Store a unit -> location map instead.

Author: GraylinKim

sc2reader/events/__init__.py

@@ -2,3 +2,4 @@
 from base import *
 from game import *
 from message import *
+from tracker import *

sc2reader/events/tracker.py

@@ -498,8 +498,8 @@ def __init__(self, frames, data):
         #: An ordered list of unit/point data interpreted as below.
         self.items = data[1]
 
-        #: A list of units that had their position updated by this event
-        self.units = list()
+        #: A dict mapping of units that had their position updated to their positions
+        self.units = dict()
 
         #: A list of (unit_index, (x,y)) derived from the first_unit_index and items
         self.positions = list()
@@ -516,7 +516,7 @@ def load_context(self, replay):
             if unit_index in replay.active_units:
                 unit = replay.active_units[unit_index]
                 unit.location = (x,y)
-                self.units.append(unit)
+                self.units[unit] = unit.location
             else:
                 print "Unit moved that doesn't exist!"