--- ray/src/cv/mgflib/context.c	1994/07/01 18:06:56	1.13
+++ ray/src/cv/mgflib/context.c	1994/09/02 16:04:19	1.16
@@ -67,6 +67,7 @@ register char	**av;
 		lp = lu_find(&clr_tab, av[1]);	/* lookup context */
 		if (lp == NULL)
 			return(MG_EMEM);
+		c_ccname = lp->key;
 		c_ccolor = (C_COLOR *)lp->data;
 		if (ac == 2) {		/* reestablish previous context */
 			if (c_ccolor == NULL)
@@ -83,10 +84,10 @@ register char	**av;
 			lp->data = (char *)malloc(sizeof(C_COLOR));
 			if (lp->data == NULL)
 				return(MG_EMEM);
+			c_ccname = lp->key;
 			c_ccolor = (C_COLOR *)lp->data;
 			c_ccolor->clock = 0;
 		}
-		c_ccname = lp->key;
 		i = c_ccolor->clock;
 		if (ac == 3) {		/* use default template */
 			*c_ccolor = c_dfcolor;
@@ -176,6 +177,7 @@ register char	**av;
 		lp = lu_find(&mat_tab, av[1]);	/* lookup context */
 		if (lp == NULL)
 			return(MG_EMEM);
+		c_cmname = lp->key;
 		c_cmaterial = (C_MATERIAL *)lp->data;
 		if (ac == 2) {		/* reestablish previous context */
 			if (c_cmaterial == NULL)
@@ -192,10 +194,10 @@ register char	**av;
 			lp->data = (char *)malloc(sizeof(C_MATERIAL));
 			if (lp->data == NULL)
 				return(MG_EMEM);
+			c_cmname = lp->key;
 			c_cmaterial = (C_MATERIAL *)lp->data;
 			c_cmaterial->clock = 0;
 		}
-		c_cmname = lp->key;
 		i = c_cmaterial->clock;
 		if (ac == 3) {		/* use default template */
 			*c_cmaterial = c_dfmaterial;
@@ -309,6 +311,7 @@ register char	**av;
 		lp = lu_find(&vtx_tab, av[1]);	/* lookup context */
 		if (lp == NULL)
 			return(MG_EMEM);
+		c_cvname = lp->key;
 		c_cvertex = (C_VERTEX *)lp->data;
 		if (ac == 2) {		/* reestablish previous context */
 			if (c_cvertex == NULL)
@@ -325,9 +328,9 @@ register char	**av;
 			lp->data = (char *)malloc(sizeof(C_VERTEX));
 			if (lp->data == NULL)
 				return(MG_EMEM);
+			c_cvname = lp->key;
 			c_cvertex = (C_VERTEX *)lp->data;
 		}
-		c_cvname = lp->key;
 		i = c_cvertex->clock;
 		if (ac == 3) {		/* use default template */
 			*c_cvertex = c_dfvertex;
@@ -373,12 +376,15 @@ c_clearall()			/* empty context tables */
 {
 	c_uncolor = c_dfcolor;
 	c_ccolor = &c_uncolor;
+	c_ccname = NULL;
 	lu_done(&clr_tab);
 	c_unmaterial = c_dfmaterial;
 	c_cmaterial = &c_unmaterial;
+	c_cmname = NULL;
 	lu_done(&mat_tab);
 	c_unvertex = c_dfvertex;
 	c_cvertex = &c_unvertex;
+	c_cvname = NULL;
 	lu_done(&vtx_tab);
 }
 
@@ -439,11 +445,12 @@ int	fl;
 	double	x, y, z;
 	register int	i;
 
-	if (clr->flags & fl)		/* already done */
+	fl &= ~clr->flags;			/* ignore what's done */
+	if (!fl)				/* everything's done! */
 		return;
 	if (!(clr->flags & (C_CSXY|C_CSSPEC)))	/* nothing set! */
 		*clr = c_dfcolor;
-	else if (fl & C_CSXY) {		/* cspec -> cxy */
+	if (fl & C_CSXY) {		/* cspec -> cxy */
 		x = y = z = 0.;
 		for (i = 0; i < C_CNSS; i++) {
 			x += cie_xf.ssamp[i] * clr->ssamp[i];
@@ -454,7 +461,7 @@ int	fl;
 		clr->cx = x / z;
 		clr->cy = y / z;
 		clr->flags |= C_CSXY;
-	} else {			/* cxy -> cspec */
+	} 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;
@@ -467,6 +474,18 @@ int	fl;
 					z * cie_zf.ssamp[i] ;
 		clr->flags |= C_CSSPEC;
 	}
+	if (fl & C_CSEFF) {		/* compute efficacy */
+		if (clr->flags & C_CDSPEC) {		/* 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) */
+			clr->eff = clr->cx*cie_xf.eff + clr->cy*cie_yf.eff +
+					(1. - clr->cx - clr->cy)*cie_zf.eff;
+		}
+		clr->flags |= C_CSEFF;
+	}
 }
 
 
@@ -537,10 +556,10 @@ double	w1, w2;
 	register int	i;
 
 	if ((c1->flags|c2->flags) & C_CDSPEC) {		/* spectral mixing */
-		c_ccvt(c1, C_CSSPEC);
-		c_ccvt(c2, C_CSSPEC);
-		w1 /= (double)c1->ssum;
-		w2 /= (double)c2->ssum;
+		c_ccvt(c1, C_CSSPEC|C_CSEFF);
+		c_ccvt(c2, C_CSSPEC|C_CSEFF);
+		w1 /= c1->eff*c1->ssum;
+		w2 /= c1->eff*c2->ssum;
 		scale = 0.;
 		for (i = 0; i < C_CNSS; i++) {
 			cmix[i] = w1*c1->ssamp[i] + w2*c2->ssamp[i];