Sprites That Follow The Player 2#
sprite_follow_simple_2.py#
1"""
2Sprite Follow Player 2
3
4This calculates a 'vector' towards the player and randomly updates it based
5on the player's location. This is a bit more complex, but more interesting
6way of following the player.
7
8Artwork from https://kenney.nl
9
10If Python and Arcade are installed, this example can be run from the command line with:
11python -m arcade.examples.sprite_follow_simple_2
12"""
13
14import random
15import arcade
16import math
17
18# --- Constants ---
19SPRITE_SCALING_PLAYER = 0.5
20SPRITE_SCALING_COIN = 0.2
21COIN_COUNT = 5
22COIN_SPEED = 0.5
23
24SCREEN_WIDTH = 800
25SCREEN_HEIGHT = 600
26SCREEN_TITLE = "Sprite Follow Player Simple Example 2"
27
28SPRITE_SPEED = 0.5
29
30
31class Coin(arcade.Sprite):
32 """
33 This class represents the coins on our screen. It is a child class of
34 the arcade library's "Sprite" class.
35 """
36
37 def follow_sprite(self, player_sprite):
38 """
39 This function will move the current sprite towards whatever
40 other sprite is specified as a parameter.
41
42 We use the 'min' function here to get the sprite to line up with
43 the target sprite, and not jump around if the sprite is not off
44 an exact multiple of SPRITE_SPEED.
45 """
46
47 self.center_x += self.change_x
48 self.center_y += self.change_y
49
50 # Random 1 in 100 chance that we'll change from our old direction and
51 # then re-aim toward the player
52 if random.randrange(100) == 0:
53 start_x = self.center_x
54 start_y = self.center_y
55
56 # Get the destination location for the bullet
57 dest_x = player_sprite.center_x
58 dest_y = player_sprite.center_y
59
60 # Do math to calculate how to get the bullet to the destination.
61 # Calculation the angle in radians between the start points
62 # and end points. This is the angle the bullet will travel.
63 x_diff = dest_x - start_x
64 y_diff = dest_y - start_y
65 angle = math.atan2(y_diff, x_diff)
66
67 # Taking into account the angle, calculate our change_x
68 # and change_y. Velocity is how fast the bullet travels.
69 self.change_x = math.cos(angle) * COIN_SPEED
70 self.change_y = math.sin(angle) * COIN_SPEED
71
72
73class MyGame(arcade.Window):
74 """ Our custom Window Class"""
75
76 def __init__(self):
77 """ Initializer """
78 # Call the parent class initializer
79 super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
80
81 # Variables that will hold sprite lists
82 self.player_list = None
83 self.coin_list = None
84
85 # Set up the player info
86 self.player_sprite = None
87 self.score = 0
88
89 # Don't show the mouse cursor
90 self.set_mouse_visible(False)
91
92 self.background_color = arcade.color.AMAZON
93
94 def setup(self):
95 """ Set up the game and initialize the variables. """
96
97 # Sprite lists
98 self.player_list = arcade.SpriteList()
99 self.coin_list = arcade.SpriteList()
100
101 # Score
102 self.score = 0
103
104 # Set up the player
105 # Character image from kenney.nl
106 self.player_sprite = arcade.Sprite(":resources:images/animated_characters/female_person/femalePerson_idle.png",
107 scale=SPRITE_SCALING_PLAYER)
108 self.player_sprite.center_x = 50
109 self.player_sprite.center_y = 50
110 self.player_list.append(self.player_sprite)
111
112 # Create the coins
113 for i in range(COIN_COUNT):
114 # Create the coin instance
115 # Coin image from kenney.nl
116 coin = Coin(":resources:images/items/coinGold.png", scale=SPRITE_SCALING_COIN)
117
118 # Position the coin
119 coin.center_x = random.randrange(SCREEN_WIDTH)
120 coin.center_y = random.randrange(SCREEN_HEIGHT)
121
122 # Add the coin to the lists
123 self.coin_list.append(coin)
124
125 def on_draw(self):
126 """ Draw everything """
127 self.clear()
128 self.coin_list.draw()
129 self.player_list.draw()
130
131 # Put the text on the screen.
132 output = f"Score: {self.score}"
133 arcade.draw_text(output, 10, 20, arcade.color.WHITE, 14)
134
135 def on_mouse_motion(self, x, y, dx, dy):
136 """ Handle Mouse Motion """
137
138 # Move the center of the player sprite to match the mouse x, y
139 self.player_sprite.center_x = x
140 self.player_sprite.center_y = y
141
142 def on_update(self, delta_time):
143 """ Movement and game logic """
144
145 for coin in self.coin_list:
146 coin.follow_sprite(self.player_sprite)
147
148 # Generate a list of all sprites that collided with the player.
149 hit_list = arcade.check_for_collision_with_list(self.player_sprite, self.coin_list)
150
151 # Loop through each colliding sprite, remove it, and add to the score.
152 for coin in hit_list:
153 coin.kill()
154 self.score += 1
155
156
157def main():
158 """ Main function """
159 window = MyGame()
160 window.setup()
161 arcade.run()
162
163
164if __name__ == "__main__":
165 main()