Point math for finding voronoi edges

point.rb

class Point
  attr_accessor :x, :y
  def initialize(x,y)
    @x = x.to_f
    @y = y.to_f
  end
  
  def pointize_args(x_or_point, y = nil)
    if x_or_point.is_a?(Point)
      x_or_point
    else
      Point[x_or_point, y]
    end
  end
  
  def distance_from(*args)
    pt = pointize_args(*args)
    Math.sqrt(((pt.x - @x).abs ** 2) + ((pt.y - @y).abs ** 2))
  end
  
  def midpoint(*args)
    pt = pointize_args(*args)
    Point[(pt.x + @x)/2, (pt.y+@y)/2]
  end
  
  def to_s
    "<Point #{@x},#{@y}>"
  end
  
  def sort_closest(*points)
    points.sort_by {|p,q| distance_from(p) <=> distance_from(q)}
  end
  
  class << self
    def [](x,y)
      new(x,y)
    end
    
    def polygonal_midpoint(*points)
      dnm = points.length
      _x = points.inject(0) {|s,i| s + i.x} / dnm
      _y = points.inject(0) {|s,i| s + i.y} / dnm
      self[_x, _y]
    end
  end
end


point_1 = Point[50, 50]
point_2 = Point[30, 30]
point_3 = Point[80, 60]

puts Point.polygonal_midpoint(point_1, point_2, point_3)