--- ray/src/px/oki20c.c	1990/07/10 09:07:48	1.9
+++ ray/src/px/oki20c.c	1992/04/18 09:10:53	2.6
@@ -1,4 +1,4 @@
-/* Copyright (c) 1986 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -13,11 +13,15 @@ static char SCCSid[] = "$SunId$ LBL";
 #include  <stdio.h>
 
 #include  "color.h"
+#include  "resolu.h"
 
-
 #define  NROWS		1440		/* 10" at 144 dpi */
 #define  NCOLS		960		/* 8" at 120 dpi */
 
+#define  ASPECT		(120./144.)	/* pixel aspect ratio */
+
+#define  FILTER		"pfilt -1 -x %d -y %d -p %f %s",NCOLS,NROWS,ASPECT
+
 /*
  *  Subtractive primaries are ordered:  Yellow, Magenta, Cyan.
  */
@@ -32,13 +36,22 @@ static char SCCSid[] = "$SunId$ LBL";
 
 long  lpat[NCOLS][3];
 
+int  dofilter = 0;		/* filter through pfilt first? */
 
+
 main(argc, argv)
 int  argc;
 char  *argv[];
 {
 	int  i, status = 0;
 	
+	if (argc > 1 && !strcmp(argv[1], "-p")) {
+		dofilter++;
+		argv++; argc--;
+	}
+#ifdef _IOLBF
+	stdout->_flag &= ~_IOLBF;
+#endif
 	if (argc < 2)
 		status = printp(NULL) == -1;
 	else
@@ -51,12 +64,23 @@ char  *argv[];
 printp(fname)				/* print a picture */
 char  *fname;
 {
+	char  buf[64];
 	FILE  *input;
 	int  xres, yres;
 	COLR  scanline[NCOLS];
 	int  i;
 
-	if (fname == NULL) {
+	if (dofilter) {
+		if (fname == NULL) {
+			sprintf(buf, FILTER, "");
+			fname = "<stdin>";
+		} else
+			sprintf(buf, FILTER, fname);
+		if ((input = popen(buf, "r")) == NULL) {
+			fprintf(stderr, "Cannot execute: %s\n", buf);
+			return(-1);
+		}
+	} else if (fname == NULL) {
 		input = stdin;
 		fname = "<stdin>";
 	} else if ((input = fopen(fname, "r")) == NULL) {
@@ -64,9 +88,12 @@ char  *fname;
 		return(-1);
 	}
 				/* discard header */
-	getheader(input, NULL);
+	if (checkheader(input, COLRFMT, NULL) < 0) {
+		fprintf(stderr, "%s: not a Radiance picture\n", fname);
+		return(-1);
+	}
 				/* get picture dimensions */
-	if (fgetresolu(&xres, &yres, input) != (YMAJOR|YDECR)) {
+	if (fgetresolu(&xres, &yres, input) < 0) {
 		fprintf(stderr, "%s: bad picture size\n", fname);
 		return(-1);
 	}
@@ -90,7 +117,10 @@ char  *fname;
 				/* advance page */
 	putchar('\f');
 	
-	fclose(input);
+	if (dofilter)
+		pclose(input);
+	else
+		fclose(input);
 
 	return(0);
 }
@@ -116,9 +146,15 @@ int  y;
 		fputs("\033\031", stdout);
 
 		for (j = 0; j < 3; j++) {
+			i = (NCOLS + len)/2;		/* center image */
 			fputs("\033%O", stdout);
-			putchar(len & 255);
-			putchar(len >> 8);
+			putchar(i & 255);
+			putchar(i >> 8);
+			while (i-- > len) {
+				putchar(0);
+				putchar(0);
+				putchar(0);
+			}
 			for (i = 0; i < len; i++) {
 				c = lpat[i][j] | colbit(scan[i],i,j);
 							/* repeat this row */
@@ -130,6 +166,7 @@ int  y;
 			putchar('\r');
 		}
 		putchar('\n');
+		fflush(stdout);
 	}
 }
 
@@ -141,14 +178,16 @@ int  s;
 {
 	static int  cerr[NCOLS][3];
 	static int  err[3];
-	int  b;
+	int  b, errp;
 	register int  a, ison;
 
 	a = sub_add(s);			/* use additive primary */
 	b = col[a];
+	errp = err[a];
 	err[a] += b + cerr[x][a];
 	ison = err[a] < 128;
 	if (!ison) err[a] -= 256;
-	cerr[x][a] = err[a] /= 2;
+	err[a] /= 3;
+	cerr[x][a] = err[a] + errp;
 	return(ison);
 }