new contrib script to help re-rendering specific parts of a map

See the top of the file for usage details

contrib/rerenderBlocks.py

@@ -0,0 +1,56 @@
+#!/usr/bin/python
+
+'''
+This is used to force the regeneration of any chunks that contain a certain
+blockID.  The output is a chunklist file that is suitable to use with the
+--chunklist option to gmap.py.
+
+Example:
+
+python contrib/rerenderBlocks.py --ids=46,79,91 --world=world/> chunklist.txt
+    python gmap.py --chunklist=chunklist.txt world/ output_dir/
+
+This will rerender any chunks that contain either TNT (46), Ice (79), or 
+a Jack-O-Lantern (91)
+'''
+
+from optparse import OptionParser
+
+import sys
+sys.path.insert(0,".")
+
+import nbt
+from chunk import get_blockarray_fromfile
+import os
+import re
+
+parser = OptionParser()
+parser.add_option("--ids", dest="ids", type="string")
+parser.add_option("--world", dest="world", type="string")
+
+
+options, args = parser.parse_args()
+
+if not options.world or not options.ids:
+    parser.print_help()
+    sys.exit(1)
+
+if not os.path.exists(options.world):
+    raise Exception("%s does not exist" % options.world)
+
+ids = map(lambda x: int(x),options.ids.split(","))
+sys.stderr.write("Searching for these blocks: %r...\n" % ids)
+
+
+matcher = re.compile(r"^c\..*\.dat$")
+
+for dirpath, dirnames, filenames in os.walk(options.world):
+    for f in filenames:
+        if matcher.match(f):
+            full = os.path.join(dirpath, f)
+            blocks = get_blockarray_fromfile(full)
+            for i in ids:
+                if i in blocks:
+                    print full
+                    break
+