# File lib/as_physics.rb, line 37
    def initialize(*objs)
      @shapes = objs
      @body = CP::Body.new(0.0, 0.0)
      
      mass = 0.0
      moment = 0.0
      @shapes.each do|shape|
        mass += shape.body.m
        moment += shape.body.i
        shape.body = @body
      end
      
      @body.m = mass
      @body.i = moment
    end