Better Move By Keyboard#
If a player presses the left key, the sprite should move left. If the player hits both left and right, the player should stop. If the player lets off the left key, keeping the right key down, the player should move right.
The simpler method of handling keystrokes will not handle this correctly. This code tracks which key is down or up, and handles it properly.
See the highlighted sections.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 | """ Better Move Sprite With Keyboard Simple program to show moving a sprite with the keyboard. This is slightly better than sprite_move_keyboard.py example in how it works, but also slightly more complex. Artwork from https://kenney.nl If Python and Arcade are installed, this example can be run from the command line with: python -m arcade.examples.sprite_move_keyboard_better """ import arcade SPRITE_SCALING = 0.5 SCREEN_WIDTH = 800 SCREEN_HEIGHT = 600 SCREEN_TITLE = "Better Move Sprite with Keyboard Example" MOVEMENT_SPEED = 5 class Player(arcade.Sprite): def update(self): """ Move the player """ # Move player. # Remove these lines if physics engine is moving player. self.center_x += self.change_x self.center_y += self.change_y # Check for out-of-bounds if self.left < 0: self.left = 0 elif self.right > SCREEN_WIDTH - 1: self.right = SCREEN_WIDTH - 1 if self.bottom < 0: self.bottom = 0 elif self.top > SCREEN_HEIGHT - 1: self.top = SCREEN_HEIGHT - 1 class MyGame(arcade.Window): """ Main application class. """ def __init__(self, width, height, title): """ Initializer """ # Call the parent class initializer super().__init__(width, height, title) # Variables that will hold sprite lists self.player_list = None # Set up the player info self.player_sprite = None # Track the current state of what key is pressed self.left_pressed = False self.right_pressed = False self.up_pressed = False self.down_pressed = False # Set the background color arcade.set_background_color(arcade.color.AMAZON) def setup(self): """ Set up the game and initialize the variables. """ # Sprite lists self.player_list = arcade.SpriteList() # Set up the player self.player_sprite = Player(":resources:images/animated_characters/female_person/femalePerson_idle.png", SPRITE_SCALING) self.player_sprite.center_x = 50 self.player_sprite.center_y = 50 self.player_list.append(self.player_sprite) def on_draw(self): """ Render the screen. """ # Clear the screen self.clear() # Draw all the sprites. self.player_list.draw() def update_player_speed(self): # Calculate speed based on the keys pressed self.player_sprite.change_x = 0 self.player_sprite.change_y = 0 if self.up_pressed and not self.down_pressed: self.player_sprite.change_y = MOVEMENT_SPEED elif self.down_pressed and not self.up_pressed: self.player_sprite.change_y = -MOVEMENT_SPEED if self.left_pressed and not self.right_pressed: self.player_sprite.change_x = -MOVEMENT_SPEED elif self.right_pressed and not self.left_pressed: self.player_sprite.change_x = MOVEMENT_SPEED def on_update(self, delta_time): """ Movement and game logic """ # Call update to move the sprite # If using a physics engine, call update player to rely on physics engine # for movement, and call physics engine here. self.player_list.update() def on_key_press(self, key, modifiers): """Called whenever a key is pressed. """ if key == arcade.key.UP: self.up_pressed = True self.update_player_speed() elif key == arcade.key.DOWN: self.down_pressed = True self.update_player_speed() elif key == arcade.key.LEFT: self.left_pressed = True self.update_player_speed() elif key == arcade.key.RIGHT: self.right_pressed = True self.update_player_speed() def on_key_release(self, key, modifiers): """Called when the user releases a key. """ if key == arcade.key.UP: self.up_pressed = False self.update_player_speed() elif key == arcade.key.DOWN: self.down_pressed = False self.update_player_speed() elif key == arcade.key.LEFT: self.left_pressed = False self.update_player_speed() elif key == arcade.key.RIGHT: self.right_pressed = False self.update_player_speed() def main(): """ Main function """ window = MyGame(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE) window.setup() arcade.run() if __name__ == "__main__": main() |