Biome tinting uses now uses the Biome Extractor data files.

See:
http://www.minecraftforum.net/viewtopic.php?f=25&t=80902&view=unread

chunk.py

@@ -14,10 +14,12 @@
 #    with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
 
 import numpy
-from PIL import Image, ImageDraw, ImageEnhance
+from PIL import Image, ImageDraw, ImageEnhance, ImageOps
 import os.path
 import hashlib
 import logging
+import time
+import math
 
 import nbt
 import textures
@@ -473,6 +475,7 @@ class ChunkRenderer(object):
         For cave mode, all blocks that have any direct sunlight are not
         rendered, and blocks are drawn with a color tint depending on their
         depth."""
+
         blocks = self.blocks
         
         if cave:
@@ -494,6 +497,11 @@ class ChunkRenderer(object):
 
         tileEntities = get_tileentity_data(self.level)
 
+        biomeColorData = textures.prepareBiomeData(self.world.worlddir,
+                self.chunkX, self.chunkY)
+        # in the 8x8 block of biome data, what chunk is this?l
+        startX = (self.chunkX - int(math.floor(self.chunkX/8)*8))
+        startY = (self.chunkY - int(math.floor(self.chunkY/8)*8))
 
         # Each block is 24x24
         # The next block on the X axis adds 12px to x and subtracts 6px from y in the image
@@ -528,8 +536,22 @@ class ChunkRenderer(object):
             if not t:
                 continue
 
-            if blockid in (2,18): # grass or leaves, tint according to biome
-                t = textures.tintForBiome(t, (16*self.chunkX) + x,y+(16*self.chunkY))
+            if blockid == 2: #grass
+                index = biomeColorData[ ((startY*16)+y) * 128 + (startX*16) + x]
+                c = textures.grasscolor[index]
+
+                # only tint the top texture
+                t = textures.prepareGrassTexture(c)
+            elif blockid == 18: # leaves
+                index = biomeColorData[ ((startY*16)+y) * 128 + (startX*16) + x]
+                c = textures.foliagecolor[index]
+                #i = textures.tintTexture(t,c)
+                i = ImageOps.colorize(ImageOps.grayscale(t[0]), (0,0,0), c)
+                i.putalpha(t[1])              
+                t = (i, t[1])
+
+
+
 
             # Check if this block is occluded
             if cave and (
@@ -648,8 +670,6 @@ class ChunkRenderer(object):
         # list above.
         self.queue.put(['removePOI', (self.chunkX, self.chunkY)])
 
-            
-
         return img
 
 # Render 3 blending masks for lighting

textures.py

@@ -538,30 +538,50 @@ def tintTexture(im, c):
     i.putalpha(im.split()[3]); # copy the alpha band back in. assuming RGBA
     return i
 
-## prepare grasscolor.png
+grassSide1 = transform_image_side(terrain_images[3])
+grassSide2 = transform_image_side(terrain_images[3]).transpose(Image.FLIP_LEFT_RIGHT)
+def prepareGrassTexture(color):
+    top = transform_image(tintTexture(terrain_images[0],color))
+    img = Image.new("RGBA", (24,24), (38,92,255,0))
+
+    img.paste(grassSide1, (0,6), grassSide1)
+    img.paste(grassSide2, (12,6), grassSide2)
+    img.paste(top, (0,0), top)
+    return (img.convert("RGB"), img.split()[3])
+
+# TODO be more intelligent about where to find these files
 grasscolor = list(Image.open("grasscolor.png").getdata())
+foliagecolor = list(Image.open("foliagecolor.png").getdata())
 
+currentBiomeFile = None
+currentBiomeData = None
+def prepareBiomeData(worlddir, chunkX, chunkY):
+    '''Opens the worlddir and reads in the biome color information
+    from the .biome files.  See also:
+    http://www.minecraftforum.net/viewtopic.php?f=25&t=80902
+    '''
+    t = sys.modules[__name__]
+    if not os.path.exists(os.path.join(worlddir, "EXTRACTEDBIOMES")):
+        raise Exception("EXTRACTEDBIOMES not found")
 
+    biomeFile = "%d.%d.biome" % (
+        int(math.floor(chunkX/8)*8),
+        int(math.floor(chunkY/8)*8)
+            )
+    if biomeFile == t.currentBiomeFile:
+        return currentBiomeData
 
-def tintForBiome(im, x, y):
-    result = gmc.submit_job("GetBiome", "%d,%d" % (x,y))
-    temp, moisture = map(lambda x: float(x),result.result.split("/"))
+    t.currentBiomeFile = biomeFile
 
-    #print result.result
-    moisture *= temp
-    i  = int((1.0 - temp) * 255)
-    j = int((1.0 - moisture) * 255)
-    #print "tintInfo for %d,%d is %f,%f coord %d, %d" % (x,y, temp, moisture, i, j)
-    #print "resulting color: %r" % (grasscolor.getpixel((i,j))[:-1],)
-    #t = tintTexture(im[0], grasscolor.getpixel((i, j))[:-1])
-    #im[0] = t
-    #c = grasscolor.getpixel((j,i))[:-1]
-    c = grasscolor[(j << 8 | i)]
-    #print "grass color: %r" % (c,)
-    i = ImageOps.colorize(ImageOps.grayscale(im[0]), (0,0,0), c)
-    i.putalpha(im[1])
-    return (i, im[1])
+    f = open(os.path.join(worlddir, "EXTRACTEDBIOMES", biomeFile))
+    rawdata = f.read()
+    f.close()
 
+    data = numpy.frombuffer(rawdata, dtype=numpy.dtype(">u2"))
+
+    t.currentBiomeData = data
+    return data
+     
 
 # This set holds block ids that require special pre-computing.  These are typically
 # things that require ancillary data to render properly (i.e. ladder plus orientation)