Fish Eye Sketch in JRubyArt

# After an openprocessing sketch
# by Michael Pinn
# translated to JRubyArt by Martin Prout
# make use of built in grid and DegLut utilities
def settings
  size(640, 640)
end

def setup
  sketch_title 'Fish Eye Grid'
  noStroke
  fill(234, 46, 73)
end

def draw
  background(51, 55, 69)
  translate(width / 2, height / 2)
  # The amount of layers
  grid(120, 360, 20, 30) do |j, q|
    h = j * 2 + 5
    # The amount of shapes per layer
    x2 = DegLut.sin(q + h) * j
    y2 = DegLut.cos(q + h) * j
    delta = map1d(dist(x2, y2, 0, 0), 0..120, 0..360).floor
    push_matrix
    translate(x2, y2)
    scale(map1d(j, 0..180, 0.1..0.4))
    rotate((-q - h).radians)
    begin_shape
    # The shape, made from openprocessing.org/sketch/162912
    (0..180).step(5) do |i|
      calc_vertex(i, delta)
    end
    36.downto(0) do |z| # no negative step
      calc_vertex(z * 5, delta, -1)
    end
    end_shape(CLOSE)
    pop_matrix
  end
  # save_frame(data_path('####.png'))
end

def calc_vertex(angle, delta, sign = 1)
  phi = sign * DegLut.sin(angle) * angle / 3
  theta = DegLut.sin((angle + frame_count * 3 + delta)) * 50
  vertex(phi - theta, angle * 2)
end