7 files changed, 12 insertions, 11 deletions
diff --git a/src/critter.cpp b/src/critter.cpp
index 21dc74bd..5b80ab81 100644
--- a/src/critter.cpp
+++ b/src/critter.cpp
@@ -362,7 +362,7 @@ Vector2 critter::ordinal_offset(Vector2b offset) const
     return Vector2(offset);
 }
 
-void critter::update(size_t i, const Ns& dt)
+void critter::update(size_t& i, const Ns& dt)
 {
     if (playable) [[unlikely]]
     {
diff --git a/src/critter.hpp b/src/critter.hpp
index 18f714e5..40423b3f 100644
--- a/src/critter.hpp
+++ b/src/critter.hpp
@@ -29,7 +29,7 @@ struct critter final : object
     object_type type() const noexcept override;
     explicit operator critter_proto() const;
 
-    void update(size_t i, const Ns& dt) override; // todo! return true when the position changed
+    void update(size_t& i, const Ns& dt) override;
     // todo!
     // add a field: last_update_frame. if doesn't equal to the current world's update
     // frame, update() gets called and last_update_frame is set to current frame.
diff --git a/src/light.cpp b/src/light.cpp
index 0e36fd6d..3e25dfc5 100644
--- a/src/light.cpp
+++ b/src/light.cpp
@@ -53,7 +53,7 @@ light::operator light_proto() const
 }
 
 object_type light::type() const noexcept { return object_type::light; }
-void light::update(size_t, const Ns&) {}
+void light::update(size_t&, const Ns&) {}
 bool light::is_dynamic() const { return true; }
 bool light::is_virtual() const { return true; }
 
diff --git a/src/light.hpp b/src/light.hpp
index 3d0d3546..ecc45d31 100644
--- a/src/light.hpp
+++ b/src/light.hpp
@@ -33,7 +33,7 @@ struct light final : object
     Vector2 ordinal_offset(Vector2b offset) const override;
     float depth_offset() const override;
     object_type type() const noexcept override;
-    void update(size_t i, const Ns& dt) override;
+    void update(size_t& i, const Ns& dt) override;
     bool is_dynamic() const override;
     bool is_virtual() const override;
 
diff --git a/src/object.hpp b/src/object.hpp
index ae930259..66cf4d6b 100644
--- a/src/object.hpp
+++ b/src/object.hpp
@@ -43,6 +43,7 @@ struct object
     fm_DECLARE_DELETED_COPY_ASSIGNMENT(object);
 
     const object_id id = 0;
+    uint64_t last_frame_no = 0;
     class chunk* const c;
     const std::shared_ptr<anim_atlas> atlas;
     const global_coords coord;
@@ -71,7 +72,7 @@ struct object
     virtual object_type type() const noexcept = 0;
     virtual bool can_activate(size_t i) const;
     virtual bool activate(size_t i);
-    virtual void update(size_t i, const Ns& dt) = 0;
+    virtual void update(size_t& i, const Ns& dt) = 0;
     void rotate(size_t i, rotation r);
     bool can_rotate(global_coords coord, rotation new_r, rotation old_r, Vector2b offset, Vector2b bbox_offset, Vector2ub bbox_size);
     bool can_move_to(Vector2i delta, global_coords coord, Vector2b offset, Vector2b bbox_offset, Vector2ub bbox_aize);
diff --git a/src/scenery.cpp b/src/scenery.cpp
index 701dde1f..fb3010f1 100644
--- a/src/scenery.cpp
+++ b/src/scenery.cpp
@@ -50,7 +50,7 @@ scenery_proto::operator bool() const { return atlas != nullptr; }
 bool generic_scenery_proto::operator==(const generic_scenery_proto& p) const = default;
 enum scenery_type generic_scenery_proto::scenery_type() const { return scenery_type::generic; }
 
-void generic_scenery::update(scenery&, size_t, Ns) {}
+void generic_scenery::update(scenery&, size_t&, Ns) {}
 Vector2 generic_scenery::ordinal_offset(const scenery&, Vector2b offset) const { return Vector2(offset); }
 bool generic_scenery::can_activate(const scenery&, size_t) const { return interactive; }
 bool generic_scenery::activate(floormat::scenery&, size_t) { return false; }
@@ -80,7 +80,7 @@ door_scenery::door_scenery(object_id, class chunk&, const door_scenery_proto& p)
     closing{p.closing}, active{p.active}, interactive{p.interactive}
 {}
 
-void door_scenery::update(scenery& s, size_t, Ns dt)
+void door_scenery::update(scenery& s, size_t&, Ns dt)
 {
     if (!s.atlas || !active)
         return;
@@ -146,7 +146,7 @@ bool scenery::can_activate(size_t i) const
     );
 }
 
-void scenery::update(size_t i, const Ns& dt)
+void scenery::update(size_t& i, const Ns& dt)
 {
     return std::visit(
         [&]<typename T>(T& sc) { sc.update(*this, i, dt); },
diff --git a/src/scenery.hpp b/src/scenery.hpp
index cb952320..cc728a4b 100644
--- a/src/scenery.hpp
+++ b/src/scenery.hpp
@@ -63,7 +63,7 @@ struct generic_scenery
     unsigned char active      : 1 = false;
     unsigned char interactive : 1 = false;
 
-    void update(scenery& sc, size_t i, Ns dt);
+    void update(scenery& sc, size_t& i, Ns dt);
     Vector2 ordinal_offset(const scenery& sc, Vector2b offset) const;
     bool can_activate(const scenery& sc, size_t i) const;
     bool activate(scenery& sc, size_t i);
@@ -80,7 +80,7 @@ struct door_scenery
     unsigned char active      : 1 = false;
     unsigned char interactive : 1 = false;
 
-    void update(scenery& sc, size_t i, Ns dt);
+    void update(scenery& sc, size_t& i, Ns dt);
     Vector2 ordinal_offset(const scenery& sc, Vector2b offset) const;
     bool can_activate(const scenery& sc, size_t i) const;
     bool activate(scenery& sc, size_t i);
@@ -97,7 +97,7 @@ struct scenery final : object
 {
     scenery_variants subtype;
 
-    void update(size_t i, const Ns& dt) override;
+    void update(size_t& i, const Ns& dt) override;
     Vector2 ordinal_offset(Vector2b offset) const override;
     float depth_offset() const override;
     bool can_activate(size_t i) const override;