added a command line interface

chunk.py

@@ -71,6 +71,11 @@ class ChunkRenderer(object):
         """Finds a hash of the block array"""
         h = hashlib.md5()
         h.update(self.level['Blocks'])
+
+        # If the render algorithm changes, change this line to re-generate all
+        # the chunks automatically:
+        #h.update("1")
+
         digest = h.hexdigest()
         # 6 digits ought to be plenty
         return digest[:6]

render.py

@@ -0,0 +1,66 @@
+#!/usr/bin/python
+
+import os
+import sys
+import os.path
+from optparse import OptionParser
+import re
+
+import world
+
+helptext = """
+%prog [-c] <Path to World> <image out.png>
+%prog -d [-c] <Path to World>"""
+
+def remove_images(worlddir, cavemode):
+    if cavemode:
+        cavestr = "cave"
+    else:
+        cavestr = "nocave"
+    imgre = r"img\.[^.]+\.[^.]+\.{0}\.\w+\.png$".format(cavestr)
+    matcher = re.compile(imgre)
+
+    for dirpath, dirnames, filenames in os.walk(worlddir):
+        for f in filenames:
+            if matcher.match(f):
+                filepath = os.path.join(dirpath, f)
+                print "Deleting {0}".format(filepath)
+                os.unlink(filepath)
+
+def confirm(imgfile):
+    answer = raw_input("Overwrite existing image at %r? [Y/n]" % imgfile).strip()
+    if not answer or answer.lower().startswith("y"):
+        return True
+    return False
+
+def main():
+    parser = OptionParser(usage=helptext)
+    parser.add_option("-c", "--caves", dest="caves", help="Render only caves", action="store_true")
+    parser.add_option("-d", "--delete-cache", dest="delete", help="Deletes the image files cached in your world directory", action="store_true")
+    parser.add_option("-p", "--processes", dest="procs", help="How many chunks to render in parallel. A good number for this is 1 more than the number of cores in your computer. Default 2", default=2, action="store", type="int")
+
+    options, args = parser.parse_args()
+
+    if len(args) < 1:
+        print "You need to give me your world directory"
+        parser.print_help()
+        sys.exit(1)
+    worlddir = args[0]
+
+    if options.delete:
+        remove_images(worlddir, options.caves)
+    else:
+        if len(args) != 2:
+            parser.error("What do you want to save the image as?")
+        imageout = args[1]
+        if not imageout.endswith(".png"):
+            imageout = imageout + ".png"
+        if os.path.exists(imageout) and not confirm(imageout):
+            return
+        imageobj = world.render_world(worlddir, options.caves, options.procs)
+        print "Saving image..."
+        imageobj.save(imageout)
+        print "Saved as", imageout
+
+if __name__ == "__main__":
+    main()

world.py

@@ -38,12 +38,13 @@ def find_chunkfiles(worlddir):
     for dirpath, dirnames, filenames in os.walk(worlddir):
         if not dirnames and filenames:
             for f in filenames:
+                if f.startswith("c.") and f.endswith(".dat"):
                     p = f.split(".")
                     all_chunks.append((base36decode(p[1]), base36decode(p[2]), 
                         os.path.join(dirpath, f)))
     return all_chunks
 
-def render_world(worlddir, cavemode=False):
+def render_world(worlddir, cavemode=False, procs=2):
     print "Scanning chunks..."
     all_chunks = find_chunkfiles(worlddir)
 
@@ -101,6 +102,8 @@ def render_world(worlddir, cavemode=False):
 
     print "Final image will be {0}x{1}. (That's {2} bytes!)".format(
             width, height, width*height*4)
+    print "Don't worry though, that's just the memory requirements"
+    print "The final png will be much smaller"
 
     # Oh god create a giant ass image
     worldimg = Image.new("RGBA", (width, height))
@@ -110,8 +113,8 @@ def render_world(worlddir, cavemode=False):
     print "Sorting chunks..."
     all_chunks.sort(key=lambda x: x[1]-x[0])
 
-    print "Starting chunk processors..."
+    print "Starting up {0} chunk processors...".format(procs)
-    pool = multiprocessing.Pool(processes=3)
+    pool = multiprocessing.Pool(processes=procs)
     resultsmap = {}
     for chunkx, chunky, chunkfile in all_chunks:
         result = pool.apply_async(chunk.render_and_save, args=(chunkfile,),
@@ -143,7 +146,7 @@ def render_world(worlddir, cavemode=False):
         # Draw the image sans alpha layer, using the alpha layer as a mask. (We
         # don't want the alpha layer actually drawn on the image, this pastes
         # it as if it was a layer)
-        worldimg.paste(chunkimg.convert("RGB"), (imgx, imgy), chunkimg.split()[3])
+        worldimg.paste(chunkimg.convert("RGB"), (imgx, imgy), chunkimg)
 
         processed += 1