Retained Shape (FBO) in Ruby Processing

Now we are cooking, this example demonstrated running ruby-processing compiled with a pre-released version of processing-2.0b7. Further it demonstrates the use of the FBO to vastly improve performance. All sketches run with this ruby-processing hack are very noisy (complaining about ambigous overloaded java methods eg background and fill).

BOX_SIZE = 20
MARGIN = BOX_SIZE * 2
DEPTH = 400
FINT = 3

attr_reader :box_fill, :grid, :fcount, :lastm, :frate

def setup
  size(640, 360, P3D)
  frame_rate(60)
  @fcount = 0
  @lastm = 0
  no_smooth()
  no_stroke()
  @grid = create_shape(GROUP)
  # Build grid using multiple translations 
  (-(DEPTH/2 + MARGIN) ... (DEPTH/2 - MARGIN)).step(BOX_SIZE) do |i|
    (-(height + MARGIN) ... (height - MARGIN)).step(BOX_SIZE) do |j|
      (-(width + MARGIN) ... (width - MARGIN)).step(BOX_SIZE) do |k|
        # Base fill color on counter values, abs function 
        # ensures values stay within legal range
        @box_fill = color(i.abs.to_i, j.abs.to_i, k.abs.to_i, 50)
        cube = create_shape(BOX, BOX_SIZE.to_f, BOX_SIZE.to_f, BOX_SIZE.to_f)
        cube.fill(box_fill)
        cube.translate(k, j, i)
        grid.add_child(cube)
      end
    end
  end
end

def draw
  background(255)
  hint(DISABLE_DEPTH_TEST)
  # Center and spin grid
  push_matrix()
  translate(width/2, height/2, -DEPTH)
  rotate_y(frame_count * 0.01)
  rotate_x(frame_count * 0.01)
  shape(grid)
  pop_matrix()
  hint(ENABLE_DEPTH_TEST)
  @fcount += 1
  m = millis()
  if (m - lastm > 1000 * FINT)
    @frate = fcount / FINT
    @fcount = 0
    @lastm = m
    puts("fps: #{frate}")
  end
  fill(0)
  text("fps: #{frate}", 10, 20)
end