add entity 'save' property support

src/objects/Entities.cpp

@@ -356,6 +356,24 @@ dynamic::Value Entities::serialize(const Entity& entity) {
     return root;
 }
 
+dynamic::List_sptr Entities::serialize(const std::vector<Entity>& entities) {
+    auto list = dynamic::create_list();
+    for (auto& entity : entities) {
+        if (!entity.getDef().save.enabled) {
+            continue;
+        }
+        level->entities->onSave(entity);
+        list->put(level->entities->serialize(entity));
+    }
+    return list;
+}
+
+void Entities::despawn(std::vector<Entity> entities) {
+    for (auto& entity : entities) {
+        entity.destroy();
+    }
+}
+
 void Entities::clean() {
     for (auto it = entities.begin(); it != entities.end();) {
         if (!registry.get<EntityId>(it->second).destroyFlag) {

src/objects/Entities.hpp

@@ -240,7 +240,9 @@ public:
     std::vector<Entity> getAllInside(AABB aabb);
     std::vector<Entity> getAllInRadius(glm::vec3 center, float radius);
     void despawn(entityid_t id);
+    void despawn(std::vector<Entity> entities);
     dynamic::Value serialize(const Entity& entity);
+    dynamic::List_sptr serialize(const std::vector<Entity>& entities);
 
     void setNextID(entityid_t id) {
         nextID = id;

src/voxels/Chunks.cpp

@@ -743,17 +743,13 @@ void Chunks::save(Chunk* chunk) {
             )
         );
         auto entities = level->entities->getAllInside(aabb);
-        auto root = dynamic::create_map();
-        auto& list = root->putList("data");
-        for (auto& entity : entities) {
-            level->entities->onSave(entity);
-            list.put(level->entities->serialize(entity));
-            entity.destroy();
-        }
         if (!entities.empty()) {
+            auto root = dynamic::create_map();
+            root->put("data", level->entities->serialize(entities));
+            level->entities->despawn(std::move(entities));
             chunk->flags.entities = true;
+            worldFiles->getRegions().put(chunk, json::to_binary(root, true));
         }
-        worldFiles->getRegions().put(chunk, json::to_binary(root, true));
     }
 }