add entity on_save event and SAVED_DATA variable

res/content/base/scripts/components/drop.lua

@@ -12,6 +12,11 @@ local rotation = mat4.rotate({
     math.random(), math.random(), math.random()
 }, 360)
 
+function on_save()
+    SAVED_DATA.test = 5
+    print("SAVE ENTITY")
+end
+
 do -- setup visuals
     local matrix = mat4.idt()
     local icon = item.icon(dropitem.id)

src/logic/scripting/scripting.cpp

@@ -263,6 +263,15 @@ bool scripting::on_item_break_block(Player* player, const ItemDef* item, int x,
     });
 }
 
+dynamic::Value scripting::get_component_value(const scriptenv& env, const std::string& name) {
+    auto L = lua::get_main_thread();
+    lua::pushenv(L, *env);
+    if (lua::getfield(L, name)) {
+        return lua::tovalue(L, -1);
+    }
+    return dynamic::NONE;
+}
+
 void scripting::on_entity_spawn(
     const EntityDef& def, 
     entityid_t eid, 
@@ -279,12 +288,17 @@ void scripting::on_entity_spawn(
         lua::pushvalue(L, -1);
     }
     for (auto& component : components) {
-        auto compenv = create_component_environment(
-            get_root_environment(), -1, component->name);
+        auto compenv = create_component_environment(get_root_environment(), -1, 
+                                                    component->name);
         lua::get_from(L, lua::CHUNKS_TABLE, component->name, true);
         lua::pushenv(L, *compenv);
+
         lua::pushvalue(L, args);
         lua::setfield(L, "ARGS");
+
+        lua::createtable(L, 0, 0);
+        lua::setfield(L, "SAVED_DATA");
+
         lua::setfenv(L);
         lua::call_nothrow(L, 0, 0);
 
@@ -379,7 +393,6 @@ void scripting::on_trigger_enter(const Entity& entity, size_t index, entityid_t
     }
 }
 
-
 void scripting::on_trigger_exit(const Entity& entity, size_t index, entityid_t oid) {
     const auto& script = entity.getScripting();
     for (auto& component : script.components) {

src/logic/scripting/scripting.hpp

@@ -76,6 +76,7 @@ namespace scripting {
     /// @return true if prevents default action
     bool on_item_break_block(Player* player, const ItemDef* item, int x, int y, int z);
 
+    dynamic::Value get_component_value(const scriptenv& env, const std::string& name);
     void on_entity_spawn(
         const EntityDef& def,
         entityid_t eid, 

src/objects/Entities.cpp

@@ -112,6 +112,10 @@ void Entities::despawn(entityid_t id) {
     }
 }
 
+void Entities::onSave(const Entity& entity) {
+    scripting::on_entity_save(entity);
+}
+
 dynamic::Value Entities::serialize(const Entity& entity) {
     auto root = dynamic::create_map();
     auto& eid = entity.getID();
@@ -140,7 +144,6 @@ dynamic::Value Entities::serialize(const Entity& entity) {
     if (rig.config->getName() != def.rigName) {
         root->put("rig", rig.config->getName());
     }
-
     if (def.save.rig.pose || def.save.rig.textures) {
         auto& rigmap = root->putMap("rig");
         if (def.save.rig.textures) {
@@ -156,6 +159,14 @@ dynamic::Value Entities::serialize(const Entity& entity) {
             }
         }
     }
+    auto& scripts = entity.getScripting();
+    if (!scripts.components.empty()) {
+        auto& compsMap = root->putMap("comps");
+        for (auto& comp : scripts.components) {
+            auto data = scripting::get_component_value(comp->env, "SAVED_DATA");
+            compsMap.put(comp->name, data);
+        }
+    }
     return root;
 }
 

src/objects/Entities.hpp

@@ -183,6 +183,7 @@ public:
         return std::nullopt;
     }
 
+    void onSave(const Entity& entity);
     std::vector<Entity> getAllInside(AABB aabb);
     void despawn(entityid_t id);
     dynamic::Value serialize(const Entity& entity);

src/voxels/Chunks.cpp

@@ -713,6 +713,7 @@ void Chunks::save(Chunk* chunk) {
         auto root = dynamic::create_map();
         auto& list = root->putList("data");
         for (auto& entity : entities) {
+            level->entities->onSave(entity);
             list.put(level->entities->serialize(entity));
         }
         if (!entities.empty()) {