FIX: msvcrt not support log-2 (#85)

Author: bitbegin

Library/Stream-IO/Stream-IO-core.reds

@@ -59,6 +59,8 @@ Red/System [
 	__mb-buffer: allocate 2 * MB_BUFFER_CHARS
 ]
 
+#define loge-2		0.6931471805599453
+
 sio-decimal-pair!: alias struct! [
 	x [float!]
 	y [float!]
@@ -169,7 +171,7 @@ getSBitsLength: func[
 ][
 	if value = 0 [return 0]
 	if value < 0 [value: 0 - value]
-	2 + as integer! (log-2 as float! value) / 0.6931471805599453
+	2 + as integer! ((log-e as float! value) / loge-2) / loge-2
 ]
 getUBitsLength: func[
 	"Returns number of bits needed to store unsigned integer value"
@@ -178,7 +180,7 @@ getUBitsLength: func[
 ][
 	if value = 0 [return 0]
 	if value < 0 [value: 0 - value]
-	1 + as integer! (log-2 as float! value) / 0.6931471805599453
+	1 + as integer! ((log-e as float! value) / loge-2) / loge-2
 ]
 
 

Scripts/mandelbrot-fast.red

@@ -54,7 +54,7 @@ fast-mandelbrot: routine [
 			i: mandelbrot-iter x y iterations
 
 			pix/value: either i > iterations [FF000000h][
-				c: 3.0 * (log-2 as-float i) / log-2 as-float (iterations - 1)
+				c: 3.0 * (log-e as-float i) / log-e as-float (iterations - 1)
 				case [
 					c < 1.0 [FF000000h or (FFh and (as-integer 255.0 * c) << 16)]
 					c < 2.0 [FFFF0000h or (FFh and (as-integer 255.0 * (c - 1.0)) << 8)]