Merge pull request #1 from tcsullivan/save-load

Save load looks good

11 files changed, 220 insertions, 9 deletions

diff --git a/src/components/Component.hpp b/src/components/Component.hpp
index 5a062bd..2928366 100644
--- a/src/components/Component.hpp
+++ b/src/components/Component.hpp
@@ -18,13 +18,27 @@
 #ifndef COMPONENT_HPP_
 #define COMPONENT_HPP_
 
+#include <cereal/cereal.hpp>
+#include <cereal/archives/json.hpp>
+
+#include <entityx/entityx.h>
 #include <sol/sol.hpp>
 
 template<typename T>
-class Component 
+class Component : public entityx::Component<T>
 {
 public:
     virtual T FromLua(sol::object) = 0;
+
+    virtual void serialize(cereal::JSONOutputArchive& ar) = 0;
+    virtual void serialize(cereal::JSONInputArchive& ar) = 0;
+
+    void internal_serialize(bool save, void *ar) final {
+        if (save)
+            serialize(*reinterpret_cast<cereal::JSONOutputArchive*>(ar));
+        else
+            serialize(*reinterpret_cast<cereal::JSONInputArchive*>(ar));
+    }
 };
 
 #endif // COMPONENT_HPP_
diff --git a/src/components/Light.hpp b/src/components/Light.hpp
index ee215a6..6849d7c 100644
--- a/src/components/Light.hpp
+++ b/src/components/Light.hpp
@@ -22,7 +22,7 @@
 
 #include "Component.hpp"
 
-struct Light : Component<Light>, entityx::Component<Light>
+struct Light : Component<Light>
 {
 public:
     float r, g, b;
@@ -49,6 +49,18 @@ public:
         }
         return *this;
     }
+
+    void serialize(cereal::JSONOutputArchive& ar) final {
+        ar(CEREAL_NVP(r), CEREAL_NVP(g), CEREAL_NVP(b), CEREAL_NVP(strength));
+    }
+
+    void serialize(cereal::JSONInputArchive& ar) final {
+        ar(CEREAL_NVP(r), CEREAL_NVP(g), CEREAL_NVP(b), CEREAL_NVP(strength));
+    }
+
+    std::string serializeName(void) const final {
+        return "Light";
+    }
 };
 
 #endif//COMPONENT_LIGHT_HPP_
diff --git a/src/components/Name.hpp b/src/components/Name.hpp
index 94b7531..a6a6d8a 100644
--- a/src/components/Name.hpp
+++ b/src/components/Name.hpp
@@ -21,7 +21,7 @@
 #include "Component.hpp"
 #include <string>
 
-struct Name : Component<Name>, entityx::Component<Name>
+struct Name : Component<Name>
 {
 public:
     std::string name;
@@ -38,6 +38,18 @@ public:
 
         return *this;
     }
+
+    void serialize(cereal::JSONOutputArchive& ar) final {
+        ar(CEREAL_NVP(name));
+    }
+
+    void serialize(cereal::JSONInputArchive& ar) final {
+        ar(CEREAL_NVP(name));
+    }
+
+    std::string serializeName(void) const final {
+        return "Name";
+    }
 };
 
 #endif // COMPONENT_NAME_HPP_
diff --git a/src/components/Player.hpp b/src/components/Player.hpp
index 5c1e870..33db1eb 100644
--- a/src/components/Player.hpp
+++ b/src/components/Player.hpp
@@ -23,13 +23,22 @@
 
 #include "Component.hpp"
 
-struct Player : Component<Player>, entityx::Component<Player>
+struct Player : Component<Player>
 {
 public:
+    char _unused;
+
     Player FromLua([[maybe_unused]] sol::object ref)
     {
         return *this;
     }
+
+    void serialize([[maybe_unused]] cereal::JSONOutputArchive& ar) final {}
+    void serialize([[maybe_unused]] cereal::JSONInputArchive& ar) final {}
+
+    std::string serializeName(void) const final {
+        return "Player";
+    }
 };
 
 #endif // COMPONENT_PLAYER_HPP_
diff --git a/src/components/Position.hpp b/src/components/Position.hpp
index c801998..56e8707 100644
--- a/src/components/Position.hpp
+++ b/src/components/Position.hpp
@@ -21,7 +21,7 @@
 
 #include "Component.hpp"
 
-struct Position : Component<Position>, entityx::Component<Position>
+struct Position : Component<Position>
 {
 public:
     double x, y;
@@ -42,6 +42,18 @@ public:
         }
         return *this;
     }
+
+    void serialize(cereal::JSONOutputArchive& ar) final {
+        ar(CEREAL_NVP(x), CEREAL_NVP(y));
+    }
+
+    void serialize(cereal::JSONInputArchive& ar) final {
+        ar(CEREAL_NVP(x), CEREAL_NVP(y));
+    }
+
+    std::string serializeName(void) const final {
+        return "Position";
+    }
 };
 
 #endif // COMPONENT_POSITION_HPP_
diff --git a/src/components/Render.hpp b/src/components/Render.hpp
index 073cbdf..81ca591 100644
--- a/src/components/Render.hpp
+++ b/src/components/Render.hpp
@@ -21,7 +21,7 @@
 #include "Component.hpp"
 #include "texture.hpp"
 
-struct Render : Component<Render>, entityx::Component<Render>
+struct Render : Component<Render>
 {
 public:
     Texture texture;
@@ -53,6 +53,18 @@ public:
         }
         return *this;
     }
+
+    void serialize(cereal::JSONOutputArchive& ar) final {
+        ar(CEREAL_NVP(visible), CEREAL_NVP(flipX));
+    }
+
+    void serialize(cereal::JSONInputArchive& ar) final {
+        ar(CEREAL_NVP(visible), CEREAL_NVP(flipX));
+    }
+
+    std::string serializeName(void) const final {
+        return "Render";
+    }
 };
 
 #endif // COMPONENT_RENDER_HPP_
diff --git a/src/components/Script.hpp b/src/components/Script.hpp
index b3c89f3..f792750 100644
--- a/src/components/Script.hpp
+++ b/src/components/Script.hpp
@@ -21,7 +21,7 @@
 
 #include "Component.hpp"
 
-struct Scripted : Component<Scripted>, entityx::Component<Scripted>
+struct Scripted : Component<Scripted>
 {
 public:
     sol::table caller;
@@ -60,6 +60,13 @@ public:
         if (caller["RenderIdle"] == sol::type::function)
             caller["RenderIdle"](caller);
     }
+
+    void serialize([[maybe_unused]] cereal::JSONOutputArchive& ar) final {}
+    void serialize([[maybe_unused]] cereal::JSONInputArchive& ar) final {}
+
+    std::string serializeName(void) const final {
+        return "Scripted";
+    }
 };
 
 #endif // COMPONENT_SCRIPT_HPP_
diff --git a/src/components/Velocity.hpp b/src/components/Velocity.hpp
index 29c0e5c..776c1dd 100644
--- a/src/components/Velocity.hpp
+++ b/src/components/Velocity.hpp
@@ -22,7 +22,7 @@
 
 #include "Component.hpp"
 
-struct Velocity : Component<Velocity>, entityx::Component<Velocity>
+struct Velocity : Component<Velocity>
 {
 public:
     double x, y;
@@ -43,6 +43,18 @@ public:
         }
         return *this;
     }
+
+    void serialize(cereal::JSONOutputArchive& ar) final {
+        ar(CEREAL_NVP(x), CEREAL_NVP(y));
+    }
+
+    void serialize(cereal::JSONInputArchive& ar) final {
+        ar(CEREAL_NVP(x), CEREAL_NVP(y));
+    }
+
+    std::string serializeName(void) const final {
+        return "Velocity";
+    }
 };
 
 #endif // COMPONENT_VELOCITY_HPP_
diff --git a/src/engine.cpp b/src/engine.cpp
index 61d119a..e959f21 100644
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -20,6 +20,7 @@
  */
 
 #include "engine.hpp"
+#include "gamestate.hpp"
 #include "gamerun.hpp"
 #include "input.hpp"
 #include "player.hpp"
@@ -30,6 +31,8 @@
 #include "components/Position.hpp"
 #include "components/Velocity.hpp"
 
+#include <fstream>
+
 using namespace std::chrono_literals;
 namespace cr = std::chrono;
 typedef std::chrono::high_resolution_clock mc;
@@ -43,7 +46,12 @@ int Engine::init(void)
     systems.add<ScriptSystem>();
     systems.configure();
 
+    // Load game script and entity data
     systems.system<ScriptSystem>()->init();
+    if (GameState::load("save.json", entities)) {
+        std::cout << "Loaded from save.json. Delete the file if you don't want "
+                     "it." << std::endl;
+    }
 
     return 0;
 }
@@ -116,6 +124,9 @@ void Engine::run(void)
 
     // Done, bring logic thread back
     logicThread.join();
+
+    // Save the entities' data
+    GameState::save("save.json", entities);
 }
 
 bool Engine::shouldRun(void)
diff --git a/src/gamestate.hpp b/src/gamestate.hpp
new file mode 100644
index 0000000..55f4e47
--- /dev/null
+++ b/src/gamestate.hpp
@@ -0,0 +1,108 @@
+/**
+ * @file gamestate.hpp
+ * Provides functionality to load and save entity data to or from JSON files.
+ *
+ * Copyright (C) 2019 Clyne Sullivan
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GAMELOAD_HPP_
+#define GAMELOAD_HPP_
+
+#include <cereal/cereal.hpp>
+#include <cereal/archives/json.hpp>
+#include <entityx/entityx.h>
+
+#include <fstream>
+
+/**
+ * @class GameState
+ * Manages save files that contain entity data.
+ */
+class GameState
+{
+public:
+    /**
+     * Loads entity data from a JSON file into entities contained in the
+     * entity manager.
+     *
+     * The order of entities and the components they have must match between
+     * those in the manager and those in the file.
+     *
+     * @param file The file to load from
+     * @param entities The entity manager to load into
+     * @return True if successful load
+     */
+    static bool load(const std::string& file, entityx::EntityManager &entities)
+    {
+        std::ifstream saveFile (file);
+        bool opened = saveFile.good();
+
+        if (opened) {
+            cereal::JSONInputArchive archive (saveFile);
+            serializeEntities(archive, false, entities);
+        }
+
+        return opened;
+    }
+
+    /**
+     * Saves entity data from the entities in the provided manager into a JSON
+     * file,
+     *
+     * @param file The file to load from
+     * @param entities The entity manager to get entity data from
+     * @return True if successful save
+     */
+    static bool save(const std::string& file, entityx::EntityManager &entities)
+    {
+        std::ofstream saveFile (file);
+        bool opened = saveFile.good();
+
+        if (opened) {
+            cereal::JSONOutputArchive archive (saveFile);
+            serializeEntities(archive, true, entities);
+        }
+
+        return opened;
+    }
+
+private:
+    /**
+     * Calls the serialization funciton for each entity in the given entity
+     * manager.
+     * @param archive The archive to save/load with (cereal::JSON...)
+     * @param save True to save data, false to load
+     * @param entities The entity manager to iterate through
+     */
+    template<class Archive>
+    static void serializeEntities(Archive& archive,
+                                  bool save,
+                                  entityx::EntityManager& entities)
+    {
+        std::string name ("entity");
+        int i = 0;
+
+        for (auto entity : entities.entities_for_debugging()) {
+            archive.setNextName((name + std::to_string(i++)).c_str());
+            archive.startNode();
+            entities.entity_serialize(entity, save, archive);
+            archive.finishNode();
+        }
+    }
+};
+
+#endif // GAMELOAD_HPP_
+
diff --git a/src/script.cpp b/src/script.cpp
index fa485bc..351aae4 100644
--- a/src/script.cpp
+++ b/src/script.cpp
@@ -57,7 +57,7 @@ void ScriptSystem::receive([[maybe_unused]] const EntitySpawnEvent &toSpawn)
 
 int ScriptSystem::init(void)
 {
-    lua.open_libraries(sol::lib::base, sol::lib::math);
+    lua.open_libraries(sol::lib::base, sol::lib::math, sol::lib::string);
 
     scriptExport();
     doFile();
@@ -176,6 +176,8 @@ sol::table ScriptSystem::spawn(sol::object param)
         }
 
         if (tab["Light"] != nullptr) {
+            if (!e.has_component<Position>()) // Position must exist for vel.
+                (*toRet)["Position"] = e.assign<Position>().get();
             (*toRet)["Light"] = 
                 e.assign<Light>(Light().FromLua(tab["Light"])).get();
         }