17 files changed, 1094 insertions, 36 deletions

diff --git a/extension/src/Checksum.hpp b/extension/src/Checksum.hpp
index ebdbd43..717910e 100644
--- a/extension/src/Checksum.hpp
+++ b/extension/src/Checksum.hpp
@@ -1,15 +1,13 @@
 #pragma once
 
-#include <godot_cpp/classes/object.hpp>
 #include <godot_cpp/core/class_db.hpp>
-#include <godot_cpp/variant/utility_functions.hpp>
 
 namespace OpenVic2 {
 	class Checksum : public godot::Object {
 		GDCLASS(Checksum, godot::Object)
 
 		//BEGIN BOILERPLATE
-		static Checksum* _checksum;
+		inline static Checksum* _checksum = nullptr;
 
 	protected:
 		static void _bind_methods() {
@@ -33,6 +31,4 @@ namespace OpenVic2 {
 			return godot::String("1234abcd");
 		}
 	};
-
-	Checksum* Checksum::_checksum = nullptr;
-}
\ No newline at end of file
+}
diff --git a/extension/src/LoadLocalisation.cpp b/extension/src/LoadLocalisation.cpp
index c95c08b..8698bb2 100644
--- a/extension/src/LoadLocalisation.cpp
+++ b/extension/src/LoadLocalisation.cpp
@@ -8,7 +8,7 @@
 using namespace godot;
 using namespace OpenVic2;
 
-LoadLocalisation *LoadLocalisation::singleton = nullptr;
+LoadLocalisation* LoadLocalisation::singleton = nullptr;
 
 void LoadLocalisation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("load_file", "file_path", "locale"), &LoadLocalisation::load_file);
@@ -16,7 +16,7 @@ void LoadLocalisation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("load_localisation_dir", "dir_path"), &LoadLocalisation::load_localisation_dir);
 }
 
-LoadLocalisation *LoadLocalisation::get_singleton() {
+LoadLocalisation* LoadLocalisation::get_singleton() {
 	return singleton;
 }
 
@@ -54,7 +54,7 @@ Error LoadLocalisation::_load_file_into_translation(String const& file_path, Ref
 }
 
 Ref<Translation> LoadLocalisation::_get_translation(String const& locale) {
-	TranslationServer *server = TranslationServer::get_singleton();
+	TranslationServer* server = TranslationServer::get_singleton();
 	Ref<Translation> translation = server->get_translation_object(locale);
 	if (translation.is_null() || translation->get_locale() != locale) {
 		translation.instantiate();
@@ -93,7 +93,7 @@ Error LoadLocalisation::load_locale_dir(String const& dir_path, String const& lo
  */
 Error LoadLocalisation::load_localisation_dir(String const& dir_path) {
 	if (DirAccess::dir_exists_absolute(dir_path)) {
-		TranslationServer *server = TranslationServer::get_singleton();
+		TranslationServer* server = TranslationServer::get_singleton();
 		Error err = OK;
 		for (String const& locale_name : DirAccess::get_directories_at(dir_path)) {
 			if (locale_name == server->standardize_locale(locale_name)) {
diff --git a/extension/src/LoadLocalisation.hpp b/extension/src/LoadLocalisation.hpp
index 90f3158..49c0313 100644
--- a/extension/src/LoadLocalisation.hpp
+++ b/extension/src/LoadLocalisation.hpp
@@ -1,14 +1,13 @@
 #pragma once
 
-#include <godot_cpp/core/class_db.hpp>
 #include <godot_cpp/classes/translation.hpp>
 
 namespace OpenVic2 {
-	class LoadLocalisation : public godot::Object
-	{
+	class LoadLocalisation : public godot::Object {
+
 		GDCLASS(LoadLocalisation, godot::Object)
 
-		static LoadLocalisation *singleton;
+		static LoadLocalisation* singleton;
 
 		godot::Error _load_file_into_translation(godot::String const& file_path, godot::Ref<godot::Translation> translation);
 		godot::Ref<godot::Translation> _get_translation(godot::String const& locale);
@@ -17,7 +16,7 @@ namespace OpenVic2 {
 		static void _bind_methods();
 
 	public:
-		static LoadLocalisation *get_singleton();
+		static LoadLocalisation* get_singleton();
 
 		LoadLocalisation();
 		~LoadLocalisation();
diff --git a/extension/src/MapMesh.cpp b/extension/src/MapMesh.cpp
new file mode 100644
index 0000000..91c7611
--- /dev/null
+++ b/extension/src/MapMesh.cpp
@@ -0,0 +1,150 @@
+#include "MapMesh.hpp"
+
+#include <godot_cpp/templates/vector.hpp>
+
+using namespace godot;
+using namespace OpenVic2;
+
+void MapMesh::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("set_aspect_ratio", "ratio"), &MapMesh::set_aspect_ratio);
+	ClassDB::bind_method(D_METHOD("get_aspect_ratio"), &MapMesh::get_aspect_ratio);
+
+	ClassDB::bind_method(D_METHOD("set_repeat_proportion", "proportion"), &MapMesh::set_repeat_proportion);
+	ClassDB::bind_method(D_METHOD("get_repeat_proportion"), &MapMesh::get_repeat_proportion);
+
+	ClassDB::bind_method(D_METHOD("set_subdivide_width", "divisions"), &MapMesh::set_subdivide_width);
+	ClassDB::bind_method(D_METHOD("get_subdivide_width"), &MapMesh::get_subdivide_width);
+
+	ClassDB::bind_method(D_METHOD("set_subdivide_depth", "divisions"), &MapMesh::set_subdivide_depth);
+	ClassDB::bind_method(D_METHOD("get_subdivide_depth"), &MapMesh::get_subdivide_depth);
+
+	ClassDB::bind_method(D_METHOD("get_core_aabb"), &MapMesh::get_core_aabb);
+	ClassDB::bind_method(D_METHOD("is_valid_uv_coord"), &MapMesh::is_valid_uv_coord);
+
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "aspect_ratio", PROPERTY_HINT_NONE, "suffix:m"), "set_aspect_ratio", "get_aspect_ratio");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "repeat_proportion", PROPERTY_HINT_NONE, "suffix:m"), "set_repeat_proportion", "get_repeat_proportion");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "subdivide_width", PROPERTY_HINT_RANGE, "0,100,1,or_greater"), "set_subdivide_width", "get_subdivide_width");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "subdivide_depth", PROPERTY_HINT_RANGE, "0,100,1,or_greater"), "set_subdivide_depth", "get_subdivide_depth");
+}
+
+void MapMesh::_request_update() {
+	// Hack to trigger _update_lightmap_size and _request_update in PrimitiveMesh
+	set_add_uv2(get_add_uv2());
+}
+
+void MapMesh::set_aspect_ratio(const float ratio) {
+	aspect_ratio = ratio;
+	_request_update();
+}
+
+float MapMesh::get_aspect_ratio() const {
+	return aspect_ratio;
+}
+
+void MapMesh::set_repeat_proportion(const float proportion) {
+	repeat_proportion = proportion;
+	_request_update();
+}
+
+float MapMesh::get_repeat_proportion() const {
+	return repeat_proportion;
+}
+
+void MapMesh::set_subdivide_width(const int divisions) {
+	subdivide_w = divisions > 0 ? divisions : 0;
+	_request_update();
+}
+
+int MapMesh::get_subdivide_width() const {
+	return subdivide_w;
+}
+
+void MapMesh::set_subdivide_depth(const int divisions) {
+	subdivide_d = divisions > 0 ? divisions : 0;
+	_request_update();
+}
+
+int MapMesh::get_subdivide_depth() const {
+	return subdivide_d;
+}
+
+AABB MapMesh::get_core_aabb() const {
+	const Vector3 size{ aspect_ratio, 0.0f, 1.0f };
+	return AABB{ size * -0.5f, size };
+}
+
+bool MapMesh::is_valid_uv_coord(godot::Vector2 const& uv) const {
+	return 0.0f <= uv.y && uv.y <= 1.0f;
+}
+
+Array MapMesh::_create_mesh_array() const {
+	Array arr;
+	arr.resize(Mesh::ARRAY_MAX);
+
+	const int vertex_count = (subdivide_w + 2) * (subdivide_d + 2);
+	const int indice_count = (subdivide_w + 1) * (subdivide_d + 1) * 6;
+
+	PackedVector3Array points;
+	PackedVector3Array normals;
+	PackedFloat32Array tangents;
+	PackedVector2Array uvs;
+	PackedInt32Array indices;
+
+	points.resize(vertex_count);
+	normals.resize(vertex_count);
+	tangents.resize(vertex_count * 4);
+	uvs.resize(vertex_count);
+	indices.resize(indice_count);
+
+	static const Vector3 normal{ 0.0f, 1.0f, 0.0f };
+	const Size2 uv_size{ 1.0f + 2.0f * repeat_proportion, 1.0f };
+	const Size2 size{ aspect_ratio * uv_size.x, uv_size.y }, start_pos = size * -0.5f;
+
+	int point_index = 0, thisrow = 0, prevrow = 0, indice_index = 0;
+	Vector2 subdivide_step{ 1.0f / (subdivide_w + 1.0f) , 1.0f / (subdivide_d + 1.0f) };
+	Vector3 point{ 0.0f, 0.0f, start_pos.y };
+	Vector2 point_step = subdivide_step * size;
+	Vector2 uv{}, uv_step = subdivide_step * uv_size;
+
+	for (int j = 0; j <= subdivide_d + 1; ++j) {
+		point.x = start_pos.x;
+		uv.x = -repeat_proportion;
+
+		for (int i = 0; i <= subdivide_w + 1; ++i) {
+			points[point_index] = point;
+			normals[point_index] = normal;
+			tangents[point_index * 4 + 0] = 1.0f;
+			tangents[point_index * 4 + 1] = 0.0f;
+			tangents[point_index * 4 + 2] = 0.0f;
+			tangents[point_index * 4 + 3] = 1.0f;
+			uvs[point_index] = uv;
+			point_index++;
+
+			if (i > 0 && j > 0) {
+				indices[indice_index + 0] = prevrow + i - 1;
+				indices[indice_index + 1] = prevrow + i;
+				indices[indice_index + 2] = thisrow + i - 1;
+				indices[indice_index + 3] = prevrow + i;
+				indices[indice_index + 4] = thisrow + i;
+				indices[indice_index + 5] = thisrow + i - 1;
+				indice_index += 6;
+			}
+
+			point.x += point_step.x;
+			uv.x += uv_step.x;
+		}
+
+		point.z += point_step.y;
+		uv.y += uv_step.y;
+		prevrow = thisrow;
+		thisrow = point_index;
+	}
+
+	arr[Mesh::ARRAY_VERTEX] = points;
+	arr[Mesh::ARRAY_NORMAL] = normals;
+	arr[Mesh::ARRAY_TANGENT] = tangents;
+	arr[Mesh::ARRAY_TEX_UV] = uvs;
+	arr[Mesh::ARRAY_INDEX] = indices;
+
+	return arr;
+}
diff --git a/extension/src/MapMesh.hpp b/extension/src/MapMesh.hpp
new file mode 100644
index 0000000..d8727cf
--- /dev/null
+++ b/extension/src/MapMesh.hpp
@@ -0,0 +1,34 @@
+#pragma once
+
+#include <godot_cpp/classes/primitive_mesh.hpp>
+
+namespace OpenVic2 {
+	class MapMesh : public godot::PrimitiveMesh {
+		GDCLASS(MapMesh, godot::PrimitiveMesh)
+
+		float aspect_ratio = 2.0f, repeat_proportion = 0.5f;
+		int subdivide_w = 0, subdivide_d = 0;
+
+	protected:
+		static void _bind_methods();
+		void _request_update();
+
+	public:
+		void set_aspect_ratio(const float ratio);
+		float get_aspect_ratio() const;
+
+		void set_repeat_proportion(const float proportion);
+		float get_repeat_proportion() const;
+
+		void set_subdivide_width(const int divisions);
+		int get_subdivide_width() const;
+
+		void set_subdivide_depth(const int divisions);
+		int get_subdivide_depth() const;
+
+		godot::AABB get_core_aabb() const;
+		bool is_valid_uv_coord(godot::Vector2 const& uv) const;
+
+		godot::Array _create_mesh_array() const override;
+	};
+}
diff --git a/extension/src/MapSingleton.cpp b/extension/src/MapSingleton.cpp
new file mode 100644
index 0000000..73cf522
--- /dev/null
+++ b/extension/src/MapSingleton.cpp
@@ -0,0 +1,335 @@
+#include "MapSingleton.hpp"
+
+#include <godot_cpp/variant/utility_functions.hpp>
+#include <godot_cpp/classes/file_access.hpp>
+#include <godot_cpp/classes/json.hpp>
+
+using namespace godot;
+using namespace OpenVic2;
+
+MapSingleton* MapSingleton::singleton = nullptr;
+
+void MapSingleton::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("load_province_identifier_file", "file_path"), &MapSingleton::load_province_identifier_file);
+	ClassDB::bind_method(D_METHOD("load_region_file", "file_path"), &MapSingleton::load_region_file);
+	ClassDB::bind_method(D_METHOD("load_province_shape_file", "file_path"), &MapSingleton::load_province_shape_file);
+
+	ClassDB::bind_method(D_METHOD("get_province_index_from_uv_coords", "coords"), &MapSingleton::get_province_index_from_uv_coords);
+	ClassDB::bind_method(D_METHOD("get_province_identifier_from_uv_coords", "coords"), &MapSingleton::get_province_identifier_from_uv_coords);
+	ClassDB::bind_method(D_METHOD("get_width"), &MapSingleton::get_width);
+	ClassDB::bind_method(D_METHOD("get_height"), &MapSingleton::get_height);
+	ClassDB::bind_method(D_METHOD("get_province_index_image"), &MapSingleton::get_province_index_image);
+	ClassDB::bind_method(D_METHOD("get_province_colour_image"), &MapSingleton::get_province_colour_image);
+
+	ClassDB::bind_method(D_METHOD("update_colour_image"), &MapSingleton::update_colour_image);
+	ClassDB::bind_method(D_METHOD("get_mapmode_count"), &MapSingleton::get_mapmode_count);
+	ClassDB::bind_method(D_METHOD("get_mapmode_identifier", "index"), &MapSingleton::get_mapmode_identifier);
+	ClassDB::bind_method(D_METHOD("set_mapmode", "identifier"), &MapSingleton::set_mapmode);
+}
+
+MapSingleton* MapSingleton::get_singleton() {
+	return singleton;
+}
+
+/* REQUIREMENTS:
+ * MAP-21, MAP-25
+ */
+MapSingleton::MapSingleton() {
+	ERR_FAIL_COND(singleton != nullptr);
+	singleton = this;
+
+	using mapmode_t = std::pair<std::string, Mapmode::colour_func_t>;
+	const std::vector<mapmode_t> mapmodes = {
+		{ "mapmode_province", [](Map const&, Province const& province) -> Province::colour_t { return province.get_colour(); } },
+		{ "mapmode_region", [](Map const&, Province const& province) -> Province::colour_t {
+			Region const* region = province.get_region();
+			if (region != nullptr) return region->get_provinces().front()->get_colour();
+			return province.get_colour();
+		} },
+		{ "mapmode_index", [](Map const& map, Province const& province) -> Province::colour_t {
+			const uint8_t f = float(province.get_index()) / float(map.get_province_count()) * 255.0f;
+			return (f << 16) | (f << 8) | f;
+		} }
+	};
+	std::string error_message = "";
+	for (mapmode_t mapmode : mapmodes)
+		if (map.add_mapmode(mapmode.first, mapmode.second, error_message) != SUCCESS)
+			UtilityFunctions::push_error(error_message.c_str());
+}
+
+MapSingleton::~MapSingleton() {
+	ERR_FAIL_COND(singleton != this);
+	singleton = nullptr;
+}
+
+Error MapSingleton::parse_json_dictionary_file(String const& file_description, String const& file_path,
+	String const& identifier_prefix, parse_json_entry_func_t parse_entry) const {
+	UtilityFunctions::print("Loading ", file_description, " file: ", file_path);
+	Ref<FileAccess> file = FileAccess::open(file_path, FileAccess::ModeFlags::READ);
+	Error err = FileAccess::get_open_error();
+	if (err != OK || file.is_null()) {
+		UtilityFunctions::push_error("Failed to load ", file_description, " file: ", file_path);
+		return err == OK ? FAILED : err;
+	}
+	const String json_string = file->get_as_text();
+	Ref<JSON> json;
+	json.instantiate();
+	err = json->parse(json_string);
+	if (err != OK) {
+		UtilityFunctions::push_error("Failed to parse ", file_description, " file as JSON: ", file_path,
+			"\nError at line ", json->get_error_line(), ": ", json->get_error_message());
+		return err;
+	}
+	const Variant json_var = json->get_data();
+	const Variant::Type type = json_var.get_type();
+	if (type != Variant::DICTIONARY) {
+		UtilityFunctions::push_error("Invalid ", file_description, " JSON: root has type ",
+			Variant::get_type_name(type), " (expected Dictionary)");
+		return FAILED;
+	}
+	const Dictionary dict = json_var;
+	const Array identifiers = dict.keys();
+	for (int idx = 0; idx < identifiers.size(); ++idx) {
+		String const& identifier = identifiers[idx];
+		Variant const& entry = dict[identifier];
+		if (identifier.is_empty()) {
+			UtilityFunctions::push_error("Empty identifier in ", file_description, " file with entry: ", entry);
+			err = FAILED;
+			continue;
+		}
+		if (!identifier.begins_with(identifier_prefix))
+			UtilityFunctions::push_warning("Identifier in ", file_description, " file missing \"", identifier_prefix, "\" prefix: ", identifier);
+		if (parse_entry(identifier, entry) != OK) err = FAILED;
+	}
+	return err;
+}
+
+Error MapSingleton::_parse_province_identifier_entry(String const& identifier, Variant const& entry) {
+	const Variant::Type type = entry.get_type();
+	Province::colour_t colour = Province::NULL_COLOUR;
+	if (type == Variant::ARRAY) {
+		const Array colour_array = entry;
+		if (colour_array.size() == 3) {
+			for (int jdx = 0; jdx < 3; ++jdx) {
+				const Variant var = colour_array[jdx];
+				if (var.get_type() != Variant::FLOAT) {
+					colour = Province::NULL_COLOUR;
+					break;
+				}
+				double colour_double = var;
+				if (std::trunc(colour_double) != colour_double) {
+					colour = Province::NULL_COLOUR;
+					break;
+				}
+				int64_t colour_int = static_cast<int64_t>(colour_double);
+				if (colour_int < 0 || colour_int > 255) {
+					colour = Province::NULL_COLOUR;
+					break;
+				}
+				colour = (colour << 8) | colour_int;
+			}
+		}
+	} else if (type == Variant::STRING) {
+		String colour_string = entry;
+		if (colour_string.is_valid_hex_number()) {
+			int64_t colour_int = colour_string.hex_to_int();
+			if (0 <= colour_int && colour_int <= 0xFFFFFF)
+				colour = colour_int;
+		}
+	} else {
+		UtilityFunctions::push_error("Invalid colour for province identifier \"", identifier, "\": ", entry);
+		return FAILED;
+	}
+	std::string error_message = "";
+	if (map.add_province(identifier.utf8().get_data(), colour, error_message) != SUCCESS) {
+		UtilityFunctions::push_error(error_message.c_str());
+		return FAILED;
+	}
+	return OK;
+}
+
+Error MapSingleton::load_province_identifier_file(String const& file_path) {
+	const Error err = parse_json_dictionary_file("province identifier", file_path, "prov_",
+		[this](String const& identifier, Variant const& entry) -> Error {
+			return this->_parse_province_identifier_entry(identifier, entry);
+		});
+	map.lock_provinces();
+	return err;
+}
+
+Error MapSingleton::_parse_region_entry(String const& identifier, Variant const& entry) {
+	Error err = OK;
+	Variant::Type type = entry.get_type();
+	std::vector<std::string> province_identifiers;
+	if (type == Variant::ARRAY) {
+		const Array province_array = entry;
+		for (int64_t idx = 0; idx < province_array.size(); ++idx) {
+			const Variant province_var = province_array[idx];
+			type = province_var.get_type();
+			if (type == Variant::STRING) {
+				String province_string = province_var;
+				province_identifiers.push_back(province_string.utf8().get_data());
+			} else {
+				UtilityFunctions::push_error("Invalid province identifier for region \"", identifier, "\": ", entry);
+				err = FAILED;
+			}
+		}
+	}
+	std::string error_message = "";
+	if (map.add_region(identifier.utf8().get_data(), province_identifiers, error_message) != SUCCESS) {
+		UtilityFunctions::push_error(error_message.c_str());
+		return FAILED;
+	}
+	return err;
+}
+
+Error MapSingleton::load_region_file(String const& file_path) {
+	const Error err = parse_json_dictionary_file("region", file_path, "region_",
+		[this](String const& identifier, Variant const& entry) -> Error {
+			return this->_parse_region_entry(identifier, entry);
+		});
+	map.lock_regions();
+	return err;
+}
+
+Error MapSingleton::load_province_shape_file(String const& file_path) {
+	if (province_index_image.is_valid()) {
+		UtilityFunctions::push_error("Province shape file has already been loaded, cannot load: ", file_path);
+		return FAILED;
+	}
+	Ref<Image> province_shape_image;
+	province_shape_image.instantiate();
+	Error err = province_shape_image->load(file_path);
+	if (err != OK) {
+		UtilityFunctions::push_error("Failed to load province shape file: ", file_path);
+		return err;
+	}
+	int32_t width = province_shape_image->get_width();
+	int32_t height = province_shape_image->get_height();
+	if (width < 1 || height < 1) {
+		UtilityFunctions::push_error("Invalid dimensions (", width, "x", height, ") for province shape file: ", file_path);
+		err = FAILED;
+	}
+	static const Image::Format expected_format = Image::FORMAT_RGB8;
+	const Image::Format format = province_shape_image->get_format();
+	if (format != expected_format) {
+		UtilityFunctions::push_error("Invalid format (", format, ", should be ", expected_format, ") for province shape file: ", file_path);
+		err = FAILED;
+	}
+	if (err != OK) return err;
+
+	std::string error_message = "";
+	if (map.generate_province_index_image(width, height, province_shape_image->get_data().ptr(), error_message) != SUCCESS) {
+		UtilityFunctions::push_error(error_message.c_str());
+		err = FAILED;
+	}
+
+	PackedByteArray index_data_array;
+	index_data_array.resize(width * height * sizeof(Province::index_t));
+	memcpy(index_data_array.ptrw(), map.get_province_index_image().data(), index_data_array.size());
+
+	province_index_image = Image::create_from_data(width, height, false, Image::FORMAT_RG8, index_data_array);
+	if (province_index_image.is_null()) {
+		UtilityFunctions::push_error("Failed to create province ID image");
+		err = FAILED;
+	}
+
+	if (update_colour_image() != OK) err = FAILED;
+
+	return err;
+}
+
+Province* MapSingleton::get_province_from_uv_coords(godot::Vector2 const& coords) {
+	if (province_index_image.is_valid()) {
+		const PackedByteArray index_data_array = province_index_image->get_data();
+		Province::index_t const* index_data = reinterpret_cast<Province::index_t const*>(index_data_array.ptr());
+		const int32_t x_mod_w = UtilityFunctions::fposmod(coords.x, 1.0f) * get_width();
+		const int32_t y_mod_h = UtilityFunctions::fposmod(coords.y, 1.0f) * get_height();
+		return map.get_province_by_index(index_data[x_mod_w + y_mod_h * get_width()]);
+	}
+	return nullptr;
+}
+
+Province const* MapSingleton::get_province_from_uv_coords(godot::Vector2 const& coords) const {
+	if (province_index_image.is_valid()) {
+		const PackedByteArray index_data_array = province_index_image->get_data();
+		Province::index_t const* index_data = reinterpret_cast<Province::index_t const*>(index_data_array.ptr());
+		const int32_t x_mod_w = UtilityFunctions::fposmod(coords.x, 1.0f) * get_width();
+		const int32_t y_mod_h = UtilityFunctions::fposmod(coords.y, 1.0f) * get_height();
+		return map.get_province_by_index(index_data[x_mod_w + y_mod_h * get_width()]);
+	}
+	return nullptr;
+}
+
+int32_t MapSingleton::get_province_index_from_uv_coords(Vector2 const& coords) const {
+	Province const* province = get_province_from_uv_coords(coords);
+	if (province != nullptr) return province->get_index();
+	return Province::NULL_INDEX;
+}
+
+String MapSingleton::get_province_identifier_from_uv_coords(Vector2 const& coords) const {
+	Province const* province = get_province_from_uv_coords(coords);
+	if (province != nullptr) return province->get_identifier().c_str();
+	return String{};
+}
+
+int32_t MapSingleton::get_width() const {
+	return map.get_width();
+}
+
+int32_t MapSingleton::get_height() const {
+	return map.get_height();
+}
+
+Ref<Image> MapSingleton::get_province_index_image() const {
+	return province_index_image;
+}
+
+Ref<Image> MapSingleton::get_province_colour_image() const {
+	return province_colour_image;
+}
+
+Error MapSingleton::update_colour_image() {
+	static PackedByteArray colour_data_array;
+	static const int64_t colour_data_array_size = (Province::MAX_INDEX + 1) * 3;
+	colour_data_array.resize(colour_data_array_size);
+
+	Error err = OK;
+	std::string error_message = "";
+	if (map.generate_mapmode_colours(mapmode_index, colour_data_array.ptrw(), error_message) != SUCCESS) {
+		UtilityFunctions::push_error(error_message.c_str());
+		err = FAILED;
+	}
+
+	static const int32_t PROVINCE_INDEX_SQRT = 1 << (sizeof(Province::index_t) * 4);
+	if (province_colour_image.is_null())
+		province_colour_image.instantiate();
+	province_colour_image->set_data(PROVINCE_INDEX_SQRT, PROVINCE_INDEX_SQRT,
+		false, Image::FORMAT_RGB8, colour_data_array);
+	if (province_colour_image.is_null()) {
+		UtilityFunctions::push_error("Failed to update province colour image");
+		return FAILED;
+	}
+	return err;
+}
+
+int32_t MapSingleton::get_mapmode_count() const {
+	return map.get_mapmode_count();
+}
+
+String MapSingleton::get_mapmode_identifier(int32_t index) const {
+	Mapmode const* mapmode = map.get_mapmode_by_index(index);
+	if (mapmode != nullptr) return mapmode->get_identifier().c_str();
+	return String{};
+}
+
+Error MapSingleton::set_mapmode(godot::String const& identifier) {
+	Mapmode const* mapmode = map.get_mapmode_by_identifier(identifier.utf8().get_data());
+	if (mapmode != nullptr) {
+		mapmode_index = mapmode->get_index();
+		return OK;
+	} else {
+		UtilityFunctions::push_error("Failed to set mapmode to: ", identifier);
+		return FAILED;
+	}
+}
diff --git a/extension/src/MapSingleton.hpp b/extension/src/MapSingleton.hpp
new file mode 100644
index 0000000..9205e92
--- /dev/null
+++ b/extension/src/MapSingleton.hpp
@@ -0,0 +1,52 @@
+#pragma once
+
+#include <functional>
+
+#include <godot_cpp/classes/image.hpp>
+
+#include "openvic2/Map.hpp"
+
+namespace OpenVic2 {
+	class MapSingleton : public godot::Object {
+		using parse_json_entry_func_t = std::function<godot::Error (godot::String const&, godot::Variant const&)>;
+
+		GDCLASS(MapSingleton, godot::Object)
+
+		static MapSingleton* singleton;
+
+		godot::Ref<godot::Image> province_index_image, province_colour_image;
+		Map map;
+		Mapmode::index_t mapmode_index = 0;
+
+		godot::Error parse_json_dictionary_file(godot::String const& file_description, godot::String const& file_path,
+			godot::String const& identifier_prefix, parse_json_entry_func_t parse_entry) const;
+		godot::Error _parse_province_identifier_entry(godot::String const& identifier, godot::Variant const& entry);
+		godot::Error _parse_region_entry(godot::String const& identifier, godot::Variant const& entry);
+	protected:
+		static void _bind_methods();
+
+	public:
+		static MapSingleton* get_singleton();
+
+		MapSingleton();
+		~MapSingleton();
+
+		godot::Error load_province_identifier_file(godot::String const& file_path);
+		godot::Error load_region_file(godot::String const& file_path);
+		godot::Error load_province_shape_file(godot::String const& file_path);
+
+		Province* get_province_from_uv_coords(godot::Vector2 const& coords);
+		Province const* get_province_from_uv_coords(godot::Vector2 const& coords) const;
+		int32_t get_province_index_from_uv_coords(godot::Vector2 const& coords) const;
+		godot::String get_province_identifier_from_uv_coords(godot::Vector2 const& coords) const;
+		int32_t get_width() const;
+		int32_t get_height() const;
+		godot::Ref<godot::Image> get_province_index_image() const;
+		godot::Ref<godot::Image> get_province_colour_image() const;
+
+		godot::Error update_colour_image();
+		int32_t get_mapmode_count() const;
+		godot::String get_mapmode_identifier(int32_t index) const;
+		godot::Error set_mapmode(godot::String const& identifier);
+	};
+}
diff --git a/extension/src/Simulation.hpp b/extension/src/Simulation.hpp
index 8959310..b84016b 100644
--- a/extension/src/Simulation.hpp
+++ b/extension/src/Simulation.hpp
@@ -1,8 +1,6 @@
 #pragma once
 
-#include <godot_cpp/classes/object.hpp>
 #include <godot_cpp/core/class_db.hpp>
-#include <godot_cpp/variant/utility_functions.hpp>
 #include <vector>
 
 namespace OpenVic2 {
@@ -11,7 +9,7 @@ namespace OpenVic2 {
 		std::vector<uint64_t> exampleProvinces;
 
 		//BEGIN BOILERPLATE
-		static Simulation* _simulation;
+		inline static Simulation* _simulation = nullptr;
 
 		protected:
 		static void _bind_methods() {
@@ -47,6 +45,4 @@ namespace OpenVic2 {
 			return exampleProvinces[provinceID];
 		}
 	};
-
-	Simulation* Simulation::_simulation = nullptr;
 }
diff --git a/extension/src/TestSingleton.cpp b/extension/src/TestSingleton.cpp
index 0855a30..d9e2b03 100644
--- a/extension/src/TestSingleton.cpp
+++ b/extension/src/TestSingleton.cpp
@@ -6,14 +6,14 @@
 using namespace godot;
 using namespace OpenVic2;
 
-TestSingleton *TestSingleton::singleton = nullptr;
+TestSingleton* TestSingleton::singleton = nullptr;
 
 void TestSingleton::_bind_methods()
 {
 	ClassDB::bind_method(D_METHOD("hello_singleton"), &TestSingleton::hello_singleton);
 }
 
-TestSingleton *TestSingleton::get_singleton()
+TestSingleton* TestSingleton::get_singleton()
 {
 	return singleton;
 }
diff --git a/extension/src/TestSingleton.hpp b/extension/src/TestSingleton.hpp
index de27589..1261573 100644
--- a/extension/src/TestSingleton.hpp
+++ b/extension/src/TestSingleton.hpp
@@ -1,20 +1,19 @@
 #pragma once
 
 #include <godot_cpp/classes/object.hpp>
-#include <godot_cpp/core/class_db.hpp>
 
 namespace OpenVic2 {
 	class TestSingleton : public godot::Object
 	{
 		GDCLASS(TestSingleton, godot::Object)
 
-		static TestSingleton *singleton;
+		static TestSingleton* singleton;
 
 	protected:
 		static void _bind_methods();
 
 	public:
-		static TestSingleton *get_singleton();
+		static TestSingleton* get_singleton();
 
 		TestSingleton();
 		~TestSingleton();
diff --git a/extension/src/openvic2/Map.cpp b/extension/src/openvic2/Map.cpp
new file mode 100644
index 0000000..1654189
--- /dev/null
+++ b/extension/src/openvic2/Map.cpp
@@ -0,0 +1,306 @@
+#include "Map.hpp"
+
+#include <cassert>
+
+using namespace OpenVic2;
+
+static const std::string SEPARATOR = "\n - ";
+
+Mapmode::Mapmode(index_t new_index, std::string const& new_identifier, colour_func_t new_colour_func)
+	: index(new_index), identifier(new_identifier), colour_func(new_colour_func) {
+	assert(!identifier.empty());
+	assert(colour_func != nullptr);
+}
+
+Mapmode::index_t Mapmode::get_index() const {
+	return index;
+}
+
+std::string const& Mapmode::get_identifier() const {
+	return identifier;
+}
+
+Mapmode::colour_func_t Mapmode::get_colour_func() const {
+	return colour_func;
+}
+
+return_t Map::add_province(std::string const& identifier, Province::colour_t colour, std::string& error_message) {
+	if (provinces_locked) {
+		error_message = "The map's province list has already been locked!";
+		return FAILURE;
+	}
+	if (provinces.size() >= Province::MAX_INDEX) {
+		error_message = "The map's province list is full - there can be at most " + std::to_string(Province::MAX_INDEX) + " provinces";
+		return FAILURE;
+	}
+	if (identifier.empty()) {
+		error_message = "Empty province identifier for colour " + Province::colour_to_hex_string(colour);
+		return FAILURE;
+	}
+	if (colour == Province::NULL_COLOUR || colour > Province::MAX_COLOUR) {
+		error_message = "Invalid province colour: " + Province::colour_to_hex_string(colour);
+		return FAILURE;
+	}
+	Province new_province{ static_cast<Province::index_t>(provinces.size() + 1), identifier, colour };
+	for (Province const& province : provinces) {
+		if (province.get_identifier() == identifier) {
+			error_message = "Duplicate province identifiers: " + province.to_string() + " and " + new_province.to_string();
+			return FAILURE;
+		}
+		if (province.get_colour() == colour) {
+			error_message = "Duplicate province colours: " + province.to_string() + " and " + new_province.to_string();
+			return FAILURE;
+		}
+	}
+	provinces.push_back(new_province);
+	error_message = "Added province: " + new_province.to_string();
+	return SUCCESS;
+}
+
+void Map::lock_provinces() {
+	provinces_locked = true;
+}
+
+return_t Map::add_region(std::string const& identifier, std::vector<std::string> const& province_identifiers, std::string& error_message) {
+	if (regions_locked) {
+		error_message = "The map's region list has already been locked!";
+		return FAILURE;
+	}
+	if (identifier.empty()) {
+		error_message = "Empty region identifier!";
+		return FAILURE;
+	}
+	if (provinces.empty()) {
+		error_message = "Empty province list for region " + identifier;
+		return FAILURE;
+	}
+	Region new_region{ identifier };
+	error_message = "Error message for region: " + identifier;
+	for (std::string const& province_identifier : province_identifiers) {
+		Province* province = get_province_by_identifier(province_identifier);
+		if (province != nullptr) {
+			if (new_region.contains_province(province))
+				error_message += SEPARATOR + "Duplicate province identifier " + province_identifier;
+			else {
+				size_t other_region_index = reinterpret_cast<size_t>(province->get_region());
+				if (other_region_index != 0) {
+					other_region_index--;
+					error_message += SEPARATOR + "Province " + province_identifier + " is already part of ";
+					if (other_region_index < regions.size())
+						error_message += regions[other_region_index].get_identifier();
+					else
+						error_message += "an unknown region with index " + std::to_string(other_region_index);
+				} else new_region.provinces.push_back(province);
+			}
+		} else error_message += SEPARATOR + "Invalid province identifier " + province_identifier;
+	}
+	if (!new_region.get_province_count()) {
+		error_message += SEPARATOR + "No valid provinces in region's list";
+		return FAILURE;
+	}
+	for (Region const& region : regions) {
+		if (region.get_identifier() == identifier) {
+			error_message += SEPARATOR + "Duplicate region identifiers: " + region.get_identifier() + " and " + identifier;
+			return FAILURE;
+		}
+	}
+	regions.push_back(new_region);
+	error_message += SEPARATOR + "Added region: " + identifier;
+	// Used to detect provinces listed in multiple regions, will
+	// be corrected once regions is stable (i.e. lock_regions).
+	Region* tmp_region_index = reinterpret_cast<Region*>(regions.size());
+	for (Province* province : new_region.get_provinces())
+		province->region = tmp_region_index;
+	return SUCCESS;
+}
+
+void Map::lock_regions() {
+	regions_locked = true;
+	for (Region& region : regions)
+		for (Province* province : region.get_provinces())
+			province->region = &region;
+}
+
+size_t Map::get_province_count() const {
+	return provinces.size();
+}
+
+Province* Map::get_province_by_index(Province::index_t index) {
+	return index != Province::NULL_INDEX && index <= provinces.size() ? &provinces[index - 1] : nullptr;
+}
+
+Province const* Map::get_province_by_index(Province::index_t index) const {
+	return index != Province::NULL_INDEX && index <= provinces.size() ? &provinces[index - 1] : nullptr;
+}
+
+Province* Map::get_province_by_identifier(std::string const& identifier) {
+	if (!identifier.empty())
+		for (Province& province : provinces)
+			if (province.get_identifier() == identifier) return &province;
+	return nullptr;
+}
+
+Province const* Map::get_province_by_identifier(std::string const& identifier) const {
+	if (!identifier.empty())
+		for (Province const& province : provinces)
+			if (province.get_identifier() == identifier) return &province;
+	return nullptr;
+}
+
+Province* Map::get_province_by_colour(Province::colour_t colour) {
+	if (colour != Province::NULL_COLOUR)
+		for (Province& province : provinces)
+			if (province.get_colour() == colour) return &province;
+	return nullptr;
+}
+
+Province const* Map::get_province_by_colour(Province::colour_t colour) const {
+	if (colour != Province::NULL_COLOUR)
+		for (Province const& province : provinces)
+			if (province.get_colour() == colour) return &province;
+	return nullptr;
+}
+
+static Province::colour_t colour_at(uint8_t const* colour_data, int32_t idx) {
+	return (colour_data[idx * 3] << 16) | (colour_data[idx * 3 + 1] << 8) | colour_data[idx * 3 + 2];
+}
+
+return_t Map::generate_province_index_image(size_t new_width, size_t new_height, uint8_t const* colour_data, std::string& error_message) {
+	if (!province_index_image.empty()) {
+		error_message = "Province index image has already been generated!";
+		return FAILURE;
+	}
+	if (!provinces_locked) {
+		error_message = "Province index image cannot be generated until after provinces are locked!";
+		return FAILURE;
+	}
+	if (new_width < 1 || new_height < 1) {
+		error_message = "Invalid province image dimensions: " + std::to_string(new_width) + "x" + std::to_string(new_height);
+		return FAILURE;
+	}
+	if (colour_data == nullptr) {
+		error_message = "Province colour data pointer is null!";
+		return FAILURE;
+	}
+	width = new_width;
+	height = new_height;
+	province_index_image.resize(width * height);
+
+	std::vector<bool> province_checklist(provinces.size());
+	return_t ret = SUCCESS;
+
+	error_message = "Error message for province index image generation:";
+
+	for (int32_t y = 0; y < height; ++y) {
+		for (int32_t x = 0; x < width; ++x) {
+			const int32_t idx = x + y * width;
+			const Province::colour_t colour = colour_at(colour_data, idx);
+			if (colour == Province::NULL_COLOUR) {
+				province_index_image[idx] = Province::NULL_INDEX;
+				continue;
+			}
+			if (x > 0) {
+				const int32_t jdx = idx - 1;
+				if (colour_at(colour_data, jdx) == colour) {
+					province_index_image[idx] = province_index_image[jdx];
+					continue;
+				}
+			}
+			if (y > 0) {
+				const int32_t jdx = idx - width;
+				if (colour_at(colour_data, jdx) == colour) {
+					province_index_image[idx] = province_index_image[jdx];
+					continue;
+				}
+			}
+			Province const* province = get_province_by_colour(colour);
+			if (province != nullptr) {
+				const Province::index_t index = province->get_index();
+				province_index_image[idx] = index;
+				province_checklist[index - 1] = true;
+				continue;
+			}
+			error_message += SEPARATOR + "Unrecognised province colour " + Province::colour_to_hex_string(colour) + " at (" + std::to_string(x) + ", " + std::to_string(x) + ")";
+			ret = FAILURE;
+			province_index_image[idx] = Province::NULL_INDEX;
+		}
+	}
+
+	for (size_t idx = 0; idx < province_checklist.size(); ++idx) {
+		if (!province_checklist[idx]) {
+			error_message += SEPARATOR + "Province missing from shape image: " + provinces[idx].to_string();
+			ret = FAILURE;
+		}
+	}
+
+	error_message += SEPARATOR + "Generated province index image";
+	return ret;
+}
+
+size_t Map::get_width() const {
+	return width;
+}
+
+size_t Map::get_height() const {
+	return height;
+}
+
+std::vector<Province::index_t> const& Map::get_province_index_image() const {
+	return province_index_image;
+}
+
+return_t Map::add_mapmode(std::string const& identifier, Mapmode::colour_func_t colour_func, std::string& error_message) {
+	if (identifier.empty()) {
+		error_message = "Empty mapmode identifier!";
+		return FAILURE;
+	}
+	if (colour_func == nullptr) {
+		error_message = "Mapmode colour function is null for identifier: " + identifier;
+		return FAILURE;
+	}
+	Mapmode new_mapmode{ mapmodes.size(), identifier, colour_func };
+	for (Mapmode const& mapmode : mapmodes) {
+		if (mapmode.get_identifier() == identifier) {
+			error_message = "Duplicate mapmode identifiers: " + mapmode.get_identifier() + " and " + identifier;
+			return FAILURE;
+		}
+	}
+	mapmodes.push_back(new_mapmode);
+	error_message = "Added mapmode: " + identifier;
+	return SUCCESS;
+}
+
+size_t Map::get_mapmode_count() const {
+	return mapmodes.size();
+}
+
+Mapmode const* Map::get_mapmode_by_index(size_t index) const {
+	return index < mapmodes.size() ? &mapmodes[index] : nullptr;
+}
+
+Mapmode const* Map::get_mapmode_by_identifier(std::string const& identifier) const {
+	if (!identifier.empty())
+		for (Mapmode const& mapmode : mapmodes)
+			if (mapmode.get_identifier() == identifier) return &mapmode;
+	return nullptr;
+}
+
+return_t Map::generate_mapmode_colours(Mapmode::index_t index, uint8_t* target, std::string& error_message) const {
+	if (target == nullptr) {
+		error_message = "Mapmode colour target pointer is null!";
+		return FAILURE;
+	}
+	if (index >= mapmodes.size()) {
+		error_message = "Invalid mapmode index: " + std::to_string(index);
+		return FAILURE;
+	}
+	Mapmode const& mapmode = mapmodes[index];
+	target += 3; // Skip past Province::NULL_INDEX
+	for (Province const& province : provinces) {
+		const Province::colour_t colour = mapmode.get_colour_func()(*this, province);
+		*target++ = (colour >> 16) & 0xFF;
+		*target++ = (colour >> 8) & 0xFF;
+		*target++ = colour & 0xFF;
+	}
+	return SUCCESS;
+}
diff --git a/extension/src/openvic2/Map.hpp b/extension/src/openvic2/Map.hpp
new file mode 100644
index 0000000..42963c9
--- /dev/null
+++ b/extension/src/openvic2/Map.hpp
@@ -0,0 +1,113 @@
+#pragma once
+
+#include <string>
+#include <cstdint>
+#include <vector>
+#include <functional>
+
+#include "Types.hpp"
+
+namespace OpenVic2 {
+	struct Region;
+	struct Map;
+
+	/* REQUIREMENTS:
+	 * MAP-43, MAP-47
+	 */
+	struct Province {
+		friend struct Map;
+
+		using colour_t = uint32_t;
+		using index_t = uint16_t;
+
+		static const colour_t NULL_COLOUR = 0, MAX_COLOUR = 0xFFFFFF;
+		static const index_t NULL_INDEX = 0, MAX_INDEX = 0xFFFF;
+	private:
+		index_t index;
+		std::string identifier;
+		colour_t colour;
+		Region* region = nullptr;
+
+		Province(index_t new_index, std::string const& new_identifier, colour_t new_colour);
+	public:
+		static std::string colour_to_hex_string(colour_t colour);
+
+		index_t get_index() const;
+		std::string const& get_identifier() const;
+		colour_t get_colour() const;
+		Region* get_region() const;
+		std::string to_string() const;
+	};
+
+	/* REQUIREMENTS:
+	 * MAP-6, MAP-44, MAP-48
+	 */
+	struct Region {
+		friend struct Map;
+	private:
+		std::string identifier;
+		std::vector<Province*> provinces;
+
+		Region(std::string const& new_identifier);
+	public:
+		std::string const& get_identifier() const;
+		size_t get_province_count() const;
+		bool contains_province(Province const* province) const;
+		std::vector<Province*> const& get_provinces() const;
+	};
+
+	struct Mapmode {
+		friend struct Map;
+
+		using colour_func_t = std::function<Province::colour_t (Map const&, Province const&)>;
+		using index_t = size_t;
+	private:
+		index_t index;
+		std::string identifier;
+		colour_func_t colour_func;
+
+		Mapmode(index_t new_index, std::string const& new_identifier, colour_func_t new_colour_func);
+	public:
+		index_t get_index() const;
+		std::string const& get_identifier() const;
+		colour_func_t get_colour_func() const;
+	};
+
+	/* REQUIREMENTS:
+	 * MAP-4
+	 */
+	struct Map {
+	private:
+		std::vector<Province> provinces;
+		std::vector<Region> regions;
+		bool provinces_locked = false, regions_locked = false;
+
+		size_t width = 0, height = 0;
+		std::vector<Province::index_t> province_index_image;
+		std::vector<Mapmode> mapmodes;
+	public:
+		return_t add_province(std::string const& identifier, Province::colour_t colour, std::string& error_message);
+		void lock_provinces();
+		return_t add_region(std::string const& identifier, std::vector<std::string> const& province_identifiers, std::string& error_message);
+		void lock_regions();
+		size_t get_province_count() const;
+
+		Province* get_province_by_index(Province::index_t index);
+		Province const* get_province_by_index(Province::index_t index) const;
+		Province* get_province_by_identifier(std::string const& identifier);
+		Province const* get_province_by_identifier(std::string const& identifier) const;
+		Province* get_province_by_colour(Province::colour_t colour);
+		Province const* get_province_by_colour(Province::colour_t colour) const;
+
+		return_t generate_province_index_image(size_t new_width, size_t new_height, uint8_t const* colour_data, std::string& error_message);
+		size_t get_width() const;
+		size_t get_height() const;
+		std::vector<Province::index_t> const& get_province_index_image() const;
+
+		return_t add_mapmode(std::string const& identifier, Mapmode::colour_func_t colour_func, std::string& error_message);
+		size_t get_mapmode_count() const;
+		Mapmode const* get_mapmode_by_index(Mapmode::index_t index) const;
+		Mapmode const* get_mapmode_by_identifier(std::string const& identifier) const;
+		return_t generate_mapmode_colours(Mapmode::index_t index, uint8_t* target, std::string& error_message) const;
+	};
+}
diff --git a/extension/src/openvic2/Province.cpp b/extension/src/openvic2/Province.cpp
new file mode 100644
index 0000000..49f1b0e
--- /dev/null
+++ b/extension/src/openvic2/Province.cpp
@@ -0,0 +1,40 @@
+#include "Map.hpp"
+
+#include <cassert>
+#include <sstream>
+#include <iomanip>
+
+using namespace OpenVic2;
+
+Province::Province(index_t new_index, std::string const& new_identifier, colour_t new_colour) :
+	index(new_index), identifier(new_identifier), colour(new_colour) {
+	assert(index != NULL_INDEX);
+	assert(!identifier.empty());
+	assert(colour != NULL_COLOUR);
+}
+
+std::string Province::colour_to_hex_string(colour_t colour) {
+	std::ostringstream stream;
+	stream << std::hex << std::setfill('0') << std::setw(6) << colour;
+	return stream.str();
+}
+
+Province::index_t Province::get_index() const {
+	return index;
+}
+
+std::string const& Province::get_identifier() const {
+	return identifier;
+}
+
+Province::colour_t Province::get_colour() const {
+	return colour;
+}
+
+Region* Province::get_region() const {
+	return region;
+}
+
+std::string Province::to_string() const {
+	return "(#" + std::to_string(index) + ", " + identifier + ", 0x" + colour_to_hex_string(colour) + ")";
+}
diff --git a/extension/src/openvic2/Region.cpp b/extension/src/openvic2/Region.cpp
new file mode 100644
index 0000000..6ee05f5
--- /dev/null
+++ b/extension/src/openvic2/Region.cpp
@@ -0,0 +1,26 @@
+#include "Map.hpp"
+
+#include <cassert>
+#include <algorithm>
+
+using namespace OpenVic2;
+
+Region::Region(std::string const& new_identifier) : identifier(new_identifier) {
+	assert(!identifier.empty());
+}
+
+std::string const& Region::get_identifier() const {
+	return identifier;
+}
+
+size_t Region::get_province_count() const {
+	return provinces.size();
+}
+
+bool Region::contains_province(Province const* province) const {
+	return province && std::find(provinces.begin(), provinces.end(), province) != provinces.end();
+}
+
+std::vector<Province*> const& Region::get_provinces() const {
+	return provinces;
+}
diff --git a/extension/src/openvic2/Types.hpp b/extension/src/openvic2/Types.hpp
new file mode 100644
index 0000000..0fb1c8b
--- /dev/null
+++ b/extension/src/openvic2/Types.hpp
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace OpenVic2 {
+	using return_t = bool;
+	// This mirrors godot::Error, where `OK = 0` and `FAILED = 1`.
+	static const return_t SUCCESS = false, FAILURE = true;
+}
diff --git a/extension/src/register_types.cpp b/extension/src/register_types.cpp
index d1613a5..9fd934e 100644
--- a/extension/src/register_types.cpp
+++ b/extension/src/register_types.cpp
@@ -1,14 +1,13 @@
 #include "register_types.h"
-#include <gdextension_interface.h>
-#include <godot_cpp/core/class_db.hpp>
-#include <godot_cpp/core/defs.hpp>
-#include <godot_cpp/godot.hpp>
+
 #include <godot_cpp/classes/engine.hpp>
 
 #include "TestSingleton.hpp"
 #include "Simulation.hpp"
 #include "Checksum.hpp"
 #include "LoadLocalisation.hpp"
+#include "MapSingleton.hpp"
+#include "MapMesh.hpp"
 
 using namespace godot;
 using namespace OpenVic2;
@@ -17,9 +16,9 @@ static TestSingleton* _test_singleton;
 static Simulation* _simulation;
 static Checksum* _checksum;
 static LoadLocalisation* _load_localisation;
+static MapSingleton* _map_singleton;
 
-void initialize_openvic2_types(ModuleInitializationLevel p_level)
-{
+void initialize_openvic2_types(ModuleInitializationLevel p_level) {
 	if (p_level != MODULE_INITIALIZATION_LEVEL_SCENE) {
 		return;
 	}
@@ -40,6 +39,11 @@ void initialize_openvic2_types(ModuleInitializationLevel p_level)
 	_load_localisation = memnew(LoadLocalisation);
 	Engine::get_singleton()->register_singleton("LoadLocalisation", LoadLocalisation::get_singleton());
 
+	ClassDB::register_class<MapSingleton>();
+	_map_singleton = memnew(MapSingleton);
+	Engine::get_singleton()->register_singleton("MapSingleton", MapSingleton::get_singleton());
+
+	ClassDB::register_class<MapMesh>();
 }
 
 void uninitialize_openvic2_types(ModuleInitializationLevel p_level) {
@@ -58,15 +62,16 @@ void uninitialize_openvic2_types(ModuleInitializationLevel p_level) {
 
 	Engine::get_singleton()->unregister_singleton("LoadLocalisation");
 	memdelete(_load_localisation);
+
+	Engine::get_singleton()->unregister_singleton("MapSingleton");
+	memdelete(_map_singleton);
 }
 
-extern "C"
-{
+extern "C" {
 
 	// Initialization.
 
-	GDExtensionBool GDE_EXPORT openvic2_library_init(const GDExtensionInterface *p_interface, const GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization)
-	{
+	GDExtensionBool GDE_EXPORT openvic2_library_init(GDExtensionInterface const* p_interface, const GDExtensionClassLibraryPtr p_library, GDExtensionInitialization* r_initialization) {
 		GDExtensionBinding::InitObject init_obj(p_interface, p_library, r_initialization);
 
 		init_obj.register_initializer(initialize_openvic2_types);
diff --git a/extension/src/register_types.h b/extension/src/register_types.h
index 860359f..1bc96f8 100644
--- a/extension/src/register_types.h
+++ b/extension/src/register_types.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include <godot_cpp/core/class_db.hpp>
+#include <godot_cpp/godot.hpp>
 
 void initialize_openvic2_types(godot::ModuleInitializationLevel);
 void uninitialize_openvic2_types(godot::ModuleInitializationLevel);
\ No newline at end of file