7 files changed, 28 insertions, 11 deletions

diff --git a/doc/saves/quicksave - Copy (60).dat b/doc/saves/quicksave - Copy (60).dat
new file mode 100644
index 00000000..90f51ec1
--- /dev/null
+++ b/doc/saves/quicksave - Copy (60).dat
diff --git a/editor/tests/walk.cpp b/editor/tests/walk.cpp
index ea764a9e..dccd5dab 100644
--- a/editor/tests/walk.cpp
+++ b/editor/tests/walk.cpp
@@ -171,6 +171,7 @@ void pf_test::update_pre(app& a, const Ns& dt)
     if (!current.has_value)
         return;
 
+#if 0
     auto& m = a.main();
     auto& C = *a.ensure_player_character(m.world()).ptr;
     fm_assert(C.is_dynamic());
@@ -250,6 +251,7 @@ void pf_test::update_pre(app& a, const Ns& dt)
         C.offset_frac = {};
         current.has_value = false;
     }
+#endif
 }
 
 } // namespace
diff --git a/serialize/old-savegame.cpp b/serialize/old-savegame.cpp
index 8159419b..111d29f3 100644
--- a/serialize/old-savegame.cpp
+++ b/serialize/old-savegame.cpp
@@ -431,7 +431,7 @@ void reader_state::read_chunks(reader_t& s)
                 }
                 SET_CHUNK_SIZE();
                 auto e = _world->make_object<critter, false>(oid, {ch, local}, proto);
-                e->offset_frac = offset_frac;
+                e->offset_frac_ = (uint16_t)((Vector2(offset_frac)*(1.f/65355)).length()*32768);
                 (void)e;
                 break;
             }
diff --git a/serialize/savegame.cpp b/serialize/savegame.cpp
index 5c22b98a..8e7039e5 100644
--- a/serialize/savegame.cpp
+++ b/serialize/savegame.cpp
@@ -110,8 +110,9 @@ struct visitor_
     // 21: oops, forgot the object counter
     // 22: add object::speed
     // 23: switch object::delta to 32-bit
+    // 24: switch object::offset_frac from Vector2us to uint16_t
 
-    static constexpr inline proto_t proto_version      = 23;
+    static constexpr inline proto_t proto_version      = 24;
     const proto_t& PROTO;
     visitor_(const proto_t& proto) : PROTO{proto} {}
 
@@ -226,10 +227,22 @@ struct visitor_
     void visit(critter& obj, F&& f)
     {
         do_visit(obj.name, f);
+
         if (PROTO >= 22) [[likely]]
             do_visit(obj.speed, f);
         fm_soft_assert(obj.speed >= 0);
-        do_visit(obj.offset_frac, f);
+
+        if (PROTO >= 24) [[likely]]
+            do_visit(obj.offset_frac_, f);
+        else
+        {
+            static_assert(std::is_same_v<uint16_t, decltype(critter::offset_frac_)>);
+            Vector2us foo1;
+            do_visit(foo1, f);
+            auto foo2 = Vector2(foo1)*(1.f/65535);
+            auto foo3 = foo2.length()*32768;
+            obj.offset_frac_ = uint16_t(foo3);
+        }
 
         constexpr struct {
             uint8_t bits;
diff --git a/src/critter.cpp b/src/critter.cpp
index d1f3caa7..3602b530 100644
--- a/src/critter.cpp
+++ b/src/critter.cpp
@@ -153,7 +153,7 @@ void critter::update(size_t i, const Ns& dt)
             const auto new_r = arrows_to_dir(movement.L, movement.R, movement.U, movement.D);
             if (new_r == rotation_COUNT)
             {
-                offset_frac = {};
+                offset_frac_ = {};
                 delta = 0;
             }
             else
@@ -193,16 +193,17 @@ void critter::update_movement(size_t i, const Ns& dt, rotation new_r)
         for (unsigned j = 0; j < nvecs; j++)
         {
             const auto vec = rotation_to_vec(rotations[j]);
-            using Frac = decltype(critter::offset_frac)::Type;
+            using Frac = decltype(critter::offset_frac_);
             constexpr auto frac = (float{limits<Frac>::max}+1)/2;
             constexpr auto inv_frac = 1 / frac;
             const auto sign_vec = Math::sign(vec);
-            const auto from_accum = Vector2(offset_frac) * sign_vec * inv_frac;
+            const auto from_accum = (offset_frac_*inv_frac) * sign_vec.normalized();
             auto offset_ = vec + from_accum;
             auto off_i = Vector2i(offset_);
             if (!off_i.isZero())
             {
-                offset_frac = Math::Vector2<Frac>(Math::abs(Math::fmod(offset_, 1.f)) * frac);
+                auto rem = (offset_ - Vector2(off_i)).length();
+                offset_frac_ = Frac(rem * frac);
                 if (can_move_to(off_i))
                 {
                     can_move = true;
@@ -214,7 +215,8 @@ void critter::update_movement(size_t i, const Ns& dt, rotation new_r)
             else
             {
                 can_move = true;
-                offset_frac = Math::Vector2<Frac>(Math::min({2.f,2.f}, Math::abs(offset_)) * frac);
+                auto rem = offset_.length();
+                offset_frac_ = Frac(rem * frac);
                 break;
             }
         }
@@ -223,7 +225,7 @@ void critter::update_movement(size_t i, const Ns& dt, rotation new_r)
     if (!can_move) [[unlikely]]
     {
         delta = {};
-        offset_frac = {};
+        offset_frac_ = {};
     }
 }
 
diff --git a/src/critter.hpp b/src/critter.hpp
index e51d37c2..f05c3352 100644
--- a/src/critter.hpp
+++ b/src/critter.hpp
@@ -39,7 +39,7 @@ struct critter final : object
 
     String name;
     float speed = 1;
-    Vector2us offset_frac; // todo! switch to Vector2ui due to `allocate_frame_time'
+    uint16_t offset_frac_ = 0;
 
     struct movement_s {
         bool L : 1 = false,
diff --git a/test/critter.cpp b/test/critter.cpp
index f9df42fa..f7c04383 100644
--- a/test/critter.cpp
+++ b/test/critter.cpp
@@ -126,7 +126,7 @@ bool run(world& w, const function_view<Ns() const>& make_dt,
                     << " dt:" << dt
                     << " dist:" << point::distance_l2(pos, start)
                     << " delta:" << npc.delta
-                    << " frac:" << npc.offset_frac;
+                    << " frac:" << npc.offset_frac_;
     };
 
     auto fail = [b = grace.no_crash](const char* file, int line) {