API:MumbleLink/Example implementation (Python)

Tested with Python 3.5.

import ctypes
import mmap
import time


class Link(ctypes.Structure):
    _fields_ = [
        ("uiVersion", ctypes.c_uint32),           # 4 bytes
        ("uiTick", ctypes.c_ulong),               # 4 bytes
        ("fAvatarPosition", ctypes.c_float * 3),  # 3*4 bytes
        ("fAvatarFront", ctypes.c_float * 3),     # 3*4 bytes
        ("fAvatarTop", ctypes.c_float * 3),       # 3*4 bytes
        ("name", ctypes.c_wchar * 256),           # 512 bytes
        ("fCameraPosition", ctypes.c_float * 3),  # 3*4 bytes
        ("fCameraFront", ctypes.c_float * 3),     # 3*4 bytes
        ("fCameraTop", ctypes.c_float * 3),       # 3*4 bytes
        ("identity", ctypes.c_wchar * 256),       # 512 bytes
        ("context_len", ctypes.c_uint32),         # 4 bytes
        # ("context", ctypes.c_ubyte * 256),      # 256 bytes, see below
        # ("description", ctypes.c_wchar * 2048), # 4096 bytes, always empty
    ]


class Context(ctypes.Structure):
    _fields_ = [
        ("serverAddress", ctypes.c_ubyte * 28),   # 28 bytes
        ("mapId", ctypes.c_uint32),               # 4 bytes
        ("mapType", ctypes.c_uint32),             # 4 bytes
        ("shardId", ctypes.c_uint32),             # 4 bytes
        ("instance", ctypes.c_uint32),            # 4 bytes
        ("buildId", ctypes.c_uint32),             # 4 bytes
        ("uiState", ctypes.c_uint32),             # 4 bytes
        ("compassWidth", ctypes.c_uint16),        # 2 bytes
        ("compassHeight", ctypes.c_uint16),       # 2 bytes
        ("compassRotation", ctypes.c_float),      # 4 bytes
        ("playerX", ctypes.c_float),              # 4 bytes
        ("playerY", ctypes.c_float),              # 4 bytes
        ("mapCenterX", ctypes.c_float),           # 4 bytes
        ("mapCenterY", ctypes.c_float),           # 4 bytes
        ("mapScale", ctypes.c_float),             # 4 bytes
        ("processId", ctypes.c_uint32),           # 4 bytes
        ("mountIndex", ctypes.c_uint8),           # 1 byte
    ]


class MumbleLink:
    data = Link
    context = Context
    
    def __init__(self):
        self.size_link = ctypes.sizeof(Link)
        self.size_context = ctypes.sizeof(Context)
        size_discarded = 256 - self.size_context + 4096 # empty areas of context and description
        
        # GW2 won't start sending data if memfile isn't big enough so we have to add discarded bits too
        memfile_length = self.size_link + self.size_context + size_discarded
        
        self.memfile = mmap.mmap(fileno=-1, length=memfile_length, tagname="MumbleLink")
    
    def read(self):
        self.memfile.seek(0)
        
        self.data = self.unpack(Link, self.memfile.read(self.size_link))
        self.context = self.unpack(Context, self.memfile.read(self.size_context))
    
    def close(self):
        self.memfile.close()
    
    @staticmethod
    def unpack(ctype, buf):
        cstring = ctypes.create_string_buffer(buf)
        ctype_instance = ctypes.cast(ctypes.pointer(cstring), ctypes.POINTER(ctype)).contents
        return ctype_instance


def main():
    ml = MumbleLink()
    
    # Loop until data could be read.
    ml.read()
    while not ml.data.uiTick:
        time.sleep(1)
        ml.read()
    
    # do stuff ...
    print("identity:", ml.data.identity)
    print("position:", [round(ml.context.playerX), round(ml.context.playerY)])
    
    ml.close()


if __name__ == "__main__":
    main()