EntityX sprite movement example

sprite.cc

// Compile with: c++ -std=c++11 -lentityx -lsfml-graphics t.cc
#include "SFML/Graphics.hpp"
#include "entityx/entityx.h"

using namespace entityx;

struct Movement : public Component<Movement> {
  sf::Vector2f position, direction;
};

struct Sprite : public Component<Sprite> {
  sf::Sprite sprite;
};


struct MovementSystem : public System<MovementSystem> {
  void update(entityx::EntityManager &es, entityx::EventManager &events,
              double dt) override {
    ComponentHandle<Movement> movement;
    for (Entity entity : es.entities_with_components(movement)) {
      movement->position += movement->direction;
    }
  }
};


struct SpriteSystem : public System<SpriteSystem> {
  void update(entityx::EntityManager &es, entityx::EventManager &events,
              double dt) override {
    ComponentHandle<Movement> movement;
    ComponentHandle<Sprite> sprite;
    for (Entity entity : es.entities_with_components(movement, sprite)) {
      // Move the sprite to its new position.
      sprite->sprite.setPosition(movement->position);
      // Do any other sprite-related stuff...
    }
  }
};


struct Level : public EntityX {
  Level() {
    systems.add<MovementSystem>();
    systems.add<SpriteSystem>();
  }

  void update(double dt) {
    systems.update<MovementSystem>(dt);
    systems.update<SpriteSystem>(dt);
  }
};

int main() {
  Level level;

  for (int i = 0; i < 100; i++) {
    level.update(0.1);
  }
}