Creating a Depth First Maze#
maze_depth_first.py#
1"""
2Create a maze using a depth-first search maze generation algorithm.
3For more information on this algorithm see:
4https://www.algosome.com/articles/maze-generation-depth-first.html
5...or search up some other examples.
6
7Artwork from https://kenney.nl
8
9If Python and Arcade are installed, this example can be run from the command line with:
10python -m arcade.examples.maze_depth_first
11"""
12import random
13import arcade
14import timeit
15
16NATIVE_SPRITE_SIZE = 128
17SPRITE_SCALING = 0.25
18SPRITE_SIZE = int(NATIVE_SPRITE_SIZE * SPRITE_SCALING)
19
20SCREEN_WIDTH = 1000
21SCREEN_HEIGHT = 700
22SCREEN_TITLE = "Maze Depth First Example"
23
24MOVEMENT_SPEED = 8
25
26TILE_EMPTY = 0
27TILE_CRATE = 1
28
29# Maze must have an ODD number of rows and columns.
30# Walls go on EVEN rows/columns.
31# Openings go on ODD rows/columns
32MAZE_HEIGHT = 51
33MAZE_WIDTH = 51
34
35MERGE_SPRITES = True
36
37# How many pixels to keep as a minimum margin between the character
38# and the edge of the screen.
39VIEWPORT_MARGIN = 200
40
41
42def _create_grid_with_cells(width, height):
43 """ Create a grid with empty cells on odd row/column combinations. """
44 grid = []
45 for row in range(height):
46 grid.append([])
47 for column in range(width):
48 if column % 2 == 1 and row % 2 == 1:
49 grid[row].append(TILE_EMPTY)
50 elif column == 0 or row == 0 or column == width - 1 or row == height - 1:
51 grid[row].append(TILE_CRATE)
52 else:
53 grid[row].append(TILE_CRATE)
54 return grid
55
56
57def make_maze_depth_first(maze_width, maze_height):
58 maze = _create_grid_with_cells(maze_width, maze_height)
59
60 w = (len(maze[0]) - 1) // 2
61 h = (len(maze) - 1) // 2
62 vis = [[0] * w + [1] for _ in range(h)] + [[1] * (w + 1)]
63
64 def walk(x: int, y: int):
65 vis[y][x] = 1
66
67 d = [(x - 1, y), (x, y + 1), (x + 1, y), (x, y - 1)]
68 random.shuffle(d)
69 for (xx, yy) in d:
70 if vis[yy][xx]:
71 continue
72 if xx == x:
73 maze[max(y, yy) * 2][x * 2 + 1] = TILE_EMPTY
74 if yy == y:
75 maze[y * 2 + 1][max(x, xx) * 2] = TILE_EMPTY
76
77 walk(xx, yy)
78
79 walk(random.randrange(w), random.randrange(h))
80
81 return maze
82
83
84class MyGame(arcade.Window):
85 """ Main application class. """
86
87 def __init__(self, width, height, title):
88 """
89 Initializer
90 """
91 super().__init__(width, height, title)
92
93 # Sprite lists
94 self.player_list = None
95 self.wall_list = None
96
97 # Player info
98 self.score = 0
99 self.player_sprite = None
100
101 # Physics engine
102 self.physics_engine = None
103
104 # Used to scroll
105 self.view_bottom = 0
106 self.view_left = 0
107
108 # Time to process
109 self.processing_time = 0
110 self.draw_time = 0
111
112 def setup(self):
113 """ Set up the game and initialize the variables. """
114
115 # Sprite lists
116 self.player_list = arcade.SpriteList()
117 self.wall_list = arcade.SpriteList()
118
119 self.score = 0
120
121 # Create the maze
122 maze = make_maze_depth_first(MAZE_WIDTH, MAZE_HEIGHT)
123
124 # Create sprites based on 2D grid
125 if not MERGE_SPRITES:
126 # This is the simple-to-understand method. Each grid location
127 # is a sprite.
128 for row in range(MAZE_HEIGHT):
129 for column in range(MAZE_WIDTH):
130 if maze[row][column] == 1:
131 wall = arcade.Sprite(":resources:images/tiles/grassCenter.png", SPRITE_SCALING)
132 wall.center_x = column * SPRITE_SIZE + SPRITE_SIZE / 2
133 wall.center_y = row * SPRITE_SIZE + SPRITE_SIZE / 2
134 self.wall_list.append(wall)
135 else:
136 # This uses new Arcade 1.3.1 features, that allow me to create a
137 # larger sprite with a repeating texture. So if there are multiple
138 # cells in a row with a wall, we merge them into one sprite, with a
139 # repeating texture for each cell. This reduces our sprite count.
140 for row in range(MAZE_HEIGHT):
141 column = 0
142 while column < len(maze):
143 while column < len(maze) and maze[row][column] == 0:
144 column += 1
145 start_column = column
146 while column < len(maze) and maze[row][column] == 1:
147 column += 1
148 end_column = column - 1
149
150 column_count = end_column - start_column + 1
151 column_mid = (start_column + end_column) / 2
152
153 wall = arcade.Sprite(":resources:images/tiles/grassCenter.png", SPRITE_SCALING)
154 wall.center_x = column_mid * SPRITE_SIZE + SPRITE_SIZE / 2
155 wall.center_y = row * SPRITE_SIZE + SPRITE_SIZE / 2
156 wall.width = SPRITE_SIZE * column_count
157 self.wall_list.append(wall)
158
159 # Set up the player
160 self.player_sprite = arcade.Sprite(":resources:images/animated_characters/female_person/"
161 "femalePerson_idle.png",
162 SPRITE_SCALING)
163 self.player_list.append(self.player_sprite)
164
165 # Randomly place the player. If we are in a wall, repeat until we aren't.
166 placed = False
167 while not placed:
168
169 # Randomly position
170 self.player_sprite.center_x = random.randrange(MAZE_WIDTH * SPRITE_SIZE)
171 self.player_sprite.center_y = random.randrange(MAZE_HEIGHT * SPRITE_SIZE)
172
173 # Are we in a wall?
174 walls_hit = arcade.check_for_collision_with_list(self.player_sprite, self.wall_list)
175 if len(walls_hit) == 0:
176 # Not in a wall! Success!
177 placed = True
178
179 self.physics_engine = arcade.PhysicsEngineSimple(self.player_sprite, self.wall_list)
180
181 # Set the background color
182 arcade.set_background_color(arcade.color.AMAZON)
183
184 # Set the viewport boundaries
185 # These numbers set where we have 'scrolled' to.
186 self.view_left = 0
187 self.view_bottom = 0
188
189 def on_draw(self):
190 """
191 Render the screen.
192 """
193
194 # This command has to happen before we start drawing
195 self.clear()
196
197 # Start timing how long this takes
198 draw_start_time = timeit.default_timer()
199
200 # Draw all the sprites.
201 self.wall_list.draw()
202 self.player_list.draw()
203
204 # Draw info on the screen
205 sprite_count = len(self.wall_list)
206
207 output = f"Sprite Count: {sprite_count}"
208 arcade.draw_text(output,
209 self.view_left + 20,
210 SCREEN_HEIGHT - 20 + self.view_bottom,
211 arcade.color.WHITE, 16)
212
213 output = f"Drawing time: {self.draw_time:.3f}"
214 arcade.draw_text(output,
215 self.view_left + 20,
216 SCREEN_HEIGHT - 40 + self.view_bottom,
217 arcade.color.WHITE, 16)
218
219 output = f"Processing time: {self.processing_time:.3f}"
220 arcade.draw_text(output,
221 self.view_left + 20,
222 SCREEN_HEIGHT - 60 + self.view_bottom,
223 arcade.color.WHITE, 16)
224
225 self.draw_time = timeit.default_timer() - draw_start_time
226
227 def on_key_press(self, key, modifiers):
228 """Called whenever a key is pressed. """
229
230 if key == arcade.key.UP:
231 self.player_sprite.change_y = MOVEMENT_SPEED
232 elif key == arcade.key.DOWN:
233 self.player_sprite.change_y = -MOVEMENT_SPEED
234 elif key == arcade.key.LEFT:
235 self.player_sprite.change_x = -MOVEMENT_SPEED
236 elif key == arcade.key.RIGHT:
237 self.player_sprite.change_x = MOVEMENT_SPEED
238
239 def on_key_release(self, key, modifiers):
240 """Called when the user releases a key. """
241
242 if key == arcade.key.UP or key == arcade.key.DOWN:
243 self.player_sprite.change_y = 0
244 elif key == arcade.key.LEFT or key == arcade.key.RIGHT:
245 self.player_sprite.change_x = 0
246
247 def on_update(self, delta_time):
248 """ Movement and game logic """
249
250 start_time = timeit.default_timer()
251
252 # Call update on all sprites (The sprites don't do much in this
253 # example though.)
254 self.physics_engine.update()
255
256 # --- Manage Scrolling ---
257
258 # Track if we need to change the viewport
259
260 changed = False
261
262 # Scroll left
263 left_bndry = self.view_left + VIEWPORT_MARGIN
264 if self.player_sprite.left < left_bndry:
265 self.view_left -= left_bndry - self.player_sprite.left
266 changed = True
267
268 # Scroll right
269 right_bndry = self.view_left + SCREEN_WIDTH - VIEWPORT_MARGIN
270 if self.player_sprite.right > right_bndry:
271 self.view_left += self.player_sprite.right - right_bndry
272 changed = True
273
274 # Scroll up
275 top_bndry = self.view_bottom + SCREEN_HEIGHT - VIEWPORT_MARGIN
276 if self.player_sprite.top > top_bndry:
277 self.view_bottom += self.player_sprite.top - top_bndry
278 changed = True
279
280 # Scroll down
281 bottom_bndry = self.view_bottom + VIEWPORT_MARGIN
282 if self.player_sprite.bottom < bottom_bndry:
283 self.view_bottom -= bottom_bndry - self.player_sprite.bottom
284 changed = True
285
286 if changed:
287 arcade.set_viewport(self.view_left,
288 SCREEN_WIDTH + self.view_left,
289 self.view_bottom,
290 SCREEN_HEIGHT + self.view_bottom)
291
292 # Save the time it took to do this.
293 self.processing_time = timeit.default_timer() - start_time
294
295
296def main():
297 """ Main function """
298 window = MyGame(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
299 window.setup()
300 arcade.run()
301
302
303if __name__ == "__main__":
304 main()