# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1441743765 -7200
# Node ID cc44040363e1de10d9ce0dd680a0e64ff5da81f0
# Parent  c9dcc6167aae5212f6641679cfe09d5653f26632
Removed redundant tables and added the statistical fallback function.

diff -r c9dcc6167aae -r cc44040363e1 optimiser.py
--- a/optimiser.py	Tue Sep 08 22:14:55 2015 +0200
+++ b/optimiser.py	Tue Sep 08 22:22:45 2015 +0200
@@ -35,14 +35,11 @@
 def match_darker(b, bases):
     return downward[b] in bases and downward[b]
 
-def neutral(bases, light):
-    l = ["W", "C", "Y", "M", "G", "R", "B", "_"]
-    if not light:
-        l.reverse()
-    for b in l:
-        if b in bases:
+def fallback(bases):
+    for b in by_frequency(bases):
+        if b not in ["_", "W"]:
             return b
-    return bases[randint(0, 3)]
+    return by_frequency(bases)[0]
 
 tones = [
     "__", "_B", "BB", # 00x
@@ -58,30 +55,6 @@
 
 colours = ["_", "R", "G", "Y", "B", "M", "C", "W"]
 
-upward = {
-    "_" : ["R", "G", "B"],
-    "R" : ["Y", "M"],
-    "G" : ["Y", "C"],
-    "B" : ["C", "M"],
-    "Y" : ["W"],
-    "C" : ["W"],
-    "M" : ["W"],
-    "W" : ["W"],
-    "*" : ["W", "Y", "C", "M"],
-    }
-
-downward = {
-    "_" : ["_"],
-    "R" : ["_"],
-    "G" : ["_"],
-    "B" : ["_"],
-    "Y" : ["R", "G"],
-    "C" : ["G", "B"],
-    "M" : ["R", "B"],
-    "W" : ["Y", "C", "M"],
-    "*" : ["R", "G", "B", "_"],
-    }
-
 if __name__ == "__main__":
     width = 320
     input_filename, output_filename = sys.argv[1:3]
@@ -117,17 +90,17 @@
     chosen = []
 
     for row, (u, bu) in enumerate(zip(usage, base_usage)):
-        light = row % 2
         best = 0
         best_bases = None
         best_missing = None
         best_map = None
         for bases in combinations(bu, 4):
+            bases = dict([(base, bu[base]) for base in bases])
             count = 0
             missing = []
             tone_map = {}
             for tone, freq in u.items():
-                base = match(light and tone[1] or tone[0], bases)
+                base = match(tone[1], bases) or match(tone[0], bases)
                 if base:
                     tone_map[tone] = base
                     count += freq
@@ -143,11 +116,10 @@
     output = []
 
     for row, (tr, ch) in enumerate(zip(toned, chosen)):
-        light = row % 2
         o = []
         for column, t in enumerate(tr):
             best, bases, tone_map, missing = ch
-            base = tone_map.get(t) or neutral(bases, light)
+            base = tone_map.get(t) or fallback(bases)
             o.append(base)
             i = colours.index(base)
             im.putpixel((column, row), colour(i))