feat: sync entity direction and rotate models accordingly

Move direction into the transform component and include it in server-to-client entity updates. Client now sets transform direction from the network message and uses it to compute yaw for model rotation, so entities visually face their movement direction. Refactor net_utils to support arbitrary Vec3 fields.

src/gameplay/client_entity_manager.cpp

@@ -49,6 +49,7 @@ void ClientEntityManager::handle_entity_update(UpdateInfo& info) {
     auto creature = m_registry.try_get<BaseClientCreature>(e);
     ASSERT(creature);
     creature->transform.position.value = info.pos;
+    creature->transform.direction.value = info.direction;
 }
 
 void ClientEntityManager::receive_entity_create(S2CEntityCreate& s2c) {
@@ -66,7 +67,8 @@ void ClientEntityManager::receive_entity_destory(EntityID id) {
 void ClientEntityManager::receive_entity_update(S2CEntityUpdate& msg) {
     UpdateInfo e;
     e.id = msg.id();
-    e.pos = Tools::get_net_pos(msg.pos());
+    e.pos = Tools::get_net_vec3(msg.pos());
+    e.direction = Tools::get_net_vec3(msg.direction());
     m_tasks.emplace(Command::UPDATE, std::move(e));
 }
 

src/gameplay/server_entity_manager.cpp

@@ -56,6 +56,9 @@ void ServerEntityManager::update_send() {
         p->set_id(entity.id);
         Tools::set_net_pos(p, creature.transform.position.value);
 
+        Tools::set_net_vec3(p->mutable_direction(),
+                            creature.transform.direction.value);
+
         for (auto& s : sessions) {
             s->send(make_packet(p));
         }

src/gameplay/server_world.cpp

@@ -875,7 +875,7 @@ void ServerWorld::handle_block_change(const BlockChangeReq& req) {
 
 void ServerWorld::handle_entity_create(C2SEntityCreateRequest& req) {
 
-    m_entity_manager.add_entity(req.name(), Tools::get_net_pos(req.pos()));
+    m_entity_manager.add_entity(req.name(), Tools::get_net_vec3(req.pos()));
 }
 void ServerWorld::handle_entity_destory(C2SEntityDestoryRequest& req) {
     m_entity_manager.destory(req.id());

src/gameplay/systems/speed_system.cpp

@@ -13,7 +13,8 @@ void SpeedSystem::update(float dt, entt::registry& registry) {
         auto& v = creature.velocity.value;
         if (moveboost.count <= moveboost.duration) {
             ++moveboost.count;
-            v += creature.direction.value * creature.movement.acceleration;
+            v += creature.transform.direction.value *
+                 creature.movement.acceleration;
         } else {
             // Decelerated by friction in all directions
             auto decay = [](float& c, float d) {

src/gameplay/systems/wander_ai_system.cpp

@@ -29,7 +29,7 @@ void WanderAISystem::do_ai(BaseServerCreature& creature,
                            MoveBoost& move_boost) {
     thread_local Random r{std::random_device()()};
     if (r.random_bool(DIRECTION_PROBABILITY)) {
-        creature.direction.value = r.random_direction_horizontal();
+        creature.transform.direction.value = r.random_direction_horizontal();
     }
     if (r.random_bool(MOVE_PROBABILITY)) {
 

src/proto/world/entity.proto

@@ -26,4 +26,5 @@ message C2SEntityCreateRequest {
 message S2CEntityUpdate {
     uint64 id = 1;
     Vec3 pos = 2;
+    Vec3 direction = 3;
 }

src/render/model_renderer.cpp

@@ -6,20 +6,23 @@
 namespace Cubed {
 ModelRender::ModelRender(Renderer& renderer) : m_renderer(renderer) {}
 
-void ModelRender::render_model(ModelID id, const glm::vec3& pos,
+void ModelRender::render_model(ModelID id, const glm::vec3& pos, float yaw,
                                Camera& camera) {
     auto& root = ModelManager::model(id).node;
-    glm::mat4 transform = glm::translate(glm::mat4(1.0f), pos);
+    glm::mat4 transform = glm::translate(glm::mat4(1.0f), pos) *
+                          glm::rotate(glm::mat4(1.0f), yaw, {0, 1, 0});
     auto& shader = m_renderer.get_shader("model_shader");
     glm::mat4 view = camera.get_camera_lookat();
     shader.set_loc("proj_matrix", m_renderer.p_mat());
     render_node(root, transform, view, shader, false);
 }
 
-void ModelRender::shadow_pass(ModelID id, const glm::vec3& pos,
+void ModelRender::shadow_pass(ModelID id, const glm::vec3& pos, float yaw,
                               Camera& camera) {
     auto& root = ModelManager::model(id).node;
-    glm::mat4 transform = glm::translate(glm::mat4(1.0f), pos);
+    glm::mat4 transform = glm::translate(glm::mat4(1.0f), pos) *
+                          glm::rotate(glm::mat4(1.0f), yaw, {0, 1, 0});
+
     auto& shader = m_renderer.get_shader("depth_model");
     glm::mat4 view = camera.get_camera_lookat();
 

src/render/world_renderer.cpp

@@ -300,8 +300,11 @@ void WorldRenderer::shadow_entity(ClientWorld& world,
     auto view = registry.view<BaseClientCreature>();
     for (auto entity : view) {
         auto& creature = view.get<BaseClientCreature>(entity);
+        float yaw = std::atan2(creature.transform.direction.value.x,
+                               creature.transform.direction.value.z);
+
         m_renderer.model_renderer().shadow_pass(
-            creature.model, creature.transform.position.value,
+            creature.model, creature.transform.position.value, yaw,
             world.world_scene().camera());
     }
     m_player_renderer.render(shader, world, true);
@@ -721,8 +724,10 @@ void WorldRenderer::render_entity(ClientWorld& world) {
     auto view = registry.view<BaseClientCreature>();
     for (auto entity : view) {
         auto& creature = view.get<BaseClientCreature>(entity);
+        float yaw = std::atan2(creature.transform.direction.value.x,
+                               creature.transform.direction.value.z);
         m_renderer.model_renderer().render_model(
-            creature.model, creature.transform.position.value,
+            creature.model, creature.transform.position.value, yaw,
             world.world_scene().camera());
     }