From 5f2644b52d69a4ce470b738f61cee36f733407b4 Mon Sep 17 00:00:00 2001
From: zhenyan121 <3367366583@qq.com>
Date: Thu, 6 Aug 2026 11:06:29 +0800
Subject: [PATCH] fix(gameplay): make entity interpolation frame-rate
 independent

---
 include/Cubed/gameplay/client_entity_manager.hpp |  4 ++--
 src/gameplay/client_entity_manager.cpp           | 15 ++++++++-------
 2 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/include/Cubed/gameplay/client_entity_manager.hpp b/include/Cubed/gameplay/client_entity_manager.hpp
index 0489291..6330f05 100644
--- a/include/Cubed/gameplay/client_entity_manager.hpp
+++ b/include/Cubed/gameplay/client_entity_manager.hpp
@@ -53,12 +53,12 @@ private:
     std::unordered_map<std::string_view, CreateFunc> m_factories;
     tbb::concurrent_queue<TaskPair> m_tasks;
 
-    void handle_task();
+    void handle_task(float dt);
     void handle_entity_destory(EntityID id);
     // not thread safe
     void handle_entity_create(EntityID id, std::string_view name,
                               const glm::vec3& pos);
-    void handle_entity_update(UpdateInfo& info);
+    void handle_entity_update(UpdateInfo& info, float dt);
     template <typename... Args>
     void create_entity_in_registry(EntityID id, Args&&... args) {
         {
diff --git a/src/gameplay/client_entity_manager.cpp b/src/gameplay/client_entity_manager.cpp
index 5543ff4..e1abd2b 100644
--- a/src/gameplay/client_entity_manager.cpp
+++ b/src/gameplay/client_entity_manager.cpp
@@ -14,7 +14,7 @@ using namespace google::protobuf;
 namespace Cubed {
 ClientEntityManager::ClientEntityManager(ClientWorld& world) : m_world(world) {}
 void ClientEntityManager::update(float dt) {
-    handle_task();
+    handle_task(dt);
 
     auto view = m_registry.view<BaseClientCreature>();
     for (auto e : view) {
@@ -51,7 +51,7 @@ void ClientEntityManager::handle_entity_create(EntityID id,
     r->position.value = pos;
 }
 
-void ClientEntityManager::handle_entity_update(UpdateInfo& info) {
+void ClientEntityManager::handle_entity_update(UpdateInfo& info, float dt) {
     entt::entity e;
     {
         cacc a;
@@ -68,10 +68,11 @@ void ClientEntityManager::handle_entity_update(UpdateInfo& info) {
     creature->pose.gait = info.gait;
     auto r = m_registry.try_get<RenderTransform>(e);
     ASSERT(r);
-    r->direction.value =
-        glm::mix(r->direction.value, creature->transform.direction.value, 0.15);
+    float alpha = 1 - std::exp(-dt / 0.1);
+    r->direction.value = glm::mix(r->direction.value,
+                                  creature->transform.direction.value, alpha);
     r->position.value =
-        glm::mix(r->position.value, creature->transform.position.value, 0.15);
+        glm::mix(r->position.value, creature->transform.position.value, alpha);
 }
 
 void ClientEntityManager::receive_entity_create(S2CEntityCreate& s2c) {
@@ -113,7 +114,7 @@ void ClientEntityManager::create(std::string_view name, const glm::vec3& pos) {
     client->send(make_packet(msg));
 }
 
-void ClientEntityManager::handle_task() {
+void ClientEntityManager::handle_task(float dt) {
     TaskPair pair;
     while (m_tasks.try_pop(pair)) {
         switch (pair.first) {
@@ -131,7 +132,7 @@ void ClientEntityManager::handle_task() {
         case Command::UPDATE: {
             auto* p = std::get_if<UpdateInfo>(&pair.second);
             ASSERT(p);
-            handle_entity_update(*p);
+            handle_entity_update(*p, dt);
         }
         }
     }