Entitas for Python

.. image:: https://travis-ci.org/Aenyhm/entitas-python.svg?branch=master :target: https://travis-ci.org/Aenyhm/entitas-python

entitas-python is a port of Entitas ECS for C# and Unity_.

Overview

Components

.. code-block:: python

  Position = namedtuple('Position', 'x y')
  Health = namedtuple('Health', 'value')
  Movable = namedtuple('Movable', '')

Entity
~~~~~~

.. code-block:: python

  entity.add(Position, 3, 7)
  entity.add(Health, 100)
  entity.add(Movable)

  entity.replace(Position, 10, 100)
  entity.replace(Health, entity.get(Health).value - 1)

  entity.remove(Position)

  has_pos = entity.has(Position)
  movable = entity.has(Movable)

Context
~~~~~~~

.. code-block:: python

  context = Context()
  entity = context.create_entity()
  entity.add(Movable)

  entities = context.entities
  for e in entities:
      # do something

Group
~~~~~

.. code-block:: python

  context.get_group(Matcher(Position)).entities

  def move(entity, new_comp):
      # do something

  context.get_group(Matcher(Position)).on_entity_added += move

Entity Collector

.. code-block:: python

group = context.get_group(Matcher(Position)) collector = Collector() collector.add(group, GroupEvent.added)

later

for e in collector.collected_entities: # do something with all the entities # that have been collected to this point of time

collector.clear_collected_entities()

stop observing

collector.deactivate()

Entity Index

.. code-block:: python

  Person = namedtuple('Person', 'name age')
  group = context.get_group(Matcher(Person))

  # get a set of 42-year-old Person
  index = EntityIndex(Person, group, 'age')
  context.add_entity_index(index)
  entities = context.get_entity_index(Person).get_entities(42)

  # get the Person named "John"
  primary_index = PrimaryEntityIndex(Person, group, 'name')
  context.add_entity_index(primary_index)
  entity = context.get_entity_index(Person).get_entity('John')

Processors
~~~~~~~~~~

.. code-block:: python

  class RenderDisplay(ExecuteProcessor):

      def execute(self):
          pygame.display.update()


  # Initialize, Cleanup and TearDown are also available.


  class Move(ReactiveProcessor):

      def __init__(self, context):
          super().__init__(context)
          self._context = context

      def get_trigger(self):
          return {Matcher(Position): GroupEvent.ADDED}

      def filter(self, entity):
          return entity.has(Position, Movable)

      def react(self, entities):
          for entity in entities:
              # use entity.get(Position).x & entity.get(Position).y

Setup example

.. code-block:: python

context = Context()

processors = Processors() processors.add(StartGame(context)) processors.add(InputProcessors(context)) processors.add(RenderDisplay()) processors.add(DestroyEntity(context))

processors.initialize() processors.activate_reactive_processors()

main loop

running = True while running: processors.execute() processors.cleanup()

  if EmitInput.quit:
      break

processors.clear_reactive_processors() processors.tear_down()

quit()

.. _Entitas ECS for C# and Unity : https://github.com/sschmid/Entitas-CSharp