--- ray/src/common/depthcodec.c	2019/07/26 18:52:32	2.3
+++ ray/src/common/depthcodec.c	2021/01/26 18:47:25	2.11
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: depthcodec.c,v 2.3 2019/07/26 18:52:32 greg Exp $";
+static const char RCSid[] = "$Id: depthcodec.c,v 2.11 2021/01/26 18:47:25 greg Exp $";
 #endif
 /*
  * Routines to encode/decoded 16-bit depths
@@ -8,7 +8,6 @@ static const char RCSid[] = "$Id: depthcodec.c,v 2.3 2
 #include "copyright.h"
 
 #include <stdlib.h>
-#include <string.h>
 #include <math.h>
 #include <ctype.h>
 #include "rtio.h"
@@ -27,7 +26,7 @@ depth2code(double d, double dref)
 	if (d > dref)
 		return (int)(32768.001 - 32768.*dref/d) - 1;
 
-	return (int)(32767.*d/dref - 32768.);
+	return (int)(32767.*d/dref - 32768.999);
 }
 #endif
 
@@ -42,11 +41,11 @@ code2depth(int c, double dref)
 
 	if (c >= 32767)
 		return FHUGE;
-		
-	if (c < 0)
-		return dref*(32767.5 + c)*(1./32767.);
-	
-	return dref*32768./(32766.5 - c);
+
+	if (c >= -1)
+		return dref*32768./(32766.5 - c);
+
+	return dref*(32768.5 + c)*(1./32767.);
 }
 #endif
 
@@ -72,9 +71,15 @@ static int
 headline(char *s, void *p)
 {
 	DEPTHCODEC	*dcp = (DEPTHCODEC *)p;
+	int		rv;
 
 	if (formatval(dcp->inpfmt, s))	/* don't pass format */
 		return 0;
+
+	if ((rv = isbigendian(s)) >= 0) {
+		dcp->swapped = (nativebigendian() != rv);
+		return 0;
+	}
 					/* check for reference depth */
 	if (!strncmp(s, DEPTHSTR, LDEPTHSTR)) {
 		char	*cp;
@@ -92,7 +97,11 @@ headline(char *s, void *p)
 			}
 			return -1;
 		}
-	} else if (isview(s))		/* get view params */
+		if (dcp->hdrflags & HF_ENCODE)
+			return 0;	/* will add this later */
+	} else if (!strncmp(s, "SAMP360=", 8))
+		dcp->gotview--;
+	else if (isview(s))		/* get view params */
 		dcp->gotview += (sscanview(&dcp->vw, s) > 0);
 	if (dcp->hdrflags & HF_HEADOUT)
 		fputs(s, stdout);	/* copy to standard output */
@@ -112,6 +121,7 @@ process_dc_header(DEPTHCODEC *dcp, int ac, char *av[])
 		}
 		return 0;
 	}
+	dcp->gotview *= (dcp->gotview > 0);
 	if (dcp->hdrflags & HF_HEADOUT) {	/* finish header */
 		if (!(dcp->hdrflags & HF_HEADIN))
 			newheader("RADIANCE", stdout);
@@ -128,9 +138,11 @@ process_dc_header(DEPTHCODEC *dcp, int ac, char *av[])
 				fputformat("ascii", stdout);
 				break;
 			case 'f':
+				fputendian(stdout);
 				fputformat("float", stdout);
 				break;
 			case 'd':
+				fputendian(stdout);
 				fputformat("double", stdout);
 				break;
 			}
@@ -215,11 +227,18 @@ check_decode_worldpos(DEPTHCODEC *dcp)
 double
 decode_depth_next(DEPTHCODEC *dcp)
 {
-	int	c = getint(2, dcp->finp);
+	int	c;
 
+	if (dcp->use_last) {
+		dcp->use_last = 0;
+		return code2depth(dcp->last_dc, dcp->refdepth);
+	}
+	c = getint(2, dcp->finp);
+
 	if (c == EOF && feof(dcp->finp))
 		return -1.;
 
+	dcp->last_dc = c;
 	dcp->curpos += 2;
 
 	return code2depth(c, dcp->refdepth);
@@ -233,14 +252,18 @@ compute_worldpos(FVECT wpos, DEPTHCODEC *dcp, int x, i
 	RREAL	loc[2];
 	FVECT	rdir;
 
+	if (d >= FHUGE*.99)
+		goto badval;
+
 	pix2loc(loc, &dcp->res, x, y);
 
-	if (viewray(wpos, rdir, &dcp->vw, loc[0], loc[1]) < -FTINY) {
-		VCOPY(wpos, dcp->vw.vp);
-		return 0;
+	if (viewray(wpos, rdir, &dcp->vw, loc[0], loc[1]) >= -FTINY) {
+		VSUM(wpos, wpos, rdir, d);
+		return 1;
 	}
-	VSUM(wpos, wpos, rdir, d);
-	return 1;
+badval:
+	VCOPY(wpos, dcp->vw.vp);
+	return 0;
 }
 
 
@@ -287,6 +310,10 @@ seek_dc_pix(DEPTHCODEC *dcp, int x, int y)
 	}
 	seekpos = dcp->dstart + 2*((long)y*scanlen(&dcp->res) + x);
 
+	if (seekpos == dcp->curpos-2) {
+		dcp->use_last++;	/* avoids seek/read */
+		return 1;
+	}
 	if (seekpos != dcp->curpos &&
 			fseek(dcp->finp, seekpos, SEEK_SET) == EOF) {
 		if (dcp->hdrflags & HF_STDERR) {
@@ -296,6 +323,7 @@ seek_dc_pix(DEPTHCODEC *dcp, int x, int y)
 		return -1;
 	}
 	dcp->curpos = seekpos;
+	dcp->use_last = 0;
 	return 1;
 }