--- ray/src/px/x11image.c	1997/04/16 20:28:47	2.46
+++ ray/src/px/x11image.c	1997/04/24 17:29:53	2.49
@@ -178,11 +178,11 @@ char  *argv[];
 				break;
 			case 'e':			/* exposure comp. */
 				i++;
-				if (!strcmp(argv[i], "auto")) {
+				if (argv[i][0] == 'a') {
 					tmflags = TM_F_CAMERA;
 					break;
 				}
-				if (!strcmp(argv[i], "human")) {
+				if (argv[i][0] == 'h') {
 					tmflags = TM_F_HUMAN;
 					break;
 				}
@@ -944,45 +944,48 @@ COLOR  clr;
 
 make_tonemap()			/* initialize tone mapping */
 {
-	int  y;
+	int  flags, y;
 
 	if (tmflags != -1 && fname == NULL) {
 		fprintf(stderr, "%s: cannot adjust tone of standard input\n",
 				progname);
 		tmflags = -1;
 	}
-	if (tmflags == -1) {
+	if (tmflags == -1) {		/* linear with clamping */
 		setcolrcor(pow, 1.0/gamcor);
 		return;
 	}
-	if (greyscale)
-		tmflags |= TM_F_BW;
-					/* initialize tm library */
-	if (tmInit(tmflags, stdprims, gamcor) == NULL)
-		goto memerr;
-	if (tmSetSpace(stdprims, WHTEFFICACY/exposure))
-		goto tmerr;
-					/* allocate encoding buffers */
-	if ((lscan = (TMbright *)malloc(xmax*sizeof(TMbright))) == NULL)
-		goto memerr;
-	if (tmflags & TM_F_BW) {
-		cscan = TM_NOCHROM;
-		if ((pscan = (BYTE *)malloc(sizeof(BYTE)*xmax)) == NULL)
+	flags = tmflags;		/* histogram adjustment */
+	if (greyscale) flags |= TM_F_BW;
+	if (tmTop != NULL) {		/* reuse old histogram if one */
+		tmTop->flags = flags;
+	} else {			/* else initialize */
+		if ((lscan = (TMbright *)malloc(xmax*sizeof(TMbright))) == NULL)
 			goto memerr;
-	} else if ((pscan=cscan = (BYTE *)malloc(3*sizeof(BYTE)*xmax)) == NULL)
-		goto memerr;
-					/* compute picture histogram */
-	for (y = 0; y < ymax; y++) {
-		getscan(y);
-		if (tmCvColrs(lscan, TM_NOCHROM, scanline, xmax))
+		if (greyscale) {
+			cscan = TM_NOCHROM;
+			if ((pscan = (BYTE *)malloc(sizeof(BYTE)*xmax)) == NULL)
+				goto memerr;
+		} else if ((pscan=cscan = (BYTE *)malloc(3*sizeof(BYTE)*xmax))
+				== NULL)
+			goto memerr;
+						/* initialize tm library */
+		if (tmInit(flags, stdprims, gamcor) == NULL)
+			goto memerr;
+		if (tmSetSpace(stdprims, WHTEFFICACY/exposure))
 			goto tmerr;
-		if (tmAddHisto(lscan, xmax, 1))
-			goto tmerr;
+						/* compute picture histogram */
+		for (y = 0; y < ymax; y++) {
+			getscan(y);
+			if (tmCvColrs(lscan, TM_NOCHROM, scanline, xmax))
+				goto tmerr;
+			if (tmAddHisto(lscan, xmax, 1))
+				goto tmerr;
+		}
 	}
-					/* compute tone mapping */
+					/* (re)compute tone mapping */
 	if (tmComputeMapping(gamcor, 0., 0.))
 		goto tmerr;
-	free((char *)lscan);
 	return;
 memerr:
 	quiterr("out of memory in make_tonemap");
@@ -1010,7 +1013,7 @@ int  len;
 	if (tmMapPixels(pscan, lscan, cscan, len))
 		goto tmerr;
 	ps = pscan;
-	if (tmflags & TM_F_BW)
+	if (greyscale)
 		while (len--) {
 			scn[0][RED] = scn[0][GRN] = scn[0][BLU] = *ps++;
 			scn[0][EXP] = COLXS;
@@ -1030,16 +1033,6 @@ tmerr:
 }
 
 
-done_tonemap()			/* clean up after tone mapping is done */
-{
-	if (tmflags == -1 || tmTop == NULL)
-		return;
-	tmDone(tmTop);			/* clear old mapping */
-	free((char *)lscan);		/* free memory */
-	free((char *)pscan);
-}
-
-
 getmono()			/* get monochrome data */
 {
 	register unsigned char	*dp;
@@ -1148,7 +1141,6 @@ getfull()			/* get full (24-bit) data */
 					(unsigned int4)scanline[x][GRN] << 8 |
 					(unsigned int4)scanline[x][BLU] << 16 ;
 	}
-	done_tonemap();
 }
 
 
@@ -1176,7 +1168,6 @@ getgrey()			/* get greyscale data */
 	for (x = 0; x < maxcolors; x++)
 		clrtab[x][RED] = clrtab[x][GRN] =
 			clrtab[x][BLU] = ((int4)x*256 + 128)/maxcolors;
-	done_tonemap();
 }
 
 
@@ -1209,7 +1200,6 @@ getmapped()			/* get color-mapped data */
 		else
 			map_colrs(ourdata+y*xmax, scanline, xmax);
 	}
-	done_tonemap();
 }