ruby-processing and fisica

talk_pile.rb

require 'ruby-processing'

# ruby port of http://www.ricardmarxer.com/fisica/examples/ContactResize/applet/ContactResize.pde

class TalkPileApp < Processing::App

  load_libraries :fisica
  java_import "fisica.Fisica"
  java_import "fisica.FWorld"
  java_import "fisica.FDrawable"
  java_import "fisica.FBody"
  java_import "fisica.FCircle"
  java_import "fisica.FContact"

  def setup
    size 400, 400
    smooth

    Fisica.init self
    @world = FWorld.new
    @world.setGravity 0, 100
    @world.setEdges
  end

  def draw
    background 255

    if (frameCount % 50 == 0)
      sz = random(30, 60);
      b = FCircle.new(sz);
      b.setPosition(random(0+30, width-30), 50);
      b.setVelocity(0, 100);
      b.setRestitution(0.7);
      b.setDamping(0.01);
      b.setNoStroke();
      b.setFill(200, 30, 90);
      @world.add(b);
    end

    @world.draw();
    @world.step();
  end

  def contactEnded(c)
    if !c.getBody1().isStatic()
      b = c.getBody1();
      if b.getSize() > 5
        b.setSize(b.getSize()*0.9);
      end
    end

    if !c.getBody2().isStatic()
      b = c.getBody2();
      if b.getSize()>5
        b.setSize(b.getSize()*0.9);
      end
    end

  end

end

TalkPileApp.new :title => "Talk Pile"

For processing-2.0, sketch should be "bare" delete line 1, 5, 61 and 63, java_import might be a synonym for it but I would also replace it with include_package. Since processing-2.0 you can use rand(0+30 .. width-30) in place of processing random.