can now specify a chunk cache directory manually

chunk.py

@@ -64,12 +64,12 @@ def get_skylight_array(level):
 transparent_blocks = set([0, 6, 8, 9, 18, 20, 37, 38, 39, 40, 50, 51, 52, 53,
     59, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 74, 75, 76, 77, 79, 83, 85])
 
-def render_and_save(chunkfile, cave=False):
+def render_and_save(chunkfile, cachedir, cave=False):
     """Used as the entry point for the multiprocessing workers (since processes
     can't target bound methods) or to easily render and save one chunk
     
     Returns the image file location"""
-    a = ChunkRenderer(chunkfile)
+    a = ChunkRenderer(chunkfile, cachedir)
     try:
         return a.render_and_save(cave)
     except Exception, e:
@@ -80,19 +80,38 @@ def render_and_save(chunkfile, cave=False):
         print
         print "You pressed Ctrl-C. Exiting..."
         # Raise an exception that is an instance of Exception. Unlike
-        # KeyboardInterrupt, that will kill the process instead of having it
+        # KeyboardInterrupt, this will re-raise in the parent, killing the
-        # propagate the exception back to the parent process.
+        # entire program, instead of this process dying and the parent waiting
+        # forever for it to finish.
         raise Exception()
 
 class ChunkRenderer(object):
-    def __init__(self, chunkfile):
+    def __init__(self, chunkfile, cachedir):
+        """Make a new chunk renderer for the given chunkfile.
+        chunkfile should be a full path to the .dat file to process
+        cachedir is a directory to save the resulting chunk images to
+        """
         if not os.path.exists(chunkfile):
             raise ValueError("Could not find chunkfile")
         self.chunkfile = chunkfile
         destdir, filename = os.path.split(self.chunkfile)
-        self.destdir = os.path.abspath(destdir)
         self.blockid = ".".join(filename.split(".")[1:3])
 
+        # Cachedir here is the base directory of the caches. We need to go 2
+        # levels deeper according to the chunk file. Get the last 2 components
+        # of destdir and use that
+        moredirs, dir2 = os.path.split(destdir)
+        _, dir1 = os.path.split(moredirs)
+        self.cachedir = os.path.join(cachedir, dir1, dir2)
+
+        if not os.path.exists(self.cachedir):
+            try:
+                os.makedirs(self.cachedir)
+            except OSError, e:
+                import errno
+                if e.errno != errno.EEXIST:
+                    raise
+
     def _load_level(self):
         """Loads and returns the level structure"""
         if not hasattr(self, "_level"):
@@ -127,12 +146,12 @@ class ChunkRenderer(object):
         # Get the name of the existing image. No way to do this but to look at
         # all the files
         oldimg = oldimg_path = None
-        for filename in os.listdir(self.destdir):
+        for filename in os.listdir(self.cachedir):
             if filename.startswith("img.{0}.{1}.".format(self.blockid,
                     "cave" if cave else "nocave")) and \
                     filename.endswith(".png"):
                 oldimg = filename
-                oldimg_path = os.path.join(self.destdir, oldimg)
+                oldimg_path = os.path.join(self.cachedir, oldimg)
                 break
         return oldimg, oldimg_path
 
@@ -141,7 +160,6 @@ class ChunkRenderer(object):
         the same directory as the source image. If the file already exists and
         is up to date, this method doesn't render anything.
         """
-        destdir = self.destdir
         blockid = self.blockid
 
         oldimg, oldimg_path = self._find_oldimage(cave)
@@ -169,7 +187,7 @@ class ChunkRenderer(object):
                 self._hash_blockarray(),
                 )
 
-        dest_path = os.path.join(destdir, dest_filename)
+        dest_path = os.path.join(self.cachedir, dest_filename)
 
         if oldimg:
             if dest_filename == oldimg:

gmap.py

@@ -28,7 +28,7 @@ import world
 import quadtree
 
 helptext = """
-%prog [-p PROCS] [-d] <World # / Path to World> <tiles dest dir>
+%prog [OPTIONS] <World # / Path to World> <tiles dest dir>
 """
 
 def main():
@@ -40,6 +40,7 @@ def main():
     parser.add_option("-p", "--processes", dest="procs", help="How many chunks to render in parallel. A good number for this is the number of cores in your computer. Default %s" % cpus, default=cpus, action="store", type="int")
     parser.add_option("-z", "--zoom", dest="zoom", help="Sets the zoom level manually instead of calculating it. This can be useful if you have outlier chunks that make your world too big. This value will make the highest zoom level contain (2**ZOOM)^2 tiles", action="store", type="int")
     parser.add_option("-d", "--delete", dest="delete", help="Clear all caches. Next time you render your world, it will have to start completely over again. This is probably not a good idea for large worlds. Use this if you change texture packs and want to re-render everything.", action="store_true")
+    parser.add_option("--cachedir", dest="cachedir", help="Sets the directory where the Overviewer will save chunk images, which is an intermediate step before the tiles are generated. You must use the same directory each time to gain any benefit from the cache. If not set, this defaults to your world directory.")
 
     options, args = parser.parse_args()
 
@@ -59,15 +60,21 @@ def main():
             parser.print_help()
             sys.exit(1)
 
+    if not options.cachedir:
+        cachedir = worlddir
+    else:
+        cachedir = options.cachedir
 
     if len(args) != 2:
+        if options.delete:
+            return delete_all(cachedir, None)
         parser.error("Where do you want to save the tiles?")
     destdir = args[1]
 
     if options.delete:
-        return delete_all(worlddir, destdir)
+        return delete_all(cachedir, destdir)
     # First generate the world's chunk images
-    w = world.WorldRenderer(worlddir)
+    w = world.WorldRenderer(worlddir, cachedir)
     w.go(options.procs)
 
     # Now generate the tiles
@@ -87,6 +94,7 @@ def delete_all(worlddir, tiledir):
                 os.unlink(filepath)
 
     # Now delete all /hash/ files in the tile dir.
+    if tiledir:
         for dirpath, dirnames, filenames in os.walk(tiledir):
             for f in filenames:
                 if f.endswith(".hash"):

world.py

@@ -58,10 +58,14 @@ def _convert_coords(chunks):
     return mincol, maxcol, minrow, maxrow, chunks_translated
 
 class WorldRenderer(object):
-    """Renders a world's worth of chunks"""
+    """Renders a world's worth of chunks.
-    def __init__(self, worlddir):
+    worlddir is the path to the minecraft world
+    cachedir is the path to a directory that should hold the resulting images.
+    It may be the same as worlddir (which used to be the default)"""
+    def __init__(self, worlddir, cachedir):
         self.worlddir = worlddir
         self.caves = False
+        self.cachedir = cachedir
 
     def go(self, procs):
         """Starts the render. This returns when it is finished"""
@@ -109,7 +113,7 @@ class WorldRenderer(object):
             # Skip the multiprocessing stuff
             print "Rendering chunks synchronously since you requested 1 process"
             for i, (col, row, chunkfile) in enumerate(chunks):
-                result = chunk.render_and_save(chunkfile, cave=self.caves)
+                result = chunk.render_and_save(chunkfile, self.cachedir, cave=self.caves)
                 results[(col, row)] = result
                 if i > 0:
                     if 1000 % i == 0 or i % 1000 == 0:
@@ -119,7 +123,8 @@ class WorldRenderer(object):
             pool = multiprocessing.Pool(processes=processes)
             asyncresults = []
             for col, row, chunkfile in chunks:
-                result = pool.apply_async(chunk.render_and_save, args=(chunkfile,),
+                result = pool.apply_async(chunk.render_and_save,
+                        args=(chunkfile,self.cachedir),
                         kwds=dict(cave=self.caves))
                 asyncresults.append((col, row, result))