--- ray/src/common/color.c	1989/03/15 13:48:37	1.2
+++ ray/src/common/color.c	1990/09/22 10:45:42	1.12
@@ -14,99 +14,7 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include  "color.h"
 
-#ifdef  SPEC_RGB
-/*
- *	The following table contains the CIE tristimulus integrals
- *  for X, Y, and Z.  The table is cumulative, so that
- *  each color coordinate integrates to 1.
- */
 
-#define  STARTWL	380		/* starting wavelength (nanometers) */
-#define  INCWL		10		/* wavelength increment */
-#define  NINC		40		/* # of values */
-
-static BYTE  chroma[3][NINC] = {
-	{							/* X */
-		0,   0,   0,   2,   6,   13,  22,  30,  36,  41,
-		42,  43,  43,  44,  46,  52,  60,  71,  87,  106,
-		128, 153, 178, 200, 219, 233, 243, 249, 252, 254,
-		255, 255, 255, 255, 255, 255, 255, 255, 255, 255
-	}, {							/* Y */
-		0,   0,   0,   0,   0,   1,   2,   4,   7,   11,
-		17,  24,  34,  48,  64,  84,  105, 127, 148, 169,
-		188, 205, 220, 232, 240, 246, 250, 253, 254, 255,
-		255, 255, 255, 255, 255, 255, 255, 255, 255, 255
-	}, {							/* Z */
-		0,   0,   2,   10,  32,  66,  118, 153, 191, 220,
-		237, 246, 251, 253, 254, 255, 255, 255, 255, 255,
-		255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
-		255, 255, 255, 255, 255, 255, 255, 255, 255, 255
-	}
-};
-
-
-spec_rgb(col, s, e)		/* comput RGB color from spectral range */
-COLOR  col;
-int  s, e;
-{
-	COLOR  ciecolor;
-
-	spec_cie(ciecolor, s, e);
-	cie_rgb(col, ciecolor);
-}
-
-
-spec_cie(col, s, e)		/* compute a color from a spectral range */
-COLOR  col;		/* returned color */
-int  s, e;		/* starting and ending wavelengths */
-{
-	register int  i, d, r;
-	
-	s -= STARTWL;
-	if (s < 0)
-		s = 0;
-
-	e -= STARTWL;
-	if (e >= INCWL*(NINC - 1))
-		e = INCWL*(NINC - 1) - 1;
-
-	d = e / INCWL;			/* interpolate values */
-	r = e % INCWL;
-	for (i = 0; i < 3; i++)
-		col[i] = chroma[i][d]*(INCWL - r) + chroma[i][d + 1]*r;
-
-	d = s / INCWL;
-	r = s % INCWL;
-	for (i = 0; i < 3; i++)
-		col[i] -= chroma[i][d]*(INCWL - r) - chroma[i][d + 1]*r;
-
-	col[RED] = (col[RED] + 0.5) / (256*INCWL);
-	col[GRN] = (col[GRN] + 0.5) / (256*INCWL);
-	col[BLU] = (col[BLU] + 0.5) / (256*INCWL);
-}
-
-
-cie_rgb(rgbcolor, ciecolor)		/* convert CIE to RGB (NTSC) */
-register COLOR  rgbcolor, ciecolor;
-{
-	static float  cmat[3][3] = {
-		1.73, -.48, -.26,
-		-.81, 1.65, -.02,
-		 .08, -.17, 1.28,
-	};
-	register int  i;
-
-	for (i = 0; i < 3; i++) {
-		rgbcolor[i] =	cmat[i][0]*ciecolor[0] +
-				cmat[i][1]*ciecolor[1] +
-				cmat[i][2]*ciecolor[2] ;
-		if (rgbcolor[i] < 0.0)
-			rgbcolor[i] = 0.0;
-	}
-}
-#endif
-
-
 fwritecolrs(scanline, len, fp)		/* write out a colr scanline */
 register COLR  *scanline;
 int  len;
@@ -289,7 +197,7 @@ double  r, g, b;
 	d = r > g ? r : g;
 	if (b > d) d = b;
 
-	if (d <= 0.0) {
+	if (d <= 1e-32) {
 		clr[RED] = clr[GRN] = clr[BLU] = 0;
 		clr[EXP] = 0;
 		return;
@@ -308,7 +216,7 @@ colr_color(col, clr)		/* convert short to float color 
 register COLOR  col;
 register COLR  clr;
 {
-	double  ldexp(), f;
+	double  f;
 	
 	if (clr[EXP] == 0)
 		col[RED] = col[GRN] = col[BLU] = 0.0;
@@ -321,31 +229,57 @@ register COLR  clr;
 }
 
 
-#ifdef  FREXP
-double
-frexp(x, ip)		/* call it paranoia, I've seen the lib version */
-register double  x;
-int  *ip;
+normcolrs(scan, len, adjust)	/* normalize a scanline of colrs */
+register COLR  *scan;
+int  len;
+int  adjust;
 {
-	int  neg;
-	register int  i;
+	register int  c;
+	register int  shift;
 
-	if (neg = (x < 0.0))
-		x = -x;
-	else if (x == 0.0) {
-		*ip = 0;
-		return(0.0);
+	while (len-- > 0) {
+		shift = scan[0][EXP] + adjust - COLXS;
+		if (shift > 0) {
+			if (shift > 8) {
+				scan[0][RED] =
+				scan[0][GRN] =
+				scan[0][BLU] = 255;
+			} else {
+				shift--;
+				c = (scan[0][RED]<<1 | 1) << shift;
+				scan[0][RED] = c > 255 ? 255 : c;
+				c = (scan[0][GRN]<<1 | 1) << shift;
+				scan[0][GRN] = c > 255 ? 255 : c;
+				c = (scan[0][BLU]<<1 | 1) << shift;
+				scan[0][BLU] = c > 255 ? 255 : c;
+			}
+		} else if (shift < 0) {
+			if (shift < -8) {
+				scan[0][RED] =
+				scan[0][GRN] =
+				scan[0][BLU] = 0;
+			} else {
+				shift = -1-shift;
+				scan[0][RED] = ((scan[0][RED]>>shift)+1)>>1;
+				scan[0][GRN] = ((scan[0][GRN]>>shift)+1)>>1;
+				scan[0][BLU] = ((scan[0][BLU]>>shift)+1)>>1;
+			}
+		}
+		scan[0][EXP] = COLXS - adjust;
+		scan++;
 	}
-	if (x < 0.5)
-		for (i = 0; x < 0.5; i--)
-			x *= 2.0;
-	else
-		for (i = 0; x >= 1.0; i++)
-			x /= 2.0;
-	*ip = i;
-	if (neg)
-		return(-x);
-	else
-		return(x);
 }
-#endif
+
+
+bigdiff(c1, c2, md)			/* c1 delta c2 > md? */
+register COLOR  c1, c2;
+double  md;
+{
+	register int  i;
+
+	for (i = 0; i < 3; i++)
+		if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) ||
+			colval(c2,i)-colval(c1,i) > md*colval(c1,i))
+			return(1);
+	return(0);
+}