Optimize parameter passing to avoid unnecessary copying

src/world/LevelEvents.cpp

@@ -3,14 +3,14 @@
 
 using std::vector;
 
-void LevelEvents::listen(lvl_event_type type, chunk_event_func func) {
+void LevelEvents::listen(lvl_event_type type, const chunk_event_func& func) {
 	auto& callbacks = chunk_callbacks[type];
 	callbacks.push_back(func);
 }
 
 void LevelEvents::trigger(lvl_event_type type, Chunk* chunk) {
 	const auto& callbacks = chunk_callbacks[type];
-	for (chunk_event_func func : callbacks) {
+	for (const chunk_event_func& func : callbacks) {
 		func(type, chunk);
 	}
 }

src/world/LevelEvents.hpp

@@ -16,7 +16,7 @@ using chunk_event_func = std::function<void(lvl_event_type, Chunk*)>;
 class LevelEvents {
     std::unordered_map<lvl_event_type, std::vector<chunk_event_func>> chunk_callbacks;
 public:
-    void listen(lvl_event_type type, chunk_event_func func);
+    void listen(lvl_event_type type, const chunk_event_func& func);
     void trigger(lvl_event_type type, Chunk* chunk);
 };
 

src/world/World.cpp

@@ -16,23 +16,24 @@
 
 #include <memory>
 #include <glm/glm.hpp>
+#include <utility>
 
 static debug::Logger logger("world");
 
-world_load_error::world_load_error(std::string message) 
+world_load_error::world_load_error(const std::string& message)
     : std::runtime_error(message) {
 }
 
 World::World(
     std::string name, 
     std::string generator,
-    fs::path directory, 
+    const fs::path& directory,
     uint64_t seed, 
     EngineSettings& settings,
     const Content* content,
-    const std::vector<ContentPack> packs
-) : name(name),
-    generator(generator),
+    const std::vector<ContentPack>& packs
+) : name(std::move(name)),
+    generator(std::move(generator)),
     seed(seed),
     settings(settings), 
     content(content),
@@ -70,7 +71,7 @@ void World::write(Level* level) {
     auto playerFile = dynamic::Map();
 
     auto& players = playerFile.putList("players");
-    for (auto object : level->objects) {
+    for (const auto& object : level->objects) {
         if (auto player = std::dynamic_pointer_cast<Player>(object)) {
             players.put(player->serialize());
         }
@@ -79,9 +80,9 @@ void World::write(Level* level) {
 }
 
 std::unique_ptr<Level> World::create(
-    std::string name, 
-    std::string generator,
-    fs::path directory, 
+    const std::string& name,
+    const std::string& generator,
+    const fs::path& directory,
     uint64_t seed,
     EngineSettings& settings, 
     const Content* content,
@@ -94,7 +95,7 @@ std::unique_ptr<Level> World::create(
 }
 
 std::unique_ptr<Level> World::load(
-    fs::path directory,
+    const fs::path& directory,
     EngineSettings& settings,
     const Content* content,
     const std::vector<ContentPack>& packs

src/world/World.hpp

@@ -22,7 +22,7 @@ namespace fs = std::filesystem;
 
 class world_load_error : public std::runtime_error {
 public:
-    world_load_error(std::string message);
+    world_load_error(const std::string &message);
 };
 
 /// @brief holds all world data except the level (chunks and objects)
@@ -55,11 +55,11 @@ public:
     World(
         std::string name, 
         std::string generator,
-        fs::path directory, 
+        const fs::path& directory,
         uint64_t seed, 
         EngineSettings& settings,
         const Content* content,
-        std::vector<ContentPack> packs
+        const std::vector<ContentPack>& packs
     );
 
     ~World();
@@ -90,9 +90,9 @@ public:
     /// @param packs vector of all world content-packs
     /// @return Level instance containing World instance
     static std::unique_ptr<Level> create(
-        std::string name, 
-        std::string generator,
-        fs::path directory, 
+        const std::string& name,
+        const std::string& generator,
+        const fs::path& directory,
         uint64_t seed, 
         EngineSettings& settings, 
         const Content* content,
@@ -108,7 +108,7 @@ public:
     /// @return Level instance containing World instance
     /// @throws world_load_error on world.json load error
     static std::unique_ptr<Level> load(
-        fs::path directory,
+        const fs::path& directory,
         EngineSettings& settings,
         const Content* content,
         const std::vector<ContentPack>& packs

src/world/WorldGenerators.cpp

@@ -16,7 +16,7 @@ std::string WorldGenerators::getDefaultGeneratorID() {
     return "core:default";
 }
 
-std::unique_ptr<WorldGenerator> WorldGenerators::createGenerator(std::string id, const Content* content) {
+std::unique_ptr<WorldGenerator> WorldGenerators::createGenerator(const std::string& id, const Content* content) {
     auto found = generators.find(id);
     if (found == generators.end()) {
         throw std::runtime_error("unknown generator id: "+id);

src/world/WorldGenerators.hpp

@@ -22,7 +22,7 @@ public:
     static std::string getDefaultGeneratorID();
 
     static std::unique_ptr<WorldGenerator> createGenerator(
-        std::string id, const Content* content
+        const std::string &id, const Content *content
     );
 };