Create an idquake character encoding.

It just does a 1:1 charmap conversion of quake text, purely to allow python
to read arbitrary qc code.

tools/io_qfmap/entityclass.py

@@ -22,6 +22,7 @@
 import os
 from .script import Script
 from .qfplist import pldata
+from . import quakechr
 
 MAX_FLAGS = 8
 
@@ -129,7 +130,7 @@ class EntityClassDict:
         self.path = ""
         self.entity_classes = {}
     def scan_source(self, fname):
-        text = open(fname, "rt").read()
+        text = open(fname, "rt", encoding="idquake").read()
         line = 1
         pos = 0
         while pos < len(text):

tools/io_qfmap/quakechr.py

@@ -0,0 +1,46 @@
+# vim:ts=4:et
+import codecs
+
+class Codec(codecs.Codec):
+
+    def encode(self,input,errors='strict'):
+        return codecs.charmap_encode(input,errors,encoding_map)
+
+    def decode(self,input,errors='strict'):
+        return codecs.charmap_decode(input,errors,decoding_table)
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input, final=False):
+        return codecs.charmap_encode(input,self.errors,encoding_map)[0]
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input, final=False):
+        return codecs.charmap_decode(input,self.errors,decoding_table)[0]
+
+class StreamWriter(Codec,codecs.StreamWriter):
+    pass
+
+class StreamReader(Codec,codecs.StreamReader):
+    pass
+
+def search_function(encoding):
+    if encoding != "idquake":
+        return None
+    return codecs.CodecInfo(
+        name='idquake',
+        encode=Codec().encode,
+        decode=Codec().decode,
+        incrementalencoder=IncrementalEncoder,
+        incrementaldecoder=IncrementalDecoder,
+        streamreader=StreamReader,
+        streamwriter=StreamWriter,
+    )
+
+decoding_table = [None]*256
+for i in range(256):
+    decoding_table[i] = i
+decoding_table = tuple(decoding_table)
+
+encoding_map = codecs.make_identity_dict(range(256))
+
+codecs.register(search_function)