# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1444481836 -7200
# Node ID b147df07482fe86e9479a8979ba3e17de41fb577
# Parent  4cafde6aa7379453e718ed03fedc5722785c1294
Converted other channel operations to explicit RGB operations.

diff -r 4cafde6aa737 -r b147df07482f optimiser.py
--- a/optimiser.py	Sat Oct 10 14:53:29 2015 +0200
+++ b/optimiser.py	Sat Oct 10 14:57:16 2015 +0200
@@ -161,13 +161,15 @@
     return x >= 0 and 1 or -1
 
 def saturate_rgb(rgb, exp):
-    return tuple([saturate_value(x, exp) for x in rgb])
+    r, g, b = rgb
+    return saturate_value(r, exp), saturate_value(g, exp), saturate_value(b, exp)
 
 def saturate_value(x, exp):
     return int(127.5 + sign(x - 127.5) * 127.5 * pow(abs(x - 127.5) / 127.5, exp))
 
 def amplify_rgb(rgb, exp):
-    return tuple([amplify_value(x, exp) for x in rgb])
+    r, g, b = rgb
+    return amplify_value(r, exp), amplify_value(g, exp), amplify_value(b, exp)
 
 def amplify_value(x, exp):
     return int(pow(x / 255.0, exp) * 255.0)
@@ -339,12 +341,20 @@
 
             if x < width - 1:
                 rgbn = im.getpixel((x+1, y))
-                rgbn = tuple(map(lambda i: clip(i[0] + (i[1] - i[2]) / 4.0), zip(rgbn, rgb, value)))
+                rgbn = (
+                    clip(rgbn[0] + (rgb[0] - value[0]) / 4.0),
+                    clip(rgbn[1] + (rgb[1] - value[1]) / 4.0),
+                    clip(rgbn[2] + (rgb[2] - value[2]) / 4.0)
+                    )
                 im.putpixel((x+1, y), rgbn)
 
             if y < height - 1:
                 rgbn = im.getpixel((x, y+1))
-                rgbn = tuple(map(lambda i: clip(i[0] + (i[1] - i[2]) / 2.0), zip(rgbn, rgb, value)))
+                rgbn = (
+                    clip(rgbn[0] + (rgb[0] - value[0]) / 2.0),
+                    clip(rgbn[1] + (rgb[1] - value[1]) / 2.0),
+                    clip(rgbn[2] + (rgb[2] - value[2]) / 2.0)
+                    )
                 im.putpixel((x, y+1), rgbn)
 
 def get_float(options, flag):