Conway’s Game of Life¶
This version of Conway’s Game of Life speeds everything up by using controlling a cell’s visibility through its alpha value, and handing the drawing logic off to the graphics card.
Grid-based games can take a while to render the program uses classic raster-based graphics. Every cell has to be re-drawn every single frame. If the cells are complex at all, that adds to the rendering time.
In this program, we create all cells in the grid to begin with. (This does causes the program to pause a while at start-up.)
After the sprites are created, we turn the cells on and off by their alpha value. We can update the entire grid by simply sending a list of alpha values to the graphics card. This significantly improves drawing time.
1"""
2Conway's Game of Life
3
4This code shows how to set up sprites in a grid, and then use their
5'alpha' value to quickly turn them on and off.
6
7After installing the "arcade" package version 2.4.4+, this program can be run by
8typing:
9python -m arcade.examples.conway_alpha
10"""
11import arcade
12import random
13
14# Set how many rows and columns we will have
15ROW_COUNT = 70
16COLUMN_COUNT = 128
17
18# This sets the WIDTH and HEIGHT of each grid location
19CELL_WIDTH = 15
20CELL_HEIGHT = 15
21
22# This sets the margin between each cell
23# and on the edges of the screen.
24CELL_MARGIN = 0
25
26# Do the math to figure out our screen dimensions
27SCREEN_WIDTH = (CELL_WIDTH + CELL_MARGIN) * COLUMN_COUNT + CELL_MARGIN
28SCREEN_HEIGHT = (CELL_HEIGHT + CELL_MARGIN) * ROW_COUNT + CELL_MARGIN
29SCREEN_TITLE = "Conway's Game of Life"
30
31# Colors and alpha values
32ALIVE_COLOR = arcade.color.BISTRE
33BACKGROUND_COLOR = arcade.color.ANTIQUE_WHITE
34ALPHA_ON = 255
35ALPHA_OFF = 0
36
37
38def create_grids():
39 """
40 Create a 2D and 1D grid of sprites. We use the 1D SpriteList for drawing,
41 and the 2D list for accessing via grid. Both lists point to the same set of
42 sprites.
43 """
44 # One dimensional list of all sprites in the two-dimensional sprite list
45 grid_sprites_one_dim = arcade.SpriteList()
46
47 # This will be a two-dimensional grid of sprites to mirror the two
48 # dimensional grid of numbers. This points to the SAME sprites that are
49 # in grid_sprite_list, just in a 2d manner.
50 grid_sprites_two_dim = []
51
52 # Create a list of sprites to represent each grid location
53 for row in range(ROW_COUNT):
54 grid_sprites_two_dim.append([])
55
56 for column in range(COLUMN_COUNT):
57
58 # Make the sprite as a soft circle
59 sprite = arcade.SpriteCircle(CELL_WIDTH // 2, ALIVE_COLOR, soft=True)
60
61 # Position the sprite
62 x = column * (CELL_WIDTH + CELL_MARGIN) + (CELL_WIDTH / 2 + CELL_MARGIN)
63 y = row * (CELL_HEIGHT + CELL_MARGIN) + (CELL_HEIGHT / 2 + CELL_MARGIN)
64 sprite.center_x = x
65 sprite.center_y = y
66
67 # Add the sprite to both lists
68 grid_sprites_one_dim.append(sprite)
69 grid_sprites_two_dim[row].append(sprite)
70
71 return grid_sprites_one_dim, grid_sprites_two_dim
72
73
74def randomize_grid(grid: arcade.SpriteList):
75 """ Randomize the grid to alive/dead """
76 for cell in grid:
77 pick = random.randrange(2)
78 if pick:
79 cell.alpha = ALPHA_ON
80 else:
81 cell.alpha = ALPHA_OFF
82
83
84class MyGame(arcade.Window):
85 """
86 Main application class.
87 """
88
89 def __init__(self, width: int, height: int, title: str):
90 """
91 Set up the application.
92 """
93 super().__init__(width, height, title)
94
95 arcade.set_background_color(BACKGROUND_COLOR)
96
97 # We need two layers. One holds the current state of our grid, the other
98 # holds the next frame's state. We flip back and forth between the two.
99 grid_sprites_one_dim1, grid_sprites_two_dim1 = create_grids()
100 grid_sprites_one_dim2, grid_sprites_two_dim2 = create_grids()
101
102 self.layers_grid_sprites_one_dim = [grid_sprites_one_dim1, grid_sprites_one_dim2]
103 self.layers_grid_sprites_two_dim = [grid_sprites_two_dim1, grid_sprites_two_dim2]
104
105 self.cur_layer = 0
106 randomize_grid(self.layers_grid_sprites_one_dim[0])
107
108 def on_draw(self):
109 """ Render the screen. """
110
111 # This command has to happen before we start drawing
112 arcade.start_render()
113 self.layers_grid_sprites_one_dim[0].draw()
114 self.layers_grid_sprites_one_dim[0].vbo_buf = None
115
116 def on_update(self, delta_time: float):
117 """ Update the grid """
118
119 # Flip layers
120 if self.cur_layer == 0:
121 layer1 = self.layers_grid_sprites_two_dim[0]
122 layer2 = self.layers_grid_sprites_two_dim[1]
123 self.cur_layer = 1
124 else:
125 layer1 = self.layers_grid_sprites_two_dim[1]
126 layer2 = self.layers_grid_sprites_two_dim[0]
127 self.cur_layer = 0
128
129 # Count the neighbors that are alive
130 for row in range(ROW_COUNT):
131 for column in range(COLUMN_COUNT):
132 live_neighbors = 0
133 # -1 -1
134 if row > 0 and column > 0 and layer1[row - 1][column - 1].alpha == ALPHA_ON:
135 live_neighbors += 1
136 # -1 0
137 if row > 0 and layer1[row - 1][column].alpha == ALPHA_ON:
138 live_neighbors += 1
139 # -1 +1
140 if row > 0 and column < COLUMN_COUNT - 1 and layer1[row - 1][column + 1].alpha == ALPHA_ON:
141 live_neighbors += 1
142 # 0 +1
143 if column < COLUMN_COUNT - 1 and layer1[row][column + 1].alpha == ALPHA_ON:
144 live_neighbors += 1
145 # +1 +1
146 if row < ROW_COUNT - 1 and column < COLUMN_COUNT - 1 and layer1[row + 1][column + 1].alpha == ALPHA_ON:
147 live_neighbors += 1
148 # +1 0
149 if row < ROW_COUNT - 1 and layer1[row + 1][column].alpha == ALPHA_ON:
150 live_neighbors += 1
151 # +1 -1
152 if row < ROW_COUNT - 1 and column > 0 and layer1[row + 1][column - 1].alpha == ALPHA_ON:
153 live_neighbors += 1
154 # 0 -1
155 if column > 0 and layer1[row][column - 1].alpha == ALPHA_ON:
156 live_neighbors += 1
157
158 """
159 Implement Conway's game of life rules
160
161 Any live cell with two or three live neighbours survives.
162 Any dead cell with three live neighbours becomes a live cell.
163 All other live cells die in the next generation. Similarly, all other dead cells stay dead.
164 """
165 if layer1[row][column].alpha == ALPHA_ON and (live_neighbors == 2 or live_neighbors == 3):
166 if layer2[row][column].alpha == ALPHA_OFF:
167 layer2[row][column].alpha = ALPHA_ON
168 elif layer1[row][column].alpha == ALPHA_OFF and live_neighbors == 3:
169 if layer2[row][column].alpha == ALPHA_OFF:
170 layer2[row][column].alpha = ALPHA_ON
171 else:
172 if layer2[row][column].alpha == ALPHA_ON:
173 layer2[row][column].alpha = ALPHA_OFF
174
175
176def main():
177 """ Main method - starting point to the program """
178 window = MyGame(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
179 window.center_window()
180 arcade.run()
181
182
183if __name__ == "__main__":
184 main()