 class Example extends fk.client.Sketch
   Vec2 = fk.math.Vec2
+  State = fk.physics.State
+
+  rng = new fk.math.Random()
+
+  cMouse = 0
 
   setup: ->
 #    console.log "w #{@width} h #{@height}"

    @timer = new fk.Timer()
    @tempo = new fk.Tempo()

    @physics = new fk.physics.Physics()

    # use 2D particles

    # draw
    @background(0)

#    @fill(255)
    for particle in @physics.particles
      if particle.state == State.ALIVE
        life = 1 - (particle.age / particle.lifetime)
        @fill 255, life
        @rect particle.position.x, particle.position.y, particle.size, particle.size

    @fill cMouse
    @rect this.mouseX, this.mouseY, 5, 5
