--- ray/src/common/normcodec.c	2019/08/26 23:33:24	2.4
+++ ray/src/common/normcodec.c	2022/09/22 21:47:13	2.9
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: normcodec.c,v 2.4 2019/08/26 23:33:24 greg Exp $";
+static const char RCSid[] = "$Id: normcodec.c,v 2.9 2022/09/22 21:47:13 greg Exp $";
 #endif
 /*
  * Routines to encode/decode 32-bit normals
@@ -7,6 +7,7 @@ static const char RCSid[] = "$Id: normcodec.c,v 2.4 20
 
 #include "copyright.h"
 
+#include <stdlib.h>
 #include "rtio.h"
 #include "rtmath.h"
 #include "normcodec.h"
@@ -20,7 +21,6 @@ set_nc_defaults(NORMCODEC *ncp)
 	ncp->finp = stdin;
 	ncp->inpname = "<stdin>";
 	ncp->format = 'a';
-	ncp->swapped = 0;
 	ncp->res.rt = PIXSTANDARD;
 	if (!progname) progname = "norm_codec";
 }
@@ -40,6 +40,24 @@ headline(char *s, void *p)
 		ncp->swapped = (nativebigendian() != rv);
 		return 0;
 	}
+	if (!strncmp(s, "NCOMP=", 6)) {
+		if (atoi(s+6) != 3) {
+			if (ncp->hdrflags & HF_STDERR) {
+				fputs(ncp->inpname, stderr);
+				fputs(": NCOMP must equal 3\n", stderr);
+			}
+			return -1;
+		}
+		return 0;
+	}
+	if (!strncmp(s, "NROWS=", 6)) {
+		ncp->res.yr = atoi(s+6);
+		return 0;
+	}
+	if (!strncmp(s, "NCOLS=", 6)) {
+		ncp->res.xr = atoi(s+6);
+		return 0;
+	}
 	if (ncp->hdrflags & HF_HEADOUT)
 		fputs(s, stdout);	/* copy to standard output */
 	return 1;
@@ -58,6 +76,16 @@ process_nc_header(NORMCODEC *ncp, int ac, char *av[])
 		}
 		return 0;
 	}
+					/* get resolution string? */
+	if (ncp->hdrflags & HF_RESIN &&
+			(ncp->res.xr <= 0) | (ncp->res.yr <= 0) &&
+			!fgetsresolu(&ncp->res, ncp->finp)) {
+		if (ncp->hdrflags & HF_STDERR) {
+			fputs(ncp->inpname, stderr);
+			fputs(": bad resolution string\n", stderr);
+		}
+		return 0;
+	}
 	if (ncp->hdrflags & HF_HEADOUT) {	/* finish header */
 		if (!(ncp->hdrflags & HF_HEADIN))
 			newheader("RADIANCE", stdout);
@@ -65,7 +93,12 @@ process_nc_header(NORMCODEC *ncp, int ac, char *av[])
 			printargs(ac, av, stdout);
 		if (ncp->hdrflags & HF_ENCODE) {
 			fputformat(NORMAL32FMT, stdout);
-		} else
+		} else {
+			fputs("NCOMP=3\n", stdout);
+			if ((ncp->hdrflags & (HF_RESIN|HF_RESOUT)) == HF_RESIN)
+				printf("NCOLS=%d\nNROWS=%d\n",
+						scanlen(&ncp->res),
+						numscans(&ncp->res));
 			switch (ncp->format) {
 			case 'a':
 				fputformat("ascii", stdout);
@@ -79,20 +112,13 @@ process_nc_header(NORMCODEC *ncp, int ac, char *av[])
 				fputformat("double", stdout);
 				break;
 			}
+		}
 		fputc('\n', stdout);
 	}
-					/* get/put resolution string */
-	if (ncp->hdrflags & HF_RESIN && !fgetsresolu(&ncp->res, ncp->finp)) {
-		if (ncp->hdrflags & HF_STDERR) {
-			fputs(ncp->inpname, stderr);
-			fputs(": bad resolution string\n", stderr);
-		}
-		return 0;
-	}
-	if (ncp->hdrflags & HF_RESOUT)
+	if (ncp->hdrflags & HF_RESOUT)	/* put resolution string? */
 		fputsresolu(&ncp->res, stdout);
 
-	ncp->dstart = ncp->curpos = ftell(ncp->finp);
+	ncp->dstart = ftell(ncp->finp);
 	return 1;
 }
 
@@ -125,15 +151,13 @@ check_decode_normals(NORMCODEC *ncp)
 int
 decode_normal_next(FVECT nrm, NORMCODEC *ncp)
 {
-	int32	lastc;
-	FVECT	lastv;
-	int32	c = getint(4, ncp->finp);
+	static int32	lastc;
+	static FVECT	lastv;
+	int32		c = getint(4, ncp->finp);
 
 	if (c == EOF && feof(ncp->finp))
 		return -1;
 
-	ncp->curpos += 4;
-
 	if (c == lastc) {			/* optimization */
 		VCOPY(nrm, lastv);
 	} else {
@@ -151,8 +175,6 @@ decode_normal_next(FVECT nrm, NORMCODEC *ncp)
 int
 seek_nc_pix(NORMCODEC *ncp, int x, int y)
 {
-	long	seekpos;
-
 	if ((ncp->res.xr <= 0) | (ncp->res.yr <= 0)) {
 		if (ncp->hdrflags & HF_STDERR) {
 			fputs(progname, stderr);
@@ -168,17 +190,14 @@ seek_nc_pix(NORMCODEC *ncp, int x, int y)
 		}
 		return 0;
 	}
-	seekpos = ncp->dstart + 4*((long)y*scanlen(&ncp->res) + x);
-
-	if (seekpos != ncp->curpos &&
-			fseek(ncp->finp, seekpos, SEEK_SET) == EOF) {
+	if (fseek(ncp->finp, ncp->dstart + 4*((long)y*scanlen(&ncp->res) + x),
+			SEEK_SET) == EOF) {
 		if (ncp->hdrflags & HF_STDERR) {
 			fputs(ncp->inpname, stderr);
 			fputs(": seek error\n", stderr);
 		}
 		return -1;
 	}
-	ncp->curpos = seekpos;
 	return 1;
 }