How to shoot a bullet in the direction of the mouse in Pygame

In Pygame, one can create a bullet that is fired in the direction of the mouse. To do this, one would need to create a class that represents the bullet and set its initial position and direction based on the mouse position.

Class for the Bullet

First, create a class for the bullet. This class should include attributes for the bullet's position, size, and surface. The surface is what will be rendered on the screen.

import pygame

class Bullet:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.height = 7
        self.width = 2
        self.bullet = pygame.Surface((self.width, self.height))
        self.bullet.fill((255, 255, 255))

Game Class Functions

Next, create a class for the game. This class will contain functions for shooting and generating bullets.

class Game:
    def __init__(self):
        self.bullets = []
    
    def shoot_bullet(self):
        mouse_x, mouse_y = pygame.mouse.get_pos() # Get the mouse position
        for bullet in self.bullets:
            rise = mouse_y - bullet.y # Calculate the difference between mouse and bullet y position
            run = mouse_x - bullet.x # Calculate the difference between mouse and bullet x position
            angle = math.atan2(rise, run) # Calculate the angle between mouse and bullet

            bullet.x  = math.cos(angle) * 10 # Update bullet x position
            bullet.y  = math.sin(angle) * 10 # Update bullet y position

            # Rotate and draw the bullet
            rotated_bullet = pygame.transform.rotate(bullet.bullet, -math.degrees(angle))
            screen.blit(rotated_bullet, (bullet.x, bullet.y))

    def generate_bullet(self):
        mouse_buttons = pygame.mouse.get_pressed() # Check if mouse is clicked
        if mouse_buttons[0]: # If left mouse button is clicked
            self.bullets.append(Bullet(player.x, player.y)) # Create a new bullet

Using the Bullet Class

In the main game loop, create an instance of the Game class and call the shoot_bullet and generate_bullet functions.

game = Game()

while running:
    # Event handling

    # Update
    game.shoot_bullet()
    game.generate_bullet()
    
    # Draw
    screen.fill((0, 0, 0))
    for bullet in game.bullets:
        screen.blit(bullet.bullet, (bullet.x, bullet.y))
    pygame.display.update()

This code will create a bullet that is shot in the direction of the mouse. The bullet will move until it goes off the screen.