--- ray/src/common/color.h	1991/07/17 11:52:25	1.12
+++ ray/src/common/color.h	1991/12/19 14:45:43	2.2
@@ -1,4 +1,4 @@
-/* Copyright (c) 1986 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 /* SCCSid "$SunId$ LBL" */
 
@@ -48,8 +48,17 @@ typedef float  COLOR[3];	/* red, green, blue */
 #define  normbright(c)		(int)((67L*(c)[RED]+168L*(c)[GRN]+21L*(c)[BLU])/256)
 #endif
 
-#define  luminance(col)		(470. * bright(col))
+				/* luminous efficacies over visible spectrum */
+#define  MAXEFFICACY		683.		/* defined maximum at 550 nm */
+#define  WHTEFFICACY		179.		/* uniform white light */
+#define  D65EFFICACY		203.		/* standard illuminant D65 */
+#define  INCEFFICACY		160.		/* illuminant A (incand.) */
+#define  SUNEFFICACY		208.		/* illuminant B (solar dir.) */
+#define  SKYEFFICACY		D65EFFICACY	/* skylight */
+#define  DAYEFFICACY		D65EFFICACY	/* combined sky and solar */
 
+#define  luminance(col)		(WHTEFFICACY * bright(col))
+
 #define  intens(col)		( (col)[0] > (col)[1] \
 				? (col)[0] > (col)[2] ? (col)[0] : (col)[2] \
 				: (col)[1] > (col)[2] ? (col)[1] : (col)[2] )
@@ -63,11 +72,6 @@ typedef float  COLOR[3];	/* red, green, blue */
 #define  WHTCOLR		{128,128,128,COLXS+1}
 #define  BLKCOLR		{0,0,0,0}
 
-				/* definitions for resolution header */
-#define  XDECR			1
-#define  YDECR			2
-#define  YMAJOR			4
-
 				/* picture format identifier */
 #define  COLRFMT		"32-bit_rle_rgbe"
 
@@ -94,4 +98,7 @@ typedef float  COLOR[3];	/* red, green, blue */
 #define  fputcolcor(cc,fp)	fprintf(fp,"%s %f %f %f\n",COLCORSTR, \
 					(cc)[RED],(cc)[GRN],(cc)[BLU])
 
-extern double  ldexp(), atof();
+extern double  ldexp();
+#ifndef atof			/* atof's a macro on some systems! */
+extern double  atof();
+#endif