ECSify

ECSify is yet another library implementing Entity-Component-System. It is header-only and uses C++23 features!

Usage

To create the world we should build it first:

#include "ecsify/component.h"
#include "ecsify/world_builder.h"

struct Position : ecsify::ComponentMixin<1> {
  float x, y;
};

struct Velocity : ecsify::ComponentMixin<2> {
  float x, y;
};

void MoveSystem(ecsify::World &world);

auto BuildTheWorld() {
  return ecsify::WorldBuilder{}
             .Component<Position>()
             .Component<Velocity>()
             .System(MoveSystem)
             .Build();
}

And now it's easy to create entities and attach components!

#include "ecsify/entity.h"
#include "ecsify/world.h"

ecsify::Entity CreateTurtle(ecsify::World &world) {
  ecsify::Entity turtle = world.Add();
  world.Add<Position>(turtle);
  world.Get<Position>(turtle) = Position{.x = 0, .y = 0};
  world.Add<Velocity>(turtle);
  world.Get<Velocity>(turtle) = Velocity{.x = 1, .y = 1};
  return turtle;
}

Then we are to write a system, which works on the created entities and components:

void MoveTurtles(ecsify::World &world) {
    for (auto [entt, pos, vel] : world.Query<ecsify::Entity, Position, Velocity>()) {
      pos.x += vel.x;
      pos.y += vel.y;
      std::cout << "Turtle #" << entt.id() << " moved to (" << pos.x << ", " << pos.y << ")\n";
    }
}