godot-cpp/include/godot_cpp/classes/wrapped.hpp

/*************************************************************************/
/*  wrapped.hpp                                                          */
/*************************************************************************/
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/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md).   */
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#ifndef GODOT_CPP_WRAPPED_HPP
#define GODOT_CPP_WRAPPED_HPP

#include <godot_cpp/core/memory.hpp>

namespace godot {
namespace internal {
struct empty_constructor {};
} // namespace internal

typedef void GodotObject;

// Base for all engine classes, to contain the pointer to the engine instance.
class Wrapped {
	friend class GDExtensionBinding;

	// Private constructor, this should not be created directly by users.
	Wrapped(GodotObject *p_owner) :
			_owner(p_owner) {}

protected:
	Wrapped() = default;
	Wrapped(internal::empty_constructor empty) {}

public:
	// Must be public but you should not touch this.
	GodotObject *_owner = nullptr;
};

} // namespace godot

#define GDCLASS(m_class, m_inherits)                                                                               \
private:                                                                                                           \
	friend class ClassDB;                                                                                          \
                                                                                                                   \
	using SelfType = m_class;                                                                                      \
                                                                                                                   \
protected:                                                                                                         \
	static void (*_get_bind_methods())() {                                                                         \
		return &m_class::_bind_methods;                                                                            \
	}                                                                                                              \
                                                                                                                   \
	m_class(godot::GodotObject *owner) : m_inherits(godot::internal::empty_constructor()) {                        \
		_owner = owner;                                                                                            \
	}                                                                                                              \
                                                                                                                   \
	m_class(godot::internal::empty_constructor empty) : m_inherits(empty) {}                                       \
                                                                                                                   \
	template <class T>                                                                                             \
	static void register_virtuals() {                                                                              \
		m_inherits::register_virtuals<T>();                                                                        \
	}                                                                                                              \
                                                                                                                   \
public:                                                                                                            \
	static void initialize_class() {                                                                               \
		static bool initialized = false;                                                                           \
		if (initialized) {                                                                                         \
			return;                                                                                                \
		}                                                                                                          \
		m_inherits::initialize_class();                                                                            \
		if (m_class::_get_bind_methods() != m_inherits::_get_bind_methods()) {                                     \
			_bind_methods();                                                                                       \
			m_inherits::register_virtuals<m_class>();                                                              \
		}                                                                                                          \
		initialized = true;                                                                                        \
	}                                                                                                              \
                                                                                                                   \
	static const char *get_class_static() {                                                                        \
		return #m_class;                                                                                           \
	}                                                                                                              \
                                                                                                                   \
	static const char *get_parent_class_static() {                                                                 \
		return #m_inherits;                                                                                        \
	}                                                                                                              \
                                                                                                                   \
	static GDExtensionClassInstancePtr create(void *data) {                                                        \
		return (GDExtensionClassInstancePtr)godot::Memory::alloc_static(sizeof(m_class));                          \
	}                                                                                                              \
                                                                                                                   \
	static void free(void *data, GDExtensionClassInstancePtr ptr) {                                                \
		godot::memdelete(reinterpret_cast<m_class *>(ptr));                                                        \
	}                                                                                                              \
                                                                                                                   \
	static void set_object_instance(GDExtensionClassInstancePtr p_instance, GDNativeObjectPtr p_object_instance) { \
		memnew_placement((void *)p_instance, m_class((godot::GodotObject *)p_object_instance));                    \
	}                                                                                                              \
                                                                                                                   \
	static void *___binding_create_callback(void *p_token, void *p_instance) {                                     \
		return memnew(m_class((godot::GodotObject *)p_instance));                                                  \
	}                                                                                                              \
	static void ___binding_free_callback(void *p_token, void *p_instance, void *p_binding) {                       \
		memdelete((m_class *)p_binding);                                                                           \
	}                                                                                                              \
	static GDNativeBool ___binding_reference_callback(void *p_token, void *p_instance, GDNativeBool p_reference) { \
		return true;                                                                                               \
	}                                                                                                              \
	static constexpr GDNativeInstanceBindingCallbacks ___binding_callbacks = {                                     \
		___binding_create_callback,                                                                                \
		___binding_free_callback,                                                                                  \
		___binding_reference_callback,                                                                             \
	};                                                                                                             \
                                                                                                                   \
private:

// Don't use this for your classes, use GDCLASS() instead.
#define GDNATIVE_CLASS(m_class, m_inherits)                                                                        \
protected:                                                                                                         \
	static void (*_get_bind_methods())() {                                                                         \
		return nullptr;                                                                                            \
	}                                                                                                              \
	m_class(godot::internal::empty_constructor empty) : m_inherits(empty) {}                                       \
                                                                                                                   \
public:                                                                                                            \
	static void initialize_class() {}                                                                              \
                                                                                                                   \
	static const char *get_class_static() {                                                                        \
		return #m_class;                                                                                           \
	}                                                                                                              \
                                                                                                                   \
	static const char *get_parent_class_static() {                                                                 \
		return #m_inherits;                                                                                        \
	}                                                                                                              \
                                                                                                                   \
	static void *___binding_create_callback(void *p_token, void *p_instance) {                                     \
		m_class *obj = memnew(m_class(godot::internal::empty_constructor()));                                      \
		obj->_owner = (godot::GodotObject *)p_instance;                                                            \
		return obj;                                                                                                \
	}                                                                                                              \
	static void ___binding_free_callback(void *p_token, void *p_instance, void *p_binding) {                       \
		memdelete((m_class *)p_binding);                                                                           \
	}                                                                                                              \
	static GDNativeBool ___binding_reference_callback(void *p_token, void *p_instance, GDNativeBool p_reference) { \
		return true;                                                                                               \
	}                                                                                                              \
	static constexpr GDNativeInstanceBindingCallbacks ___binding_callbacks = {                                     \
		___binding_create_callback,                                                                                \
		___binding_free_callback,                                                                                  \
		___binding_reference_callback,                                                                             \
	};                                                                                                             \
                                                                                                                   \
private:

#endif // ! GODOT_CPP_WRAPPED_HPP