Ruby Processing Context Free DSL (how to do a cfdg PATH)

One way to create an equivalent of PATH (from C++ cfdg) is to use the processing shape facilities, here I have created a custom line-strip hexagon shape (ie no fill). But of course you could just as easily create a filled shape.


#########################
# hextube.rb
#########################
load_library 'context_free'

def setup_the_hextube
  @hexa = ContextFree.define do
    ############ Begin defining custom terminal, as a hexagon (path C++ cfdg)
    class << self    
      define_method(:hexagon) do |some_options|
        size, options = *self.get_shape_values(some_options)
        rot = (options[:rotation])? options[:rotation]: 0
        no_fill
        stroke(*options[:color])
        stroke_weight(size/30)
        begin_shape
        6.times do |i|
          vertex(size * Math.cos(Math::PI * i/3 + rot), size * Math.sin(Math::PI * i/3 + rot))
        end
        end_shape(CLOSE)
      end
    end
    ########### End definition of custom terminal 'hexagon'
    rule :hextube do
      hexa :brightness => 1.0
    end

    rule :hexa do
      hexagon :size => 1, :brightness => 1.0
      hexa :size => 0.9, :rotation => 5
    end
  end
end

def setup
  size 800, 800
  background 0
  smooth
  setup_the_hextube
  draw_it
end

def draw_it
  @hexa.render :hextube, :start_x => width/2, :start_y => height/2,
               :size => height/2.1, :color => [0, 1, 1, 0.5]
end