diff --git a/server/gameserver/grid.cc b/server/gameserver/grid.cc
index ba45982..5e89ce4 100644
--- a/server/gameserver/grid.cc
+++ b/server/gameserver/grid.cc
@@ -34,6 +34,11 @@ void Grid::Init(int width, int height, int cell_width)
     grid_offset_arr_[6] = cell_count_per_row_ - 1;
     grid_offset_arr_[7] = cell_count_per_row_;
     grid_offset_arr_[8] = cell_count_per_row_ + 1;
+
+    min_x_ = cell_width_ * 1;
+    min_y_ = cell_width_ * 1;
+    max_x_ = cell_width_ * (cell_count_per_row_ - 1);
+    max_y_ = cell_width_ * (cell_count_per_col_ - 1);
 }
 
 void Grid::UnInit()
@@ -44,57 +49,75 @@ void Grid::UnInit()
     }
 }
 
-void Grid::Get123456789(int grid_id, std::vector<GridCell*>& grid_list)
+void Grid::Get123456789(int grid_id, std::set<GridCell*>& grid_list)
 {
     for (size_t i = 1; i <= 9; ++i) {
         GetGridList(grid_id, i, grid_list);
     }
 }
 
-void Grid::Get123(int grid_id, std::vector<GridCell*>& grid_list)
+void Grid::Get123(int grid_id, std::set<GridCell*>& grid_list)
 {
     GetGridList(grid_id, 1, grid_list);
     GetGridList(grid_id, 2, grid_list);
     GetGridList(grid_id, 3, grid_list);
 }
 
-void Grid::Get456(int grid_id, std::vector<GridCell*>& grid_list)
+void Grid::Get456(int grid_id, std::set<GridCell*>& grid_list)
 {
     GetGridList(grid_id, 4, grid_list);
     GetGridList(grid_id, 5, grid_list);
     GetGridList(grid_id, 6, grid_list);
 }
 
-void Grid::Get789(int grid_id, std::vector<GridCell*>& grid_list)
+void Grid::Get789(int grid_id, std::set<GridCell*>& grid_list)
 {
     GetGridList(grid_id, 7, grid_list);
     GetGridList(grid_id, 8, grid_list);
     GetGridList(grid_id, 9, grid_list);
 }
 
-void Grid::Get147(int grid_id, std::vector<GridCell*>& grid_list)
+void Grid::Get147(int grid_id, std::set<GridCell*>& grid_list)
 {
     GetGridList(grid_id, 1, grid_list);
     GetGridList(grid_id, 4, grid_list);
     GetGridList(grid_id, 7, grid_list);
 }
 
-void Grid::Get258(int grid_id, std::vector<GridCell*>& grid_list)
+void Grid::Get258(int grid_id, std::set<GridCell*>& grid_list)
 {
     GetGridList(grid_id, 2, grid_list);
     GetGridList(grid_id, 5, grid_list);
     GetGridList(grid_id, 8, grid_list);
 }
 
-void Grid::Get369(int grid_id, std::vector<GridCell*>& grid_list)
+void Grid::Get369(int grid_id, std::set<GridCell*>& grid_list)
 {
     GetGridList(grid_id, 3, grid_list);
     GetGridList(grid_id, 6, grid_list);
     GetGridList(grid_id, 9, grid_list);
 }
 
+void Grid::AddHuman(Human* hum, std::set<GridCell*>& inc_grid_list)
+{
+
+}
+
+void Grid::MoveHuman(Human* hum, float x, float y,
+                     std::set<GridCell*>& inc_grid_list,
+                     std::set<GridCell*>& dec_grid_list
+                     )
+{
+
+}
+
+void Grid::AddEntity(Entity* entity)
+{
+
+}
+
 void Grid::GetGridList(int grid_id, int offset,
-                       std::vector<GridCell*>& grid_list)
+                       std::set<GridCell*>& grid_list)
 {
     if (offset <1 || offset > 9) {
         abort();
@@ -104,6 +127,6 @@ void Grid::GetGridList(int grid_id, int offset,
     }
     int tmp_grid_id = grid_id + grid_offset_arr_[offset - 1];
     if (tmp_grid_id > 0) {
-        grid_list.push_back(&cells_[tmp_grid_id]);
+        grid_list.insert(&cells_[tmp_grid_id]);
     }
 }
diff --git a/server/gameserver/grid.h b/server/gameserver/grid.h
index 159909d..a64e75c 100644
--- a/server/gameserver/grid.h
+++ b/server/gameserver/grid.h
@@ -12,6 +12,8 @@ struct GridCell
   4 5 6
   7 8 9
  */
+class Human;
+class Entity;
 class Room;
 class Grid
 {
@@ -21,17 +23,25 @@ class Grid
 
     void Init(int width, int height, int cell_width);
     void UnInit();
-    void Get123456789(int grid_id, std::vector<GridCell*>& grid_list);
-    void Get123(int grid_id, std::vector<GridCell*>& grid_list);
-    void Get456(int grid_id, std::vector<GridCell*>& grid_list);
-    void Get789(int grid_id, std::vector<GridCell*>& grid_list);
-    void Get147(int grid_id, std::vector<GridCell*>& grid_list);
-    void Get258(int grid_id, std::vector<GridCell*>& grid_list);
-    void Get369(int grid_id, std::vector<GridCell*>& grid_list);
+    void Get123456789(int grid_id, std::set<GridCell*>& grid_list);
+    void Get123(int grid_id, std::set<GridCell*>& grid_list);
+    void Get456(int grid_id, std::set<GridCell*>& grid_list);
+    void Get789(int grid_id, std::set<GridCell*>& grid_list);
+    void Get147(int grid_id, std::set<GridCell*>& grid_list);
+    void Get258(int grid_id, std::set<GridCell*>& grid_list);
+    void Get369(int grid_id, std::set<GridCell*>& grid_list);
+
+    void AddHuman(Human* hum, std::set<GridCell*>& inc_grid_list);
+    void MoveHuman(Human* hum, float x, float y,
+                   std::set<GridCell*>& inc_grid_list,
+                   std::set<GridCell*>& dec_grid_list
+                   );
+
+    void AddEntity(Entity* entity);
 
  private:
     inline void GetGridList(int grid_id, int offset,
-                            std::vector<GridCell*>& grid_list);
+                            std::set<GridCell*>& grid_list);
 
  private:
     Room* room_ = nullptr;
@@ -42,7 +52,10 @@ class Grid
     int cell_width_ = 0;
     int cell_count_per_row_ = 0;
     int cell_count_per_col_ = 0;
-    Vector2D min_;
-    Vector2D max_;
+    int min_x_ = 0;
+    int min_y_ = 0;
+    int max_x_ = 0;
+    int max_y_ = 0;
     int grid_offset_arr_[9] = {0};
+
 };