     @buildings = []
 
   draw_scene: ->
-    @clear()
-    @draw_the_sun()
-    @draw_buildings()
-    @draw_gorillas()
+    unless @empty
+      @clear()
+      @draw_the_sun()
+      @redraw_buildings()
+      @draw_gorillas()
+    else
+      @empty = false
+      @draw_the_sun()
+      @draw_buildings()
+      @draw_gorillas()
+
+  redraw_buildings:()->
+    for pos in [0...9]
+      @buildings[pos].redraw()
 
   draw_buildings:()->
     position = 0


class Painter
  constructor: ->
    @canvas = document.getElementById "gorillas"
    @context = @canvas.getContext "2d"
    @color = '#00FFFF'

    @height = @base_height + y
    @context.fillRect @position_at_x(), @position_at_y(), @width, @height
    @build_windows(@position_at_x(), @position_at_y())

  redraw: ->
    @draw(@x, @y)

  build_windows:(x, y) ->
    times = Math.round (@height)/31
