Game Engine Architecture

#include <iostream>
#include <vector>
#include <memory>
#include <string>
#include <unordered_map>
using namespace std;

// Component base
struct Component {
    virtual ~Component() = default;
    virtual void update(float deltaTime) {}
};

// Position component
struct Transform : Component {
    float x, y;
    float rotation = 0.0f;
    Transform(float x = 0, float y = 0) : x(x), y(y) {}
    
    void update(float dt) override {
        // Physics update would go here
    }
};

// Velocity component
struct Velocity : Component {
    float vx, vy;
    Velocity(float vx = 0, float vy = 0) : vx(vx), vy(vy) {}
};

// Entity (game object)
class Entity {
    string name;
    unordered_map<string, unique_ptr<Component>> components;
public:
    Entity(const string &name) : name(name) {}

    template <typename T, typename... Args>
    T &addComponent(Args&&... args) {
        auto comp = make_unique<T>(forward<Args>(args)...);
        T &ref = *comp;
        components[typeid(T).name()] = move(comp);
        return ref;
    }

    template <typename T>
    T *getComponent() {
        auto it = components.find(typeid(T).name());
        if (it != components.end())
            return static_cast<T*>(it->second.get());
        return nullptr;
    }

    void update(float dt) {
        // Apply velocity to transform
        auto *transform = getComponent<Transform>();
        auto *velocity = getComponent<Velocity>();
        if (transform && velocity) {
            transform->x += velocity->vx * dt;
            transform->y += velocity->vy * dt;
        }
    }

    const string &getName() const { return name; }
};

// Game loop
class Game {
    vector<unique_ptr<Entity>> entities;
    bool running = true;
public:
    Entity &createEntity(const string &name) {
        entities.push_back(make_unique<Entity>(name));
        return *entities.back();
    }

    void update(float deltaTime) {
        for (auto &entity : entities) {
            entity->update(deltaTime);
        }
    }

    void run() {
        float dt = 1.0f / 60.0f;  // 60 FPS
        for (int frame = 0; frame < 5; frame++) {
            update(dt);
            // render() would go here
        }
    }
};

int main() {
    Game game;
    
    auto &player = game.createEntity("Player");
    player.addComponent<Transform>(100.0f, 200.0f);
    player.addComponent<Velocity>(50.0f, 0.0f);

    auto &enemy = game.createEntity("Enemy");
    enemy.addComponent<Transform>(400.0f, 200.0f);
    enemy.addComponent<Velocity>(-30.0f, 10.0f);

    game.run();
    
    auto *pos = player.getComponent<Transform>();
    if (pos) cout << "Player pos: (" << pos->x << ", " << pos->y << ")" << endl;

    return 0;
}