Component Lifecycle

A Component is the smallest functional unit in SAPIEN. The behavior of a component is determined by 2 lifecycle functions on_add_to_scene() and on_remove_from_scene()

on_add_to_scene

on_add_to_scene() is called once immediately after the component is added to a scene. Specifically, it is called when the following 3 conditions all become true component.enabled, component.entity is not None, component.entity.scene is not None. For example, adding an entity with the component to a scene, adding the component to an entity in a scene, or enabling the component on an entity in a scene.

The implementation of this function should register itself to a suitable system of the scene.

on_remove_from_scene

on_remove_from_scene() is called immediately after the condition above are no longer all true. For example, disabling a component, or removing the parent entity of the component from the scene.

The implementation of this function should unregister itself from the system.