chart.rb

class Point
  attr_accessor :x, :y
  def initialize(x, y)
    @x, @y = x, y
  end
end

ENTRY_COUNT = 40
INCREMENT = 0.01

class Entry
  
  attr_accessor :rank, :position
  
  def initialize(rank)
    @rank = rank
    @size = (width/2)/ENTRY_COUNT
    @radius = rank * @size
    @position = Point.new(width/2, height/2 - rank)
  end
  
  def render(p)
    (1..20).to_a.each do |i|
      fill 0.8, 0.6
      x = (width/2) + @radius * Math.cos(p + (i*INCREMENT*2))
      y = (height/2) + @radius * Math.sin(p + (i*INCREMENT*2))
      oval(x, y, @size/2, @size/2)
    end
  end
end

def setup
  size 800, 800
  
  color_mode RGB, 1.0
  frame_rate 30
  smooth
  
  @entries = (1..ENTRY_COUNT).to_a.map { |i| Entry.new(i) }
end

$p = 0  
def draw
  background 0
  $p += INCREMENT
  @entries.each do |entry|
    entry.render($p)
  end
end