func New() (world *World) {
world = new(World)
world.Manifold = space.NewManifold()
world.terrain = make(map[space.Location]Terrain)
world.Spatial = space.NewIndex()
world.actors = []entity.Entity{}
world.nextActors = []entity.Entity{}
return
}
func New() (result *Anim) {
result = new(Anim)
result.index = space.NewIndex()
return
}