--- ray/src/cv/mgflib/context.c	1995/02/24 16:50:08	1.17
+++ ray/src/cv/mgflib/context.c	1995/05/10 17:46:09	1.22
@@ -36,12 +36,53 @@ static LUTAB	clr_tab = LU_SINIT(free,free);	/* color l
 static LUTAB	mat_tab = LU_SINIT(free,free);	/* material lookup table */
 static LUTAB	vtx_tab = LU_SINIT(free,free);	/* vertex lookup table */
 
-				/* CIE 1931 Standard Observer */
-static C_COLOR	cie_xf = C_CIEX;
-static C_COLOR	cie_yf = C_CIEY;
-static C_COLOR	cie_zf = C_CIEZ;
+				/* CIE 1931 Standard Observer curves */
+static C_COLOR	cie_xf = { 1, C_CDSPEC|C_CSSPEC|C_CSXY|C_CSEFF,
+			{14,42,143,435,1344,2839,3483,3362,2908,1954,956,
+			320,49,93,633,1655,2904,4334,5945,7621,9163,10263,
+			10622,10026,8544,6424,4479,2835,1649,874,468,227,
+			114,58,29,14,7,3,2,1,0}, 106836L, .467, .368, 362.230
+			};
+static C_COLOR	cie_yf = { 1, C_CDSPEC|C_CSSPEC|C_CSXY|C_CSEFF,
+			{0,1,4,12,40,116,230,380,600,910,1390,2080,3230,
+			5030,7100,8620,9540,9950,9950,9520,8700,7570,6310,
+			5030,3810,2650,1750,1070,610,320,170,82,41,21,10,
+			5,2,1,1,0,0}, 106856L, .398, .542, 493.525
+			};
+static C_COLOR	cie_zf = { 1, C_CDSPEC|C_CSSPEC|C_CSXY|C_CSEFF,
+			{65,201,679,2074,6456,13856,17471,17721,16692,
+			12876,8130,4652,2720,1582,782,422,203,87,39,21,17,
+			11,8,3,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0},
+			106770L, .147, .077, 54.363
+			};
+				/* Derived CIE 1931 Primaries (imaginary) */
+static C_COLOR	cie_xp = { 1, C_CDSPEC|C_CSSPEC|C_CSXY,
+			{-174,-198,-195,-197,-202,-213,-235,-272,-333,
+			-444,-688,-1232,-2393,-4497,-6876,-6758,-5256,
+			-3100,-815,1320,3200,4782,5998,6861,7408,7754,
+			7980,8120,8199,8240,8271,8292,8309,8283,8469,
+			8336,8336,8336,8336,8336,8336},
+			127424L, 1., .0,
+			};
+static C_COLOR	cie_yp = { 1, C_CDSPEC|C_CSSPEC|C_CSXY,
+			{-451,-431,-431,-430,-427,-417,-399,-366,-312,
+			-204,57,691,2142,4990,8810,9871,9122,7321,5145,
+			3023,1123,-473,-1704,-2572,-3127,-3474,-3704,
+			-3846,-3927,-3968,-3999,-4021,-4038,-4012,-4201,
+			-4066,-4066,-4066,-4066,-4066,-4066},
+			-23035L, .0, 1.,
+			};
+static C_COLOR	cie_zp = { 1, C_CDSPEC|C_CSSPEC|C_CSXY,
+			{4051,4054,4052,4053,4054,4056,4059,4064,4071,
+			4074,4056,3967,3677,2933,1492,313,-440,-795,
+			-904,-918,-898,-884,-869,-863,-855,-855,-851,
+			-848,-847,-846,-846,-846,-845,-846,-843,-845,
+			-845,-845,-845,-845,-845},
+			36057L, .0, .0,
+			};
 
 static int	setspectrum();
+static int	setbbtemp();
 static void	mixcolors();
 
 
@@ -64,6 +105,8 @@ register char	**av;
 			c_ccname = NULL;
 			return(MG_OK);
 		}
+		if (!isname(av[1]))
+			return(MG_EILL);
 		lp = lu_find(&clr_tab, av[1]);	/* lookup context */
 		if (lp == NULL)
 			return(MG_EMEM);
@@ -105,7 +148,7 @@ register char	**av;
 	case MG_E_CXY:		/* assign CIE XY value */
 		if (ac != 3)
 			return(MG_EARGC);
-		if (!isflt(av[1]) || !isflt(av[2]))
+		if (!isflt(av[1]) | !isflt(av[2]))
 			return(MG_ETYPE);
 		c_ccolor->cx = atof(av[1]);
 		c_ccolor->cy = atof(av[2]);
@@ -118,10 +161,16 @@ register char	**av;
 	case MG_E_CSPEC:	/* assign spectral values */
 		if (ac < 5)
 			return(MG_EARGC);
-		if (!isflt(av[1]) || !isflt(av[2]))
+		if (!isflt(av[1]) | !isflt(av[2]))
 			return(MG_ETYPE);
 		return(setspectrum(c_ccolor, atof(av[1]), atof(av[2]),
 				ac-3, av+3));
+	case MG_E_CCT:		/* assign black body spectrum */
+		if (ac != 2)
+			return(MG_EARGC);
+		if (!isflt(av[1]))
+			return(MG_ETYPE);
+		return(setbbtemp(c_ccolor, atof(av[1])));
 	case MG_E_CMIX:		/* mix colors */
 		if (ac < 5 || (ac-1)%2)
 			return(MG_EARGC);
@@ -174,6 +223,8 @@ register char	**av;
 			c_cmname = NULL;
 			return(MG_OK);
 		}
+		if (!isname(av[1]))
+			return(MG_EILL);
 		lp = lu_find(&mat_tab, av[1]);	/* lookup context */
 		if (lp == NULL)
 			return(MG_EMEM);
@@ -212,6 +263,17 @@ register char	**av;
 		*c_cmaterial = *(C_MATERIAL *)lp->data;
 		c_cmaterial->clock = i + 1;
 		return(MG_OK);
+	case MG_E_IR:		/* set index of refraction */
+		if (ac != 3)
+			return(MG_EARGC);
+		if (!isflt(av[1]) | !isflt(av[2]))
+			return(MG_ETYPE);
+		c_cmaterial->nr = atof(av[1]);
+		c_cmaterial->ni = atof(av[2]);
+		if (c_cmaterial->nr <= FTINY)
+			return(MG_EILL);
+		c_cmaterial->clock++;
+		return(MG_OK);
 	case MG_E_RD:		/* set diffuse reflectance */
 		if (ac != 2)
 			return(MG_EARGC);
@@ -248,7 +310,7 @@ register char	**av;
 	case MG_E_RS:		/* set specular reflectance */
 		if (ac != 3)
 			return(MG_EARGC);
-		if (!isflt(av[1]) || !isflt(av[2]))
+		if (!isflt(av[1]) | !isflt(av[2]))
 			return(MG_ETYPE);
 		c_cmaterial->rs = atof(av[1]);
 		c_cmaterial->rs_a = atof(av[2]);
@@ -261,7 +323,7 @@ register char	**av;
 	case MG_E_TS:		/* set specular transmittance */
 		if (ac != 3)
 			return(MG_EARGC);
-		if (!isflt(av[1]) || !isflt(av[2]))
+		if (!isflt(av[1]) | !isflt(av[2]))
 			return(MG_ETYPE);
 		c_cmaterial->ts = atof(av[1]);
 		c_cmaterial->ts_a = atof(av[2]);
@@ -308,6 +370,8 @@ register char	**av;
 			c_cvname = NULL;
 			return(MG_OK);
 		}
+		if (!isname(av[1]))
+			return(MG_EILL);
 		lp = lu_find(&vtx_tab, av[1]);	/* lookup context */
 		if (lp == NULL)
 			return(MG_EMEM);
@@ -348,7 +412,7 @@ register char	**av;
 	case MG_E_POINT:	/* set point */
 		if (ac != 4)
 			return(MG_EARGC);
-		if (!isflt(av[1]) || !isflt(av[2]) || !isflt(av[3]))
+		if (!isflt(av[1]) | !isflt(av[2]) | !isflt(av[3]))
 			return(MG_ETYPE);
 		c_cvertex->p[0] = atof(av[1]);
 		c_cvertex->p[1] = atof(av[2]);
@@ -358,7 +422,7 @@ register char	**av;
 	case MG_E_NORMAL:	/* set normal */
 		if (ac != 4)
 			return(MG_EARGC);
-		if (!isflt(av[1]) || !isflt(av[2]) || !isflt(av[3]))
+		if (!isflt(av[1]) | !isflt(av[2]) | !isflt(av[3]))
 			return(MG_ETYPE);
 		c_cvertex->n[0] = atof(av[1]);
 		c_cvertex->n[1] = atof(av[2]);
@@ -465,25 +529,27 @@ int	fl;
 		clr->cy = y / z;
 		clr->flags |= C_CSXY;
 	} else if (fl & C_CSSPEC) {	/* cxy -> cspec */
-		z = (cie_xf.ssum + cie_yf.ssum + cie_zf.ssum) / 3.;
-		x = clr->cx * z / cie_xf.ssum;
-		y = clr->cy * z / cie_yf.ssum;
-		z = (1. - clr->cx - clr->cy) * z / cie_zf.ssum;
+		x = clr->cx;
+		y = clr->cy;
+		z = 1. - x - y;
 		clr->ssum = 0;
-		for (i = 0; i < C_CNSS; i++)
-			clr->ssum += clr->ssamp[i] =
-					x * cie_xf.ssamp[i] +
-					y * cie_yf.ssamp[i] +
-					z * cie_zf.ssamp[i] ;
+		for (i = 0; i < C_CNSS; i++) {
+			clr->ssamp[i] = x*cie_xp.ssamp[i] + y*cie_yp.ssamp[i]
+					+ z*cie_zp.ssamp[i] + .5;
+			if (clr->ssamp[i] < 0)		/* out of gamut! */
+				clr->ssamp[i] = 0;
+			else
+				clr->ssum += clr->ssamp[i];
+		}
 		clr->flags |= C_CSSPEC;
 	}
 	if (fl & C_CSEFF) {		/* compute efficacy */
-		if (clr->flags & C_CDSPEC) {		/* from spectrum */
+		if (clr->flags & C_CSSPEC) {		/* from spectrum */
 			y = 0.;
 			for (i = 0; i < C_CNSS; i++)
 				y += cie_yf.ssamp[i] * clr->ssamp[i];
 			clr->eff = C_CLPWM * y / clr->ssum;
-		} else /* clr->flags & C_CDXY */ {	/* from (x,y) */
+		} else /* clr->flags & C_CSXY */ {	/* from (x,y) */
 			clr->eff = clr->cx*cie_xf.eff + clr->cy*cie_yf.eff +
 					(1. - clr->cx - clr->cy)*cie_zf.eff;
 		}
@@ -505,6 +571,7 @@ char	**av;
 	int	n, imax;
 	int	wl;
 	double	wl0, wlstep;
+	double	boxpos, boxstep;
 					/* check bounds */
 	if (wlmax <= C_CMINWL | wlmax <= wlmin | wlmin >= C_CMAXWL)
 		return(MG_EILL);
@@ -517,22 +584,25 @@ char	**av;
 		wlmax -= wlstep;
 		ac--;
 	}
-	if (ac < 2)
-		return(MG_EILL);
 	imax = ac;			/* box filter if necessary */
+	boxpos = 0;
+	boxstep = 1;
 	if (wlstep < C_CWLI) {
+		imax = (wlmax - wlmin)/C_CWLI + (1-FTINY);
+		boxpos = (wlmin - C_CMINWL)/C_CWLI;
+		boxstep = wlstep/C_CWLI;
 		wlstep = C_CWLI;
-		imax = (wlmax - wlmin)/wlstep;
 	}
 	scale = 0.;			/* get values and maximum */
 	pos = 0;
 	for (i = 0; i < imax; i++) {
 		va[i] = 0.; n = 0;
-		while (pos < (i+.5)*ac/imax) {
+		while (boxpos < i+.5 && pos < ac) {
 			if (!isflt(av[pos]))
 				return(MG_ETYPE);
 			va[i] += atof(av[pos++]);
 			n++;
+			boxpos += boxstep;
 		}
 		if (n > 1)
 			va[i] /= (double)n;
@@ -541,7 +611,7 @@ char	**av;
 		if (va[i] > scale)
 			scale = va[i];
 	}
-	if (scale == 0.)
+	if (scale <= FTINY)
 		return(MG_EILL);
 	scale = C_CMAXV / scale;
 	clr->ssum = 0;			/* convert to our spacing */
@@ -556,9 +626,9 @@ char	**av;
 				pos++;
 			}
 			if (wl+FTINY >= wl0 & wl-FTINY <= wl0)
-				clr->ssamp[i] = scale*va[pos];
+				clr->ssamp[i] = scale*va[pos] + .5;
 			else		/* interpolate if necessary */
-				clr->ssamp[i] = scale / wlstep *
+				clr->ssamp[i] = .5 + scale / wlstep *
 						( va[pos]*(wl0+wlstep - wl) +
 							va[pos+1]*(wl - wl0) );
 			clr->ssum += clr->ssamp[i];
@@ -603,3 +673,41 @@ double	w1, w2;
 		cres->flags = C_CDXY|C_CSXY;
 	}
 }
+
+
+#define	C1		3.741832e-16	/* W-m^2 */
+#define C2		1.4388e-2	/* m-K */
+
+#define bbsp(l,t)	(C1/((l)*(l)*(l)*(l)*(l)*(exp(C2/((t)*(l)))-1.)))
+#define bblm(t)		(C2/5./(t))
+
+static int
+setbbtemp(clr, tk)		/* set black body spectrum */
+register C_COLOR	*clr;
+double	tk;
+{
+	double	sf, wl;
+	register int	i;
+
+	if (tk < 1000)
+		return(MG_EILL);
+	wl = bblm(tk);			/* scalefactor based on peak */
+	if (wl < C_CMINWL*1e-9)
+		wl = C_CMINWL*1e-9;
+	else if (wl > C_CMAXWL*1e-9)
+		wl = C_CMAXWL*1e-9;
+	sf = C_CMAXV/bbsp(wl,tk);
+	clr->ssum = 0;
+	for (i = 0; i < C_CNSS; i++) {
+		wl = (C_CMINWL + i*C_CWLI)*1e-9;
+		clr->ssum += clr->ssamp[i] = sf*bbsp(wl,tk) + .5;
+	}
+	clr->flags = C_CDSPEC|C_CSSPEC;
+	clr->clock++;
+	return(MG_OK);
+}
+
+#undef	C1
+#undef	C2
+#undef	bbsp
+#undef	bblm