Nature of Code examples now ported to ruby

Thanks to Pierre-Pat, Shiffmans the nature of code examples have now been ported to ruby-processing, get them here. Naturally enough PVectors were retained in the examples (the code after all originally comes from Dan Shiffman). I am not a big fan of the PVector class (which I think is trying to do too much, which is why I created the vecmath library for ruby-processing) so here is one of examples that could easily use the Vec2D class instead of PVector:-

# The Nature of Code
# http://natureofcode.com
# NOC_1_11_motion101_acceleration_array

load_library :vecmath

class Mover
  TOP_SPEED = 6
  attr_reader :location, :velocity, :topspeed_squared

  def initialize(width, height)
    @location = Vec2D.new(rand(width/2), rand(height/2))
    @velocity = Vec2D.new(0, 0)
    @topspeed_squared = TOP_SPEED * TOP_SPEED
  end

  def update
    mouse = Vec2D.new(mouse_x, mouse_y)
    acceleration = mouse - location
    acceleration.normalize!
    acceleration *= 0.2

    @velocity += acceleration
    @velocity.set_mag(TOP_SPEED) if velocity.mag_squared > topspeed_squared
    @location += velocity
  end

  def display
    stroke(0)
    stroke_weight(2)
    fill(127)
    ellipse(location.x, location.y, 48, 48)
  end
end

def setup
  size(800, 200)
  @movers = Array.new(20) { Mover.new(width, height) }
end

def draw
  background(255)

  @movers.each do |mover|
    mover.update
    mover.display
  end
end