// Wrappers for extension functions that must be located using vkGetInstanceProcAddr
VkResult CreateDebugReportCallbackEXT(VkInstance instance, const VkDebugReportCallbackCreateInfoEXT* pCreateInfo,
const VkAllocationCallbacks* pAllocator, VkDebugReportCallbackEXT* pCallback) {
	auto func = (PFN_vkCreateDebugReportCallbackEXT) vkGetInstanceProcAddr(instance, "vkCreateDebugReportCallbackEXT");
	if(func != nullptr) {
		return func(instance, pCreateInfo, pAllocator, pCallback);
	} else {
		return VK_ERROR_EXTENSION_NOT_PRESENT;
	}
}

void DestroyDebugReportCallbackEXT(VkInstance instance, VkDebugReportCallbackEXT callback, const VkAllocationCallbacks* pAllocator) {
	auto func = (PFN_vkDestroyDebugReportCallbackEXT) vkGetInstanceProcAddr(instance, "vkDestroyDebugReportCallbackEXT");
	if(func != nullptr) {
		func(instance, callback, pAllocator);
	}
}

// VDeleter utility class that automatically destroys objects when they fall out of scope.
template <typename T>
class VDeleter {
public:
    VDeleter() : VDeleter([](T, VkAllocationCallbacks*) {}) {}

    VDeleter(std::function<void(T, VkAllocationCallbacks*)> deletef) {
        this->deleter = [=](T obj) { deletef(obj, nullptr); };
    }

    VDeleter(const VDeleter<VkInstance>& instance, std::function<void(VkInstance, T, VkAllocationCallbacks*)> deletef) {
        this->deleter = [&instance, deletef](T obj) { deletef(instance, obj, nullptr); };
    }

    VDeleter(const VDeleter<VkDevice>& device, std::function<void(VkDevice, T, VkAllocationCallbacks*)> deletef) {
        this->deleter = [&device, deletef](T obj) { deletef(device, obj, nullptr); };
    }

    ~VDeleter() {
        cleanup();
    }

    const T* operator &() const {
        return &object;
    }

    T* replace() {
        cleanup();
        return &object;
    }

    operator T() const {
        return object;
    }

    void operator=(T rhs) {
        if (rhs != object) {
            cleanup();
            object = rhs;
        }
    }

    template<typename V>
    bool operator==(V rhs) {
        return object == T(rhs);
    }

private:
    T object{VK_NULL_HANDLE};
    std::function<void(T)> deleter;

    void cleanup() {
        if (object != VK_NULL_HANDLE) {
            deleter(object);
        }
        object = VK_NULL_HANDLE;
    }
};

struct QueueFamilyIndices {
    int graphicsFamily = -1;
    int presentFamily = -1;

    bool isComplete() {
        return graphicsFamily >= 0 && presentFamily >= 0;
    }
};

struct SwapChainSupportDetails {
    VkSurfaceCapabilitiesKHR capabilities;
    std::vector<VkSurfaceFormatKHR> formats;
    std::vector<VkPresentModeKHR> presentModes;
};