--- ray/src/common/spec_rgb.c	2009/11/02 23:45:11	2.17
+++ ray/src/common/spec_rgb.c	2020/09/16 00:42:36	2.26
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: spec_rgb.c,v 2.17 2009/11/02 23:45:11 greg Exp $";
+static const char	RCSid[] = "$Id: spec_rgb.c,v 2.26 2020/09/16 00:42:36 greg Exp $";
 #endif
 /*
  * Convert colors and spectral ranges.
@@ -16,9 +16,9 @@ static const char	RCSid[] = "$Id: spec_rgb.c,v 2.17 20
 
 #define CEPS	1e-4			/* color epsilon */
 
-#define CEQ(v1,v2)	((v1) <= (v2)+CEPS && (v2) <= (v1)+CEPS)
+#define CEQ(v1,v2)	(((v1) <= (v2)+CEPS) & ((v2) <= (v1)+CEPS))
 
-#define XYEQ(c1,c2)	(CEQ((c1)[CIEX],(c2)[CIEX]) && CEQ((c1)[CIEY],(c2)[CIEY]))
+#define XYEQ(c1,c2)	(CEQ((c1)[CIEX],(c2)[CIEX]) & CEQ((c1)[CIEY],(c2)[CIEY]))
 
 
 RGBPRIMS  stdprims = STDPRIMS;	/* standard primary chromaticities */
@@ -38,7 +38,7 @@ float  xyneu[2] = {1./3., 1./3.};	/* neutral xy chroma
 #define  INCWL		10		/* wavelength increment */
 #define  NINC		40		/* # of values */
 
-static BYTE  chroma[3][NINC] = {
+static uby8  chroma[3][NINC] = {
 	{							/* X */
 		0,   0,   0,   2,   6,   13,  22,  30,  36,  41,
 		42,  43,  43,  44,  46,  52,  60,  71,  87,  106,
@@ -111,7 +111,7 @@ int  s,			/* starting and ending wavelengths */
 int  e
 )
 {
-	register int  i, d, r;
+	int  i, d, r;
 	
 	s -= STARTWL;
 	if (s < 0)
@@ -164,7 +164,7 @@ COLOR  upper
 	int  rflags = 0;
 	double  brtmin, brtmax, v, vv;
 	COLOR  cgry;
-	register int  i;
+	int  i;
 					/* check for no check */
 	if (gamut == 0) return(0);
 					/* check brightness limits */
@@ -202,9 +202,9 @@ COLOR  upper
 
 void
 colortrans(			/* convert c1 by mat and put into c2 */
-register COLOR  c2,
-register COLORMAT  mat,
-register COLOR  c1
+COLOR  c2,
+COLORMAT  mat,
+COLOR  c1
 )
 {
 	COLOR	cout;
@@ -225,7 +225,7 @@ COLORMAT  m1
 )
 {
 	COLORMAT  mt;
-	register int  i, j;
+	int  i, j;
 
 	for (i = 0; i < 3; i++)
 		for (j = 0; j < 3; j++)
@@ -241,16 +241,32 @@ colorprimsOK(			/* are color primaries reasonable? */
 RGBPRIMS  pr
 )
 {
-	int	i;
-	
-	for (i = 0; i < 4; i++) {
-		if ((pr[i][CIEX] <= -CEPS) | (pr[i][CIEY] <= -CEPS))
+	int	i, j;
+				/* check white point */
+	if ((pr[3][CIEX] <= CEPS) | (pr[3][CIEX] >= 1.-CEPS) |
+			(pr[3][CIEY] <= CEPS) | (pr[3][CIEY] >= 1.-CEPS))
+		return(0);
+	for (i = 3; i--; )	/* check for XYZ color primaries */
+		if (!CEQ(pr[i][CIEX],(i==0)) | !CEQ(pr[i][CIEY],(i==1)))
+			break;
+	if (i < 0)
+		return(-1);	/* flag as XYZ color space */
+				/* check color primaries */
+	for (i = 0; i < 3; i++) {
+		if ((pr[i][CIEX] <= -2.) | (pr[i][CIEY] <= -2.))
 			return(0);
-		if ((pr[i][CIEX] >= 1.+CEPS) | (pr[i][CIEY] >= 1.+CEPS))
+		if ((pr[i][CIEX] >= 3.) | (pr[i][CIEY] >= 3.))
 			return(0);
-		if (pr[i][CIEX] + pr[i][CIEY] >= 1.+CEPS)
+		if (pr[i][CIEX] + pr[i][CIEY] <= -2.)
 			return(0);
+		if (pr[i][CIEX] + pr[i][CIEY] >= 3.)
+			return(0);
 	}
+	for (i = 0; i < 4; i++)	/* make sure space is 3-dimensional */
+		for (j = i+1; j < 4; j++)
+			if (CEQ(pr[i][CIEX],pr[j][CIEX]) &
+					CEQ(pr[i][CIEY],pr[j][CIEY]))
+				return(0);
 	return(1);
 }
 
@@ -259,7 +275,7 @@ RGBPRIMS  pr
 int
 compxyz2rgbmat(			/* compute conversion from CIE to RGB space */
 COLORMAT  mat,
-register RGBPRIMS  pr
+RGBPRIMS  pr
 )
 {
 	double  C_rD, C_gD, C_bD;
@@ -319,7 +335,7 @@ register RGBPRIMS  pr
 int
 comprgb2xyzmat(			/* compute conversion from RGB to CIE space */
 COLORMAT  mat,
-register RGBPRIMS  pr
+RGBPRIMS  pr
 )
 {
 	double  C_rD, C_gD, C_bD, D;