cfnptr / ecsm

Easy to use and fast Entity Component System Manager (ECS) C++ library.

ECSM

Easy to use template based C++ Entity Component System Manager library.

The ECS pattern, or Entity-Component-System pattern, is a design pattern commonly used in game development and simulation software. It is a way to organize and manage the behavior and data of objects within a system. The ECS pattern is particularly useful for systems with a large number of entities that can have varying and dynamic sets of attributes.

See the documentation

Features

• Straightforward template architecture
• Custom event creation support
• Cache friendly linear pools
• Acceptable compilation time
• Fast component iteration
• Fast entity component access

Usage example

using namespace ecsm;

struct RigidBodyComponent final : public Component
{
    float size = 0.0f;
};

class PhysicsSystem final : public System
{
    LinearPool<RigidBodyComponent, false> components;

    PhysicsSystem(Manager* manager) : System(manager)
    {
        SUBSCRIBE_TO_EVENT("Update", PhysicsSystem::update);
    }
    ~PhysicsSystem() final
    {
        auto manager = getManager();
        if (manager->isRunning())
            UNSUBSCRIBE_FROM_EVENT("Update", PhysicsSystem::update);
    }

    void update()
    {
        // Process components...
    }

    const string& getComponentName() const final
    {
        static const string name = "Rigid Body";
        return name;
    }
    type_index getComponentType() const final
    {
        return typeid(RigidBodyComponent);
    }
    ID<Component> createComponent(ID<Entity> entity) final
    {
        return ID<Component>(components.create());
    }
    void destroyComponent(ID<Component> instance) final
    {
        components.destroy(ID<RigidBodyComponent>(instance));
    }
    View<Component> getComponent(ID<Component> instance) final
    {
        return View<Component>(components.get(ID<RigidBodyComponent>(instance)));
    }
    void disposeComponents() final { components.dispose(); }

    friend class ecsm::Manager;
};

void ecsmExample()
{
    ecsm::Manager manager;

    manager.createSystem<PhysicsSystem>();
    manager.createSystem<GraphicsSystem>(false, 123);
    // ...

    manager.initialize();

    auto rigidBody = manager.createEntity();
    auto rigidBodyComponent = manager.add<RigidBodyComponent>(rigidBody);
    rigidBodyComponent->size = 1.0f;

    manager.start();
}

Supported operating systems

• Windows
• macOS
• Ubuntu (Linux)

Build requirements

• C++17 compiler
• Git 2.30+
• CMake 3.16+

Use building instructions to install all required tools and libraries.

CMake options

Name	Description	Default value
ECSM_BUILD_SHARED	Build ECSM shared library	ON
ECSM_BUILD_TESTS	Build ECSM library tests	ON

CMake targets

Name	Description	Windows	macOS	Linux
ecsm-static	Static ECSM library	.lib	.a	.a
ecsm-shared	Dynamic ECSM library	.dll	.dylib	.so

Cloning

git clone https://github.com/cfnptr/ecsm