# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1444344059 -7200
# Node ID 4d2f52b71f3c4df24177139ddb70520fed8db762
# Parent  aa75aca1ebd7832775caaf35e6725b2960172142
Removed the colour cache: entries seemed to acquire rounded probabilities.

diff -r aa75aca1ebd7 -r 4d2f52b71f3c optimiser.py
--- a/optimiser.py	Fri Oct 09 00:34:32 2015 +0200
+++ b/optimiser.py	Fri Oct 09 00:40:59 2015 +0200
@@ -62,39 +62,33 @@
 
 # Colour distribution functions.
 
-cache = {}
-
 def combination(rgb):
 
     "Return the colour distribution for 'rgb'."
 
-    if not cache.has_key(rgb):
-
-        # Get the colour with components scaled from 0 to 1, plus the inverted
-        # component values.
+    # Get the colour with components scaled from 0 to 1, plus the inverted
+    # component values.
 
-        rgb = extra(scale(rgb))
-        rgbi = invert(rgb)
-        pairs = zip(rgbi, rgb)
+    rgb = extra(scale(rgb))
+    rgbi = invert(rgb)
+    pairs = zip(rgbi, rgb)
 
-        # For each corner of the colour cube (primary and secondary colours plus
-        # black and white), calculate the corner value's contribution to the
-        # input colour.
+    # For each corner of the colour cube (primary and secondary colours plus
+    # black and white), calculate the corner value's contribution to the
+    # input colour.
 
-        d = []
-        for corner in corners:
-            rs, gs, bs = scale(corner)
-
-            # Obtain inverted channel values where corner channels are low;
-            # obtain original channel values where corner channels are high.
+    d = []
+    for corner in corners:
+        rs, gs, bs = scale(corner)
 
-            d.append((pairs[0][int(rs)] * pairs[1][int(gs)] * pairs[2][int(bs)], corner))
-
-        # Balance the corner contributions.
+        # Obtain inverted channel values where corner channels are low;
+        # obtain original channel values where corner channels are high.
 
-        cache[rgb] = balance(d)
+        d.append((pairs[0][int(rs)] * pairs[1][int(gs)] * pairs[2][int(bs)], corner))
 
-    return cache[rgb]
+    # Balance the corner contributions.
+
+    return balance(d)
 
 def complements(rgb):