Merge pull request #163 from Spartan322/improve-binding

2 files changed, 196 insertions, 0 deletions

diff --git a/extension/src/openvic-extension/utility/ClassBindings.hpp b/extension/src/openvic-extension/utility/ClassBindings.hpp
new file mode 100644
index 0000000..616250b
--- /dev/null
+++ b/extension/src/openvic-extension/utility/ClassBindings.hpp
@@ -0,0 +1,90 @@
+#pragma once
+
+#include <concepts>
+#include <initializer_list>
+#include <string_view>
+#include <type_traits>
+
+#include <godot_cpp/core/class_db.hpp>
+#include <godot_cpp/variant/string_name.hpp>
+
+#include "openvic-extension/utility/StringLiteral.hpp"
+
+namespace godot {
+	class Object;
+}
+
+#define OV_BIND_METHOD(Function, ...) \
+	::OpenVic::detail::bind_method<::OpenVic::detail::get_function_name<#Function>()>(&Function __VA_OPT__(, ) __VA_ARGS__)
+
+#define OV_BIND_SMETHOD(Function, ...) \
+	::OpenVic::detail::bind_static_method<::OpenVic::detail::get_function_name<#Function>()>( \
+		get_class_static(), &Function __VA_OPT__(, ) __VA_ARGS__ \
+	)
+
+#define OV_BIND_SMETHOD_T(ClassType, Function, ...) \
+	::OpenVic::detail::bind_static_method<ClassType, ::OpenVic::detail::get_function_name<#Function>()>( \
+		&Function __VA_OPT__(, ) __VA_ARGS__ \
+	)
+
+namespace OpenVic::detail {
+	template<typename Func>
+	concept IsFunctionPointer = std::is_function_v<std::remove_pointer_t<Func>>;
+	template<typename Func>
+	concept IsMemberFunctionPointer = std::is_member_function_pointer_v<Func>;
+
+	template<StringLiteral In>
+	consteval auto get_function_name() {
+		constexpr auto result = [] {
+			constexpr auto prefix = std::string_view { "::" };
+
+			constexpr std::string_view in_sv = In;
+			constexpr auto start = in_sv.find_last_of(prefix);
+
+			if constexpr (start == std::string_view::npos) {
+				return In;
+			} else {
+				constexpr auto result = in_sv.substr(start + 1);
+				return StringLiteral<result.size()> { result };
+			}
+		}();
+
+		return result;
+	}
+
+	template<StringLiteral Name, IsMemberFunctionPointer Func, typename... DefaultsT>
+	void bind_method(Func func, std::initializer_list<godot::StringName> arg_names, DefaultsT&&... defaults) {
+		godot::MethodDefinition definition { Name.data() };
+		definition.args = { arg_names };
+		godot::ClassDB::bind_method(definition, func, defaults...);
+	}
+
+	template<StringLiteral Name, IsMemberFunctionPointer Func, typename... DefaultsT>
+	void bind_method(Func func, DefaultsT&&... defaults) {
+		bind_method<Name, Func>(func, {}, defaults...);
+	}
+
+	template<StringLiteral Name, IsFunctionPointer Func, typename... DefaultsT>
+	void bind_static_method(
+		godot::StringName class_name, Func func, std::initializer_list<godot::StringName> arg_names, DefaultsT&&... defaults
+	) {
+		godot::MethodDefinition definition { Name.data() };
+		definition.args = { arg_names };
+		godot::ClassDB::bind_static_method(class_name, definition, func, defaults...);
+	}
+
+	template<StringLiteral Name, IsFunctionPointer Func, typename... DefaultsT>
+	void bind_static_method(godot::StringName class_name, Func func, DefaultsT&&... defaults) {
+		bind_static_method<Name>(class_name, func, {}, defaults...);
+	}
+
+	template<std::derived_from<godot::Object> ClassT, StringLiteral Name, IsFunctionPointer Func, typename... DefaultsT>
+	void bind_static_method(Func func, std::initializer_list<godot::StringName> arg_names, DefaultsT&&... defaults) {
+		bind_static_method<Name>(ClassT::get_class_static(), func, arg_names, defaults...);
+	}
+
+	template<std::derived_from<godot::Object> ClassT, StringLiteral Name, IsFunctionPointer Func, typename... DefaultsT>
+	void bind_static_method(Func func, DefaultsT&&... defaults) {
+		bind_static_method<ClassT, Name>(func, {}, defaults...);
+	}
+}
diff --git a/extension/src/openvic-extension/utility/StringLiteral.hpp b/extension/src/openvic-extension/utility/StringLiteral.hpp
new file mode 100644
index 0000000..90b18cd
--- /dev/null
+++ b/extension/src/openvic-extension/utility/StringLiteral.hpp
@@ -0,0 +1,106 @@
+#pragma once
+
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <iterator>
+#include <string_view>
+#include <type_traits>
+
+namespace OpenVic {
+	template<std::size_t N>
+	struct StringLiteral {
+		constexpr StringLiteral(const char (&str)[N]) {
+			std::copy_n(str, N, value);
+		}
+
+		consteval StringLiteral(std::string_view string) {
+			assert(string.size() == N);
+			std::copy_n(string.begin(), N, value);
+		}
+
+		char value[N];
+		static const constexpr std::integral_constant<std::size_t, N - 1> size {};
+
+		struct iterator {
+			using iterator_concept [[maybe_unused]] = std::contiguous_iterator_tag;
+			using difference_type = std::ptrdiff_t;
+			using element_type = const char; // element_type is a reserved name that must be used in the definition
+			using pointer = element_type*;
+			using reference = element_type&;
+
+			constexpr iterator() = default;
+			constexpr iterator(pointer p) : _ptr(p) {}
+			constexpr reference operator*() const {
+				return *_ptr;
+			}
+			constexpr pointer operator->() const {
+				return _ptr;
+			}
+			constexpr auto& operator++() {
+				_ptr++;
+				return *this;
+			}
+			constexpr auto operator++(int) {
+				auto tmp = *this;
+				++(*this);
+				return tmp;
+			}
+			constexpr iterator& operator+=(int i) {
+				_ptr += i;
+				return *this;
+			}
+			constexpr iterator operator+(const difference_type other) const {
+				return _ptr + other;
+			}
+			constexpr friend iterator operator+(const difference_type value, const iterator& other) {
+				return other + value;
+			}
+			constexpr iterator& operator--() {
+				_ptr--;
+				return *this;
+			}
+			constexpr iterator operator--(int) {
+				iterator tmp = *this;
+				--(*this);
+				return tmp;
+			}
+			constexpr iterator& operator-=(int i) {
+				_ptr -= i;
+				return *this;
+			}
+			constexpr difference_type operator-(const iterator& other) const {
+				return _ptr - other._ptr;
+			}
+			constexpr iterator operator-(const difference_type other) const {
+				return _ptr - other;
+			}
+			friend iterator operator-(const difference_type value, const iterator& other) {
+				return other - value;
+			}
+			constexpr reference operator[](difference_type idx) const {
+				return _ptr[idx];
+			}
+			constexpr auto operator<=>(const iterator&) const = default; // three-way comparison C++20
+
+		private:
+			pointer _ptr;
+		};
+
+		constexpr iterator begin() const {
+			return iterator { &value };
+		}
+
+		constexpr iterator end() const {
+			return iterator { &value + N };
+		}
+
+		constexpr operator std::string_view() const {
+			return std::string_view { value, N };
+		}
+
+		constexpr decltype(auto) data() const {
+			return static_cast<std::string_view>(*this).data();
+		}
+	};
+}