def upgrade(self):
     if self.level < Tower.PLUTONIUM:
         self.state = Tower.IDLE
         self.level += 1
         frs = parse_spritesheet(util.enums.RES +
                                 "spritesheets/" +
                                 str(self.name) + "_" +
                                 str(self.level) +
                                 "_ss.png")
         for f in range(len(frs)):
             self.frames[f] = frs[f]
         self.frame = 0
         self.srf = self.frames[self.frame]
         self.add_to_bg()
 def __init__(self):
     Tower.__init__(self, parse_spritesheet(util.enums.RES +
                                            "spritesheets/" +
                                            "proj_0_ss.png"),
                    10, 15, 5, "proj", 3)