+	int	i, an, rval;
 
 	progname = argv[0];
 
-	for (i = 1; i < argc && argv[i][0] == '-'; i++) {
-		rval = getviewopt(&ourview, argc-i, argv+i);
+	for (an = 1; an < argc && argv[an][0] == '-'; an++) {
+		rval = getviewopt(&ourview, argc-an, argv+an);
 		if (rval >= 0) {
-			i += rval;
+			an += rval;
 			continue;
 		}
-		switch (argv[i][1]) {
+		switch (argv[an][1]) {
+		case 'e':				/* exposure */
+			check(2,"f");
+			expcomp = argv[++an];
+			break;
 		case 't':				/* threshold */
-			check(2,1);
-			zeps = atof(argv[++i]);
+			check(2,"f");
+			zeps = atof(argv[++an]);
 			break;
+		case 'a':				/* average */
+			check(2,NULL);
+			doavg = 1;
+			break;
+		case 'B':				/* blur views */
+			check(2,NULL);
+			doblur = 1;
+			break;
+		case 'q':				/* quick (no avg.) */
+			check(2,NULL);
+			doavg = 0;
+			break;
 		case 'n':				/* dist. normalized? */
-			check(2,0);
+			check(2,NULL);
 			normdist = !normdist;
 			break;
 		case 'f':				/* fill type */
-			switch (argv[i][2]) {
+			switch (argv[an][2]) {
 			case '0':				/* none */
-				check(3,0);
-				fill = 0;
+				check(3,NULL);
+				fillo = 0;
 				break;
 			case 'f':				/* foreground */
-				check(3,0);
-				fill = F_FORE;
+				check(3,NULL);
+				fillo = F_FORE;
 				break;
 			case 'b':				/* background */
-				check(3,0);
-				fill = F_BACK;
+				check(3,NULL);
+				fillo = F_BACK;
 				break;
 			case 'a':				/* all */
-				check(3,0);
-				fill = F_FORE|F_BACK;
+				check(3,NULL);
+				fillo = F_FORE|F_BACK;
 				break;
+			case 's':				/* sample */
+				check(3,"i");
+				fillsamp = atoi(argv[++an]);
+				break;
 			case 'c':				/* color */
-				check(3,3);
-				deffill = backfill;
-				setcolr(backcolr, atof(argv[i+1]),
-					atof(argv[i+2]), atof(argv[i+3]));
-				i += 3;
+				check(3,"fff");
+				fillfunc = backfill;
+				setcolor(backcolor, atof(argv[an+1]),
+					atof(argv[an+2]), atof(argv[an+3]));
+				setcolr(backcolr, colval(backcolor,RED),
+						colval(backcolor,GRN),
+						colval(backcolor,BLU));
+				an += 3;
 				break;
 			case 'z':				/* z value */
-				check(3,1);
-				deffill = backfill;
-				backz = atof(argv[++i]);
+				check(3,"f");
+				fillfunc = backfill;
+				backz = atof(argv[++an]);
 				break;
 			case 'r':				/* rtrace */
-				check(3,1);
-				deffill = rcalfill;
-				calstart(RTCOM, argv[++i]);
+				check(3,"s");
+				fillfunc = rcalfill;
+				calstart(RTCOM, argv[++an]);
 				break;
 			default:
 				goto badopt;
 			}
 			break;
 		case 'z':				/* z file */
-			check(2,1);
-			zfile = argv[++i];
+			check(2,"s");
+			zfile = argv[++an];
 			break;
 		case 'x':				/* x resolution */
-			check(2,1);
-			hresolu = atoi(argv[++i]);
+			check(2,"i");
+			hresolu = atoi(argv[++an]);
 			break;
 		case 'y':				/* y resolution */
-			check(2,1);
-			vresolu = atoi(argv[++i]);
+			check(2,"i");
+			vresolu = atoi(argv[++an]);
 			break;
 		case 'p':				/* pixel aspect */
-			check(2,1);
-			pixaspect = atof(argv[++i]);
+			if (argv[an][2] != 'a')
+				goto badopt;
+			check(3,"f");
+			pixaspect = atof(argv[++an]);
 			break;
 		case 'v':				/* view file */
-			if (argv[i][2] != 'f')
+			if (argv[an][2] != 'f')
 				goto badopt;
-			check(3,1);
-			gotvfile = viewfile(argv[++i], &ourview, 0, 0);
-			if (gotvfile < 0) {
-				perror(argv[i]);
-				exit(1);
-			} else if (gotvfile == 0) {
+			check(3,"s");
+			gotvfile = viewfile(argv[++an], &ourview, 0, 0);
+			if (gotvfile < 0)
+				syserror(argv[an]);
+			else if (gotvfile == 0) {
 				fprintf(stderr, "%s: bad view file\n",
-						argv[i]);
+						argv[an]);
 				exit(1);
 			}
 			break;
 		default:
 		badopt:
 			fprintf(stderr, "%s: command line error at '%s'\n",
-					progname, argv[i]);
+					progname, argv[an]);
 			goto userr;
 		}
 	}
 						/* check arguments */
-	if ((argc-i)%2)
+	if ((argc-an)%2)
 		goto userr;
+	if (fillsamp == 1)
+		fillo &= ~F_BACK;
+	if (doavg < 0)
+		doavg = (argc-an) > 2;
+	if (expcomp != NULL)
+		if (expcomp[0] == '+' | expcomp[0] == '-') {
+			expadj = atof(expcomp) + (expcomp[0]=='+' ? .5 : -.5);
+			if (doavg | doblur)
+				rexpadj = pow(2.0, atof(expcomp));
+			else
+				rexpadj = pow(2.0, (double)expadj);
+		} else {
+			if (!isflt(expcomp))
+				goto userr;
+			rexpadj = atof(expcomp);
+			expadj = log(rexpadj)/LOG2 + (rexpadj>1 ? .5 : -.5);
+			if (!(doavg | doblur))
+				rexpadj = pow(2.0, (double)expadj);
+		}
 						/* set view */
-	if (err = setview(&ourview)) {
-		fprintf(stderr, "%s: %s\n", progname, err);
+	if (nextview(doblur ? stdin : (FILE *)NULL) == EOF) {
+		fprintf(stderr, "%s: no view on standard input!\n",
+				progname);
 		exit(1);
 	}
 	normaspect(viewaspect(&ourview), &pixaspect, &hresolu, &vresolu);
 						/* allocate frame */
-	ourpict = (COLR *)malloc(hresolu*vresolu*sizeof(COLR));
-	ourzbuf = (float *)calloc(hresolu*vresolu,sizeof(float));
-	if (ourpict == NULL || ourzbuf == NULL)
-		syserror();
-							/* get input */
-	for ( ; i < argc; i += 2)
-		addpicture(argv[i], argv[i+1]);
-							/* fill in spaces */
-	if (fill&F_BACK)
-		backpicture();
-	else
-		fillpicture();
+	if (doavg) {
+		ourspict = (COLOR *)bmalloc(hresolu*vresolu*sizeof(COLOR));
+		ourweigh = (float *)bmalloc(hresolu*vresolu*sizeof(float));
+		if (ourspict == NULL | ourweigh == NULL)
+			syserror(progname);
+	} else {
+		ourpict = (COLR *)bmalloc(hresolu*vresolu*sizeof(COLR));
+		if (ourpict == NULL)
+			syserror(progname);
+	}
+	if (doblur) {
+		ourbpict = (COLOR *)bmalloc(hresolu*vresolu*sizeof(COLOR));
+		if (ourbpict == NULL)
+			syserror(progname);
+	}
+	ourzbuf = (float *)bmalloc(hresolu*vresolu*sizeof(float));
+	if (ourzbuf == NULL)
+		syserror(progname);
+							/* new header */
+	newheader("RADIANCE", stdout);
+							/* run pictures */
+	do {
+		bzero((char *)ourzbuf, hresolu*vresolu*sizeof(float));
+		for (i = an; i < argc; i += 2)
+			addpicture(argv[i], argv[i+1]);
+		if (fillo&F_BACK)			/* fill in spaces */
+			backpicture(fillfunc, fillsamp);
+		else
+			fillpicture(fillfunc);
+							/* aft clipping */
+		clipaft();
+	} while (addblur() && nextview(stdin) != EOF);
 							/* close calculation */
 	caldone();
 							/* add to header */
 	printargs(argc, argv, stdout);
-	if (gotvfile) {
-		printf(VIEWSTR);
-		fprintview(&ourview, stdout);
-		printf("\n");
+	compavgview();
+	if (doblur | gotvfile) {
+		fputs(VIEWSTR, stdout);
+		fprintview(&avgview, stdout);
+		putc('\n', stdout);
 	}
-	if (pixaspect < .99 || pixaspect > 1.01)
+	if (pixaspect < .99 | pixaspect > 1.01)
 		fputaspect(pixaspect, stdout);
-	if (ourexp > 0 && (ourexp < .995 || ourexp > 1.005))
+	if (ourexp > 0)
+		ourexp *= rexpadj;
+	else
+		ourexp = rexpadj;
+	if (ourexp < .995 | ourexp > 1.005)
 		fputexpos(ourexp, stdout);
-	printf("\n");
+	if (strcmp(ourfmt, PICFMT))		/* print format if known */
+		fputformat(ourfmt, stdout);
+	putc('\n', stdout);
 							/* write picture */
 	writepicture();
 							/* write z file */
@@ -215,58 +321,129 @@ char	*argv[];
 	exit(0);
 userr:
 	fprintf(stderr,
-	"Usage: %s [view opts][-t eps][-z zout][-fT][-n] pfile zspec ..\n",
+	"Usage: %s [view opts][-t eps][-z zout][-e spec][-B][-a|-q][-fT][-n] pfile zspec ..\n",
 			progname);
 	exit(1);
 #undef check
 }
 
 
+int
 headline(s)				/* process header string */
 char	*s;
 {
-	static char	*altname[] = {"rview","rpict","pinterp",VIEWSTR,NULL};
-	register char	**an;
+	char	fmt[32];
 
-	printf("\t%s", s);
-
+	if (isheadid(s))
+		return(0);
+	if (formatval(fmt, s)) {
+		if (globmatch(ourfmt, fmt)) {
+			wrongformat = 0;
+			strcpy(ourfmt, fmt);
+		} else
+			wrongformat = 1;
+		return(0);
+	}
+	if (nvavg < 2) {
+		putc('\t', stdout);
+		fputs(s, stdout);
+	}
 	if (isexpos(s)) {
 		theirexp *= exposval(s);
+		return(0);
+	}
+	if (isview(s) && sscanview(&theirview, s) > 0)
+		gotview++;
+	return(0);
+}
+
+
+nextview(fp)				/* get and set next view */
+FILE	*fp;
+{
+	char	linebuf[256];
+	char	*err;
+	register int	i;
+
+	if (fp != NULL) {
+		do			/* get new view */
+			if (fgets(linebuf, sizeof(linebuf), fp) == NULL)
+				return(EOF);
+		while (!isview(linebuf) || !sscanview(&ourview, linebuf));
+	}
+					/* set new view */
+	if ((err = setview(&ourview)) != NULL) {
+		fprintf(stderr, "%s: %s\n", progname, err);
+		exit(1);
+	}
+	if (!nvavg) {			/* first view */
+		copystruct(&avgview, &ourview);
+		return(nvavg++);
+	}
+					/* add to average view */
+	for (i = 0; i < 3; i++) {
+		avgview.vp[i] += ourview.vp[i];
+		avgview.vdir[i] += ourview.vdir[i];
+		avgview.vup[i] += ourview.vup[i];
+	}
+	avgview.horiz += ourview.horiz;
+	avgview.vert += ourview.vert;
+	avgview.hoff += ourview.hoff;
+	avgview.voff += ourview.voff;
+	avgview.vfore += ourview.vfore;
+	avgview.vaft += ourview.vaft;
+	return(nvavg++);
+}
+
+
+compavgview()				/* compute average view */
+{
+	register int	i;
+	double	f;
+
+	if (nvavg < 2)
 		return;
+	f = 1.0/nvavg;
+	for (i = 0; i < 3; i++) {
+		avgview.vp[i] *= f;
+		avgview.vdir[i] *= f;
+		avgview.vup[i] *= f;
 	}
-	for (an = altname; *an != NULL; an++)
-		if (!strncmp(*an, s, strlen(*an))) {
-			if (sscanview(&theirview, s+strlen(*an)) > 0)
-				gotview++;
-			break;
-		}
+	avgview.horiz *= f;
+	avgview.vert *= f;
+	avgview.hoff *= f;
+	avgview.voff *= f;
+	avgview.vfore *= f;
+	avgview.vaft *= f;
+	if (setview(&avgview) != NULL)		/* in case of emergency... */
+		copystruct(&avgview, &ourview);
+	pixaspect = viewaspect(&avgview) * hresolu / vresolu;
 }
 
 
 addpicture(pfile, zspec)		/* add picture to output */
 char	*pfile, *zspec;
 {
-	extern double	atof();
 	FILE	*pfp;
 	int	zfd;
 	char	*err;
 	COLR	*scanin;
 	float	*zin;
 	struct position	*plast;
+	struct bound	*xlim, ylim;
 	int	y;
 					/* open picture file */
-	if ((pfp = fopen(pfile, "r")) == NULL) {
-		perror(pfile);
-		exit(1);
-	}
+	if ((pfp = fopen(pfile, "r")) == NULL)
+		syserror(pfile);
 					/* get header with exposure and view */
 	theirexp = 1.0;
+	copystruct(&theirview, &stdview);
 	gotview = 0;
-	printf("%s:\n", pfile);
-	getheader(pfp, headline);
-	if (!gotview || fgetresolu(&thresolu, &tvresolu, pfp)
-			!= (YMAJOR|YDECR)) {
-		fprintf(stderr, "%s: picture view error\n", pfile);
+	if (nvavg < 2)
+		printf("%s:\n", pfile);
+	getheader(pfp, headline, NULL);
+	if (wrongformat || !gotview || !fgetsresolu(&tresolu, pfp)) {
+		fprintf(stderr, "%s: picture format error\n", pfile);
 		exit(1);
 	}
 	if (ourexp <= 0)
@@ -278,38 +455,60 @@ char	*pfile, *zspec;
 		exit(1);
 	}
 					/* compute transformation */
-	pixform(theirs2ours, &theirview, &ourview);
-					/* allocate scanlines */
-	scanin = (COLR *)malloc(thresolu*sizeof(COLR));
-	zin = (float *)malloc(thresolu*sizeof(float));
-	plast = (struct position *)calloc(thresolu, sizeof(struct position));
-	if (scanin == NULL || zin == NULL || plast == NULL)
-		syserror();
+	hasmatrix = pixform(theirs2ours, &theirview, &ourview);
 					/* get z specification or file */
+	zin = (float *)malloc(scanlen(&tresolu)*sizeof(float));
+	if (zin == NULL)
+		syserror(progname);
 	if ((zfd = open(zspec, O_RDONLY)) == -1) {
 		double	zvalue;
 		register int	x;
-		if (!isfloat(zspec) || (zvalue = atof(zspec)) <= 0.0) {
-			perror(zspec);
-			exit(1);
-		}
-		for (x = 0; x < thresolu; x++)
+		if (!isflt(zspec) || (zvalue = atof(zspec)) <= 0.0)
+			syserror(zspec);
+		for (x = scanlen(&tresolu); x-- > 0; )
 			zin[x] = zvalue;
 	}
-					/* load image */
-	for (y = tvresolu-1; y >= 0; y--) {
-		if (freadcolrs(scanin, thresolu, pfp) < 0) {
+					/* compute transferrable perimeter */
+	xlim = (struct bound *)malloc(numscans(&tresolu)*sizeof(struct bound));
+	if (xlim == NULL)
+		syserror(progname);
+	if (!getperim(xlim, &ylim, zin, zfd)) {	/* overlapping area? */
+		free((char *)zin);
+		free((char *)xlim);
+		if (zfd != -1)
+			close(zfd);
+		fclose(pfp);
+		return;
+	}
+					/* allocate scanlines */
+	scanin = (COLR *)malloc(scanlen(&tresolu)*sizeof(COLR));
+	plast = (struct position *)calloc(scanlen(&tresolu),
+			sizeof(struct position));
+	if (scanin == NULL | plast == NULL)
+		syserror(progname);
+					/* skip to starting point */
+	for (y = 0; y < ylim.min; y++)
+		if (freadcolrs(scanin, scanlen(&tresolu), pfp) < 0) {
 			fprintf(stderr, "%s: read error\n", pfile);
 			exit(1);
 		}
-		if (zfd != -1 && read(zfd,(char *)zin,thresolu*sizeof(float))
-				< thresolu*sizeof(float)) {
-			fprintf(stderr, "%s: read error\n", zspec);
+	if (zfd != -1 && lseek(zfd,
+			(long)ylim.min*scanlen(&tresolu)*sizeof(float), 0) < 0)
+		syserror(zspec);
+					/* load image */
+	for (y = ylim.min; y <= ylim.max; y++) {
+		if (freadcolrs(scanin, scanlen(&tresolu), pfp) < 0) {
+			fprintf(stderr, "%s: read error\n", pfile);
 			exit(1);
 		}
-		addscanline(y, scanin, zin, plast);
+		if (zfd != -1 && read(zfd, (char *)zin,
+				scanlen(&tresolu)*sizeof(float))
+				< scanlen(&tresolu)*sizeof(float))
+			syserror(zspec);
+		addscanline(xlim+y, y, scanin, zin, plast);
 	}
 					/* clean up */
+	free((char *)xlim);
 	free((char *)scanin);
 	free((char *)zin);
 	free((char *)plast);
@@ -320,11 +519,15 @@ char	*pfile, *zspec;
 
 
 pixform(xfmat, vw1, vw2)		/* compute view1 to view2 matrix */
-register double	xfmat[4][4];
+register MAT4	xfmat;
 register VIEW	*vw1, *vw2;
 {
 	double	m4t[4][4];
 
+	if (vw1->type != VT_PER & vw1->type != VT_PAR)
+		return(0);
+	if (vw2->type != VT_PER & vw2->type != VT_PAR)
+		return(0);
 	setident4(xfmat);
 	xfmat[0][0] = vw1->hvec[0];
 	xfmat[0][1] = vw1->hvec[1];
@@ -352,66 +555,50 @@ register VIEW	*vw1, *vw2;
 	m4t[2][2] = vw2->vdir[2];
 	m4t[3][2] = -DOT(vw2->vp,vw2->vdir);
 	multmat4(xfmat, xfmat, m4t);
+	return(1);
 }
 
 
-addscanline(y, pline, zline, lasty)	/* add scanline to output */
+addscanline(xl, y, pline, zline, lasty)	/* add scanline to output */
+struct bound	*xl;
 int	y;
 COLR	*pline;
 float	*zline;
 struct position	*lasty;		/* input/output */
 {
-	extern double	sqrt();
-	double	pos[3];
+	FVECT	pos;
 	struct position	lastx, newpos;
+	double	wt;
 	register int	x;
 
 	lastx.z = 0;
-	for (x = thresolu-1; x >= 0; x--) {
-		pos[0] = (x+.5)/thresolu + theirview.hoff - .5;
-		pos[1] = (y+.5)/tvresolu + theirview.voff - .5;
+	for (x = xl->max; x >= xl->min; x--) {
+		pix2loc(pos, &tresolu, x, y);
 		pos[2] = zline[x];
-		if (theirview.type == VT_PER) {
-			if (normdist)	/* adjust for eye-ray distance */
-				pos[2] /= sqrt( 1.
-					+ pos[0]*pos[0]*theirview.hn2
-					+ pos[1]*pos[1]*theirview.vn2 );
-			pos[0] *= pos[2];
-			pos[1] *= pos[2];
-		}
-		multp3(pos, pos, theirs2ours);
-		if (pos[2] <= 0) {
+		if ((wt = movepixel(pos)) <= FTINY) {
 			lasty[x].z = lastx.z = 0;	/* mark invalid */
 			continue;
 		}
-		if (ourview.type == VT_PER) {
-			pos[0] /= pos[2];
-			pos[1] /= pos[2];
-		}
-		pos[0] += .5 - ourview.hoff;
-		pos[1] += .5 - ourview.voff;
+					/* add pixel to our image */
 		newpos.x = pos[0] * hresolu;
 		newpos.y = pos[1] * vresolu;
 		newpos.z = zline[x];
-					/* add pixel to our image */
-		if (pos[0] >= 0 && newpos.x < hresolu
-				&& pos[1] >= 0 && newpos.y < vresolu) {
-			addpixel(&newpos, &lastx, &lasty[x], pline[x], pos[2]);
-			lasty[x].x = lastx.x = newpos.x;
-			lasty[x].y = lastx.y = newpos.y;
-			lasty[x].z = lastx.z = newpos.z;
-		} else
-			lasty[x].z = lastx.z = 0;	/* mark invalid */
+		addpixel(&newpos, &lastx, &lasty[x], pline[x], wt, pos[2]);
+		lasty[x].x = lastx.x = newpos.x;
+		lasty[x].y = lastx.y = newpos.y;
+		lasty[x].z = lastx.z = newpos.z;
 	}
 }
 
 
-addpixel(p0, p1, p2, pix, z)		/* fill in pixel parallelogram */
+addpixel(p0, p1, p2, pix, w, z)		/* fill in pixel parallelogram */
 struct position	*p0, *p1, *p2;
 COLR	pix;
+double	w;
 double	z;
 {
 	double	zt = 2.*zeps*p0->z;		/* threshold */
+	COLOR	pval;				/* converted+weighted pixel */
 	int	s1x, s1y, s2x, s2y;		/* step sizes */
 	int	l1, l2, c1, c2;			/* side lengths and counters */
 	int	p1isy;				/* p0p1 along y? */
@@ -419,18 +606,20 @@ double	z;
 	register int	x, y;			/* final position */
 
 					/* compute vector p0p1 */
-	if (fill&F_FORE && ABS(p1->z-p0->z) <= zt) {
+	if (fillo&F_FORE && ABS(p1->z-p0->z) <= zt) {
 		s1x = p1->x - p0->x;
 		s1y = p1->y - p0->y;
 		l1 = ABS(s1x);
 		if (p1isy = (ABS(s1y) > l1))
 			l1 = ABS(s1y);
+		else if (l1 < 1)
+			l1 = 1;
 	} else {
 		l1 = s1x = s1y = 1;
 		p1isy = -1;
 	}
 					/* compute vector p0p2 */
-	if (fill&F_FORE && ABS(p2->z-p0->z) <= zt) {
+	if (fillo&F_FORE && ABS(p2->z-p0->z) <= zt) {
 		s2x = p2->x - p0->x;
 		s2y = p2->y - p0->y;
 		if (p1isy == 1)
@@ -440,35 +629,203 @@ double	z;
 			if (p1isy != 0 && ABS(s2x) > l2)
 				l2 = ABS(s2x);
 		}
+		if (l2 < 1)
+			l2 = 1;
 	} else
 		l2 = s2x = s2y = 1;
 					/* fill the parallelogram */
+	if (averaging) {
+		colr_color(pval, pix);
+		scalecolor(pval, w);
+	}
 	for (c1 = l1; c1-- > 0; ) {
 		x1 = p0->x + c1*s1x/l1;
 		y1 = p0->y + c1*s1y/l1;
 		for (c2 = l2; c2-- > 0; ) {
 			x = x1 + c2*s2x/l2;
+			if (x < 0 | x >= hresolu)
+				continue;
 			y = y1 + c2*s2y/l2;
-			if (zscan(y)[x] <= 0 || zscan(y)[x]-z
+			if (y < 0 | y >= vresolu)
+				continue;
+			if (averaging) {
+				if (zscan(y)[x] <= 0 || zscan(y)[x]-z
 						> zeps*zscan(y)[x]) {
-				zscan(y)[x] = z;
+					copycolor(sscan(y)[x], pval);
+					wscan(y)[x] = w;
+					zscan(y)[x] = z;
+				} else if (z-zscan(y)[x] <= zeps*zscan(y)[x]) {
+					addcolor(sscan(y)[x], pval);
+					wscan(y)[x] += w;
+				}
+			} else if (zscan(y)[x] <= 0 || zscan(y)[x]-z
+						> zeps*zscan(y)[x]) {
 				copycolr(pscan(y)[x], pix);
+				zscan(y)[x] = z;
 			}
 		}
 	}
 }
 
 
-backpicture()				/* background fill algorithm */
+double
+movepixel(pos)				/* reposition image point */
+register FVECT	pos;
 {
+	FVECT	pt, tdir, odir;
+	double	d;
+	register int	i;
+	
+	if (pos[2] <= 0)		/* empty pixel */
+		return(0);
+	if (usematrix) {
+		pos[0] += theirview.hoff - .5;
+		pos[1] += theirview.voff - .5;
+		if (normdist & theirview.type == VT_PER)
+			d = sqrt(1. + pos[0]*pos[0]*theirview.hn2
+					+ pos[1]*pos[1]*theirview.vn2);
+		else
+			d = 1.;
+		pos[2] += d*theirview.vfore;
+		if (theirview.type == VT_PER) {
+			pos[2] /= d;
+			pos[0] *= pos[2];
+			pos[1] *= pos[2];
+		}
+		multp3(pos, pos, theirs2ours);
+		if (pos[2] <= ourview.vfore)
+			return(0);
+		if (ourview.type == VT_PER) {
+			pos[0] /= pos[2];
+			pos[1] /= pos[2];
+		}
+		pos[0] += .5 - ourview.hoff;
+		pos[1] += .5 - ourview.voff;
+		pos[2] -= ourview.vfore;
+	} else {
+		if (viewray(pt, tdir, &theirview, pos[0], pos[1]) < -FTINY)
+			return(0);
+		if (!normdist & theirview.type == VT_PER)	/* adjust */
+			pos[2] *= sqrt(1. + pos[0]*pos[0]*theirview.hn2
+					+ pos[1]*pos[1]*theirview.vn2);
+		pt[0] += tdir[0]*pos[2];
+		pt[1] += tdir[1]*pos[2];
+		pt[2] += tdir[2]*pos[2];
+		viewloc(pos, &ourview, pt);
+		if (pos[2] <= 0)
+			return(0);
+	}
+	if (pos[0] < 0 | pos[0] >= 1-FTINY | pos[1] < 0 | pos[1] >= 1-FTINY)
+		return(0);
+	if (!averaging)
+		return(1);
+	if (ourview.type == VT_PAR)		/* compute our direction */
+		VCOPY(odir, ourview.vdir);
+	else
+		for (i = 0; i < 3; i++)
+			odir[i] = (pt[i] - ourview.vp[i])/pos[2];
+	d = DOT(odir,tdir);			/* compute pixel weight */
+	if (d >= 1.-1./MAXWT/MAXWT)
+		return(MAXWT);		/* clip to maximum weight */
+	return(1./sqrt(1.-d));
+}
+
+
+getperim(xl, yl, zline, zfd)		/* compute overlapping image area */
+register struct bound	*xl;
+struct bound	*yl;
+float	*zline;
+int	zfd;
+{
+	int	step;
+	FVECT	pos;
+	register int	x, y;
+						/* set up step size */
+	if (scanlen(&tresolu) < numscans(&tresolu))
+		step = scanlen(&tresolu)/NSTEPS;
+	else
+		step = numscans(&tresolu)/NSTEPS;
+	if (step < MINSTEP) {			/* not worth cropping? */
+		yl->min = 0;
+		yl->max = numscans(&tresolu) - 1;
+		x = scanlen(&tresolu) - 1;
+		for (y = numscans(&tresolu); y--; ) {
+			xl[y].min = 0;
+			xl[y].max = x;
+		}
+		return(1);
+	}
+	yl->min = 32000; yl->max = 0;		/* search for points on image */
+	for (y = step - 1; y < numscans(&tresolu); y += step) {
+		if (zfd != -1) {
+			if (lseek(zfd, (long)y*scanlen(&tresolu)*sizeof(float),
+					0) < 0)
+				syserror("lseek");
+			if (read(zfd, (char *)zline,
+					scanlen(&tresolu)*sizeof(float))
+					< scanlen(&tresolu)*sizeof(float))
+				syserror("read");
+		}
+		xl[y].min = 32000; xl[y].max = 0;		/* x max */
+		for (x = scanlen(&tresolu); (x -= step) > 0; ) {
+			pix2loc(pos, &tresolu, x, y);
+			pos[2] = zline[x];
+			if (movepixel(pos) > FTINY) {
+				xl[y].max = x + step - 1;
+				xl[y].min = x - step + 1;	/* x min */
+				if (xl[y].min < 0)
+					xl[y].min = 0;
+				for (x = step - 1; x < xl[y].max; x += step) {
+					pix2loc(pos, &tresolu, x, y);
+					pos[2] = zline[x];
+					if (movepixel(pos) > FTINY) {
+						xl[y].min = x - step + 1;
+						break;
+					}
+				}
+				if (y < yl->min)		/* y limits */
+					yl->min = y - step + 1;
+				yl->max = y + step - 1;
+				break;
+			}
+		}
+							/* fill in between */
+		if (y < step) {
+			xl[y-1].min = xl[y].min;
+			xl[y-1].max = xl[y].max;
+		} else {
+			if (xl[y].min < xl[y-step].min)
+				xl[y-1].min = xl[y].min;
+			else
+				xl[y-1].min = xl[y-step].min;
+			if (xl[y].max > xl[y-step].max)
+				xl[y-1].max = xl[y].max;
+			else
+				xl[y-1].max = xl[y-step].max;
+		}
+		for (x = 2; x < step; x++)
+			copystruct(xl+y-x, xl+y-1);
+	}
+	if (yl->max >= numscans(&tresolu))
+		yl->max = numscans(&tresolu) - 1;
+	y -= step;
+	for (x = numscans(&tresolu) - 1; x > y; x--)	/* fill bottom rows */
+		copystruct(xl+x, xl+y);
+	return(yl->max >= yl->min);
+}
+
+
+backpicture(fill, samp)			/* background fill algorithm */
+int	(*fill)();
+int	samp;
+{
 	int	*yback, xback;
 	int	y;
-	COLR	pfill;
 	register int	x, i;
 							/* get back buffer */
 	yback = (int *)malloc(hresolu*sizeof(int));
 	if (yback == NULL)
-		syserror();
+		syserror(progname);
 	for (x = 0; x < hresolu; x++)
 		yback[x] = -2;
 	/*
@@ -510,28 +867,53 @@ backpicture()				/* background fill algorithm */
 						xback = x-1;
 				}
 				/*
-				 * Check to see if we have no background for
-				 * this pixel.  If not, use background color.
+				 * If we have no background for this pixel,
+				 * use the given fill function.
 				 */
-				if (xback < 0 && yback[x] < 0) {
-					(*deffill)(x,y);
-					continue;
-				}
+				if (xback < 0 && yback[x] < 0)
+					goto fillit;
 				/*
 				 * Compare, and use the background that is
 				 * farther, unless one of them is next to us.
+				 * If the background is too distant, call
+				 * the fill function.
 				 */
 				if ( yback[x] < 0
 					|| (xback >= 0 && ABS(x-xback) <= 1)
 					|| ( ABS(y-yback[x]) > 1
 						&& zscan(yback[x])[x]
 						< zscan(y)[xback] ) ) {
-					copycolr(pscan(y)[x],pscan(y)[xback]);
+					if (samp > 0 && ABS(x-xback) >= samp)
+						goto fillit;
+					if (averaging) {
+						copycolor(sscan(y)[x],
+							sscan(y)[xback]);
+						wscan(y)[x] = wscan(y)[xback];
+					} else
+						copycolr(pscan(y)[x],
+							pscan(y)[xback]);
 					zscan(y)[x] = zscan(y)[xback];
 				} else {
-					copycolr(pscan(y)[x],pscan(yback[x])[x]);
+					if (samp > 0 && ABS(y-yback[x]) > samp)
+						goto fillit;
+					if (averaging) {
+						copycolor(sscan(y)[x],
+							sscan(yback[x])[x]);
+						wscan(y)[x] =
+							wscan(yback[x])[x];
+					} else
+						copycolr(pscan(y)[x],
+							pscan(yback[x])[x]);
 					zscan(y)[x] = zscan(yback[x])[x];
 				}
+				continue;
+			fillit:
+				(*fill)(x,y);
+				if (fill == rcalfill) {		/* use it */
+					clearqueue();
+					xback = x;
+					yback[x] = y;
+				}
 			} else {				/* full pixel */
 				yback[x] = -2;
 				xback = -2;
@@ -541,139 +923,218 @@ backpicture()				/* background fill algorithm */
 }
 
 
-fillpicture()				/* paint in empty pixels with default */
+fillpicture(fill)		/* paint in empty pixels using fill */
+int	(*fill)();
 {
 	register int	x, y;
 
 	for (y = 0; y < vresolu; y++)
 		for (x = 0; x < hresolu; x++)
 			if (zscan(y)[x] <= 0)
-				(*deffill)(x,y);
+				(*fill)(x,y);
+	if (fill == rcalfill)
+		clearqueue();
 }
 
 
-writepicture()				/* write out picture */
+clipaft()			/* perform aft clipping as indicated */
 {
+	register int	x, y;
+	int	adjtest = ourview.type == VT_PER & zisnorm;
+	double	tstdist;
+	double	yzn2, vx;
+
+	if (ourview.vaft <= FTINY)
+		return(0);
+	tstdist = ourview.vaft - ourview.vfore;
+	for (y = 0; y < vresolu; y++) {
+		if (adjtest) {				/* adjust test */
+			yzn2 = (y+.5)/vresolu + ourview.voff - .5;
+			yzn2 = 1. + yzn2*yzn2*ourview.vn2;
+			tstdist = (ourview.vaft - ourview.vfore)*sqrt(yzn2);
+		}
+		for (x = 0; x < hresolu; x++)
+			if (zscan(y)[x] > tstdist) {
+				if (adjtest) {
+					vx = (x+.5)/hresolu + ourview.hoff - .5;
+					if (zscan(y)[x] <= (ourview.vaft -
+							ourview.vfore) *
+						sqrt(vx*vx*ourview.hn2 + yzn2))
+						continue;
+				}
+				if (averaging)
+					bzero(sscan(y)[x], sizeof(COLOR));
+				else
+					bzero(pscan(y)[x], sizeof(COLR));
+				zscan(y)[x] = 0.0;
+			}
+	}
+	return(1);
+}
+
+
+addblur()				/* add to blurred picture */
+{
+	COLOR	cval;
+	double	d;
+	register int	i;
+
+	if (!blurring)
+		return(0);
+	i = hresolu*vresolu;
+	if (nvavg < 2)
+		if (averaging)
+			while (i--) {
+				copycolor(ourbpict[i], ourspict[i]);
+				d = 1.0/ourweigh[i];
+				scalecolor(ourbpict[i], d);
+			}
+		else
+			while (i--)
+				colr_color(ourbpict[i], ourpict[i]);
+	else
+		if (averaging)
+			while (i--) {
+				copycolor(cval, ourspict[i]);
+				d = 1.0/ourweigh[i];
+				scalecolor(cval, d);
+				addcolor(ourbpict[i], cval);
+			}
+		else
+			while (i--) {
+				colr_color(cval, ourpict[i]);
+				addcolor(ourbpict[i], cval);
+			}
+				/* print view */
+	printf("VIEW%d:", nvavg);
+	fprintview(&ourview, stdout);
+	putchar('\n');
+	return(1);
+}
+
+
+writepicture()				/* write out picture (alters buffer) */
+{
 	int	y;
+	register int	x;
+	double	d;
 
-	fputresolu(YMAJOR|YDECR, hresolu, vresolu, stdout);
+	fprtresolu(hresolu, vresolu, stdout);
 	for (y = vresolu-1; y >= 0; y--)
-		if (fwritecolrs(pscan(y), hresolu, stdout) < 0)
-			syserror();
+		if (blurring) {
+			for (x = 0; x < hresolu; x++) {	/* compute avg. */
+				d = rexpadj/nvavg;
+				scalecolor(bscan(y)[x], d);
+			}
+			if (fwritescan(bscan(y), hresolu, stdout) < 0)
+				syserror(progname);
+		} else if (averaging) {
+			for (x = 0; x < hresolu; x++) {	/* average pixels */
+				d = rexpadj/wscan(y)[x];
+				scalecolor(sscan(y)[x], d);
+			}
+			if (fwritescan(sscan(y), hresolu, stdout) < 0)
+				syserror(progname);
+		} else {
+			if (expadj)
+				shiftcolrs(pscan(y), hresolu, expadj);
+			if (fwritecolrs(pscan(y), hresolu, stdout) < 0)
+				syserror(progname);
+		}
 }
 
 
-writedistance(fname)			/* write out z file */
+writedistance(fname)			/* write out z file (alters buffer) */
 char	*fname;
 {
-	extern double	sqrt();
-	int	donorm = normdist && ourview.type == VT_PER;
+	int	donorm = normdist & !zisnorm ? 1 :
+			ourview.type == VT_PER & !normdist & zisnorm ? -1 : 0;
 	int	fd;
 	int	y;
-	float	*zout;
 
-	if ((fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) == -1) {
-		perror(fname);
-		exit(1);
-	}
-	if (donorm
-	&& (zout = (float *)malloc(hresolu*sizeof(float))) == NULL)
-		syserror();
+	if ((fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) == -1)
+		syserror(fname);
 	for (y = vresolu-1; y >= 0; y--) {
 		if (donorm) {
-			double	vx, yzn2;
+			double	vx, yzn2, d;
 			register int	x;
-			yzn2 = y - .5*(vresolu-1);
+			yzn2 = (y+.5)/vresolu + ourview.voff - .5;
 			yzn2 = 1. + yzn2*yzn2*ourview.vn2;
 			for (x = 0; x < hresolu; x++) {
-				vx = x - .5*(hresolu-1);
-				zout[x] = zscan(y)[x]
-					* sqrt(vx*vx*ourview.hn2 + yzn2);
+				vx = (x+.5)/hresolu + ourview.hoff - .5;
+				d = sqrt(vx*vx*ourview.hn2 + yzn2);
+				if (donorm > 0)
+					zscan(y)[x] *= d;
+				else
+					zscan(y)[x] /= d;
 			}
-		} else
-			zout = zscan(y);
-		if (write(fd, (char *)zout, hresolu*sizeof(float))
-				< hresolu*sizeof(float)) {
-			perror(fname);
-			exit(1);
 		}
+		if (write(fd, (char *)zscan(y), hresolu*sizeof(float))
+				< hresolu*sizeof(float))
+			syserror(fname);
 	}
-	if (donorm)
-		free((char *)zout);
 	close(fd);
 }
 
 
-isfloat(s)				/* see if string is floating number */
-register char	*s;
-{
-	for ( ; *s; s++)
-		if ((*s < '0' || *s > '9') && *s != '.' && *s != '-'
-				&& *s != 'e' && *s != 'E' && *s != '+')
-			return(0);
-	return(1);
-}
-
-
 backfill(x, y)				/* fill pixel with background */
 int	x, y;
 {
-	register BYTE	*dest = pscan(y)[x];
-
-	copycolr(dest, backcolr);
+	if (averaging) {
+		copycolor(sscan(y)[x], backcolor);
+		wscan(y)[x] = 1;
+	} else
+		copycolr(pscan(y)[x], backcolr);
 	zscan(y)[x] = backz;
 }
 
 
-calstart(prog, args)			/* start fill calculation */
+calstart(prog, args)                    /* start fill calculation */
 char	*prog, *args;
 {
 	char	combuf[512];
-	int	p0[2], p1[2];
+	char	*argv[64];
+	int	rval;
+	register char	**wp, *cp;
 
 	if (childpid != -1) {
 		fprintf(stderr, "%s: too many calculations\n", progname);
 		exit(1);
 	}
-	sprintf(combuf, prog, PACKSIZ, args);
-	if (pipe(p0) < 0 || pipe(p1) < 0)
-		syserror();
-	if ((childpid = vfork()) == 0) {	/* fork calculation */
-		close(p0[1]);
-		close(p1[0]);
-		if (p0[0] != 0) {
-			dup2(p0[0], 0);
-			close(p0[0]);
-		}
-		if (p1[1] != 1) {
-			dup2(p1[1], 1);
-			close(p1[1]);
-		}
-		execl("/bin/sh", "sh", "-c", combuf, 0);
-		perror("/bin/sh");
-		_exit(127);
+	strcpy(combuf, prog);
+	strcat(combuf, args);
+	cp = combuf;
+	wp = argv;
+	for ( ; ; ) {
+		while (isspace(*cp))	/* nullify spaces */
+			*cp++ = '\0';
+		if (!*cp)		/* all done? */
+			break;
+		*wp++ = cp;		/* add argument to list */
+		while (*++cp && !isspace(*cp))
+			;
 	}
-	if (childpid == -1)
-		syserror();
-	close(p0[0]);
-	close(p1[1]);
-	if ((psend = fdopen(p0[1], "w")) == NULL)
-		syserror();
-	if ((precv = fdopen(p1[0], "r")) == NULL)
-		syserror();
+	*wp = NULL;
+						/* start process */
+	if ((rval = open_process(PDesc, argv)) < 0)
+		syserror(progname);
+	if (rval == 0) {
+		fprintf(stderr, "%s: command not found\n", argv[0]);
+		exit(1);
+	}
+	packsiz = rval/(6*sizeof(float)) - 1;
+	if (packsiz > PACKSIZ)
+		packsiz = PACKSIZ;
 	queuesiz = 0;
 }
 
 
-caldone()				/* done with calculation */
+caldone()                               /* done with calculation */
 {
-	int	pid;
-
 	if (childpid == -1)
 		return;
-	clearqueue(1);
-	while ((pid = wait(0)) != -1 && pid != childpid)
-		;
+	clearqueue();
+	close_process(PDesc);
 	childpid = -1;
 }
 
@@ -681,8 +1142,8 @@ caldone()				/* done with calculation */
 rcalfill(x, y)				/* fill with ray-calculated pixel */
 int	x, y;
 {
-	if (queuesiz >= PACKSIZ)	/* flush queue if needed */
-		clearqueue(0);
+	if (queuesiz >= packsiz)	/* flush queue if needed */
+		clearqueue();
 					/* add position to queue */
 	queue[queuesiz][0] = x;
 	queue[queuesiz][1] = y;
@@ -690,46 +1151,64 @@ int	x, y;
 }
 
 
-clearqueue(done)			/* process queue */
-int	done;
+clearqueue()				/* process queue */
 {
 	FVECT	orig, dir;
-	float	fbuf[6];
+	float	fbuf[6*(PACKSIZ+1)];
+	register float	*fbp;
 	register int	i;
+	double	vx, vy;
 
+	if (queuesiz == 0)
+		return;
+	fbp = fbuf;
 	for (i = 0; i < queuesiz; i++) {
 		viewray(orig, dir, &ourview,
 				(queue[i][0]+.5)/hresolu,
 				(queue[i][1]+.5)/vresolu);
-		fbuf[0] = orig[0]; fbuf[1] = orig[1]; fbuf[2] = orig[2];
-		fbuf[3] = dir[0]; fbuf[4] = dir[1]; fbuf[5] = dir[2];
-		fwrite((char *)fbuf, sizeof(float), 6, psend);
+		*fbp++ = orig[0]; *fbp++ = orig[1]; *fbp++ = orig[2];
+		*fbp++ = dir[0]; *fbp++ = dir[1]; *fbp++ = dir[2];
 	}
-	if ((done ? fclose(psend) : fflush(psend)) == EOF)
-		syserror();
+					/* mark end and get results */
+	bzero((char *)fbp, 6*sizeof(float));
+	if (process(PDesc, fbuf, fbuf, 4*sizeof(float)*(queuesiz+1),
+			6*sizeof(float)*(queuesiz+1)) !=
+			4*sizeof(float)*(queuesiz+1)) {
+		fprintf(stderr, "%s: error reading from rtrace process\n",
+				progname);
+		exit(1);
+	}
+	fbp = fbuf;
 	for (i = 0; i < queuesiz; i++) {
-		if (fread((char *)fbuf, sizeof(float), 4, precv) < 4) {
-			fprintf(stderr, "%s: read error in clearqueue\n",
-					progname);
-			exit(1);
-		}
 		if (ourexp > 0 && ourexp != 1.0) {
-			fbuf[0] *= ourexp;
-			fbuf[1] *= ourexp;
-			fbuf[2] *= ourexp;
+			fbp[0] *= ourexp;
+			fbp[1] *= ourexp;
+			fbp[2] *= ourexp;
 		}
-		setcolr(pscan(queue[i][1])[queue[i][0]],
-				fbuf[0], fbuf[1], fbuf[2]);
-		zscan(queue[i][1])[queue[i][0]] = fbuf[3];
+		if (averaging) {
+			setcolor(sscan(queue[i][1])[queue[i][0]],
+					fbp[0], fbp[1], fbp[2]);
+			wscan(queue[i][1])[queue[i][0]] = 1;
+		} else
+			setcolr(pscan(queue[i][1])[queue[i][0]],
+					fbp[0], fbp[1], fbp[2]);
+		if (zisnorm)
+			zscan(queue[i][1])[queue[i][0]] = fbp[3];
+		else {
+			vx = (queue[i][0]+.5)/hresolu + ourview.hoff - .5;
+			vy = (queue[i][1]+.5)/vresolu + ourview.voff - .5;
+			zscan(queue[i][1])[queue[i][0]] = fbp[3] / sqrt(1. +
+					vx*vx*ourview.hn2 + vy*vy*ourview.vn2);
+		}
+		fbp += 4;
 	}
-	if (done)
-		fclose(precv);
 	queuesiz = 0;
 }
 
 
-syserror()			/* report error and exit */
+syserror(s)			/* report error and exit */
+char	*s;
 {
-	perror(progname);
+	perror(s);
 	exit(1);
 }