Camera Shake#
You can cause the camera to shake, as this example does when the player encounters a bomb. See the highlighted lines below.
sprite_move_scrolling_shake.py#
1"""
2Scroll around a large screen.
3
4Artwork from https://kenney.nl
5
6If Python and Arcade are installed, this example can be run from the command line with:
7python -m arcade.examples.sprite_move_scrolling_shake
8"""
9
10from __future__ import annotations
11
12import random
13import math
14import arcade
15
16SPRITE_SCALING = 0.5
17
18DEFAULT_SCREEN_WIDTH = 800
19DEFAULT_SCREEN_HEIGHT = 600
20SCREEN_TITLE = "Camera Shake Example"
21
22# How many pixels to keep as a minimum margin between the character
23# and the edge of the screen.
24VIEWPORT_MARGIN = 220
25
26# How fast the camera pans to the player. 1.0 is instant.
27CAMERA_SPEED = 0.1
28
29# How fast the character moves
30PLAYER_MOVEMENT_SPEED = 7
31
32BOMB_COUNT = 50
33PLAYING_FIELD_WIDTH = 1600
34PLAYING_FIELD_HEIGHT = 1600
35
36
37class MyGame(arcade.Window):
38 """ Main application class. """
39
40 def __init__(self, width, height, title):
41 """
42 Initializer
43 """
44 super().__init__(width, height, title, resizable=True)
45
46 # Sprite lists
47 self.player_list = None
48 self.wall_list = None
49 self.bomb_list = None
50
51 # Set up the player
52 self.player_sprite = None
53
54 # Physics engine so we don't run into walls.
55 self.physics_engine = None
56
57 # Create the cameras. One for the GUI, one for the sprites.
58 # We scroll the 'sprite world' but not the GUI.
59 self.camera_sprites = arcade.Camera()
60 self.camera_gui = arcade.Camera()
61
62 self.explosion_sound = arcade.load_sound(":resources:sounds/explosion1.wav")
63
64 def setup(self):
65 """ Set up the game and initialize the variables. """
66
67 # Sprite lists
68 self.player_list = arcade.SpriteList()
69 self.wall_list = arcade.SpriteList()
70 self.bomb_list = arcade.SpriteList()
71
72 # Set up the player
73 self.player_sprite = arcade.Sprite(":resources:images/animated_characters/female_person/femalePerson_idle.png",
74 scale=0.4)
75 self.player_sprite.center_x = 512
76 self.player_sprite.center_y = 512
77 self.player_list.append(self.player_sprite)
78
79 # -- Set up several columns of walls
80 for x in range(200, PLAYING_FIELD_WIDTH, 210):
81 for y in range(0, PLAYING_FIELD_HEIGHT, 64):
82 # Randomly skip a box so the player can find a way through
83 if random.randrange(5) > 0:
84 wall = arcade.Sprite(":resources:images/tiles/grassCenter.png", scale=SPRITE_SCALING)
85 wall.center_x = x
86 wall.center_y = y
87 self.wall_list.append(wall)
88
89 for i in range(BOMB_COUNT):
90 bomb = arcade.Sprite(":resources:images/tiles/bomb.png", scale=0.25)
91 placed = False
92 while not placed:
93 bomb.center_x = random.randrange(PLAYING_FIELD_WIDTH)
94 bomb.center_y = random.randrange(PLAYING_FIELD_HEIGHT)
95 if not arcade.check_for_collision_with_list(bomb, self.wall_list):
96 placed = True
97 self.bomb_list.append(bomb)
98
99 self.physics_engine = arcade.PhysicsEngineSimple(self.player_sprite, self.wall_list)
100
101 # Set the background color
102 self.background_color = arcade.color.AMAZON
103
104 def on_draw(self):
105 """
106 Render the screen.
107 """
108
109 # This command has to happen before we start drawing
110 self.clear()
111
112 # Select the camera we'll use to draw all our sprites
113 self.camera_sprites.use()
114
115 # Draw all the sprites.
116 self.wall_list.draw()
117 self.bomb_list.draw()
118 self.player_list.draw()
119
120 def on_key_press(self, key, modifiers):
121 """Called whenever a key is pressed. """
122
123 if key == arcade.key.UP:
124 self.player_sprite.change_y = PLAYER_MOVEMENT_SPEED
125 elif key == arcade.key.DOWN:
126 self.player_sprite.change_y = -PLAYER_MOVEMENT_SPEED
127 elif key == arcade.key.LEFT:
128 self.player_sprite.change_x = -PLAYER_MOVEMENT_SPEED
129 elif key == arcade.key.RIGHT:
130 self.player_sprite.change_x = PLAYER_MOVEMENT_SPEED
131
132 def on_key_release(self, key, modifiers):
133 """Called when the user releases a key. """
134
135 if key == arcade.key.UP or key == arcade.key.DOWN:
136 self.player_sprite.change_y = 0
137 elif key == arcade.key.LEFT or key == arcade.key.RIGHT:
138 self.player_sprite.change_x = 0
139
140 def on_update(self, delta_time):
141 """ Movement and game logic """
142
143 # Call update on all sprites (The sprites don't do much in this
144 # example though.)
145 self.physics_engine.update()
146
147 # Scroll the screen to the player
148 self.scroll_to_player()
149
150 hit_list = arcade.check_for_collision_with_list(self.player_sprite, self.bomb_list)
151 for bomb in hit_list:
152 # Remove the bomb and go 'boom'
153 bomb.remove_from_sprite_lists()
154 self.explosion_sound.play()
155
156 # --- Shake the camera ---
157 # Pick a random direction
158 shake_direction = random.random() * 2 * math.pi
159 # How 'far' to shake
160 shake_amplitude = 10
161 # Calculate a vector based on that
162 shake_vector = (
163 math.cos(shake_direction) * shake_amplitude,
164 math.sin(shake_direction) * shake_amplitude
165 )
166 # Frequency of the shake
167 shake_speed = 1.5
168 # How fast to damp the shake
169 shake_damping = 0.9
170 # Do the shake
171 self.camera_sprites.shake(shake_vector,
172 speed=shake_speed,
173 damping=shake_damping)
174
175 def scroll_to_player(self):
176 """
177 Scroll the window to the player.
178
179 if CAMERA_SPEED is 1, the camera will immediately move to the desired position.
180 Anything between 0 and 1 will have the camera move to the location with a smoother
181 pan.
182 """
183
184 position = (
185 self.player_sprite.center_x - self.width / 2,
186 self.player_sprite.center_y - self.height / 2
187 )
188 self.camera_sprites.move_to(position, CAMERA_SPEED)
189
190 def on_resize(self, width: int, height: int):
191 """
192 Resize window
193 Handle the user grabbing the edge and resizing the window.
194 """
195 self.camera_sprites.resize(width, height)
196 self.camera_gui.resize(width, height)
197
198
199def main():
200 """ Main function """
201 window = MyGame(DEFAULT_SCREEN_WIDTH, DEFAULT_SCREEN_HEIGHT, SCREEN_TITLE)
202 window.setup()
203 arcade.run()
204
205
206if __name__ == "__main__":
207 main()