diff --git a/pyshoot.py b/pyshoot.py
index 85e53a7..d1d86b6 100755
--- a/pyshoot.py
+++ b/pyshoot.py
@@ -7,7 +7,7 @@
 import pygame
 from pygame.locals import *
 import os
-
+import random
 
 
 # constants
@@ -97,20 +97,24 @@ class Player(Object):
 		""" initiate moving sequence """
 		globals.moving_objects.add(self)
 		self.speed = (self.speed[0] + vector[0], self.speed[1] + vector[1])
-		if not globals.moving_objects.has(self):
-			print "error should contain self after start_move"
 	
-	def stop_move(self):
+	def stop_move(self, vector):
 		""" stop moving sequence """
-		globals.moving_objects.remove(self)
-		self.speed = (0, 0)
-		if globals.moving_objects.has(self):
-			print "error should NOT contain self after stop_move"
+		self.speed = (self.speed[0] - vector[0], self.speed[1] - vector[1])
+		
+		if self.speed == (0, 0):
+			globals.moving_objects.remove(self)
+
+	def start_shoot(self):
+		self.shoot()
+
+	def stop_shoot(self):
+		pass
 
 def init_gfx():
 	"""graphics initialisation"""
 	
-	globals.screen = pygame.display.set_mode((SCREEN_X, SCREEN_Y))
+	globals.screen = pygame.display.set_mode((SCREEN_X, SCREEN_Y), HWSURFACE|DOUBLEBUF)
 	globals.screen.fill(0)
 	pygame.display.flip()
 
@@ -123,9 +127,11 @@ def init():
 	pygame.init()
 	init_gfx()
 	globals.clock = pygame.time.Clock()
+	random.seed()
 	#globals.event_type = {'create_enemeny' : create_enemey, 'vanish_object': vanish_object()}
 
 
+
 def create_enemy(type):
 	""" create an enemy """
 	pass
@@ -163,17 +169,48 @@ def process_key(event, player):
 			player.start_shoot()
 	if event.type == KEYUP:
 		if event.key == K_UP:
-			player.stop_move()
+			player.stop_move((0, -1))
 		elif event.key == K_DOWN:
-			player.stop_move()
+			player.stop_move((0, 1))
 		elif event.key == K_LEFT:
-			player.stop_move()
+			player.stop_move((-1, 0))
 		elif event.key == K_RIGHT:
-			player.stop_move()
+			player.stop_move((1,0))
 		elif event.key == K_x:
 			player.stop_shoot()
 
 
+def transition(type):
+	""" transition selector """
+
+	if type == 0:
+		transition_disintegrate()
+	elif type == 1:
+		transition_fade_to_black()
+	elif type == 2:
+		transition_fade_to_white()
+
+def transition_disintegrate():
+	""" put black pixels at randoom location"""
+	for i in range(0, 200000):
+		x = random.randint(0, SCREEN_X)
+		y = random.randint(0, SCREEN_Y)
+		globals.screen.set_at((x, y), (0,0,0, 255))
+		if i % 1000 == 0 :
+			pygame.display.update()
+	globals.screen.fill((0, 0, 0))
+	pygame.display.update()
+
+
+def transition_fade_to_black():
+	""" darken every pixels on screen """
+	array = pygame.PixelArray(globals.screen)
+	pass
+
+def transition_fade_to_white():
+	""" lighten every pixels on screen """
+	pass
+
 ##
 # Main
 ##
@@ -228,6 +265,8 @@ while not globals.die:
 	# reinitializing moving objects list
 	#globals.moving_objects = pygame.sprite.RenderUpdates()
 
+# transition(0)
+
 print "frames : %d" % nbframe