World Builder

The WorldBuilder module is a factory, that provides a flexible options signature, and hides the post intialization of Box2D. Note that app: is a required keyword.

module WorldBuilder
  def self.build(app:, **opts)
    b2d = Box2D.new(app)
    b2d.init_options(opts)
    b2d.create_world
    b2d
  end
end

Usage: Strictly the gravity: option is optional here, it is only used to demonstrate a valid argument. No acceleration in horizontal plane and negative (falling) acceleration in vertical plane.

@box2d = WorldBuilder.build(app: self, gravity: [0, -20])

See :init_options and :defaults methods for a list of available options