# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1441742953 -7200
# Node ID 23cf22b7cfbff3e15fac6b812132568c5339b9fc
# Parent  b5004853e37e97e2db4c58a4f8910ddefe30bd6a
Experimenting with three tone values. Added automatic image height sizing.

diff -r b5004853e37e -r 23cf22b7cfbf optimiser.py
--- a/optimiser.py	Tue Sep 08 21:29:00 2015 +0200
+++ b/optimiser.py	Tue Sep 08 22:09:13 2015 +0200
@@ -2,7 +2,6 @@
 
 from array import array
 from itertools import combinations
-from random import randint
 import PIL.Image
 import sys
 
@@ -35,25 +34,22 @@
 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
-    "_G", "_C", "BC", # 01x
-    "GG", "GC", "CC", # 02x
-    "_R", "_M", "BM", # 10x
-    "_Y", "**", "WB", # 11x
-    "GY", "WG", "WC", # 12x
-    "RR", "RM", "MM", # 20x
-    "RY", "WR", "WM", # 21x
-    "YY", "WY", "WW", # 22x
+    "___", "_BB", "BBB", # 00x
+    "_GG", "_CC", "BCC", # 01x
+    "GGG", "GCC", "CCC", # 02x
+    "_RR", "_MM", "BMM", # 10x
+    "_YY", "_*W", "BBW", # 11x
+    "GYY", "GGW", "CCW", # 12x
+    "RRR", "RMM", "MMM", # 20x
+    "RYY", "RRW", "MMW", # 21x
+    "YYY", "YYW", "WWW", # 22x
     ]
 
 colours = ["_", "R", "G", "Y", "B", "M", "C", "W"]
@@ -84,10 +80,11 @@
 
 if __name__ == "__main__":
     width = 320
-    height = 192
     input_filename, output_filename = sys.argv[1:3]
 
     im = PIL.Image.open(input_filename)
+    w, h = im.size
+    height = (width * h) / w
     im = im.resize((width, height))
 
     usage = []
@@ -111,6 +108,8 @@
                 add(bu, t[0])
             if t[1] != "*":
                 add(bu, t[1])
+            if t[2] != "*":
+                add(bu, t[2])
             tr.append(t)
 
     chosen = []
@@ -122,11 +121,12 @@
         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(light and tone[2] or tone[0], bases)
                 if base:
                     tone_map[tone] = base
                     count += freq
@@ -142,11 +142,10 @@
     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))