--- ray/src/px/pcomb.c	1991/05/23 13:46:05	1.14
+++ ray/src/px/pcomb.c	2023/12/09 23:46:51	2.57
@@ -1,133 +1,149 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: pcomb.c,v 2.57 2023/12/09 23:46:51 greg Exp $";
 #endif
-
 /*
  *  Combine picture files according to calcomp functions.
  *
  *	1/4/89
  */
 
-#include <stdio.h>
-
-#include <errno.h>
-
+#include "platform.h"
+#include "standard.h"
+#include "paths.h"
 #include "color.h"
-
 #include "calcomp.h"
+#include "view.h"
 
-#define MAXINP		32		/* maximum number of input files */
-#define WINSIZ		9		/* scanline window size */
-#define MIDSCN		4		/* current scan position */
+#define MAXINP		1024		/* maximum number of input files */
+#define WINSIZ		127		/* scanline window size */
+#define MIDSCN		((WINSIZ-1)/2+1)
 
-#define BRT		(-1)		/* special index for brightness */
-
 struct {
-	char	*name;		/* file name */
+	char	*name;		/* file or command name */
 	FILE	*fp;		/* stream pointer */
+	VIEW	vw;		/* view for picture */
+	RESOLU	rs;		/* image resolution and orientation */
+	int	infloat;	/* input is floating point (#comp)? */
+	float	pa;		/* pixel aspect ratio */
 	COLOR	*scan[WINSIZ];	/* input scanline window */
 	COLOR	coef;		/* coefficient */
+	COLOR	expos;		/* recorded exposure */
 }	input[MAXINP];			/* input pictures */
 
 int	nfiles;				/* number of input files */
 
-char	*vcolin[3] = {"ri", "gi", "bi"};
-char	*vcolout[3] = {"ro", "go", "bo"};
-#define	vbrtin		"li"
-#define vbrtout		"lo"
+VIEW	*commvp = NULL;			/* common view parameters */
 
-#define vnfiles		"nfiles"
-#define vxres		"xres"
-#define vyres		"yres"
-#define vxpos		"x"
-#define vypos		"y"
+char	ourfmt[MAXFMTLEN] = PICFMT;	/* input picture format */
+int	outfloat = 0;			/* #component float output? */
 
+char	StandardInput[] = "<stdin>";
+char	Command[] = "<Command>";
+char	vcolin[3][4] = {"ri", "gi", "bi"};
+char	vcolout[3][4] = {"ro", "go", "bo"};
+char	vbrtin[] = "li";
+char	vbrtout[] = "lo";
+char	vcolexp[3][4] = {"re", "ge", "be"};
+char	vbrtexp[] = "le";
+char	vpixaspect[] = "pa";
+
+char	vray[7][4] = {"Ox", "Oy", "Oz", "Dx", "Dy", "Dz", "T"};
+
+char	vpsize[] = "S";
+
+char	vnfiles[] = "nfiles";
+char	vwhteff[] = "WE";
+char	vxmax[] = "xmax";
+char	vymax[] = "ymax";
+char	vxres[] = "xres";
+char	vyres[] = "yres";
+char	vxpos[] = "x";
+char	vypos[] = "y";
+
 int	nowarn = 0;			/* no warning messages? */
 
-int	original = 0;			/* origninal values? */
+int	xmax = 0, ymax = 0;		/* input resolution */
 
-int	xres=0, yres=0;			/* picture resolution */
+int	xscan, yscan;			/* input position */
 
-int	xpos, ypos;			/* picture position */
+int	xres, yres;			/* output resolution */
 
-int	wrongformat = 0;
+int	xpos, ypos;			/* output position */
 
+char	*progname;			/* global argv[0] */
 
-tputs(s)			/* put out string preceded by a tab */
-char	*s;
-{
-	char	fmt[32];
-	double	d;
-	COLOR	ctmp;
+int	echoheader = 1;
+int	wrongformat = 0;
+int	gotview;
 
-	if (isformat(s)) {			/* check format */
-		formatval(fmt, s);
-		wrongformat = strcmp(fmt, COLRFMT);
-	} else if (original && isexpos(s)) {	/* exposure */
-		d = 1.0/exposval(s);
-		scalecolor(input[nfiles].coef, d);
-	} else if (original && iscolcor(s)) {	/* color correction */
-		colcorval(ctmp, s);
-		colval(input[nfiles].coef,RED) /= colval(ctmp,RED);
-		colval(input[nfiles].coef,GRN) /= colval(ctmp,GRN);
-		colval(input[nfiles].coef,BLU) /= colval(ctmp,BLU);
-	} else {				/* echo unaffected line */
-		putchar('\t');
-		fputs(s, stdout);
-	}
 
-}
+static gethfunc headline;
+static void checkfile(int orig);
+static double rgb_bright(COLOR  clr);
+static double xyz_bright(COLOR  clr);
+static void init(void);
+static void combine(void);
+static void advance(void);
+static double l_expos(char	*nam);
+static double l_pixaspect(char *nm);
+static double l_colin(char	*nam);
+static double l_ray(char	*nam);
+static double l_psize(char *nm);
 
 
-main(argc, argv)
-int	argc;
-char	*argv[];
+int
+main(
+	int	argc,
+	char	*argv[]
+)
 {
-	extern double	l_redin(), l_grnin(), l_bluin(), l_brtin(), atof();
+	int	original;
 	double	f;
-	int	a, i;
-	
-	funset(vcolin[RED], 1, '=', l_redin);
-	funset(vcolin[GRN], 1, '=', l_grnin);
-	funset(vcolin[BLU], 1, '=', l_bluin);
-	funset(vbrtin, 1, '=', l_brtin);
-	
-	for (a = 1; a < argc; a++)
+	int	a;
+
+	SET_DEFAULT_BINARY();
+	SET_FILE_BINARY(stdin);
+	SET_FILE_BINARY(stdout);
+	progname = argv[0];
+	esupport |= E_VARIABLE|E_FUNCTION|E_RCONST;
+	esupport &= ~(E_OUTCHAN|E_INCHAN);
+						/* scan options */
+	for (a = 1; a < argc; a++) {
 		if (argv[a][0] == '-')
 			switch (argv[a][1]) {
-			case '\0':
-			case 's':
-			case 'c':
-				goto getfiles;
 			case 'x':
-				xres = atoi(argv[++a]);
-				break;
 			case 'y':
-				yres = atoi(argv[++a]);
-				break;
+				a++;
+				continue;
 			case 'w':
 				nowarn = !nowarn;
-				break;
-			case 'o':
-				original = !original;
-				break;
+				continue;
+			case 'h':
+				echoheader = !echoheader;
+				continue;
 			case 'f':
-				fcompile(argv[++a]);
-				break;
+				if (argv[a][2]) {
+					outfloat = (argv[a][2] == 'f');
+					continue;
+				}
+				/* fall through */
 			case 'e':
-				scompile(argv[++a], NULL, 0);
-				break;
- 			default:
-				goto usage;
+				a++;
+				continue;
 			}
-		else
-			break;
-getfiles:
-	for (nfiles = 0; nfiles < MAXINP; nfiles++)
+		break;
+	}
+	newheader("RADIANCE", stdout);	/* start header */
+	fputnow(stdout);
+					/* process files */
+	for (nfiles = 0; nfiles < MAXINP; nfiles++) {
 		setcolor(input[nfiles].coef, 1.0, 1.0, 1.0);
+		setcolor(input[nfiles].expos, 1.0, 1.0, 1.0);
+		input[nfiles].vw = stdview;
+		input[nfiles].pa = 1.0;
+	}
 	nfiles = 0;
+	original = 0;
 	for ( ; a < argc; a++) {
 		if (nfiles >= MAXINP) {
 			eputs(argv[0]);
@@ -137,9 +153,12 @@ getfiles:
 		if (argv[a][0] == '-')
 			switch (argv[a][1]) {
 			case '\0':
-				input[nfiles].name = "<stdin>";
+				input[nfiles].name = StandardInput;
 				input[nfiles].fp = stdin;
 				break;
+			case 'o':
+				original++;
+				continue;
 			case 's':
 				f = atof(argv[++a]);
 				scalecolor(input[nfiles].coef, f);
@@ -153,61 +172,290 @@ getfiles:
 				goto usage;
 			}
 		else {
-			input[nfiles].name = argv[a];
-			input[nfiles].fp = fopen(argv[a], "r");
+			if (argv[a][0] == '!') {
+				input[nfiles].name = Command;
+				input[nfiles].fp = popen(argv[a]+1, "r");
+			} else {
+				input[nfiles].name = argv[a];
+				input[nfiles].fp = fopen(argv[a], "r");
+			}
 			if (input[nfiles].fp == NULL) {
 				perror(argv[a]);
 				quit(1);
 			}
 		}
-		fputs(input[nfiles].name, stdout);
-		fputs(":\n", stdout);
-		getheader(input[nfiles].fp, tputs, NULL);
-		if (wrongformat) {
-			eputs(input[nfiles].name);
-			eputs(": not in Radiance picture format\n");
-			quit(1);
-		}
-		if (fgetresolu(&xpos, &ypos, input[nfiles].fp) !=
-				(YMAJOR|YDECR)) {
-			eputs(input[nfiles].name);
-			eputs(": bad picture size\n");
-			quit(1);
-		}
-		if (xres == 0 && yres == 0) {
-			xres = xpos;
-			yres = ypos;
-		} else if (xpos != xres || ypos != yres) {
-			eputs(argv[0]);
-			eputs(": resolution mismatch\n");
-			quit(1);
-		}
-		for (i = 0; i < WINSIZ; i++)
-			input[nfiles].scan[i] =
-					(COLOR *)emalloc(xres*sizeof(COLOR));
+		checkfile(original);
 		nfiles++;
+		original = 0;
 	}
-	printargs(argc, argv, stdout);
-	fputformat(COLRFMT, stdout);
-	putchar('\n');
-	fputresolu(YMAJOR|YDECR, xres, yres, stdout);
-	combine();
+	init();				/* set constants */
+					/* go back and get expressions */
+	for (a = 1; a < argc; a++) {
+		char	*fpath;
+		if (argv[a][0] == '-')
+			switch (argv[a][1]) {
+			case 'x':
+				varset(vxres, ':', eval(argv[++a]));
+				continue;
+			case 'y':
+				varset(vyres, ':', eval(argv[++a]));
+				continue;
+			case 'w':
+				continue;
+			case 'h':
+				continue;
+			case 'f':
+				if (argv[a][2])
+					continue;
+				fpath = getpath(argv[++a], getrlibpath(), 0);
+				if (fpath == NULL) {
+					eputs(argv[0]);
+					eputs(": cannot find file '");
+					eputs(argv[a]);
+					eputs("'\n");
+					quit(1);
+				}
+				fcompile(fpath);
+				continue;
+			case 'e':
+				scompile(argv[++a], NULL, 0);
+				continue;
+			}
+		break;
+	}
+						/* get output resolution */
+	xres = varvalue(vxres) + .5;
+	yres = varvalue(vyres) + .5;
+	if (xres <= 0 || yres <= 0) {
+		eputs(argv[0]);
+		eputs(": illegal output resolution\n");
+		quit(1);
+	}
+	if (!vardefined(vbrtout))		/* single or 3-channel? */
+		outfloat *= 3;
+
+	printargs(argc, argv, stdout);		/* complete header */
+	if (commvp != NULL) {
+		fputs(VIEWSTR, stdout);
+		fprintview(commvp, stdout);
+		fputc('\n', stdout);
+	}
+	if (outfloat) {				/* print format if known */
+		printf("NROWS=%d\nNCOLS=%d\n", yres, xres);
+		fputncomp(outfloat, stdout);
+		fputendian(stdout);
+		fputformat("float", stdout);
+	} else if (strcmp(ourfmt, PICFMT))
+		fputformat(ourfmt, stdout);
+	fputc('\n', stdout);			/* end header */
+	if (!outfloat)
+		fprtresolu(xres, yres, stdout);
+
+	combine();				/* combine pictures */
 	quit(0);
 usage:
 	eputs("Usage: ");
 	eputs(argv[0]);
 	eputs(
-" [-w][-h][-x xr][-y yr][-e expr][-f file] [ [-s f][-c r g b] pic ..]\n");
+" [-w][-h][-ff][-x xr][-y yr][-e expr][-f file] [ [-o][-s f][-c r g b] hdr ..]\n");
 	quit(1);
+	return 1; /* pro forma return */
 }
 
 
-combine()			/* combine pictures */
+static int
+headline(			/* check header line & echo if requested */
+	char	*s,
+	void	*p
+)
 {
+	int	orig = *(int *)p;
+	char	fmt[MAXFMTLEN];
+	double	d;
+	int	bigend;
+	COLOR	ctmp;
+
+	if (isheadid(s))			/* header id */
+		return(0);	/* don't echo */
+	if (formatval(fmt, s)) {		/* check format */
+		if (globmatch(ourfmt, fmt)) {
+			wrongformat = 0;
+			strcpy(ourfmt, fmt);
+		} else if (!strcmp("float", fmt))
+			input[nfiles].infloat *= -1;
+		else
+			wrongformat = globmatch(PICFMT, fmt) ? 1 : -1;
+		return(0);	/* don't echo */
+	}
+	if ((bigend = isbigendian(s)) >= 0) {
+		if (bigend != nativebigendian()) {
+			eputs(input[nfiles].name);
+			eputs(": unsupported input byte ordering\n");
+			quit(1);
+		}
+		return(0);	/* don't echo */
+	}
+	if (!strncmp("NROWS=", s, 6)) {		/* X-resolution */
+		input[nfiles].rs.yr = atoi(s+6);
+		return(0);	/* don't echo */
+	}
+	if (!strncmp("NCOLS=", s, 6)) {		/* Y-resolution */
+		input[nfiles].rs.xr = atoi(s+6);
+		return(0);	/* don't echo */
+	}
+	if (isncomp(s))				/* # components */
+		input[nfiles].infloat *= ncompval(s);
+
+	if (orig) {				/* undo exposure? */
+		if (isexpos(s)) {
+			d = 1./exposval(s);
+			scalecolor(input[nfiles].coef, d);
+			return(0);	/* don't echo */
+		}
+		if (iscolcor(s)) {
+			int	i;
+			colcorval(ctmp, s);
+			for (i = 3; i--; )
+				colval(input[nfiles].coef,i) /= colval(ctmp,i);
+			return(0);	/* don't echo */
+		}
+	} else if (isexpos(s)) {		/* record exposure? */
+		d = exposval(s);
+		scalecolor(input[nfiles].expos, d);
+	} else if (iscolcor(s)) {
+		colcorval(ctmp, s);
+		multcolor(input[nfiles].expos, ctmp);
+	}
+	if (isaspect(s))
+		input[nfiles].pa *= aspectval(s);
+	else if (isview(s) && sscanview(&input[nfiles].vw, s) > 0)
+		gotview++;
+
+	if (echoheader) {			/* echo line */
+		putchar('\t');
+		return(fputs(s, stdout));
+	}
+	return(0);
+}
+
+
+static void
+checkfile(int orig)			/* ready a file */
+{
+	int	i;
+					/* process header */
+	gotview = 0;
+	input[nfiles].infloat = -1;
+	input[nfiles].rs.rt = PIXSTANDARD;
+	input[nfiles].rs.xr = input[nfiles].rs.yr = 0;
+	if (echoheader) {
+		fputs(input[nfiles].name, stdout);
+		fputs(":\n", stdout);
+	}
+	getheader(input[nfiles].fp, headline, &orig);
+
+	if (input[nfiles].infloat <= 0)
+		input[nfiles].infloat = 0;
+	else if ((input[nfiles].infloat != 3) &
+				(input[nfiles].infloat != 1)) {
+		eputs(input[nfiles].name);
+		eputs(": unsupported number of components\n");
+		quit(1);
+	}
+	if (wrongformat < 0) {
+		eputs(input[nfiles].name);
+		eputs(": not a Radiance picture or float matrix\n");
+		quit(1);
+	}
+	if (wrongformat > 0) {
+		wputs(input[nfiles].name);
+		wputs(": warning -- incompatible picture format\n");
+	}
+	if (!gotview || setview(&input[nfiles].vw) != NULL)
+		input[nfiles].vw.type = 0;
+	else if (commvp == NULL)
+		commvp = &input[nfiles].vw;
+	if ((input[nfiles].rs.xr <= 0) | (input[nfiles].rs.yr <= 0) &&
+			!fgetsresolu(&input[nfiles].rs, input[nfiles].fp)) {
+		eputs(input[nfiles].name);
+		eputs(": bad picture size\n");
+		quit(1);
+	}
+	if (xmax == 0 && ymax == 0) {
+		xmax = scanlen(&input[nfiles].rs);
+		ymax = numscans(&input[nfiles].rs);
+	} else if (scanlen(&input[nfiles].rs) != xmax ||
+			numscans(&input[nfiles].rs) != ymax) {
+		eputs(input[nfiles].name);
+		eputs(": resolution mismatch\n");
+		quit(1);
+	}
+					/* allocate scanlines */
+	for (i = 0; i < WINSIZ; i++)
+		input[nfiles].scan[i] = (COLOR *)emalloc(xmax*sizeof(COLOR));
+}
+
+
+static double
+rgb_bright(
+	COLOR  clr
+)
+{
+	return(bright(clr));
+}
+
+
+static double
+xyz_bright(
+	COLOR  clr
+)
+{
+	return(clr[CIEY]);
+}
+
+
+double	(*ourbright)() = rgb_bright;
+
+
+static void
+init(void)					/* perform final setup */
+{
+	int	i;
+						/* define constants */
+	varset("PI", ':', PI);
+	varset(vnfiles, ':', (double)nfiles);
+	varset(vxmax, ':', (double)xmax);
+	varset(vymax, ':', (double)ymax);
+						/* set functions */
+	for (i = 0; i < 3; i++) {
+		funset(vcolexp[i], 1, ':', l_expos);
+		funset(vcolin[i], 1, '=', l_colin);
+	}
+	funset(vbrtexp, 1, ':', l_expos);
+	funset(vbrtin, 1, '=', l_colin);
+	funset(vpixaspect, 1, ':', l_pixaspect);
+	for (i = 0; i < 7; i++)
+		funset(vray[i], 1, '=', l_ray);
+	funset(vpsize, 1, '=', l_psize);
+						/* set brightness function */
+	if (!strcmp(ourfmt, CIEFMT)) {
+		varset(vwhteff, ':', 1.0);
+		ourbright = xyz_bright;
+	} else
+		varset(vwhteff, ':', WHTEFFICACY);
+						/* these may be overridden */
+	varset(vxres, ':', (double)xmax);
+	varset(vyres, ':', (double)ymax);
+}
+
+
+static void
+combine(void)			/* combine pictures */
+{
 	EPNODE	*coldef[3], *brtdef;
 	COLOR	*scanout;
 	double	d;
-	register int	i, j;
+	int	i, j;
 						/* check defined variables */
 	for (j = 0; j < 3; j++) {
 		if (vardefined(vcolout[j]))
@@ -219,25 +467,21 @@ combine()			/* combine pictures */
 		brtdef = eparse(vbrtout);
 	else
 		brtdef = NULL;
-						/* define constants */
-	varset(vnfiles, ':', (double)nfiles);
-	varset(vxres, ':', (double)xres);
-	varset(vyres, ':', (double)yres);
 						/* allocate scanline */
 	scanout = (COLOR *)emalloc(xres*sizeof(COLOR));
-						/* initialize input */
-	initinp();
+						/* set input position */
+	yscan = ymax+MIDSCN;
 						/* combine files */
 	for (ypos = yres-1; ypos >= 0; ypos--) {
 	    advance();
 	    varset(vypos, '=', (double)ypos);
 	    for (xpos = 0; xpos < xres; xpos++) {
+		xscan = (xpos+.5)*xmax/xres;
 		varset(vxpos, '=', (double)xpos);
 		eclock++;
 		if (brtdef != NULL) {
 		    d = evalue(brtdef);
-		    if (d < 0.0)
-			d = 0.0;
+		    d *= (outfloat > 0) | (d >= 0);
 		    setcolor(scanout[xpos], d, d, d);
 		} else {
 		    for (j = 0; j < 3; j++) {
@@ -246,80 +490,153 @@ combine()			/* combine pictures */
 			} else {
 			    d = 0.0;
 			    for (i = 0; i < nfiles; i++)
-				d += colval(input[i].scan[MIDSCN][xpos],j);
+				d += colval(input[i].scan[MIDSCN][xscan],j);
 			}
-			if (d < 0.0)
-			    d = 0.0;
+			d *= (outfloat > 0) | (d >= 0);
 			colval(scanout[xpos],j) = d;
 		    }
 		}
 	    }
-	    if (fwritescan(scanout, xres, stdout) < 0) {
-		    perror("write error");
-		    quit(1);
+	    switch (outfloat) {
+	    case 3:			/* writing out float triplets */
+	    	if (fwrite(scanout, sizeof(float)*3, xres, stdout) != xres)
+		    goto writerr;
+	    	break;
+	    case 1:			/* writing out gray float values */
+	    	for (xpos = 0; xpos < xres; xpos++)
+		    if (putbinary(&scanout[xpos][CIEY],
+		    		sizeof(float), 1, stdout) != 1)
+		    	goto writerr;
+	    	break;
+	    default:			/* writing out Radiance picture */
+	   	if (fwritescan(scanout, xres, stdout) < 0)
+	    	    goto writerr;
+		break;
 	    }
 	}
-	efree(scanout);
+	efree((char *)scanout);
+	return;
+writerr:
+    perror("write error");
+    quit(1);
 }
 
 
-initinp()			/* initilize scan windows */
+static void
+advance(void)			/* read in data for next scanline */
 {
-	for (ypos = yres+(MIDSCN-1); ypos >= yres; ypos--)
-		advance();
+	int	ytarget;
+	COLOR	*st;
+	int	i, j;
+
+	for (ytarget = (ypos+.5)*ymax/yres; yscan > ytarget; yscan--)
+		for (i = 0; i < nfiles; i++) {
+			st = input[i].scan[WINSIZ-1];
+			for (j = WINSIZ-1; j > 0; j--)	/* rotate window */
+				input[i].scan[j] = input[i].scan[j-1];
+			input[i].scan[0] = st;
+			if (yscan <= MIDSCN)		/* hit bottom? */
+				continue;
+				 			 /* read scanline */
+			if (input[i].infloat) {
+				if (fread(st, sizeof(float)*input[i].infloat,
+						xmax, input[i].fp) != xmax)
+					goto readerr;
+				if (input[i].infloat == 1) {
+					const COLORV	*f = st[0] + xmax;
+					int		x = xmax;
+					while (x-- > 0)
+						st[x][BLU] = st[x][GRN] =
+							st[x][RED] = *--f;
+				}
+			} else if (freadscan(st, xmax, input[i].fp) < 0)
+				goto readerr;
+			for (j = 0; j < xmax; j++)	/* adjust color */
+				multcolor(st[j], input[i].coef);
+		}
+	return;
+readerr:
+	eputs(input[i].name);
+	eputs(": read error\n");
+	quit(1);
 }
 
 
-advance()			/* read in next scanline */
+static double
+l_expos(			/* return picture exposure */
+	char	*nam
+)
 {
-	register COLOR	*st;
-	register int	i, j;
+	int	fn, n;
+	double	d;
 
-	for (i = 0; i < nfiles; i++) {
-		st = input[i].scan[WINSIZ-1];
-		for (j = WINSIZ-1; j > 0; j--)	/* rotate window */
-			input[i].scan[j] = input[i].scan[j-1];
-		input[i].scan[0] = st;
-		if (ypos < MIDSCN)		/* hit bottom */
-			continue;
-		if (freadscan(st, xres, input[i].fp) < 0) {
-			eputs(input[i].name);
-			eputs(": read error\n");
-			quit(1);
-		}
-		for (j = 0; j < xres; j++)	/* adjust color */
-			multcolor(st[j], input[i].coef);
+	d = argument(1);
+	if (d <= -0.5 || d >= nfiles+0.5) {
+		errno = EDOM;
+		return(0.0);
 	}
+	if (d < 0.5)
+		return((double)nfiles);
+	fn = d - 0.5;
+	if (nam == vbrtexp)
+		return((*ourbright)(input[fn].expos));
+	n = 3;
+	while (n--)
+		if (nam == vcolexp[n])
+			return(colval(input[fn].expos,n));
+	eputs("Bad call to l_expos()!\n");
+	quit(1);
+	return 1; /* pro forma return */
 }
 
 
-double
-colin(ci)			/* return color value for picture */
-register int	ci;
+static double
+l_pixaspect(char *nm)		/* return pixel aspect ratio */
 {
-	int	n, fn;
-	register int	xoff, yoff;
+	int	fn;
 	double	d;
 
-	fn = (d = argument(1)) - .5;
-	if (d <= -.5 || fn >= nfiles) {
+	d = argument(1);
+	if (d <= -0.5 || d >= nfiles+0.5) {
 		errno = EDOM;
 		return(0.0);
 	}
-	if (d < .5)
+	if (d < 0.5)
 		return((double)nfiles);
+	fn = d - 0.5;
+	return(input[fn].pa);
+}
+
+
+static double
+l_colin(			/* return color value for picture */
+	char	*nam
+)
+{
+	int	fn;
+	int	n, xoff, yoff;
+	double	d;
+
+	d = argument(1);
+	if (d <= -0.5 || d >= nfiles+0.5) {
+		errno = EDOM;
+		return(0.0);
+	}
+	if (d < 0.5)
+		return((double)nfiles);
+	fn = d - 0.5;
 	xoff = yoff = 0;
 	n = nargum();
 	if (n >= 2) {
 		d = argument(2);
 		if (d < 0.0) {
 			xoff = d-.5;
-			if (xpos+xoff < 0)
-				xoff = -xpos;
+			if (xscan+xoff < 0)
+				xoff = -xscan;
 		} else {
 			xoff = d+.5;
-			if (xpos+xoff >= xres)
-				xoff = xres-1-xpos;
+			if (xscan+xoff >= xmax)
+				xoff = xmax-1-xscan;
 		}
 	}
 	if (n >= 3) {
@@ -328,67 +645,147 @@ register int	ci;
 			yoff = d-.5;
 			if (yoff+MIDSCN < 0)
 				yoff = -MIDSCN;
-			if (ypos+yoff < 0)
-				yoff = -ypos;
+			if (yscan+yoff < 0)
+				yoff = -yscan;
 		} else {
 			yoff = d+.5;
 			if (yoff+MIDSCN >= WINSIZ)
 				yoff = WINSIZ-1-MIDSCN;
-			if (ypos+yoff >= yres)
-				yoff = yres-1-ypos;
+			if (yscan+yoff >= ymax)
+				yoff = ymax-1-yscan;
 		}
 	}
-	if (ci == BRT)
-		return(bright(input[fn].scan[MIDSCN+yoff][xpos+xoff]));
-	return(colval(input[fn].scan[MIDSCN+yoff][xpos+xoff],ci));
+	if (nam == vbrtin)
+		return((*ourbright)(input[fn].scan[MIDSCN+yoff][xscan+xoff]));
+	n = 3;
+	while (n--)
+	    if (nam == vcolin[n])
+		return(colval(input[fn].scan[MIDSCN+yoff][xscan+xoff],n));
+	eputs("Bad call to l_colin()!\n");
+	quit(1);
+	return 1; /* pro forma return */
 }
 
 
-double
-l_redin()			/* get red color */
+static double
+l_ray(		/* return ray origin or direction */
+	char	*nam
+)
 {
-	return(colin(RED));
-}
+	static unsigned long	ltick[MAXINP];
+	static FVECT	lorg[MAXINP], ldir[MAXINP];
+	static double	ldist[MAXINP];
+	RREAL	loc[2];
+	double	d;
+	int	fn;
+	int	i;
 
-
-double
-l_grnin()			/* get green color */
-{
-	return(colin(GRN));
+	d = argument(1);
+	if (d <= -0.5 || d >= nfiles+0.5) {
+		errno = EDOM;
+		return(0.0);
+	}
+	if (d < 0.5)
+		return((double)nfiles);
+	fn = d - 0.5;
+	if (ltick[fn] != eclock) {		/* need to compute? */
+		if (input[fn].vw.type == 0) {
+			lorg[fn][0] = lorg[fn][1] = lorg[fn][2] = 0.0;
+			ldir[fn][0] = ldir[fn][1] = ldir[fn][2] = 0.0;
+			ldist[fn] = -1.0;
+			errno = EDOM;
+		} else {
+			pix2loc(loc, &input[fn].rs, xscan, ymax-1-yscan);
+			ldist[fn] = viewray(lorg[fn], ldir[fn],
+					&input[fn].vw, loc[0], loc[1]);
+			if (ldist[fn] < -FTINY)
+				errno = EDOM;
+		}
+		ltick[fn] = eclock;
+	}
+	if (nam == vray[i=6])
+		return(ldist[fn]);
+	while (i--)
+		if (nam == vray[i])
+			return(i < 3 ? lorg[fn][i] : ldir[fn][i-3]);
+	eputs("Bad call to l_ray()!\n");
+	quit(1);
+	return 1; /* pro forma return */
 }
 
 
-double
-l_bluin()			/* get blue color */
+static double
+l_psize(char *nm)		/* compute pixel size in steradians */
 {
-	return(colin(BLU));
-}
+	static unsigned long	ltick[MAXINP];
+	static double	psize[MAXINP];
+	FVECT	dir0, org, dirx, diry;
+	RREAL	locx[2], locy[2];
+	double	d;
+	int	fn;
+	int	i;
 
-
-double
-l_brtin()			/* get brightness value */
-{
-	return(colin(BRT));
+	d = argument(1);
+	if (d <= -0.5 || d >= nfiles+0.5) {
+		errno = EDOM;
+		return(0.0);
+	}
+	if (d < 0.5)
+		return((double)nfiles);
+	fn = d - 0.5;
+	if (ltick[fn] != eclock) {		/* need to compute? */
+		psize[fn] = 0.0;
+		if (input[fn].vw.type == 0)
+			errno = EDOM;
+		else if (input[fn].vw.type != VT_PAR &&
+				funvalue(vray[6], 1, &d) >= -FTINY) {
+			for (i = 0; i < 3; i++)
+				dir0[i] = funvalue(vray[3+i], 1, &d);
+			pix2loc(locx, &input[fn].rs, xscan+1, ymax-1-yscan);
+			pix2loc(locy, &input[fn].rs, xscan, ymax-yscan);
+			if (viewray(org, dirx, &input[fn].vw,
+					locx[0], locx[1]) >= -FTINY &&
+					viewray(org, diry, &input[fn].vw,
+					locy[0], locy[1]) >= -FTINY) {
+						/* approximate solid angle */
+				for (i = 0; i < 3; i++) {
+					dirx[i] -= dir0[i];
+					diry[i] -= dir0[i];
+				}
+				fcross(dir0, dirx, diry);
+				psize[fn] = VLEN(dir0);
+			}
+		}
+		ltick[fn] = eclock;
+	}
+	return(psize[fn]);
 }
 
 
-wputs(msg)
-char	*msg;
+extern void
+wputs(const char *msg)
 {
 	if (!nowarn)
 		eputs(msg);
 }
 
 
-eputs(msg)
-char	*msg;
+extern void
+eputs(const char *msg)
 {
 	fputs(msg, stderr);
 }
 
 
-quit(code)
-int	code;
+extern void
+quit(int code)		/* exit gracefully */
 {
+	int  i;
+				/* close input files */
+	for (i = 0; i < nfiles; i++)
+		if (input[i].name == Command)
+			pclose(input[i].fp);
+		else
+			fclose(input[i].fp);
 	exit(code);
 }