Sprites: Aim and shoot bulletsΒΆ

Screenshot of using sprites to shoot things
"""
Sprite Bullets

Simple program to show basic sprite usage.

Artwork from http://kenney.nl
"""
import random
import arcade
import math

SPRITE_SCALING = 0.5

SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600

BULLET_SPEED = 5

window = None


class Bullet(arcade.Sprite):
    def update(self):
        self.center_x += self.change_x
        self.center_y += self.change_y


class MyApplication(arcade.Window):
    """ Main application class. """

    def __init__(self, screen_width, screen_height):
        super().__init__(SCREEN_WIDTH, SCREEN_HEIGHT, "Sprites and Bullets Demo")

        """ Set up the game and initialize the variables. """

        # Sprite lists
        self.all_sprites_list = arcade.SpriteList()
        self.coin_list = arcade.SpriteList()
        self.bullet_list = arcade.SpriteList()

        # Set up the player
        self.score = 0
        self.player_sprite = arcade.Sprite("images/character.png",
                                           SPRITE_SCALING)
        self.player_sprite.center_x = 50
        self.player_sprite.center_y = 70
        self.all_sprites_list.append(self.player_sprite)

        for i in range(50):

            # Create the coin instance
            coin = arcade.Sprite("images/coin_01.png", SPRITE_SCALING / 3)

            # Position the coin
            coin.center_x = random.randrange(screen_width)
            coin.center_y = random.randrange(120, screen_height)

            # Add the coin to the lists
            self.all_sprites_list.append(coin)
            self.coin_list.append(coin)

        # Set the background color
        arcade.set_background_color(arcade.color.AMAZON)

    def on_draw(self):
        """
        Render the screen.
        """

        # This command has to happen before we start drawing
        arcade.start_render()

        # Draw all the sprites.
        self.all_sprites_list.draw()

        # Put the text on the screen.
        output = "Score: {}".format(self.score)
        arcade.draw_text(output, 10, 20, arcade.color.WHITE, 14)

    def on_mouse_press(self, x, y, button, modifiers):
        """
        Called whenever the mouse moves.
        """
        # Create a bullet
        bullet = Bullet("images/laserBlue01.png", SPRITE_SCALING * 1.5)

        # Position the bullet at the player's current location
        start_x = self.player_sprite.center_x
        start_y = self.player_sprite.center_y
        bullet.center_x = start_x
        bullet.center_y = start_y

        # Get from the mouse the destination location for the bullet
        dest_x = x
        dest_y = y

        # Do math to calculate how to get the bullet to the destination.
        # Calculation the angle in radians between the start points
        # and end points. This is the angle the bullet will travel.
        x_diff = dest_x - start_x
        y_diff = dest_y - start_y
        angle = math.atan2(y_diff, x_diff)
        print("Bullet angle: {:.2f}".format(bullet.angle))

        # Angle the bullet sprite so it doesn't look like it is flying
        # sideways.
        bullet.angle = math.degrees(angle)

        # Taking into account the angle, calculate our change_x
        # and change_y. Velocity is how fast the bullet travels.
        bullet.change_x = math.cos(angle) * BULLET_SPEED
        bullet.change_y = math.sin(angle) * BULLET_SPEED

        # Add the bullet to the appropriate lists
        self.all_sprites_list.append(bullet)
        self.bullet_list.append(bullet)

    def animate(self, delta_time):
        """ Movement and game logic """

        # Call update on all sprites (The sprites don't do much in this
        # example though.)
        self.all_sprites_list.update()

        # Loop through each bullet
        for bullet in self.bullet_list:

            # Check this bullet to see if it hit a coin
            hit_list = arcade.check_for_collision_with_list(bullet,
                                                            self.coin_list)

            # If it did, get rid of the bullet
            if len(hit_list) > 0:
                bullet.kill()

            # For every coin we hit, add to the score and remove the coin
            for coin in hit_list:
                coin.kill()
                self.score += 1

            # If the bullet flies off-screen, remove it.
            if bullet.bottom > SCREEN_HEIGHT:
                bullet.kill()


def main():
    MyApplication(SCREEN_WIDTH, SCREEN_HEIGHT)
    arcade.run()


if __name__ == "__main__":
    main()