fix pbox2d examples

Author: monkstone

external_library/gem/pbox2d/bumpy_surface_noise.rb

@@ -9,9 +9,8 @@
 
 def setup
   sketch_title 'Bumpy Surface Noise'
-  smooth 4
   # Initialize box2d physics and create the world
-  @box2d = WorldBuilder(app: self, gravity: [0, -20])
+  @box2d = WorldBuilder.build(app: self, gravity: [0, -20])
   # to later set a custom gravity
   # box2d.gravity([0, -20])
   # Create the empty list
@@ -40,4 +39,5 @@ def draw
 
 def settings
   size(500, 300)
+  smooth 4
 end

external_library/gem/pbox2d/lib/shape_system.rb

@@ -1,3 +1,5 @@
+require 'forwardable'
+
 module Runnable
   def run
     reject! { |item| item.done }

external_library/gem/pbox2d/liquidy.rb

@@ -3,6 +3,7 @@
 require_relative 'lib/boundary'
 attr_reader :box2d, :boundaries, :systems
 
+# holder for vector values
 Vect = Struct.new(:x, :y)
 
 def setup

external_library/gem/pbox2d/polygons.rb

@@ -6,6 +6,7 @@
 
 attr_reader :box2d, :boundaries, :system
 
+# holder for vector values
 Vect = Struct.new(:x, :y)
 
 def setup