--- ray/src/common/tonemap.c	2006/01/18 00:24:38	3.21
+++ ray/src/common/tonemap.c	2021/04/07 21:13:52	3.47
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: tonemap.c,v 3.21 2006/01/18 00:24:38 greg Exp $";
+static const char	RCSid[] = "$Id: tonemap.c,v 3.47 2021/04/07 21:13:52 greg Exp $";
 #endif
 /*
  * Tone mapping functions.
@@ -12,7 +12,9 @@ static const char	RCSid[] = "$Id: tonemap.c,v 3.21 200
 #include "copyright.h"
 
 #include	<stdio.h>
+#include	<stdlib.h>
 #include	<math.h>
+#include	<string.h>
 #include	"tmprivat.h"
 #include	"tmerrmsg.h"
 
@@ -22,7 +24,12 @@ static const char	RCSid[] = "$Id: tonemap.c,v 3.21 200
 struct tmPackage	*tmPkg[TM_MAXPKG];
 int	tmNumPkgs = 0;			/* number of registered packages */
 
+					/* luminance->brightness lookup */
+static TMbright		*tmFloat2BrtLUT = NULL;
 
+#define tmCvLumLUfp(pf)	tmFloat2BrtLUT[*(int32 *)(pf) >> 15]
+
+
 TMstruct *
 tmInit(					/* initialize new tone mapping */
 int	flags,
@@ -48,7 +55,7 @@ double	gamval
 		tmnew->clf[GRN] = rgb2xyzmat[1][1];
 		tmnew->clf[BLU] = rgb2xyzmat[1][2];
 	} else {
-		comprgb2xyzWBmat(cmat, tmnew->monpri=monpri);
+		comprgb2xyzmat(cmat, tmnew->monpri=monpri);
 		tmnew->clf[RED] = cmat[1][0];
 		tmnew->clf[GRN] = cmat[1][1];
 		tmnew->clf[BLU] = cmat[1][2];
@@ -60,7 +67,7 @@ double	gamval
 		tmnew->mongam = gamval;
 						/* set color divisors */
 	for (i = 0; i < 3; i++)
-		tmnew->cdiv[i] = 256.*pow(tmnew->clf[i], 1./tmnew->mongam);
+		tmnew->cdiv[i] = TM_BRES*pow(tmnew->clf[i], 1./tmnew->mongam);
 
 						/* set input transform */
 	tmnew->inppri = tmnew->monpri;
@@ -111,35 +118,32 @@ MEM_PTR	dat
 			tms->clf[CIEX] = tms->clf[CIEZ] = 0.;
 			tms->clf[CIEY] = 1.;
 		} else {
-			comprgb2xyzWBmat(tms->cmat, tms->monpri);
+			comprgb2xyzmat(tms->cmat, tms->monpri);
 			tms->clf[RED] = tms->cmat[1][0];
 			tms->clf[GRN] = tms->cmat[1][1];
 			tms->clf[BLU] = tms->cmat[1][2];
 		}
-		tms->cmat[0][0] = tms->cmat[1][1] = tms->cmat[2][2] =
-				tms->inpsf;
+		tms->cmat[0][0] = tms->cmat[1][1] = tms->cmat[2][2] = 1.;
 		tms->cmat[0][1] = tms->cmat[0][2] = tms->cmat[1][0] =
 		tms->cmat[1][2] = tms->cmat[2][0] = tms->cmat[2][1] = 0.;
 
-	} else if (tms->inppri == TM_XYZPRIM)	/* input is XYZ */
+	} else if (tms->inppri == TM_XYZPRIM) {		/* input is XYZ */
 		compxyz2rgbWBmat(tms->cmat, tms->monpri);
 
-	else {					/* input is RGB */
+	} else {					/* input is RGB */
 		if (tms->inppri != tms->monpri &&
 				PRIMEQ(tms->inppri, tms->monpri))
 			tms->inppri = tms->monpri;	/* no xform */
-		comprgb2rgbWBmat(tms->cmat, tms->inppri, tms->monpri);
+		if (!comprgb2rgbWBmat(tms->cmat, tms->inppri, tms->monpri))
+			returnErr(TM_E_ILLEGAL);
 	}
 	for (i = 0; i < 3; i++)
 		for (j = 0; j < 3; j++)
 			tms->cmat[i][j] *= tms->inpsf;
 						/* set color divisors */
 	for (i = 0; i < 3; i++)
-		if (tms->clf[i] > .001)
-			tms->cdiv[i] =
-				256.*pow(tms->clf[i], 1./tms->mongam);
-		else
-			tms->cdiv[i] = 1;
+		tms->cdiv[i] = TM_BRES*pow(tms->clf[i] < .001 ? .001 :
+						tms->clf[i], 1./tms->mongam);
 						/* notify packages */
 	for (i = tmNumPkgs; i--; )
 		if (tms->pd[i] != NULL && tmPkg[i]->NewSpace != NULL)
@@ -149,39 +153,123 @@ MEM_PTR	dat
 
 
 void
-tmClearHisto(			/* clear current histogram */
+tmClearHisto(				/* clear current histogram */
 TMstruct	*tms
 )
 {
 	if (tms == NULL || tms->histo == NULL)
 		return;
-	free((MEM_PTR)tms->histo);
+	free(tms->histo);
 	tms->histo = NULL;
 }
 
 
+TMbright
+tmCvLuminance(				/* convert a single luminance */
+double	lum
+)
+{
+	double	d;
+
+#ifdef isfinite
+	if (!isfinite(lum) || lum <= TM_NOLUM)
+#else
+	if (lum <= TM_NOLUM)
+#endif
+		return(TM_NOBRT);
+	d = TM_BRTSCALE*log(lum);
+	return((TMbright)(d + .5 - (d < 0.)));
+}
+
+
 int
+tmCvLums(				/* convert luminances using lookup */
+TMbright	*ls,
+float		*scan,
+int		len
+)
+{
+	if (tmFloat2BrtLUT == NULL) {	/* initialize lookup table */
+		int32	i;
+		tmFloat2BrtLUT = (TMbright *)malloc(sizeof(TMbright)*0x10000);
+		if (tmFloat2BrtLUT == NULL)
+			return(TM_E_NOMEM);
+		for (i = 0; i < 0x10000; i++) {
+			int32	l = (i<<1 | 1) << 14;
+#ifndef isfinite
+			if ((l & 0x7f800000) == 0x7f800000)
+				tmFloat2BrtLUT[i] = TM_NOBRT;
+			else
+#endif
+			tmFloat2BrtLUT[i] = tmCvLuminance(*(float *)&l);
+		}
+	}
+	if (len <= 0)
+		return(TM_E_OK);
+	if ((ls == NULL) | (scan == NULL))
+		return(TM_E_ILLEGAL);
+	while (len--) {
+		if (*scan <= TM_NOLUM) {
+			*ls++ = TM_NOBRT;
+			++scan;
+			continue;
+		}
+		*ls++ = tmCvLumLUfp(scan++);
+	}
+	return(TM_E_OK);
+}
+
+
+int
+tmCvGrays(				/* convert float gray values */
+TMstruct	*tms,
+TMbright	*ls,
+float		*scan,
+int		len
+)
+{
+	static const char funcName[] = "tmCvGrays";
+	int	i;
+
+	if (tms == NULL)
+		returnErr(TM_E_TMINVAL);
+	if ((ls == NULL) | (scan == NULL) | (len < 0))
+		returnErr(TM_E_ILLEGAL);
+	if (tmFloat2BrtLUT == NULL)			/* initialize */
+		tmCvLums(NULL, NULL, 0);
+	for (i = len; i--; ) {
+		float	lum = tms->inpsf * scan[i];
+		if (lum <= TM_NOLUM)
+			ls[i] = TM_NOBRT;
+		else
+			ls[i] = tmCvLumLUfp(&lum);
+	}
+	returnOK;
+}
+
+
+int
 tmCvColors(				/* convert float colors */
 TMstruct	*tms,
 TMbright	*ls,
-BYTE	*cs,
+uby8	*cs,
 COLOR	*scan,
 int	len
 )
 {
 	static const char funcName[] = "tmCvColors";
-	static COLOR	csmall = {.5*MINLUM, .5*MINLUM, .5*MINLUM};
-	static BYTE	gamtab[1024];
+	static uby8	gamtab[1024];
 	static double	curgam = .0;
 	COLOR	cmon;
-	double	lum, slum;
-	double	d;
+	float	lum, slum, d;
 	int	i;
 
 	if (tms == NULL)
 		returnErr(TM_E_TMINVAL);
 	if ((ls == NULL) | (scan == NULL) | (len < 0))
 		returnErr(TM_E_ILLEGAL);
+	if (tmFloat2BrtLUT == NULL)			/* initialize */
+		tmCvLums(NULL, NULL, 0);
 	if (cs != TM_NOCHROM && fabs(tms->mongam - curgam) > .02) {
 		curgam = tms->mongam;			/* (re)build table */
 		for (i = 1024; i--; )
@@ -195,36 +283,38 @@ int	len
 			cmon[GRN] = tms->inpsf*scan[i][GRN];
 			cmon[BLU] = tms->inpsf*scan[i][BLU];
 		}
+#ifdef isfinite
+		if (!isfinite(cmon[RED]) || cmon[RED] < .0f) cmon[RED] = .0f;
+		if (!isfinite(cmon[GRN]) || cmon[GRN] < .0f) cmon[GRN] = .0f;
+		if (!isfinite(cmon[BLU]) || cmon[BLU] < .0f) cmon[BLU] = .0f;
+#else
+		if (cmon[RED] < .0f) cmon[RED] = .0f;
+		if (cmon[GRN] < .0f) cmon[GRN] = .0f;
+		if (cmon[BLU] < .0f) cmon[BLU] = .0f;
+#endif
 							/* world luminance */
 		lum =	tms->clf[RED]*cmon[RED] +
 			tms->clf[GRN]*cmon[GRN] +
 			tms->clf[BLU]*cmon[BLU] ;
-							/* check range */
-		if (clipgamut(cmon, lum, CGAMUT_LOWER, csmall, cwhite))
-			lum =	tms->clf[RED]*cmon[RED] +
-				tms->clf[GRN]*cmon[GRN] +
-				tms->clf[BLU]*cmon[BLU] ;
-		if (lum < MINLUM) {
-			ls[i] = MINBRT-1;		/* bogus value */
-			lum = MINLUM;
-		} else {
-			d = TM_BRTSCALE*log(lum);	/* encode it */
-			ls[i] = d>0. ? (int)(d+.5) : (int)(d-.5);
-		}
+		if (lum <= TM_NOLUM) {			/* convert brightness */
+			lum = cmon[RED] = cmon[GRN] = cmon[BLU] = TM_NOLUM;
+			ls[i] = TM_NOBRT;
+		} else
+			ls[i] = tmCvLumLUfp(&lum);
 		if (cs == TM_NOCHROM)			/* no color? */
 			continue;
 		if (tms->flags & TM_F_MESOPIC && lum < LMESUPPER) {
 			slum = scotlum(cmon);		/* mesopic adj. */
-			if (lum < LMESLOWER)
+			if (lum < LMESLOWER) {
 				cmon[RED] = cmon[GRN] = cmon[BLU] = slum;
-			else {
+			} else {
 				d = (lum - LMESLOWER)/(LMESUPPER - LMESLOWER);
 				if (tms->flags & TM_F_BW)
 					cmon[RED] = cmon[GRN] =
 							cmon[BLU] = d*lum;
 				else
 					scalecolor(cmon, d);
-				d = (1.-d)*slum;
+				d = (1.f-d)*slum;
 				cmon[RED] += d;
 				cmon[GRN] += d;
 				cmon[BLU] += d;
@@ -233,60 +323,17 @@ int	len
 			cmon[RED] = cmon[GRN] = cmon[BLU] = lum;
 		}
 		d = tms->clf[RED]*cmon[RED]/lum;
-		cs[3*i  ] = d>=.999 ? 255 : gamtab[(int)(1024.*d)];
+		cs[3*i  ] = d>=.999f ? 255 : gamtab[(int)(1024.f*d)];
 		d = tms->clf[GRN]*cmon[GRN]/lum;
-		cs[3*i+1] = d>=.999 ? 255 : gamtab[(int)(1024.*d)];
+		cs[3*i+1] = d>=.999f ? 255 : gamtab[(int)(1024.f*d)];
 		d = tms->clf[BLU]*cmon[BLU]/lum;
-		cs[3*i+2] = d>=.999 ? 255 : gamtab[(int)(1024.*d)];
+		cs[3*i+2] = d>=.999f ? 255 : gamtab[(int)(1024.f*d)];
 	}
 	returnOK;
 }
 
 
-TMbright
-tmCvLuminance(				/* convert a single luminance */
-double	lum
-)
-{
-	double	d;
-
-	if (lum <= TM_NOLUM)
-		return(TM_NOBRT);
-	d = TM_BRTSCALE*log(lum);
-	if (d > 0.)
-		return((TMbright)(d+.5));
-	return((TMbright)(d-.5));
-}
-
-
 int
-tmCvGrays(				/* convert float gray values */
-TMstruct	*tms,
-TMbright	*ls,
-float	*scan,
-int	len
-)
-{
-	static const char funcName[] = "tmCvGrays";
-	double	d;
-	int	i;
-
-	if (tms == NULL)
-		returnErr(TM_E_TMINVAL);
-	if ((ls == NULL) | (scan == NULL) | (len < 0))
-		returnErr(TM_E_ILLEGAL);
-	for (i = len; i--; )
-		if (scan[i] <= TM_NOLUM) {
-			ls[i] = TM_NOBRT;		/* bogus value */
-		} else {
-			d = TM_BRTSCALE*log(scan[i]);	/* encode it */
-			ls[i] = d>0. ? (int)(d+.5) : (int)(d-.5);
-		}
-	returnOK;
-}
-
-
-int
 tmAddHisto(				/* add values to histogram */
 TMstruct	*tms,
 TMbright	*ls,
@@ -313,8 +360,8 @@ int	wt
 		tms->hbrmin = tms->hbrmax = ls[i];
 		oldlen = 0;
 	} else {
-		oldorig = (tms->hbrmin-MINBRT)/HISTEP;
-		oldlen = (tms->hbrmax-MINBRT)/HISTEP + 1 - oldorig;
+		oldorig = HISTI(tms->hbrmin);
+		oldlen = HISTI(tms->hbrmax) + 1 - oldorig;
 	}
 	for (i = len; i--; ) {
 		if ((j = ls[i]) < MINBRT)
@@ -324,16 +371,16 @@ int	wt
 		else if (j > tms->hbrmax)
 			tms->hbrmax = j;
 	}
-	horig = (tms->hbrmin-MINBRT)/HISTEP;
-	hlen = (tms->hbrmax-MINBRT)/HISTEP + 1 - horig;
+	horig = HISTI(tms->hbrmin);
+	hlen = HISTI(tms->hbrmax) + 1 - horig;
 	if (hlen > oldlen) {			/* (re)allocate histogram */
-		int	*newhist = (int *)calloc(hlen, sizeof(int));
+		HIST_TYP  *newhist = (HIST_TYP *)calloc(hlen, sizeof(HIST_TYP));
 		if (newhist == NULL)
 			returnErr(TM_E_NOMEM);
 		if (oldlen) {			/* copy and free old */
-			for (i = oldlen, j = i+oldorig-horig; i; )
-				newhist[--j] = tms->histo[--i];
-			free((MEM_PTR)tms->histo);
+			memcpy(newhist+(oldorig-horig),
+					tms->histo, oldlen*sizeof(HIST_TYP));
+			free(tms->histo);
 		}
 		tms->histo = newhist;
 	}
@@ -341,7 +388,7 @@ int	wt
 		returnOK;
 	for (i = len; i--; )			/* add in new counts */
 		if (ls[i] >= MINBRT)
-			tms->histo[ (ls[i]-MINBRT)/HISTEP - horig ] += wt;
+			tms->histo[ HISTI(ls[i]) - horig ] += wt;
 	returnOK;
 }
 
@@ -369,49 +416,35 @@ double	La
 }
 
 
-static int
-tmNewMap(			/* allocate new tone-mapping array */
-TMstruct	*tms
-)
-{
-	if (tms->lumap != NULL && (tms->mbrmax - tms->mbrmin) !=
-					(tms->hbrmax - tms->hbrmin)) {
-		free((MEM_PTR)tms->lumap);
-		tms->lumap = NULL;
-	}
-	tms->mbrmin = tms->hbrmin;
-	tms->mbrmax = tms->hbrmax;
-	if (tms->mbrmin > tms->mbrmax)
-		return 0;
-	if (tms->lumap == NULL)
-		tms->lumap = (unsigned short *)malloc(sizeof(unsigned short)*
-					(tms->mbrmax-tms->mbrmin+1));
-	return(tms->lumap != NULL);
-}
-
-
 int
 tmFixedMapping(			/* compute fixed, linear tone-mapping */
 TMstruct	*tms,
 double	expmult,
-double	gamval
+double	gamval,
+double  Lddyn
 )
 {
 	static const char funcName[] = "tmFixedMapping";
-	double		d;
-	int	i;
+	const int	maxV = (1L<<(8*sizeof(TMAP_TYP))) - 1;
+	double		minD;
+	int		i;
 	
 	if (!tmNewMap(tms))
 		returnErr(TM_E_NOMEM);
-	if (expmult <= .0)
-		expmult = 1.;
-	if (gamval < MINGAM)
-		gamval = tms->mongam;
-	d = log(expmult/tms->inpsf);
-	for (i = tms->mbrmax-tms->mbrmin+1; i--; )
-		tms->lumap[i] = 256. * exp(
-			( d + (tms->mbrmin+i)*(1./TM_BRTSCALE) )
-			/ gamval );
+					/* check arguments */
+	if (expmult <= .0) expmult = 1.;
+	if (gamval < MINGAM) gamval = tms->mongam;
+	if (Lddyn < MINLDDYN) Lddyn = DEFLDDYN;
+	minD = 1./Lddyn;
+	for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
+		double	d;
+		d = expmult/tms->inpsf * tmLuminance(tms->mbrmin + i);
+		if (d <= minD)
+			break;		/* map initialized to zeroes */
+		d = (d - minD)/(1. - minD);
+		d = TM_BRES*pow(d, 1./gamval);
+		tms->lumap[i] = (d > maxV) ? maxV : (int)d;
+	}
 	returnOK;
 }
 
@@ -425,11 +458,11 @@ double	Ldmax
 )
 {
 	static const char funcName[] = "tmComputeMapping";
-	int	*histo;
+	HIST_TYP	*histo;
 	float	*cumf;
-	int	brt0, histlen, threshold, ceiling, trimmings;
-	double	logLddyn, Ldmin, Ldavg, Lwavg, Tr, Lw, Ld;
-	int32	histot;
+	int	brt0, histlen;
+	HIST_TYP	threshold, ceiling, trimmings, histot;
+	double	logLddyn, Ldmin, Lwavg, Tr, Lw, Ld;
 	double	sum;
 	double	d;
 	int	i, j;
@@ -443,44 +476,41 @@ double	Ldmax
 					/* compute handy values */
 	Ldmin = Ldmax/Lddyn;
 	logLddyn = log(Lddyn);
-	Ldavg = sqrt(Ldmax*Ldmin);
-	i = (tms->hbrmin-MINBRT)/HISTEP;
-	brt0 = MINBRT + HISTEP/2 + i*HISTEP;
-	histlen = (tms->hbrmax-MINBRT)/HISTEP + 1 - i;
+	i = HISTI(tms->hbrmin);
+	brt0 = HISTV(i);
+	histlen = HISTI(tms->hbrmax) + 1 - i;
 					/* histogram total and mean */
 	histot = 0; sum = 0;
 	j = brt0 + histlen*HISTEP;
 	for (i = histlen; i--; ) {
 		histot += tms->histo[i];
-		sum += (j -= HISTEP) * tms->histo[i];
+		sum += (double)(j -= HISTEP) * tms->histo[i];
 	}
-	threshold = histot*0.005 + .5;
-	if (threshold < 4)
+	threshold = histot*0.002 + .5;
+	if (!histot)
 		returnErr(TM_E_TMFAIL);
 	Lwavg = tmLuminance( (double)sum / histot );
-					/* allocate space for mapping */
-	if (!tmNewMap(tms))
-		returnErr(TM_E_NOMEM);
 					/* use linear tone mapping? */
-	if (tms->flags & TM_F_LINEAR)
+	if (tms->flags & TM_F_LINEAR || threshold < 4 ||
+			tms->hbrmax - tms->hbrmin < TM_BRTSCALE*logLddyn)
 		goto linearmap;
 					/* clamp histogram */
-	histo = (int *)malloc(histlen*sizeof(int));
+	histo = (HIST_TYP *)malloc(histlen*sizeof(HIST_TYP));
 	cumf = (float *)malloc((histlen+2)*sizeof(float));
 	if ((histo == NULL) | (cumf == NULL))
 		returnErr(TM_E_NOMEM);
 	cumf[histlen+1] = 1.;		/* guard for assignment code */
-	for (i = histlen; i--; )	/* make malleable copy */
-		histo[i] = tms->histo[i];
+					/* make malleable copy */
+	memcpy(histo, tms->histo, histlen*sizeof(HIST_TYP));
 	do {				/* iterate to solution */
 		sum = 0;		/* cumulative probability */
 		for (i = 0; i < histlen; i++) {
-			cumf[i] = (double)sum/histot;
-			sum += histo[i];
+			cumf[i] = sum/histot;
+			sum += (double)histo[i];
 		}
 		cumf[histlen] = 1.;
 		Tr = histot * (double)(tms->hbrmax - tms->hbrmin) /
-			((double)histlen*TM_BRTSCALE) / logLddyn;
+				((double)TM_BRTSCALE*histlen*logLddyn);
 		ceiling = Tr + 1.;
 		trimmings = 0;		/* clip to envelope */
 		for (i = histlen; i--; ) {
@@ -498,58 +528,67 @@ double	Ldmax
 		}
 					/* check if we're out of data */
 		if ((histot -= trimmings) <= threshold) {
-			free((MEM_PTR)histo);
-			free((MEM_PTR)cumf);
+			free(histo);
+			free(cumf);
 			goto linearmap;
 		}
 	} while (trimmings > threshold);
+					/* allocate space for mapping */
+	if (!tmNewMap(tms))
+		returnErr(TM_E_NOMEM);
 					/* assign tone-mapping */
 	for (i = tms->mbrmax-tms->mbrmin+1; i--; ) {
 		j = d = (double)i/(tms->mbrmax-tms->mbrmin)*histlen;
 		d -= (double)j;
 		Ld = Ldmin*exp(logLddyn*((1.-d)*cumf[j]+d*cumf[j+1]));
 		d = (Ld - Ldmin)/(Ldmax - Ldmin);
-		tms->lumap[i] = 256.*pow(d, 1./gamval);
+		tms->lumap[i] = TM_BRES*pow(d, 1./gamval);
 	}
-	free((MEM_PTR)histo);		/* clean up and return */
-	free((MEM_PTR)cumf);
+	free(histo);			/* clean up and return */
+	free(cumf);
 	returnOK;
 linearmap:				/* linear tone-mapping */
 	if (tms->flags & TM_F_HCONTR)
-		d = htcontrs(Ldavg) / htcontrs(Lwavg);
+		d = htcontrs(sqrt(Ldmax*Ldmin)) / htcontrs(Lwavg);
 	else
-		d = Ldavg / Lwavg;
-	return(tmFixedMapping(tms, tms->inpsf*d/Ldmax, gamval));
+		d = Ldmax / tmLuminance(tms->hbrmax);
+	return(tmFixedMapping(tms, tms->inpsf*d/Ldmax, gamval, Lddyn));
 }
 
 
 int
 tmMapPixels(			/* apply tone-mapping to pixel(s) */
 TMstruct	*tms,
-BYTE	*ps,
+uby8	*ps,
 TMbright	*ls,
-BYTE	*cs,
+uby8	*cs,
 int	len
 )
 {
 	static const char funcName[] = "tmMapPixels";
-	int32	li, pv;
+	TMbright	lv;
+	TMAP_TYP	li;
+	int		pv;
 
 	if (tms == NULL || tms->lumap == NULL)
 		returnErr(TM_E_TMINVAL);
 	if ((ps == NULL) | (ls == NULL) | (len < 0))
 		returnErr(TM_E_ILLEGAL);
 	while (len--) {
-		if ((li = *ls++) < tms->mbrmin) {
+		if ((lv = *ls++) < tms->mbrmin) {
 			li = 0;
 		} else {
-			if (li > tms->mbrmax)
-				li = tms->mbrmax;
-			li = tms->lumap[li - tms->mbrmin];
+			if (lv > tms->mbrmax)
+				lv = tms->mbrmax;
+			li = tms->lumap[lv - tms->mbrmin];
 		}
-		if (cs == TM_NOCHROM)
-			*ps++ = li>255 ? 255 : li;
-		else {
+		if (cs == TM_NOCHROM) {
+#if !(TM_BRES & 0xff)
+			*ps++ = li>=TM_BRES ? 255 : li/(TM_BRES>>8);
+#else
+			*ps++ = li>=TM_BRES ? 255 : (li<<8)/TM_BRES;
+#endif
+		} else {
 			pv = *cs++ * li / tms->cdiv[RED];
 			*ps++ = pv>255 ? 255 : pv;
 			pv = *cs++ * li / tms->cdiv[GRN];
@@ -562,10 +601,8 @@ int	len
 }
 
 
-
-
 TMstruct *
-tmDup(				/* duplicate top tone mapping */
+tmDup(				/* duplicate tone mapping */
 TMstruct	*tms
 )
 {
@@ -580,20 +617,16 @@ TMstruct	*tms
 		return(NULL);
 	*tmnew = *tms;		/* copy everything */
 	if (tmnew->histo != NULL) {	/* duplicate histogram */
-		len = (tmnew->hbrmax-MINBRT)/HISTEP + 1 -
-				(tmnew->hbrmin-MINBRT)/HISTEP;
-		tmnew->histo = (int *)malloc(len*sizeof(int));
+		len = HISTI(tmnew->hbrmax) + 1 - HISTI(tmnew->hbrmin);
+		tmnew->histo = (HIST_TYP *)malloc(len*sizeof(HIST_TYP));
 		if (tmnew->histo != NULL)
-			for (i = len; i--; )
-				tmnew->histo[i] = tms->histo[i];
+			memcpy(tmnew->histo, tms->histo, len*sizeof(HIST_TYP));
 	}
 	if (tmnew->lumap != NULL) {	/* duplicate luminance mapping */
 		len = tmnew->mbrmax-tmnew->mbrmin+1;
-		tmnew->lumap = (unsigned short *)malloc(
-						len*sizeof(unsigned short) );
+		tmnew->lumap = (TMAP_TYP *)malloc(len*sizeof(TMAP_TYP));
 		if (tmnew->lumap != NULL)
-			for (i = len; i--; )
-				tmnew->lumap[i] = tms->lumap[i];
+			memcpy(tmnew->lumap, tms->lumap, len*sizeof(TMAP_TYP));
 	}
 					/* clear package data */
 	for (i = tmNumPkgs; i--; )
@@ -613,19 +646,19 @@ TMstruct	*tms;
 		return;
 					/* free tables */
 	if (tms->histo != NULL)
-		free((MEM_PTR)tms->histo);
+		free(tms->histo);
 	if (tms->lumap != NULL)
-		free((MEM_PTR)tms->lumap);
+		free(tms->lumap);
 					/* free private data */
 	for (i = tmNumPkgs; i--; )
 		if (tms->pd[i] != NULL)
 			(*tmPkg[i]->Free)(tms->pd[i]);
-	free((MEM_PTR)tms);		/* free basic structure */
+	free(tms);			/* free basic structure */
 }
 
 /******************** Shared but Private library routines *********************/
 
-BYTE	tmMesofact[BMESUPPER-BMESLOWER];
+uby8	tmMesofact[BMESUPPER-BMESLOWER];
 
 void
 tmMkMesofact()				/* build mesopic lookup factor table */
@@ -639,6 +672,30 @@ tmMkMesofact()				/* build mesopic lookup factor table
 		tmMesofact[i-BMESLOWER] = 256. *
 				(tmLuminance(i) - LMESLOWER) /
 				(LMESUPPER - LMESLOWER);
+}
+
+
+int
+tmNewMap(			/* allocate new tone-mapping array */
+TMstruct	*tms
+)
+{
+	if (tms->lumap != NULL && (tms->mbrmax - tms->mbrmin) !=
+					(tms->hbrmax - tms->hbrmin)) {
+		free(tms->lumap);
+		tms->lumap = NULL;
+	}
+	tms->mbrmin = tms->hbrmin;
+	tms->mbrmax = tms->hbrmax;
+	if (tms->mbrmin > tms->mbrmax)
+		return(0);
+	if (tms->lumap == NULL)
+		tms->lumap = (TMAP_TYP *)calloc(tms->mbrmax-tms->mbrmin+1,
+						sizeof(TMAP_TYP));
+	else
+		memset(tms->lumap, 0, (tms->mbrmax-tms->mbrmin+1)*sizeof(TMAP_TYP));
+
+	return(tms->lumap != NULL);
 }