Watch Mode Working in Ruby-Processing-3.0

Hey not only can I run sketches in ruby-processing-3.0 using my toxiclibs gem but I can also run them in watch mode, my only problem is can't dispose of the frame of the old sketch (has black background, which is frozen so probably not eating resources). Here I am using jEdit as my ruby-processing ide, which has advantages if you you want test different java versions etc...:-

# A ruby processing-3.0 sketch
#
#
# This example implements a custom VolumetricSpace using an implicit function
# to calculate each voxel. This is slower than the default array or HashMap
# based implementations, but also has much less memory requirements and so might
# be an interesting and more viable approach for very highres voxel spaces
# (e.g. >32 million voxels). This implementation here also demonstrates how to
# achieve an upper boundary on the iso value (in addition to the one given and
# acting as lower threshold when computing the iso surface)
#
# Usage:
# move mouse to rotate camera
# w: toggle wireframe on/off
# -/=: zoom in/out
# l: apply laplacian mesh smooth
#
#

#
# Copyright (c) 2010 Karsten Schmidt & ruby-processing version Martin Prout 2012
# This sketch relies on a custom toxiclibscore library for PovRAY export
#
# This library is free software you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation either
# version 2.1 of the License, or (at your option) any later version.
#
# http://creativecommons.org/licenses/LGPL/2.1/
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#

require 'toxiclibs'
load_library :vecmath
RES = 64
ISO = 0.2
MAX_ISO = 0.66
attr_reader :mesh, :gfx, :curr_zoom, :is_wire_frame

def setup
  sketch_title 'Isosurface'
  ArcBall.init(self)
  @gfx = Gfx::ToxiclibsSupport.new(self)
  vol = EvaluatingVolume.new(TVec3D.new(400, 400, 400), RES, RES, RES, MAX_ISO)
  surface = Volume::HashIsoSurface.new(vol)
  @mesh = WETriangleMesh.new
  surface.compute_surface_mesh(mesh, ISO)
  @is_wire_frame = false
end

def settings
  size(720, 720, P3D)
end

def draw
  background(200, 0, 200)
  if is_wire_frame
    no_fill
    stroke(255)
  else
    fill(255)
    no_stroke
    define_lights
    lights
  end
  @gfx.mesh(mesh, true)
end

def key_pressed
  case key
  when 'w', 'W'
    @is_wire_frame = !is_wire_frame
  when 'l', 'L'
    LaplacianSmooth.new.filter(mesh, 1)
  when 's', 'S'
    save_frame('implicit.png')
  end
end

def define_lights
  ambient_light(50, 50, 50)
  point_light(30, 30, 30, 200, -150, 0)
  directional_light(0, 30, 50, 1, 0, 0)
  spot_light(30, 30, 30, 0, 40, 200, 0, -0.5, -0.5, PI / 2, 2)
end

# Creating a volumetric space class
#
class EvaluatingVolume < Volume::VolumetricSpace
  include Processing::Proxy
  attr_reader :upper_bound
  FREQ = PI * 3.8

  def initialize(scal_vec, resX, resY, resZ, upper_limit)
    super(scal_vec, resX, resY, resZ)
    @upper_bound = upper_limit
  end

  def clear
    # nothing to do here
  end

  def getVoxelAt(i)
    getVoxel(i % resX, (i % sliceRes) / resX, i / sliceRes)
  end

  def getVoxel(x, y, z)  # can't overload so we renamed
    val = 0
    if x > 0 && x < resX1 && y > 0 && y < resY1 && z > 0 && z < resZ1
      xx = x * 1.0 / resX - 0.5  # NB: careful about integer division !!!
      yy = y * 1.0 / resY - 0.5
      zz = z * 1.0 / resZ - 0.5
      val = cos(xx * FREQ) * sin(yy * FREQ) + cos(yy * FREQ) * sin(zz* FREQ) + cos(zz * FREQ) * sin(xx * FREQ)
      # val = sin(xx * FREQ) + cos(yy * FREQ) + sin(zz * FREQ)
      # val = sin(xx * FREQ) * (xx * FREQ) + sin(yy * FREQ) * (yy * FREQ) + sin(zz * FREQ) * (zz * FREQ)
      val = 0 if val > upper_bound
    end
    val
  end
end