Almost working save sytem but the data I store is totally wrong. I need to also save the entity IDs being used and map them to the components.

combat.cpp

@@ -1,6 +1,7 @@
 #include "combat.hpp"
 #include "rand.hpp"
 
+namespace components {
   int Combat::attack(Combat &target) {
     int attack = Random::uniform<int>(0,1);
     int my_dmg = 0;
@@ -12,3 +13,4 @@ int Combat::attack(Combat &target) {
 
     return my_dmg;
   }
+}

combat.hpp

@@ -1,7 +1,6 @@
 #pragma once
 
-#include "components.hpp"
+namespace components {
-
   struct Combat {
     int hp;
     int damage;
@@ -9,3 +8,4 @@ struct Combat {
 
     int attack(Combat &target);
   };
+}

components.hpp

@@ -3,27 +3,33 @@
 #include "map.hpp"
 #include "combat.hpp"
 #include <deque>
+#include "tser.hpp"
 
-namespace Components {
+namespace components {
   struct Player {
     DinkyECS::Entity entity;
+    DEFINE_SERIALIZABLE(Player, entity);
   };
 
   struct Position {
     Point location;
+    DEFINE_SERIALIZABLE(Position, location);
   };
 
   struct Motion {
     int dx;
     int dy;
+    DEFINE_SERIALIZABLE(Motion, dx, dy);
   };
 
   struct Treasure {
     int amount;
+    DEFINE_SERIALIZABLE(Treasure, amount);
   };
 
   struct Tile {
     std::string chr = "!";
+    DEFINE_SERIALIZABLE(Tile, chr);
   };
 
   struct MapConfig {

dinkyecs.hpp

@@ -7,6 +7,7 @@
 #include <any>
 #include <tuple>
 #include <queue>
+#include "tser.hpp"
 
 namespace DinkyECS {
 
@@ -116,4 +117,6 @@ namespace DinkyECS {
         return !queue.empty();
       }
   };
+
+
 }

gui.cpp

@@ -24,7 +24,7 @@ using std::string;
 using namespace fmt;
 using namespace std::chrono_literals;
 using namespace ftxui;
-using namespace Components;
+using namespace components;
 
 
 GUI::GUI(DinkyECS::World &world, Map& game_map) :
@@ -56,6 +56,13 @@ void GUI::resize_map(int new_size) {
   }
 }
 
+void GUI::save_world() {
+  tser::BinaryArchive archive;
+  archive.save($world);
+  std::string_view archive_view = archive.get_buffer();
+  $log.log(format("Game saved! {} bytes.", archive_view.size()));
+}
+
 void GUI::create_renderer() {
   Terminal::SetColorSupport(Terminal::Color::TrueColor);
   auto player = $world.get_the<Player>();
@@ -151,6 +158,8 @@ bool GUI::handle_ui_events() {
         resize_map(map_font_size + 10);
       } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Hyphen)) {
         resize_map(map_font_size - 10);
+      } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::S)) {
+        save_world();
       }
     }
   }

gui.hpp

@@ -58,6 +58,7 @@ public:
   void handle_world_events();
   void draw_screen(bool clear=true, float map_off_x=0.0f, float map_off_y=0.0f);
   void run_systems();
+  void save_world();
 
   int main();
 };

meson.build

@@ -21,6 +21,7 @@ runtests = executable('runtests', [
   'collider.cpp',
   'ansi_parser.cpp',
   'config.cpp',
+  'save.cpp',
   'tests/fsm.cpp',
   'tests/dbc.cpp',
   'tests/map.cpp',
@@ -29,6 +30,7 @@ runtests = executable('runtests', [
   'tests/dinkyecs.cpp',
   'tests/ansi_parser.cpp',
   'tests/config.cpp',
+  'tests/save.cpp',
   ],
   dependencies: dependencies)
 
@@ -45,6 +47,7 @@ roguish = executable('roguish', [
   'ansi_parser.cpp',
   'render.cpp',
   'config.cpp',
+  'save.cpp',
   ],
   dependencies: dependencies)
 

point.hpp

@@ -1,4 +1,5 @@
 #pragma once
+#include "tser.hpp"
 
 struct Point {
   size_t x = 0;
@@ -7,6 +8,8 @@ struct Point {
   bool operator==(const Point& other) const {
     return other.x == x && other.y == y;
   }
+
+  DEFINE_SERIALIZABLE(Point, x, y);
 };
 
 typedef std::vector<Point> PointList;

save.cpp

@@ -0,0 +1,63 @@
+#include "save.hpp"
+#include <fstream>
+#include "dbc.hpp"
+#include <fmt/core.h>
+
+using namespace components;
+
+
+template<typename CompT>
+inline void extract(DinkyECS::World &world, std::vector<CompT> &into) {
+  auto from_world = world.entity_map_for<CompT>();
+  for(auto [entity, value] : from_world) {
+    into.push_back(std::any_cast<CompT>(value));
+  }
+}
+
+void save::to_file(std::string path, DinkyECS::World &world) {
+  SaveData save_data;
+  tser::BinaryArchive archive;
+
+  save_data.player = world.get_the<Player>();
+  extract<Position>(world, save_data.position);
+  extract<Combat>(world, save_data.combat);
+  extract<Motion>(world, save_data.motion);
+
+  archive.save(save_data);
+  std::string_view archive_view = archive.get_buffer();
+
+  std::ofstream out(path, std::ios::binary);
+  out << archive_view;
+  out.flush();
+}
+
+
+void save::from_file(std::string path, DinkyECS::World &world_out) {
+  tser::BinaryArchive archive(0);
+
+  if(std::ifstream in_file{path, std::ios::binary | std::ios::ate}) {
+    auto size = in_file.tellg();
+    std::string in_data(size, '\0');
+    in_file.seekg(0);
+
+    if(in_file.read(&in_data[0], size)) {
+      std::string_view in_view(in_data);
+      archive.initialize(in_view);
+    } else {
+      dbc::sentinel(fmt::format("wrong size or error reading {}", path));
+    }
+  } else {
+    dbc::sentinel(fmt::format("failed to load file {}", path));
+  }
+
+  auto save_data = archive.load<SaveData>();
+
+  // BUG: need the entities!
+  world_out.set_the<Player>(save_data.player);
+
+  for(auto position : save_data.position) {
+    auto entity = world_out.entity();
+    // BUG: actually do need the entities
+    world_out.set<Position>(entity, position);
+  }
+}

save.hpp

@@ -0,0 +1,21 @@
+#pragma once
+
+#include "components.hpp"
+#include "dinkyecs.hpp"
+#include "tser.hpp"
+#include <string>
+#include <vector>
+
+namespace save {
+  struct SaveData {
+    components::Player player;
+    std::vector<components::Position> position;
+    std::vector<components::Motion> motion;
+    std::vector<components::Combat> combat;
+
+    DEFINE_SERIALIZABLE(SaveData, player, position, motion, combat);
+  };
+
+  void to_file(std::string path, DinkyECS::World &world);
+  void from_file(std::string path, DinkyECS::World &world_out);
+}

systems.cpp

@@ -10,7 +10,7 @@
 
 using std::string;
 using namespace fmt;
-using namespace Components;
+using namespace components;
 using ftxui::Color;
 
 void System::enemy_pathing(DinkyECS::World &world, Map &game_map, Player &player) {

systems.hpp

@@ -4,7 +4,7 @@
 #include "components.hpp"
 #include <ftxui/dom/canvas.hpp>
 
-using namespace Components;
+using namespace components;
 
 namespace System {
   void motion(DinkyECS::World &world, Map &game_map);

tests/config.cpp

@@ -6,6 +6,7 @@
 #include "dinkyecs.hpp"
 #include "components.hpp"
 
+
 using namespace fmt;
 using std::string;
 
@@ -61,47 +62,3 @@ TEST_CASE("can go into a world", "[config]") {
   Config &cfg = world.get_the<Config>();
   REQUIRE(cfg["types"]["NUMBER"] == 1234);
 }
-
-
-#include <optional>
-#include <iostream>
-#include "tser.hpp"
-
-enum class Item : char {
-  RADAR = 'R',
-  TRAP = 'T',
-  ORE = 'O'
-};
-
-struct Pixel {
-  int x = 0;
-  int y = 0;
-
-  DEFINE_SERIALIZABLE(Pixel, x, y);
-};
-
-struct Robot {
-  Pixel point;
-  std::wstring name;
-  std::optional<Item> item;
-
-  DEFINE_SERIALIZABLE(Robot, point, name, item);
-};
-
-TEST_CASE("test using tser for serialization", "[config]") {
-  auto robot = Robot{ Pixel{3,4}, L"BIG NAME", Item::RADAR};
-  std::cout << robot << '\n';
-
-  tser::BinaryArchive archive;
-  archive.save(robot);
-  std::string_view archive_view = archive.get_buffer();
-
-  tser::BinaryArchive archive2(0);
-  archive2.initialize(archive_view);
-  auto loadedRobot = archive2.load<Robot>();
-
-  REQUIRE(loadedRobot.point.x == robot.point.x);
-  REQUIRE(loadedRobot.point.y == robot.point.y);
-  REQUIRE(loadedRobot.name == robot.name);
-  REQUIRE(loadedRobot.item == robot.item);
-}

tests/save.cpp

@@ -0,0 +1,80 @@
+#include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
+#include <string>
+#include "dinkyecs.hpp"
+#include "components.hpp"
+#include "save.hpp"
+#include <optional>
+#include <iostream>
+#include "tser.hpp"
+
+using namespace fmt;
+using std::string;
+using namespace components;
+
+enum class Item : char {
+  RADAR = 'R',
+  TRAP = 'T',
+  ORE = 'O'
+};
+
+struct Pixel {
+  int x = 0;
+  int y = 0;
+
+  DEFINE_SERIALIZABLE(Pixel, x, y);
+};
+
+struct Robot {
+  Pixel point;
+  std::wstring name;
+  std::optional<Item> item;
+
+  DEFINE_SERIALIZABLE(Robot, point, name, item);
+};
+
+
+TEST_CASE("test using tser for serialization", "[config]") {
+  auto robot = Robot{ Pixel{3,4}, L"BIG NAME", Item::RADAR};
+  std::cout << robot << '\n';
+
+  tser::BinaryArchive archive;
+  archive.save(robot);
+  std::string_view archive_view = archive.get_buffer();
+
+  tser::BinaryArchive archive2(0);
+  archive2.initialize(archive_view);
+  auto loadedRobot = archive2.load<Robot>();
+
+  REQUIRE(loadedRobot.point.x == robot.point.x);
+  REQUIRE(loadedRobot.point.y == robot.point.y);
+  REQUIRE(loadedRobot.name == robot.name);
+  REQUIRE(loadedRobot.item == robot.item);
+}
+
+TEST_CASE("basic save a world", "[save]") {
+  DinkyECS::World world;
+
+  // configure a player as a fact of the world
+  Player player{world.entity()};
+  world.set_the<Player>(player);
+
+  world.set<Position>(player.entity, {10,10});
+  world.set<Motion>(player.entity, {0, 0});
+  world.set<Combat>(player.entity, {100, 10});
+
+  save::to_file("./savetest.world", world);
+
+  DinkyECS::World in_world;
+  save::from_file("./savetest.world", in_world);
+
+  Position &position1 = world.get<Position>(player.entity);
+  Position &position2 = in_world.get<Position>(player.entity);
+
+  // BUGGGGGGGG! This doesn't actually work, it's all fake
+  // The world uses an internal id to increment entities so
+  // by default player gets the first one, but all data after
+  // that is wrong.
+  REQUIRE(position1.location.x == position2.location.x);
+  REQUIRE(position1.location.y == position2.location.y);
+}

tser.hpp

@@ -8,6 +8,7 @@
 #include <string_view>
 #include <type_traits>
 #include <tuple>
+#include <locale>
 #include <codecvt>
 
 namespace tser{