Entities × Renderers (OpenGL, Vulkan, Headless)

#include <print>
#include <string>

// Naive design: combines every entity type with every graphics API via inheritance.
// Result: N entities * M renderers = N * M classes!

class NaiveEntity {
public:
    virtual ~NaiveEntity() = default;
    virtual void render() = 0;
};

// 1. HeroSprite variations
class OpenGlHeroSprite : public NaiveEntity {
    std::string name_;
    float x_, y_;
public:
    OpenGlHeroSprite(std::string name, float x, float y)
        : name_(std::move(name)), x_(x), y_(y) {}
    void render() override {
        std::println("[OpenGL] glBind(hero.png) -> glDrawQuad at ({:.1f}, {:.1f}) for Hero '{}'", x_, y_, name_);
    }
};

class VulkanHeroSprite : public NaiveEntity {
    std::string name_;
    float x_, y_;
public:
    VulkanHeroSprite(std::string name, float x, float y)
        : name_(std::move(name)), x_(x), y_(y) {}
    void render() override {
        std::println("[Vulkan] vkCmdBindPipeline -> vkCmdDrawQuad at ({:.1f}, {:.1f}) for Hero '{}'", x_, y_, name_);
    }
};

class HeadlessHeroSprite : public NaiveEntity {
    std::string name_;
    float x_, y_;
public:
    HeadlessHeroSprite(std::string name, float x, float y)
        : name_(std::move(name)), x_(x), y_(y) {}
    void render() override {
        std::println("[Headless] Record draw: Hero '{}' at ({:.1f}, {:.1f})", name_, x_, y_);
    }
};

// 2. BossSprite variations (duplicated for each backend)
class OpenGlBossSprite : public NaiveEntity {
    std::string name_;
public:
    explicit OpenGlBossSprite(std::string name) : name_(std::move(name)) {}
    void render() override {
        std::println("[OpenGL] glDrawBoss '{}' with rage aura", name_);
    }
};

class VulkanBossSprite : public NaiveEntity {
    std::string name_;
public:
    explicit VulkanBossSprite(std::string name) : name_(std::move(name)) {}
    void render() override {
        std::println("[Vulkan] vkDrawBoss '{}' with rage aura", name_);
    }
};

class HeadlessBossSprite : public NaiveEntity {
    std::string name_;
public:
    explicit HeadlessBossSprite(std::string name) : name_(std::move(name)) {}
    void render() override {
        std::println("[Headless] Record draw: Boss '{}'", name_);
    }
};

// 3. ParticleBanner variations (3 more classes...)
class OpenGlParticleBanner : public NaiveEntity {
public:
    void render() override { std::println("[OpenGL] glDrawParticles"); }
};
class VulkanParticleBanner : public NaiveEntity {
public:
    void render() override { std::println("[Vulkan] vkDrawParticles"); }
};
class HeadlessParticleBanner : public NaiveEntity {
public:
    void render() override { std::println("[Headless] Record draw: Particles"); }
};

int main() {
    // 3 entities * 3 renderers = 9 subclasses already!
    // Adding DirectX12 requires writing 3 new classes.
    // Adding NpcSprite requires writing 4 new classes (one per backend).
    OpenGlHeroSprite heroGl("Valeria", 10.0f, 20.0f);
    VulkanBossSprite bossVk("Dragon Lord");
    HeadlessParticleBanner bannerHl;

    heroGl.render();
    bossVk.render();
    bannerHl.render();

    return 0;
}