Implement `callable_mp()` and `callable_mp_static()`

4 files changed, 310 insertions, 0 deletions

diff --git a/include/godot_cpp/core/binder_common.hpp b/include/godot_cpp/core/binder_common.hpp
index 09da62b..a51e15e 100644
--- a/include/godot_cpp/core/binder_common.hpp
+++ b/include/godot_cpp/core/binder_common.hpp
@@ -277,6 +277,60 @@ void call_with_variant_args_retc_helper(T *p_instance, R (T::*p_method)(P...) co
 }
 
 template <class T, class... P>
+void call_with_variant_args(T *p_instance, void (T::*p_method)(P...), const Variant **p_args, int p_argcount, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_helper<T, P...>(p_instance, p_method, p_args, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class R, class... P>
+void call_with_variant_args_ret(T *p_instance, R (T::*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_ret_helper<T, R, P...>(p_instance, p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class R, class... P>
+void call_with_variant_args_retc(T *p_instance, R (T::*p_method)(P...) const, const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_retc_helper<T, R, P...>(p_instance, p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class... P>
 void call_with_variant_args_dv(T *p_instance, void (T::*p_method)(P...), const GDExtensionConstVariantPtr *p_args, int p_argcount, GDExtensionCallError &r_error, const std::vector<Variant> &default_values) {
 #ifdef DEBUG_ENABLED
 	if ((size_t)p_argcount > sizeof...(P)) {
@@ -538,6 +592,42 @@ void call_with_ptr_args_static_method(void (*p_method)(P...), const GDExtensionC
 	call_with_ptr_args_static_method_helper<P...>(p_method, p_args, BuildIndexSequence<sizeof...(P)>{});
 }
 
+template <class R, class... P>
+void call_with_variant_args_static_ret(R (*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_static_ret<R, P...>(p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class... P>
+void call_with_variant_args_static_ret(void (*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_static<P...>(p_method, p_args, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
 template <class R, class... P, size_t... Is>
 void call_with_variant_args_static_ret(R (*p_method)(P...), const Variant **p_args, Variant &r_ret, GDExtensionCallError &r_error, IndexSequence<Is...>) {
 	r_error.error = GDEXTENSION_CALL_OK;
diff --git a/include/godot_cpp/core/class_db.hpp b/include/godot_cpp/core/class_db.hpp
index af81037..c974fa4 100644
--- a/include/godot_cpp/core/class_db.hpp
+++ b/include/godot_cpp/core/class_db.hpp
@@ -40,6 +40,10 @@
 
 #include <godot_cpp/classes/class_db_singleton.hpp>
 
+// Makes callable_mp readily available in all classes connecting signals.
+// Needs to come after method_bind and object have been included.
+#include <godot_cpp/variant/callable_method_pointer.hpp>
+
 #include <list>
 #include <set>
 #include <string>
diff --git a/include/godot_cpp/godot.hpp b/include/godot_cpp/godot.hpp
index a3fae75..4561a75 100644
--- a/include/godot_cpp/godot.hpp
+++ b/include/godot_cpp/godot.hpp
@@ -164,6 +164,7 @@ extern "C" GDExtensionInterfaceObjectGetClassName gdextension_interface_object_g
 extern "C" GDExtensionInterfaceObjectCastTo gdextension_interface_object_cast_to;
 extern "C" GDExtensionInterfaceObjectGetInstanceFromId gdextension_interface_object_get_instance_from_id;
 extern "C" GDExtensionInterfaceObjectGetInstanceId gdextension_interface_object_get_instance_id;
+extern "C" GDExtensionInterfaceCallableCustomCreate gdextension_interface_callable_custom_create;
 extern "C" GDExtensionInterfaceRefGetObject gdextension_interface_ref_get_object;
 extern "C" GDExtensionInterfaceRefSetObject gdextension_interface_ref_set_object;
 extern "C" GDExtensionInterfaceScriptInstanceCreate2 gdextension_interface_script_instance_create2;
diff --git a/include/godot_cpp/variant/callable_method_pointer.hpp b/include/godot_cpp/variant/callable_method_pointer.hpp
new file mode 100644
index 0000000..bd31ea1
--- /dev/null
+++ b/include/godot_cpp/variant/callable_method_pointer.hpp
@@ -0,0 +1,215 @@
+/**************************************************************************/
+/*  callable_method_pointer.hpp                                           */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef GODOT_CALLABLE_METHOD_POINTER_HPP
+#define GODOT_CALLABLE_METHOD_POINTER_HPP
+
+#include <godot_cpp/core/binder_common.hpp>
+#include <godot_cpp/variant/variant.hpp>
+
+namespace godot {
+
+class CallableCustomMethodPointerBase {
+public:
+	virtual Object *get_object() const = 0;
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const = 0;
+};
+
+namespace internal {
+
+Callable create_custom_callable(CallableCustomMethodPointerBase *p_callable_method_pointer);
+
+} // namespace internal
+
+//
+// No return value.
+//
+
+template <class T, class... P>
+class CallableCustomMethodPointer : public CallableCustomMethodPointerBase {
+	T *instance;
+	void (T::*method)(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return instance;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args(instance, method, p_arguments, p_argcount, r_call_error);
+	}
+
+	CallableCustomMethodPointer(T *p_instance, void (T::*p_method)(P...)) {
+		instance = p_instance;
+		method = p_method;
+	}
+};
+
+template <class T, class... P>
+Callable create_custom_callable_function_pointer(T *p_instance, void (T::*p_method)(P...)) {
+	typedef CallableCustomMethodPointer<T, P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// With return value.
+//
+
+template <class T, class R, class... P>
+class CallableCustomMethodPointerRet : public CallableCustomMethodPointerBase {
+	T *instance;
+	R(T::*method)
+	(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return instance;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_ret(instance, method, p_arguments, p_argcount, r_return_value, r_call_error);
+	}
+
+	CallableCustomMethodPointerRet(T *p_instance, R (T::*p_method)(P...)) {
+		instance = p_instance;
+		method = p_method;
+	}
+};
+
+template <class T, class R, class... P>
+Callable create_custom_callable_function_pointer(T *p_instance, R (T::*p_method)(P...)) {
+	typedef CallableCustomMethodPointerRet<T, R, P...> CCMP; // Messes with memnew otherwise.
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// Const with return value.
+//
+
+template <class T, class R, class... P>
+class CallableCustomMethodPointerRetC : public CallableCustomMethodPointerBase {
+	T *instance;
+	R(T::*method)
+	(P...) const;
+
+public:
+	virtual Object *get_object() const override {
+		return instance;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_retc(instance, method, p_arguments, p_argcount, r_return_value, r_call_error);
+	}
+
+	CallableCustomMethodPointerRetC(const T *p_instance, R (T::*p_method)(P...) const) {
+		instance = const_cast<T *>(p_instance);
+		method = p_method;
+	}
+};
+
+template <class T, class R, class... P>
+Callable create_custom_callable_function_pointer(const T *p_instance, R (T::*p_method)(P...) const) {
+	typedef CallableCustomMethodPointerRetC<T, R, P...> CCMP; // Messes with memnew otherwise.
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// Static method with no return value.
+//
+
+template <class... P>
+class CallableCustomStaticMethodPointer : public CallableCustomMethodPointerBase {
+	void (*method)(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return nullptr;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_static_ret(method, p_arguments, p_argcount, r_return_value, r_call_error);
+		r_return_value = Variant();
+	}
+
+	CallableCustomStaticMethodPointer(void (*p_method)(P...)) {
+		method = p_method;
+	}
+};
+
+template <class... P>
+Callable create_custom_callable_static_function_pointer(void (*p_method)(P...)) {
+	typedef CallableCustomStaticMethodPointer<P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// Static method with return value.
+//
+
+template <class R, class... P>
+class CallableCustomStaticMethodPointerRet : public CallableCustomMethodPointerBase {
+	R(*method)
+	(P...);
+
+public:
+	virtual Object *get_object() const override {
+		return nullptr;
+	}
+
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
+		call_with_variant_args_static_ret(method, p_arguments, p_argcount, r_return_value, r_call_error);
+	}
+
+	CallableCustomStaticMethodPointerRet(R (*p_method)(P...)) {
+		method = p_method;
+	}
+};
+
+template <class R, class... P>
+Callable create_custom_callable_static_function_pointer(R (*p_method)(P...)) {
+	typedef CallableCustomStaticMethodPointerRet<R, P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_method));
+	return ::godot::internal::create_custom_callable(ccmp);
+}
+
+//
+// The API:
+//
+
+#define callable_mp(I, M) ::godot::create_custom_callable_function_pointer(I, M)
+#define callable_mp_static(M) ::godot::create_custom_callable_static_function_pointer(M)
+
+} // namespace godot
+
+#endif // GODOT_CALLABLE_METHOD_POINTER_HPP