diff options
| -rw-r--r-- | CMakeLists.txt | 2 | ||||
| -rw-r--r-- | README.md | 42 | ||||
| -rw-r--r-- | entityx/Manager.cc (renamed from entityx/World.cc) | 8 | ||||
| -rw-r--r-- | entityx/Manager.h (renamed from entityx/World.h) | 8 | ||||
| -rw-r--r-- | entityx/System_test.cc | 24 |
5 files changed, 42 insertions, 42 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt index 253cc70..afb3146 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -59,7 +59,7 @@ set(CMAKE_CXX_FLAGS_MINSIZEREL "-Os -DNDEBUG") set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG") set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -g") -set(sources entityx/Components.cc entityx/System.cc entityx/Event.cc entityx/Entity.cc entityx/World.cc) +set(sources entityx/Components.cc entityx/System.cc entityx/Event.cc entityx/Entity.cc entityx/Manager.cc) add_library(entityx STATIC ${sources}) add_library(entityx_shared SHARED ${sources}) @@ -1,18 +1,18 @@ # EntityX - A fast, type-safe C++ Entity-Component system -Entity-Component (EC) systems are a form of decomposition that completely decouple entity logic and data from the entity "objects" themselves. The [Evolve your Hierarchy](http://cowboyprogramming.com/2007/01/05/evolve-your-heirachy/) article provides a solid overview of EC systems. +Entity-Component (EC) systems are a form of decomposition that completely decouples entity logic and data from the entity "objects" themselves. The [Evolve your Hierarchy](http://cowboyprogramming.com/2007/01/05/evolve-your-heirachy/) article provides a solid overview of EC systems and why you should use them. -EntityX is an EC system that uses C++11 features to provide type-safe component management, event delivery, etc. +EntityX is an EC system that uses C++11 features to provide type-safe component management, event delivery, etc. It was built during the creation of a 2D space shooter. ## Overview -In EntityX data associated with an entity is called a `Component`. `Systems` use components to implement behavior and can utilize as many components as necessary. An `EventManager` allows systems to interact without being tightly coupled. Finally, a `World` object ties all of the systems together for convenience. +In EntityX data associated with an entity is called a `Component`. `Systems` encapsulate logic and can use as many component types as necessary. An `EventManager` allows systems to interact without being tightly coupled. Finally, a `Manager` object ties all of the systems together for convenience. As an example, a physics system might need *position* and *mass* data, while a collision system might only need *position* - the data would be logically separated into two components, but usable by any system. The physics system might emit *collision* events whenever two entities collide. ## Tutorial - +Following is some skeleton code that implements `Position` and `Direction` components, a `MovementSystem` using these data components, and a `CollisionSystem` that emits `Collision` events when two entities collide. ### Entities @@ -66,15 +66,6 @@ entities.assign(entity, position); #### Querying entities and their components -To retrieve a component associated with an entity use ``EntityManager::component()``: - -``` -boost::shared_ptr<Position> position = entities.component<Position>(); -if (position) { - // Do stuff with position -} -``` - To query all components with a set of components assigned use ``EntityManager::entities_with_components()``. This method will return only those entities that have *all* of the specified components associated with them, assigning each component pointer to the corresponding component instance: ``` @@ -85,6 +76,15 @@ for (auto entity : entities.entities_with_components(position, direction)) { } ``` +To retrieve a component associated with an entity use ``EntityManager::component()``: + +``` +boost::shared_ptr<Position> position = entities.component<Position>(); +if (position) { + // Do stuff with position +} +``` + ### Systems (implementing behavior) Systems implement behavior using one or more components. Implementations are subclasses of `System<T>` and *must* implement the `update()` method, as shown below. @@ -94,8 +94,8 @@ A basic movement system might be implemented with something like the following: ``` struct MovementSystem : public System<MovementSystem> { void update(EntityManager &es, EventManager &events, double dt) override { - Position *position; - Direction *direction; + boost::shared_ptr<Position> position; + boost::shared_ptr<Direction> direction; for (auto entity : es.entities_with_components(position, direction)) { position->x += direction->x; position->y += direction->y; @@ -154,7 +154,7 @@ struct DebugCollisions : public Receiver<DebugCollisions> { }; ``` -Note that a single class can receive any number of types of events by implementing a ``receive(const EventType &)`` method for each event type. +***Note:** a single class can receive any number of types of events by implementing a ``receive(const EventType &)`` method for each event type.* Finally, we subscribe our receiver to collision events: @@ -168,14 +168,14 @@ DebugCollisions debug_collisions; events.subscribe<Collision>(debug_collisions); ``` -### World (tying it all together) +### Manager (tying it all together) -Managing systems, components and entities can be streamlined by subclassing `World`. It is not necessary, but it provides callbacks for configuring systems, initializing entities and the world, and so on. +Managing systems, components and entities can be streamlined by subclassing `Manager`. It is not necessary, but it provides callbacks for configuring systems, initializing entities, and so on. -To use it, subclass `World` and implement `configure()`, `initialize()` and `update()`: +To use it, subclass `Manager` and implement `configure()`, `initialize()` and `update()`: ``` -class GameWorld : public World { +class GameManager : public Manager { protected: void configure() { system_manager.add<MovementSystem>(); @@ -202,7 +202,7 @@ class GameWorld : public World { EntityX has the following build and runtime requirements: -- A C++ compiler that supports a basic set of C++11 features (eg. recent clang, recent gcc). +- A C++ compiler that supports a basic set of C++11 features (ie. recent clang, recent gcc, but **NOT** Visual C++). - [CMake](http://cmake.org/) - [Boost](http://boost.org) `1.48.0` or higher (links against `boost::signals`). - [Glog](http://code.google.com/p/google-glog/) (tested with `0.3.2`). diff --git a/entityx/World.cc b/entityx/Manager.cc index 05a10d7..012e06f 100644 --- a/entityx/World.cc +++ b/entityx/Manager.cc @@ -8,17 +8,17 @@ * Author: Alec Thomas <alec@swapoff.org> */ -#include "World.h" +#include "Manager.h" namespace entity { -void World::start() { +void Manager::start() { configure(); system_manager.configure(); initialize(); } -void World::run() { +void Manager::run() { running_ = true; double dt; timer_.restart(); @@ -29,7 +29,7 @@ void World::run() { } } -void World::stop() { +void Manager::stop() { running_ = false; } diff --git a/entityx/World.h b/entityx/Manager.h index 0cca1e2..66ace3f 100644 --- a/entityx/World.h +++ b/entityx/Manager.h @@ -17,10 +17,10 @@ namespace entity { -class World { +class Manager { public: - World() : entity_manager(event_manager), system_manager(entity_manager, event_manager) {} - virtual ~World() {} + Manager() : entity_manager(event_manager), system_manager(entity_manager, event_manager) {} + virtual ~Manager() {} void start(); void run(); @@ -30,7 +30,7 @@ class World { /** * Configure the world. * - * This is called once on World initialization. It is typically used to add Systems to the world, load permanent + * This is called once on Manager initialization. It is typically used to add Systems to the world, load permanent * resources, global configuration, etc. */ virtual void configure() = 0; diff --git a/entityx/System_test.cc b/entityx/System_test.cc index 0c54dab..2dad4d9 100644 --- a/entityx/System_test.cc +++ b/entityx/System_test.cc @@ -12,7 +12,7 @@ #include <vector> #include <glog/logging.h> #include <gtest/gtest.h> -#include "entityx/World.h" +#include "entityx/Manager.h" #include "entityx/System.h" @@ -52,7 +52,7 @@ class MovementSystem : public System<MovementSystem> { }; -class TestWorld : public entity::World { +class TestManager : public entity::Manager { public: std::vector<Entity> entities; @@ -81,31 +81,31 @@ class TestWorld : public entity::World { class SystemManagerTest : public ::testing::Test { protected: - TestWorld world; + TestManager manager; virtual void SetUp() override { - world.start(); + manager.start(); } }; TEST_F(SystemManagerTest, TestConstructSystemWithArgs) { - world.sm().add<MovementSystem>("movement"); - world.sm().configure(); + manager.sm().add<MovementSystem>("movement"); + manager.sm().configure(); - ASSERT_EQ("movement", world.sm().system<MovementSystem>()->label); + ASSERT_EQ("movement", manager.sm().system<MovementSystem>()->label); } TEST_F(SystemManagerTest, TestApplySystem) { - world.sm().add<MovementSystem>(); - world.sm().configure(); + manager.sm().add<MovementSystem>(); + manager.sm().configure(); - world.sm().update<MovementSystem>(0.0); + manager.sm().update<MovementSystem>(0.0); shared_ptr<Position> position; shared_ptr<Direction> direction; - for (auto entity : world.entities) { - world.em().unpack<Position, Direction>(entity, position, direction); + for (auto entity : manager.entities) { + manager.em().unpack<Position, Direction>(entity, position, direction); if (position && direction) { ASSERT_FLOAT_EQ(2.0, position->x); ASSERT_FLOAT_EQ(3.0, position->y); |