en:toolworks:docs:apparatus:ecs

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Introduction to ECS+

ECS+ is a newer data-driven programming paradigm based on ECS and implemented in Apparatus.

Talking about OOP (object-oriented programming), we consider our practical task as multiplicity of special abstract things. In terms of Unreal Engine these abstractions are mainly called Objects (or UObjects code-wise). Furthermore we apply a principle like an inheritance upon them. We create some main abstraction layer called ‘Base class’, define some properties (i.e. variables and functions) and by deriving from that class we can create other abstractions which in turn get all the parent properties and define their own additional, distinctive ones. The most popular example for that approach is a tree of animal inheritance, where the base class represent any animal existing, but the others (derived from the base one) represent some separate animal sorts and kinds:

By using the base class properties we can change the current state of the objects in the derived class. But the problem is the game logic can become too scattered across those classes and layers.

A solution to this game development problem is an approach called ECS. Apparatus provides all of the basic ECS idioms and even more. To be unambiguous the framework it uses a different naming scheme as compared to classic ECS. Here is the list of analogous terms:

ECS Term Apparatus Term
Entity Subject
Component Detail
System Mechanic
A group of Systems Mechanism
Archetype Fingerprint
Chunk Belt

At a lower level, Subjective is an interface and any class that implements it may be called a Subject. There are several subjects already implemented in the framework:

  • SubjectiveActorComponent (based on ActorComponent),
  • SubjectiveUserWidget (based on UserWidget),
  • SubjectiveActor (based on Actor).

Those should be sufficient for the most cases, but you can easily implement your own additional subject classes in C++.

The Mechanical class is also an interface, with the most useful mechanisms already implemented:

  • MechanicalActor (inherited from Actor),
  • MechanicalGameModeBase (GameModeBase),
  • MechanicalGameMode (GameMode).

You would hardly ever need to implement your own mechanisms. Should you wish to, you can also do it in C++.

  • en/toolworks/docs/apparatus/ecs.1617832625.txt.gz
  • Last modified: 2021/04/08 00:57
  • by vladius