require 'ruby-processing' class RotateRectangles < Processing::App def setup color_mode HSB, 100 background 0 no_stroke end def draw 5.times do |i| i += 1 fill 30, i*20, 99 sz = 60 - i*10 rect 0, 0, sz, sz end end end RotateRectangles.new :title => "Rotate Rectangles", :width => 400, :height => 400