diff --git a/01_dynamic_bsp_map.py b/01_dynamic_bsp_map.py
new file mode 100644
index 0000000..51a94c2
--- /dev/null
+++ b/01_dynamic_bsp_map.py
@@ -0,0 +1,163 @@
+import pyglet
+from pyglet.window import key
+
+import sys
+import re
+
+import random
+
+# constants
+TILE_SIZE_X = 16
+TILE_SIZE_Y = 16
+
+MIN_LEAF_SIZE = 4
+
+class Leaf:
+    """  Leaf of the BSP """
+
+    def __init__(self, x, y, w, h, id):
+        self.id = id
+        self.x = x
+        self.y = y
+        self.width = w
+        self.height = h
+        self.left_leaf = None
+        self.right_leaf = None
+
+    def print_leaf(self):
+        print(str(self.id) + ': (' + str(self.x) + '), (' + str(self.y) + ')' +
+              ' - ' + str(self.width) + 'x' + str(self.height)              )
+
+    def split(self):
+        """
+        :return: True if the leaf has been split
+        """
+
+        self.print_leaf()
+        # choose direction
+        # TODO: if leaf is not so square, split along the long side
+        # if width > XX% height (25, 33 ?) -> split vertical
+        if random.random() < 0.5:
+            # x
+            if self.width < MIN_LEAF_SIZE * 2:  # leaf is too small
+                return False
+            split_point = random.randint(MIN_LEAF_SIZE, self.width - MIN_LEAF_SIZE)
+            self.left_leaf = Leaf(self.x, self.y, split_point, self.height, self.id+1)
+            self.right_leaf = Leaf(self.x + split_point-1, self.y, self.width - split_point+1, self.height, self.id+2)
+
+        else:
+            # y
+            if self.height < MIN_LEAF_SIZE * 2:     # leaf is too small
+                return False
+            split_point = random.randint(MIN_LEAF_SIZE, self.height - MIN_LEAF_SIZE)
+            self.left_leaf = Leaf(self.x, self.y, self.width, split_point, self.id+1)
+            self.right_leaf = Leaf(self.x, self.y + split_point-1, self.width, self.height - split_point+1, self.id+2)
+
+        return True
+
+    def draw(self, wall, ground):
+        # first wall
+        for x in range(0, self.width):
+            wall.blit((self.x+x)*TILE_SIZE_X, self.y*TILE_SIZE_Y)
+        # middle
+        for y in range(1, self.height-1):
+            wall.blit(self.x*TILE_SIZE_X, (self.y+y)*TILE_SIZE_Y)
+            for x in range(1, self.width - 1):
+                ground.blit((self.x + x)*TILE_SIZE_X, (self.y+y)*TILE_SIZE_Y)
+            wall.blit((self.x+self.width-1)*TILE_SIZE_X, (self.y+y)*TILE_SIZE_Y)
+        # end
+        for x in range(0, self.width):
+            wall.blit((self.x+x)*TILE_SIZE_X, (self.y + self.height-1)*TILE_SIZE_Y)
+
+def generate_tree():
+    # init tree
+    tree = [Leaf(0, 0, 24, 24, 0)]
+    #tree = [Leaf(0, 0, 10, 10, 0)]
+    #tree = [Leaf(0, 0, 5, 5, 0)]
+
+    # split leaves until none succeed
+    split_done = True
+    while split_done:
+        split_done = False
+        for l in tree:
+            if l.left_leaf == None and l.right_leaf == None:
+                if (l.split()):
+                    tree.append(l.left_leaf)
+                    tree.append(l.right_leaf)
+                    split_done = True
+
+    return tree
+
+
+##
+# main
+##
+
+# main window
+window = pyglet.window.Window()
+
+@window.event
+def on_key_press(symbol, modifiers):
+    #TODO: ugly hack
+    global level_tree
+    
+    if symbol == key.Q:
+        print('Will quit')
+    if symbol == key.R:
+        print('Regeneration')
+        level_tree = generate_tree()
+        window.invalid = True
+    elif symbol == key.LEFT:
+        print('Left arrow')
+    elif symbol == key.ENTER:
+        print('Enter !')
+
+@window.event
+def on_draw():
+    window.clear()
+    draw_tree(level_tree)
+
+    label.draw()
+
+def draw_tree(t):
+    """
+    :param t: each leave of t will be draw()
+    """
+    for l in t:
+        # draw only last leaves
+        if l.left_leaf == None and l.right_leaf == None:
+            l.draw(tiles[TILE_WALL], tiles[TILE_GROUND])
+
+
+# init random
+#TODO add seed mode (how ?)
+random.seed()
+
+label = pyglet.text.Label('Plop World', x = window.width*3/4, y = window.height*3/4, anchor_x='center', anchor_y='center')
+
+# load images
+tiles = []
+resource_file = open('tiles.txt')
+line = resource_file.readline().strip()
+while line:
+    tile_file = re.compile('\d: ').split(line)[1]
+    print('loading tile: ' + str(tile_file))
+    tiles.append(pyglet.resource.image(tile_file))
+    line = resource_file.readline().strip()
+
+TILE_WALL = 0
+TILE_GROUND = 2
+
+level_tree = generate_tree()
+
+# artificial tree to test drawing
+# troot = Leaf(0, 0, 24, 24, 0)
+# tll = Leaf(0, 0, 16, 24, 1)
+# trl = Leaf(16, 0, 8, 24, 2)
+# troot.left_leaf = tll
+# troot.right_leaf = trl
+# tllvl = Leaf(0, 0, 16, 4, 3)
+# tllvr = Leaf(0, 4, 16, 20, 4)
+# level_tree = [troot, tll, trl, tllvl, tllvr]
+
+pyglet.app.run()
diff --git a/ground.png b/ground.png
new file mode 100644
index 0000000..094c282
Binary files /dev/null and b/ground.png differ
diff --git a/tiles.txt b/tiles.txt
new file mode 100644
index 0000000..90d6aa3
--- /dev/null
+++ b/tiles.txt
@@ -0,0 +1,3 @@
+0: brick.png
+1: road.png
+2: ground.png