diff --git a/module/libkey.nas b/module/libkey.nas
index ab0c769..48ba8df 100644
--- a/module/libkey.nas
+++ b/module/libkey.nas
@@ -7,30 +7,40 @@ var libkey=func(){
     var nb=dylib.dlsym(lib,"nas_noblock");
     var init=dylib.dlsym(lib,"nas_init");
     var cls=dylib.dlsym(lib,"nas_close");
+    var call=dylib.dlcall;
     var is_init=0;
     return {
         init:func(){
-            dylib.dlcall(init);
+            # change io mode to no echo
+            call(init);
             is_init=1;
         },
         kbhit:func(){
+            # check if kerboard is hit
+            # if keyboard is hit this function will return 1
+            # until getch() gets all the input characters
+            # and the input flow becomes empty
             if(!is_init)
                 me.init();
-            return dylib.dlcall(kb);
+            return call(kb);
         },
         getch:func(){
+            # get input one character without echo
+            # block until get one input
             if(!is_init)
                 me.init();
-            return dylib.dlcall(gt);
+            return call(gt);
         },
         nonblock:func(){
+            # nonblock input without echo
             if(!is_init)
                 me.init();
-            return dylib.dlcall(nb);
+            return call(nb);
         },
         close:func(){
             # must call this function before exiting the program
-            dylib.dlcall(cls);
+            # this will change terminal mode to normal io mode
+            call(cls);
             dylib.dlclose(lib);
         }
     }
diff --git a/test/tetris.nas b/test/tetris.nas
index 96b14a8..1578cb4 100644
--- a/test/tetris.nas
+++ b/test/tetris.nas
@@ -1,58 +1,176 @@
 import("lib.nas");
 import("module/libkey.nas");
 
-var brick=[
-    [
-        [1,1],
-        [1,0],
-        [1,0]
-    ],
-    [
-        [0,1],
-        [1,1],
-        [1,0]
-    ],
-    [
-        [1,1],
-        [0,1],
-        [0,1],
-    ],
-    [
-        [1,0],
-        [1,1],
-        [0,1]
-    ],
-    [
-        [1,1,1,1]
-    ],
-    [
-        [1,1],
-        [1,1]
-    ],
-    [
-        [0,1,0],
-        [1,1,1]
-    ]
-];
+var mapgen=func(mapx,mapy){
+    if(mapx<1 or mapy<1)
+        die("map_x or map_y must be greater than 1");
+    # use in print
+    var table="\e[44m ";
+    for(var i=0;i<mapx;i+=1)
+        table~="  ";
+    table~=" \e[0m\n";
+    # generate new map
+    var map=[];
+    for(var y=0;y<mapy;y+=1){
+        var tmp=[];
+        for(var x=0;x<mapx;x+=1)
+            append(tmp,rand()>0.9);
+        append(map,tmp);
+    }
 
-func(){
+    # color print
+    var front=[
+    "31","32","33","34","35","36",
+    "91","92","93","94","95","96",
+    ];
+    var map_print=func(){
+        var s="\e[1;1H"~table;
+        for(var y=0;y<mapy;y+=1){
+            s~="\e[44m \e[0m";
+            for(var x=0;x<mapx;x+=1)
+                s~=map[y][x]?"\e["~front[rand()*12]~"m██\e[0m":"  ";
+            s~="\e[44m \e[0m\n";
+        }
+        s~=table;
+        print(s);
+    }
+
+    var moveleft=func(block){
+        for(var y=0;y<mapy;y+=1){
+            var tmp=map[y][0];
+            for(var x=1;x<mapx;x+=1)
+                map[y][x-1]=map[y][x];
+            map[y][mapx-1]=tmp;
+        }
+    }
+
+    var moveright=func(block){
+        for(var y=0;y<mapy;y+=1){
+            var tmp=map[y][mapx-1];
+            for(var x=mapx-1;x>=1;x-=1)
+                map[y][x]=map[y][x-1];
+            map[y][0]=tmp;
+        }
+    }
+
+    var rotate=func(block){
+
+    }
+
+    var setblock=func(block){
+
+    }
+
+    var checkmap=func(block){
+        map_print(map);
+    }
+    return {
+        print:map_print,
+        moveleft:moveleft,
+        moveright:moveright,
+        rotate:rotate,
+        setblock:setblock,
+        checkmap:checkmap
+    };
+}
+
+var blocktype=[
+    [0,1,2,3],
+    [4,5,6,7],
+    [8,9,10,11],
+    [12,13],
+    [14],
+    [15,16],
+    [17,18]
+];
+var blockshape=[
+    # [][]            []  [][][]
+    # []    []        []      []
+    # []    [][][]  [][]
+    [[0,0],[1,0],[0,1],[0,2]],
+    [[0,0],[0,1],[1,1],[2,1]],
+    [[0,0],[0,1],[0,2],[-1,2]],
+    [[0,0],[1,0],[2,0],[2,1]],
+    # [][]  [][][]  []
+    #   []  []      []        []
+    #   []          [][]  [][][]
+    [[0,0],[1,0],[1,1],[1,2]],
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]],
+    #   []      []  [][][]  []
+    # [][][]  [][]    []    [][]
+    #           []          []
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]],
+    # []  [][][][]
+    # []
+    # []
+    # []
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]],
+    # [][]
+    # [][]
+    [[0,0],[],[],[]],
+    #   []  [][]
+    # [][]    [][]
+    # []
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]],
+    # []      [][]
+    # [][]  [][]
+    #   []
+    [[0,0],[],[],[]],
+    [[0,0],[],[],[]]
+];
+var block={
+    x:0,
+    y:0,
+    type:nil,
+    shape:nil,
+    new:func(x=0,y=0){
+        (me.x,me.y)=(x,y);
+        me.type=blocktype[rand()*size(blocktype)];
+        me.shape=blockshape[me.type][0];
+        return {parents:[block]};
+    }
+};
+
+var main=func(){
+    print("\ec");
+
+    rand(time(0));
+    var map=mapgen(mapx:15,mapy:15);
+    var blk=block.new();
+    
     libkey.init();
-    print('\ec');
-    var cnt=0;
     while(1){
         var ch=libkey.nonblock();
-        ch=ch?chr(ch)~chr(ch):"[]";
-        var s="\ec+--------------+\n";
-        var normal="|              |\n";
-        var character="|      "~ch~"      |\n";
-        for(var i=0;i<6;i+=1)
-            s~=(i==cnt)?character:normal;
-        s~="+--------------+\n";
-        print(s);
-        unix.sleep(0.3);
-        cnt+=1;
-        if(cnt==6)
-            cnt=0;
+        if(ch){
+            if(ch=='a'[0])     # move left
+                map.moveleft(blk);
+            elsif(ch=='d'[0])  # move right
+                map.moveright(blk);
+            elsif(ch=='s'[0])  # rotate
+                map.rotate(blk);
+            elsif(ch==' '[0])  # set block
+                map.setblock(blk);
+            elsif(ch=='q'[0])
+                break;
+            map.checkmap(blk);
+            unix.sleep(0.03);
+        }
+        else{
+            blk.y+=1;
+            map.checkmap(blk);
+            unix.sleep(0.3);
+        }
     }
     libkey.close();
-}();
\ No newline at end of file
+
+    print("\ec\e[91ms\e[92me\e[93me \e[94my\e[95mo\e[96mu \e[34m~\e[0m\n");
+};
+
+main();