ContextFreeArt gem for propane

#!/usr/bin/env jruby
require 'propane'
require 'cf3propane'

class City < Propane::App

  def setup_the_city
    @city = Propane::ContextFree.define do

      shape :neighborhood do
        split do
          block x: -0.25, y: -0.25
          rewind
          block x: 0.25, y: -0.25
          rewind
          block x: 0.25, y: 0.25
          rewind
          block x: -0.25, y: 0.25
        end
      end

      shape :block do
        buildings size: 0.85
      end

      shape :block, 5 do
        neighborhood size: 0.5, rotation: rand(-PI..PI), hue: rand(2), brightness: rand(0.75..1.75)
      end

      shape :block, 0.1 do
        # Do nothing
      end

      shape :buildings do
        square
      end

    end
  end

  def settings
    size 600, 600
  end

  def setup
    sketch_title 'City'
    setup_the_city
    @background = color 255, 255, 255
    draw_it
  end

  def draw
    # Do nothing
  end

  def draw_it
    background @background
    @city.render :neighborhood,
                 start_x: width/2, start_y: height/2,
                 size: height/2.5, color: [0.1, 0.1, 0.1]
  end

  def mouse_clicked
    draw_it
  end
end

City.new