# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1444583535 -7200
# Node ID aaa2938a0ac2b3e467c2aba8642b27d99957d3ff
# Parent  904b2295aca58e32e8eef4378028065140ed81dd# Parent  680956899c9e8142ff2881c6283722f707c6353f
Replaced "for" loops with "while" loops for extra performance.

diff -r 904b2295aca5 -r aaa2938a0ac2 optimiser.py
diff -r 904b2295aca5 -r aaa2938a0ac2 optimiserlib.py
--- a/optimiserlib.py	Sun Oct 11 18:07:59 2015 +0200
+++ b/optimiserlib.py	Sun Oct 11 19:12:15 2015 +0200
@@ -181,7 +181,8 @@
 
     width, height = im.size
     c = {}
-    for x in range(0, width):
+    x = 0
+    while x < width:
         rgb = im.getpixel((x, y))
 
         # Sum the colour probabilities.
@@ -192,6 +193,8 @@
             else:
                 c[value] += f
 
+        x += 1
+
     d = [(n/width, value) for value, n in c.items()]
     d.sort(reverse=True)
     return d
@@ -222,12 +225,16 @@
 
     width, height = im.size
 
-    for y in range(0, height):
+    y = 0
+    while y < height:
         l = set()
-        for x in range(0, width):
+        x = 0
+        while x < width:
             l.add(im.getpixel((x, y)))
+            x += 1
         if len(l) > colours:
             return (y, l)
+        y += 1
     return None
 
 def process_image(im, saturate, desaturate, darken, brighten):
@@ -240,14 +247,18 @@
     width, height = im.size
 
     if saturate or desaturate or darken or brighten:
-        for y in range(0, height):
-            for x in range(0, width):
+        y = 0
+        while y < height:
+            x = 0
+            while x < width:
                 rgb = im.getpixel((x, y))
                 if saturate or desaturate:
                     rgb = saturate_rgb(rgb, saturate and 0.5 / saturate or 2.0 * desaturate)
                 if darken or brighten:
                     rgb = amplify_rgb(rgb, brighten and 0.5 / brighten or 2.0 * darken)
                 im.putpixel((x, y), rgb)
+                x += 1
+            y += 1
 
 def convert_image(im, colours):
 
@@ -255,7 +266,8 @@
 
     width, height = im.size
 
-    for y in range(0, height):
+    y = 0
+    while y < height:
         c = get_colours(im, y)
 
         suggestions = []
@@ -264,11 +276,13 @@
             most = [value for f, value in l]
             missing = 0
 
-            for x in range(0, width):
+            x = 0
+            while x < width:
                 rgb = im.getpixel((x, y))
                 value = get_value(rgb, most, True)
                 if value is None:
                     missing += 1
+                x += 1
 
             if not missing:
                 break # use this combination
@@ -280,7 +294,8 @@
             suggestions.sort()
             most = [value for f, value in suggestions[0][1]] # get the combination
 
-        for x in range(0, width):
+        x = 0
+        while x < width:
             rgb = im.getpixel((x, y))
             value = get_value(rgb, most)
             im.putpixel((x, y), value)
@@ -303,6 +318,10 @@
                     )
                 im.putpixel((x, y+1), rgbn)
 
+            x += 1
+
+        y += 1
+
 class SimpleImage:
 
     "An image behaving like PIL.Image."