grrrisu/Simulator

module Sim
  module Matrix
    class Globe < Base

      # returns a position within the bounderies, stopping at the bounderies
      def check_bounderies x, y
        x = width() -1 if x < 0
        y = height() -1 if y < 0
        x = 0 if x >= width
        y = 0 if y >= height
        [x, y]
      end

      # returns a position within the bounderies going around the world
      def around_position x, y
        # Array[] handles negative index until -size
        if (0...width) === x && (0...height) === y
          [x, y]
        else
          if x >= width
            x -= width
          elsif x < 0
            x += width
          end
          if y >= height
            y -= height
          elsif y < 0
            y += height
          end
          around_position x, y
        end
      end

      def get_field x, y
        super(*around_position(x, y))
      end
      alias [] get_field

      def set_field x, y, value
        super(*around_position(x, y), value)
      end
      alias []= set_field

    end
  end
end