Break NumPy compatibility

Author: jbdyn

pelita/maze_generator.py

@@ -133,20 +133,6 @@ def distribute_food(all_tiles, chamber_tiles, trapped_food, total_food, rng=None
     return tf_pos | ff_pos | leftover_food_pos
 
 
-def sample(x, k, rng):
-    # temporary replacement wrapper for `rng.shuffle` conformant with
-    # the `random.sample` API (minus the `count` parameter)
-
-    # copy population
-    result = x.copy()
-
-    # shuffle all items
-    rng.shuffle(result)
-
-    # return the first `k` results
-    return result[:k]
-
-
 def identity(point):
     # identity transformation
     return point
@@ -248,25 +234,14 @@ def add_inner_walls(walls, pmin, pmax, ngaps, vertical, rng=None):
         above = 1 if wmin in walls else 2
         below = 1 if wmax in walls else 2
 
-        # sliced continuous wall in `x`-`y`-space
-        wall = {transform((upos, v)) for v in range(vmin + above, vmax - below + 1)}
-        # sample gap coordinates along the wall, i.e in `v`-direction
-        #
-        # TODO: 
-        # when we drop compatibility with numpy mazes, the range of sampled
-        # gaps can be adjusted to remove them directly from the full wall
-        # OR we sample the wall segments to keep with k = len(wall) - ngaps
-        gaps = list(range(vmin + 1, vmax))
-        gaps = sample(gaps, ngaps, rng)
-
-        # combine gap coordinates to wall gaps in `x`-`y`-space
-        sampled = {transform((upos, v)) for v in gaps}
-
-        # remove sampled gaps from the wall
-        wall -= sampled
+        # sample inner wall tiles in `x`-`y`-space including the end index;
+        # ensure a connected graph by always subtracting `ngaps` from
+        # number of candidates
+        candidates = list(range(vmin + above, vmax - below + 1))
+        sampled = rng.sample(candidates, k=max(0, len(candidates) - ngaps))
 
-        # collect this wall into the global wall set
-        walls |= wall
+        # add the inner wall tiles to the global wall set
+        walls |= set(transform((upos, v)) for v in sampled)
 
         #
         # PARTITIONING
@@ -286,10 +261,7 @@ def add_inner_walls(walls, pmin, pmax, ngaps, vertical, rng=None):
         )
 
         # queue the new partitions next
-        #
-        # TODO:
-        # when we drop compatibility with numpy mazes, remove inversion
-        partitions.extend(new[::-1])
+        partitions.extend(new)
 
 
 def generate_half_maze(trapped_food, total_food, width, height, rng=None):
@@ -338,12 +310,8 @@ def generate_half_maze(trapped_food, total_food, width, height, rng=None):
 
     # possible locations for gaps;
     # these gaps need to be symmetric around the center
-    #
-    # TODO:
-    # when we drop compatibility with numpy mazes, this might be rewritten to
-    # sample wall segments to keep with k = len(wall) - ngaps
     candidates = list(range(y_border))
-    candidates = sample(candidates, ngaps, rng)
+    candidates = rng.sample(candidates, k=ngaps)
 
     # save gaps and bridges for chamber finding
     border_gaps = set()
@@ -392,6 +360,11 @@ def generate_half_maze(trapped_food, total_food, width, height, rng=None):
     # see the `FOOD` section below for application
     graph = walls_to_graph(walls, shape=(width // 2, height))
 
+    # the algorithm should actually guarantee this, but just to make sure, let's
+    # fail if the graph is not fully connected
+    if not nx.is_connected(graph):
+        raise ValueError("Generated maze is not fully connected, try a different random seed")
+
     # emulate the presence of the right maze side by wiring up
     # pairs of left border gaps, i.e. "bridges" from the
     # `BORDER WALLS, GAPS AND BRIDGES` section above,
@@ -417,11 +390,6 @@ def generate_half_maze(trapped_food, total_food, width, height, rng=None):
     # wall segment in the middle on odd heights
     graph.add_edges_from(border_bridges)
 
-    # the algorithm should actually guarantee this, but just to make sure, let's
-    # fail if the graph is not fully connected
-    if not nx.is_connected(graph):
-        raise ValueError("Generated maze is not fully connected, try a different random seed")
-
     #
     # FOOD
     #

test/test_maze_generation.py

@@ -27,38 +27,38 @@ def layout_str_to_graph(l_str):
 
 maze_103525239_even = """
 ################################
-#.   .....#....##    .      . y#
-# .# #########      # .    #  x#
-#  # # .     .    # ######    ##
-#  #    .    # ##.         #   #
-#  ####### ###    #.      .# ..#
-# .#     .  ..    ### # ##.#####
-# ### ###### ####  .    #.   . #
-# .   .#    .  #### ###### ### #
-#####.## # ###    ..  .     #. #
-#.. #.      .#    ### #######  #
-#   #         .## #    .    #  #
-##    ###### #    .     . # #  #
-#a  #    . #      ######### #. #
-#b .      .    ##....#.....   .#
+#.. ... .   #       .         y#
+#######.##  # ###        .    x#
+# ..     #  .      #######   ###
+#.  .#.#.#  #      #  # #. .   #
+###.#### #  .. ##  #..#.#.     #
+#    #.#.### #### ### # # ### ##
+#    #   # . .          # # #. #
+# .# # #          . . #   #    #
+## ### # # ### #### ###.#.#    #
+#     .#.#..#  ## ..  # ####.###
+#   . .# #  #      #  #.#.#.  .#
+###   #######      .  #     .. #
+#a    .        ### #  ##.#######
+#b         .       #   . ... ..#
 ################################
 """
 
 maze_103525239_odd = """
 ################################
-#.   .  #..  . ##       .   . y#
-#    #  ######    ### #####  #x#
-# .  ## # .# #   .     .  #.  .#
-#.   # .#....#.## # .   . #    #
-#    #. ### ##    # .     ## ###
-#    #..   .   ########## #    #
-#    # .#.#  #.##.#  #.#. #    #
-#    # ##########   .   ..#    #
-### ##     . #    ## ### .#    #
-#    # .   . # ##.#....#. #   .#
-#.  .#  .     .   # #. # ##  . #
-#a#  ##### ###    ######  #    #
-#b .   .       ## .  ..#  .   .#
+#    # .#   .     .#  . #.    y#
+#.      #..#   ## .  #   .#.##x#
+# .  # ####### ##..# #. #.     #
+#.   #  ..         #    #   .# #
+#### #### #    ## #######  # ###
+# .    .#.#  .       ...#   . .#
+### .####### ###### #######. ###
+#. .   #...       .  #.#.    . #
+### #  ####### ##    # #### ####
+# #.   #    #         ..  #   .#
+#     .# .# #..## ####### #  . #
+#a##.#.   #  . ##   #..#      .#
+#b    .# .  #.     .   #. #    #
 ################################
 """