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