Add a very simple wad reader.

It supports only MipTex data (for automatic data conversion), and it's very
fragile, but it will do for now.

tools/io_qfmap/wad.py

@@ -0,0 +1,80 @@
+# vim:ts=4:et
+
+from struct import unpack, pack
+
+def read_byte(file, count=1):
+    size = 1 * count
+    data = file.read(size)
+    data = unpack("<%dB" % count, data)
+    if count == 1:
+        return data[0]
+    return data
+
+def read_int(file, count=1):
+    size = 4 * count
+    data = file.read(size)
+    data = unpack("<%di" % count, data)
+    if count == 1:
+        return data[0]
+    return data
+
+def read_string(file, size):
+    data = file.read(size)
+    s = ""
+    for c in data:
+        s = s + chr(c)
+    return s
+
+class WadFile:
+    class LumpInfo:
+        def __init__(self, filepos, disksize, size, type, compression):
+            self.filepos = filepos
+            self.disksize = disksize
+            self.size = size
+            self.type = type
+            self.compression = compression
+        pass
+    class MipTex:
+        def __init__(self, data):
+            width, height = unpack("<ii", data[16:24])
+            self.width, self.height = width, height
+            offsets = unpack("<4i", data[24:40])
+            self.texels = [None] * 4
+            self.texels[0] = data[offsets[0]:offsets[0] + width * height]
+            self.texels[1] = data[offsets[1]:offsets[1] + width * height >> 2]
+            self.texels[2] = data[offsets[2]:offsets[2] + width * height >> 4]
+            self.texels[3] = data[offsets[3]:offsets[3] + width * height >> 6]
+
+    def __init__(self):
+        self.lumps = {}
+    @classmethod
+    def load(cls, path):
+        f = open(path,"rb")
+        id = read_string(f, 4)
+        numlumps = read_int(f)
+        infotableofs = read_int(f)
+        if id == 'WAD2':
+            wf = WadFile()
+            wf.path = path
+            f.seek(infotableofs, 0)
+            for i in range(numlumps):
+                filepos, disksize, size = read_int (f, 3)
+                type, compression, pad1, pad2 = read_byte(f, 4)
+                name = read_string(f, 16)
+                name = name.split("\0")[0]
+                wf.lumps[name] = WadFile.LumpInfo(filepos, disksize, size,
+                                                  type, compression)
+            return wf
+        return None
+    def getLump(self, name):
+        return self.lumps[name]
+    def getData(self, name):
+        lump = self.getLump(name)
+        f = open(self.path, "rb")
+        f.seek(lump.filepos, 0)
+        data = f.read(lump.disksize)
+        if lump.type == 68:
+            return WadFile.MipTex(data)
+        else:
+            return data
+        return data