--- ray/src/px/x11image.c	1993/07/19 15:18:05	2.28
+++ ray/src/px/x11image.c	1993/11/15 10:55:33	2.34
@@ -21,6 +21,7 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include  "standard.h"
 
+#include  <signal.h>
 #include  <X11/Xlib.h>
 #include  <X11/cursorfont.h>
 #include  <X11/Xutil.h>
@@ -71,6 +72,8 @@ int  scale = 0;				/* scalefactor; power of two */
 int  xoff = 0;				/* x image offset */
 int  yoff = 0;				/* y image offset */
 
+int  parent = 0;			/* number of children, -1 if child */
+
 VIEW  ourview = STDVIEW;		/* image view parameters */
 int  gotview = 0;			/* got parameters from file */
 
@@ -116,7 +119,11 @@ extern long  ftell();
 Display  *thedisplay;
 Atom  closedownAtom, wmProtocolsAtom;
 
+int  sigrecv;
 
+int  onsig() { sigrecv++; }
+
+
 main(argc, argv)
 int  argc;
 char  *argv[];
@@ -125,6 +132,7 @@ char  *argv[];
 	char  *gv;
 	int  headline();
 	int  i;
+	int  pid;
 	
 	progname = argv[0];
 	if ((gv = getenv("GAMMA")) != NULL)
@@ -170,15 +178,28 @@ char  *argv[];
 		else
 			break;
 
-	if (i == argc-1) {
+	if (i > argc)
+		goto userr;
+	while (i < argc-1) {
+		sigrecv = 0;
+		signal(SIGCONT, onsig);
+		if ((pid=fork()) == 0) {	/* a child for each picture */
+			parent = -1;
+			break;
+		}
+		if (pid < 0)
+			quiterr("fork failed");
+		parent++;
+		while (!sigrecv)
+			pause();	/* wait for wake-up call */
+		i++;
+	}
+	if (i < argc) {			/* open picture file */
 		fname = argv[i];
 		fin = fopen(fname, "r");
-		if (fin == NULL) {
-			sprintf(errmsg, "cannot open file \"%s\"", fname);
-			quiterr(errmsg);
-		}
-	} else if (i != argc)
-		goto userr;
+		if (fin == NULL)
+			quiterr("cannot open picture file");
+	}
 				/* get header */
 	getheader(fin, headline, NULL);
 				/* get picture dimensions */
@@ -194,11 +215,15 @@ char  *argv[];
 
 	init(argc, argv);			/* get file and open window */
 
+	if (parent < 0) {
+		kill(getppid(), SIGCONT);	/* signal parent if child */
+		sigrecv--;
+	}
 	for ( ; ; )
 		getevent();		/* main loop */
 userr:
 	fprintf(stderr,
-"Usage: %s [-di disp][[-ge] spec][-b][-m][-d][-f][-c nclrs][-e +/-stops] pic\n",
+"Usage: %s [-di disp][[-ge] spec][-b][-m][-d][-f][-c nclrs][-e +/-stops] pic ..\n",
 			progname);
 	exit(1);
 }
@@ -289,10 +314,11 @@ char **argv;
 		quiterr("cannot create window");
 	width = xmax;
 	height = ymax;
-	xgcv.foreground = ourblack;
-	xgcv.background = ourwhite;
+	/* prepare graphics drawing context */
 	if ((xgcv.font = XLoadFont(thedisplay, FONTNAME)) == 0)
 		quiterr("cannot get font");
+	xgcv.foreground = ourblack;
+	xgcv.background = ourwhite;
 	ourgc = XCreateGC(thedisplay, wind, GCForeground|GCBackground|
 			GCFont, &xgcv);
 	xgcv.function = GXinvert;
@@ -328,11 +354,23 @@ char **argv;
 quiterr(err)		/* print message and exit */
 char  *err;
 {
-	if (err != NULL) {
-		fprintf(stderr, "%s: %s\n", progname, err);
-		exit(1);
+	register int  es;
+	int  cs;
+
+	if (es = err != NULL)
+		fprintf(stderr, "%s: %s: %s\n", progname, 
+				fname==NULL?"<stdin>":fname, err);
+	if (parent > 0 & wind != 0) {
+		XDestroyWindow(thedisplay, wind);
+		XFlush(thedisplay);
+	} else if (parent < 0 & sigrecv == 0)
+		kill(getppid(), SIGCONT);
+	while (parent > 0 && wait(&cs) != -1) {	/* wait for any children */
+		if (es == 0)
+			es = cs>>8 & 0xff;
+		parent--;
 	}
-	exit(0);
+	exit(es);
 }
 
 
@@ -536,7 +574,7 @@ getevent()				/* process the next event */
 		else
 			getbox(&xev.xbutton);
 		break;
-   case ClientMessage:
+	case ClientMessage:
 		if ((xev.xclient.message_type == wmProtocolsAtom) &&
 				(xev.xclient.data.l[0] == closedownAtom))
 			quiterr(NULL);
@@ -634,9 +672,16 @@ XKeyPressedEvent  *ekey;
 	case '@':				/* adaptation level */
 		if (avgbox(cval) == -1)
 			return(-1);
-		comp = com=='@'
-		? 106./pow(1.219+pow(luminance(cval)/exposure,.4),2.5)/exposure
-		: .5/bright(cval) ;
+		comp = bright(cval);
+		if (comp < 1e-20) {
+			XBell(thedisplay, 0);
+			return(-1);
+		}
+		if (com == '@')
+			comp = 106./exposure/
+			pow(1.219+pow(comp*WHTEFFICACY/exposure,.4),2.5);
+		else
+			comp = .5/comp;
 		comp = log(comp)/.69315 - scale;
 		n = comp < 0 ? comp-.5 : comp+.5 ;	/* round */
 		if (n == 0)
@@ -943,13 +988,16 @@ getgrey()			/* get greyscale data */
 getmapped()			/* get color-mapped data */
 {
 	int	y;
+					/* make sure we can do it first */
+	if (fname == NULL)
+		quiterr("cannot map colors from standard input");
 					/* set gamma correction */
 	setcolrgam(gamcor);
 					/* make histogram */
 	new_histo();
 	for (y = 0; y < ymax; y++) {
 		if (getscan(y) < 0)
-			quiterr("seek error in getmapped");
+			break;
 		add2icon(y, scanline);
 		if (scale)
 			shiftcolrs(scanline, xmax, scale);
@@ -960,8 +1008,7 @@ getmapped()			/* get color-mapped data */
 	if (!new_clrtab(maxcolors))
 		quiterr("cannot create color map");
 	for (y = 0; y < ymax; y++) {
-		if (getscan(y) < 0)
-			quiterr("seek error in getmapped");
+		getscan(y);
 		if (scale)
 			shiftcolrs(scanline, xmax, scale);
 		colrs_gambs(scanline, xmax);
@@ -1004,6 +1051,12 @@ double	sf;
 getscan(y)
 int  y;
 {
+	static int  trunced = -1;		/* truncated file? */
+skipit:
+	if (trunced >= 0 && y >= trunced) {
+		bzero(scanline, xmax*sizeof(COLR));
+		return(-1);
+	}
 	if (y != cury) {
 		if (scanpos == NULL || scanpos[y] == -1)
 			return(-1);
@@ -1013,9 +1066,12 @@ int  y;
 	} else if (scanpos != NULL && scanpos[y] == -1)
 		scanpos[y] = ftell(fin);
 
-	if (freadcolrs(scanline, xmax, fin) < 0)
-		quiterr("read error");
-
+	if (freadcolrs(scanline, xmax, fin) < 0) {
+		fprintf(stderr, "%s: %s: unfinished picture\n",
+				progname, fname==NULL?"<stdin>":fname);
+		trunced = y;
+		goto skipit;
+	}
 	cury++;
 	return(0);
 }