diff --git a/main.py b/main.py
index 71446bd..dc81bf7 100755
--- a/main.py
+++ b/main.py
@@ -2,7 +2,7 @@
 try:
     from numpy import complex256
 except ImportError:
-    from numpy import complex128 as complex256 
+    from numpy import complex128 as complex256
     print("Warning! Cannot use full precision!")
 
 from time import time_ns, sleep
@@ -87,12 +87,22 @@ def renderDebugInfo(gPlayer, clock, fontSize = 18):
 
     return fps_surf, cPos_surf, cRot_surf
 
+def make_wall(wall_buffer):
+    if (len(wall_buffer) != 2):
+        print('Warning: wall buffer not contains 2 points.')
+        return
+
+    level.append(
+        Segment(True, wall_buffer[0], wall_buffer[1], (23,74,183))
+    )
+
 def mainLoop():
     gPlayer = GyroVector(0,1)
     display = pygame.display.set_mode((1280,720))
     clock = pygame.time.Clock()
     fontSize = 18
     debugInfo = True
+    wall_buffer = []
 
     while True:
         for event in pygame.event.get():
@@ -103,6 +113,14 @@ def mainLoop():
                     gPlayer.cRot *= -1
                 if event.key == pygame.K_F3:
                     debugInfo = not debugInfo
+                if event.key == pygame.K_F2:
+                    if (len(wall_buffer) == 1):
+                        wall_buffer.append(gPlayer.cPos)
+                        make_wall(wall_buffer)
+                        wall_buffer.clear()
+                    else:
+                        wall_buffer.append(gPlayer.cPos)
+
         keys = pygame.key.get_pressed()
         if keys[pygame.K_d]:
             gPlayer.rotate(ROT)