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https://github.com/ikvk/ecs_pattern
ECS pattern (Entity Component System) for creating games on python
https://github.com/ikvk/ecs_pattern
architecture data-oriented-design ecs gamedev games pattern python python3
Last synced: 4 days ago
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ECS pattern (Entity Component System) for creating games on python
- Host: GitHub
- URL: https://github.com/ikvk/ecs_pattern
- Owner: ikvk
- License: apache-2.0
- Created: 2022-08-24T07:12:55.000Z (about 2 years ago)
- Default Branch: master
- Last Pushed: 2024-10-16T07:20:43.000Z (24 days ago)
- Last Synced: 2024-10-17T20:46:35.139Z (22 days ago)
- Topics: architecture, data-oriented-design, ecs, gamedev, games, pattern, python, python3
- Language: Python
- Homepage:
- Size: 27.2 MB
- Stars: 39
- Watchers: 3
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.rst
- License: LICENSE
Awesome Lists containing this project
- awesome-ccamel - ikvk/ecs_pattern - ECS pattern (Entity Component System) for creating games on python (Python)
README
.. http://docutils.sourceforge.net/docs/user/rst/quickref.html
========================================================================================================================
ecs_pattern 🚀
========================================================================================================================
Implementation of the ECS pattern (Entity Component System) for creating games.
Make a game instead of architecture for a game.
`Документация на Русском `_.
.. image:: https://img.shields.io/pypi/dm/ecs_pattern.svg?style=social
=============== ====================================================================================
Python version 3.3+
License Apache-2.0
PyPI https://pypi.python.org/pypi/ecs_pattern/
Dependencies dataclasses before 3.7, typing before 3.5
Repo mirror https://gitflic.ru/project/ikvk/ecs-pattern
=============== ====================================================================================
.. contents::
Intro
========================================================================================================================
| ECS - Entity-Component-System - it is an architectural pattern created for game development.
It is great for describing a dynamic virtual world.
Basic principles of ECS:
* Composition over inheritance
* Data separated from logic (Data Oriented Design)
| *Component* - Property with object data
| *Entity* - Container for properties
| *System* - Data processing logic
| *EntityManager* - Entity database
| *SystemManager* - Container for systems
Installation
========================================================================================================================
::
$ pip install ecs-pattern
Guide
========================================================================================================================
.. code-block:: python
from ecs_pattern import component, entity, EntityManager, System, SystemManager
* Describe components - component
* Describe entities based on components - entity
* Distribute the responsibility of processing entities by systems - System
* Store entities in entity manager - EntityManager
* Manage your systems with SystemManager
Component
------------------------------------------------------------------------------------------------------------------------
| Property with object data. Contains only data, no logic.
| The component is used as a mixin in entities.
| Use the ecs_pattern.component decorator to create components.
| Technically this is python dataclass.
.. code-block:: python
@component
class ComPosition:
x: int = 0
y: int = 0
@component
class ComPerson:
name: str
health: int
Entity
------------------------------------------------------------------------------------------------------------------------
| Container for properties. Consists of components only.
| It is forbidden to add attributes to an entity dynamically.
| Use the ecs_pattern.entity decorator to create entities.
| Technically this is python dataclass with slots=True.
.. code-block:: python
@entity
class Player(ComPosition, ComPerson):
pass
@entity
class Ball(ComPosition):
pass
System
------------------------------------------------------------------------------------------------------------------------
| Entity processing logic.
| Does not contain data about entities and components.
| Use the ecs_pattern.System abstract class to create concrete systems:
| *system.start* - Initialize the system. It is called once before the main system update cycle.
| *system.update* - Update the system status. Called in the main loop.
| *system.stop* - Stops the system. It is called once after the completion of the main loop.
| Use SystemManager to manage systems.
.. code-block:: python
class SysInit(System):
def __init__(self, entities: EntityManager):
self.entities = entities
def start(self):
self.entities.init(
TeamScoredGoalEvent(Team.LEFT),
Spark(spark_sprite(pygame.display.Info()), 0, 0, 0, 0)
)
self.entities.add(
GameStateInfo(play=True, pause=False),
WaitForBallMoveEvent(1000),
)
class SysGravitation(System):
def __init__(self, entities: EntityManager):
self.entities = entities
def update(self):
for entity_with_pos in self.entities.get_with_component(ComPosition):
if entity_with_pos.y > 0:
entity_with_pos.y -= 1
EntityManager
------------------------------------------------------------------------------------------------------------------------
| Container for entities.
| Use the ecs_pattern class.EntityManager for creating an entity manager.
| Time complexity of get_by_class and get_with_component - like a dict
| *entities.add* - Add entities.
| *entities.delete* - Delete entities.
| *entities.delete_buffer_add* - Save entities to the delete buffer to delete later.
| *entities.delete_buffer_purge* - Delete all entities in the deletion buffer and clear the buffer.
| *entities.init* - Let manager know about entities. KeyError are raising on access to unknown entities.
| *entities.get_by_class* - Get all entities of the specified classes. Respects the order of entities.
| *entities.get_with_component* - Get all entities with the specified components.
.. code-block:: python
entities = EntityManager()
entities.add(
Player('Ivan', 20, 1, 2),
Player('Vladimir', 30, 3, 4),
Ball(0, 7)
)
for entity_with_pos in entities.get_with_component(ComPosition):
print(entity_with_pos.x, entity_with_pos.y)
for player_entity in entities.get_by_class(Player):
print(player_entity.name)
entities.delete_buffer_add(player_entity)
entities.delete_buffer_purge()
entities.delete(*tuple(entities.get_by_class(Ball))) # one line del
SystemManager
------------------------------------------------------------------------------------------------------------------------
| Container for systems.
| Works with systems in a given order.
| Use the ecs_pattern.SystemManager class to manage systems.
| *system_manager.start_systems* - Initialize systems. Call once before the main systems update cycle.
| *system_manager.update_systems* - Update systems status. Call in the main loop.
| *system_manager.stop_systems* - Stop systems. Call once after the main loop completes.
.. code-block:: python
entities = EntityManager()
entities.add(
Player('Ivan', 20, 1, 2),
Player('Vladimir', 30, 3, 4),
Ball(0, 7)
)
system_manager = SystemManager([
SysPersonHealthRegeneration(entities),
SysGravitation(entities)
])
system_manager.start_systems()
while play:
system_manager.update_systems()
clock.tick(24) # *pygame clock
system_manager.stop_systems()
Examples
========================================================================================================================
* `Pong `_: game - pygame + ecs_pattern
* `Snow day `_: scene - pygame + ecs_pattern
* `Trig fall `_: commercial game - pygame + ecs_pattern + numpy
Advantages
========================================================================================================================
* Memory efficient - Component and Entity use dataclass
* Convenient search for objects - by entity class and by entity components
* Flexibility - loose coupling in the code allows you to quickly expand the project
* Modularity - the code is easy to test, analyze performance, and reuse
* Execution control - systems work strictly one after another
* Following the principles of the pattern helps to write quality code
* Convenient to parallelize processing
* Compact implementation
Difficulties
========================================================================================================================
* It can take a lot of practice to learn how to cook ECS properly
* Data is available from anywhere - hard to find errors
Newbie mistakes
========================================================================================================================
* Inheritance of components, entities, systems
* Ignoring the principles of ECS, such as storing data in the system
* Raising ECS to the absolute, no one cancels the OOP
* Adaptation of the existing project code under ECS "as is"
* Use of recursive or reactive logic in systems
* Using EntityManager.delete in get_by_class, get_with_component loops
Good Practices
========================================================================================================================
* Use "Singleton" components with data and flags
* Minimize component change locations
* Do not create methods in components and entities
* Divide the project into scenes, a scene can be considered a cycle for the SystemManager with its EntityManager
* Use packages to separate scenes
Project tree example:
::
/common_tools
__init__.py
resources.py
i18n.py
gui.py
consts.py
components.py
math.py
/menu_scene
__init__.py
entities.py
main_loop.py
surfaces.py
systems.py
/game_scene
__init__.py
entities.py
main_loop.py
surfaces.py
systems.py
main.py
Releases
========================================================================================================================
History of important changes: `release_notes.rst `_
Help the project
========================================================================================================================
* Found a bug or have a suggestion - issue / merge request 🎯
* There is nothing to help this project with - help another open project that you are using ✋
* Nowhere to put the money - spend it on family, friends, loved ones or people around you 💰
* Star the project ⭐