python - Pygame Rotated Shooting

Question

Me and a few friends have been coding an intresting new shooting mechanic. For It to work, we need to shoot in the direction the player is facing. The Sprite is being rotated with Pygame.Transform.Rotate. How can we get an angle, and shoot our bullet in that direction?

Here is Our Code for rotation of the Sprite

 char_image_number = pygame.mouse.get_pressed()

    if char_image_number == (0, 0, 0):
            char_image = pygame.image.load(player_none).convert_alpha()
            char_image = pygame.transform.rotate(char_image, angle)
            screen.blit(background, (0,0))
            screen.blit(char_image,(540, 260))
            pygame.display.update()
    elif char_image_number == (1, 0, 0):
            print (angle)
            char_image = pygame.image.load(player_left).convert_alpha()
            angle+=1
            char_image = pygame.transform.rotate(char_image, angle)
            screen.blit(background, (0,0))
            screen.blit(char_image,(540, 260))
            pygame.display.update()
    elif char_image_number == (0, 0, 1):
            print (angle)
            angle-=1
            char_image = pygame.image.load(player_right).convert_alpha()

            char_image=pygame.transform.rotate(char_image, angle)
            screen.blit(background, (0,0))
            screen.blit(char_image,(540, 260))

            pygame.display.update()

    elif char_image_number == (1, 0, 1):
            char_image = pygame.image.load(player_both).convert_alpha()
            char_image = pygame.transform.rotate(char_image, angle)
            screen.blit(background, (0,0))
            screen.blit(char_image,(540, 260))
            pygame.display.update()

How can we shoot at the angle the player is facing?

Answer 1

Here's a quick'n'dirty executable example of how to use vector math to do what you want.

import pygame

class Player(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((32, 32))
        self.image.fill((0, 0, 0))
        self.image.set_colorkey((0, 0, 0))
        pygame.draw.polygon(self.image, pygame.Color('dodgerblue'), ((0, 0), (32, 16), (0, 32)))
        self.org_image = self.image.copy()
        self.angle = 0
        self.direction = pygame.Vector2(1, 0)
        self.rect = self.image.get_rect(center=(200, 200))
        self.pos = pygame.Vector2(self.rect.center)

    def update(self, events, dt):
        for e in events:
            if e.type == pygame.KEYDOWN:
                if e.key == pygame.K_SPACE:
                    self.groups()[0].add(Projectile(self.rect.center, self.direction.normalize()))
        pressed = pygame.key.get_pressed()
        if pressed[pygame.K_a]:
            self.angle += 3
        if pressed[pygame.K_d]:
            self.angle -= 3

        self.direction = pygame.Vector2(1, 0).rotate(-self.angle)
        self.image = pygame.transform.rotate(self.org_image, self.angle)
        self.rect = self.image.get_rect(center=self.rect.center)

class Projectile(pygame.sprite.Sprite):
    def __init__(self, pos, direction):
        super().__init__()
        self.image = pygame.Surface((8, 8))
        self.image.fill((0, 0, 0))
        self.image.set_colorkey((0, 0, 0))
        pygame.draw.circle(self.image, pygame.Color('orange'), (4, 4), 4)
        self.rect = self.image.get_rect(center=pos)
        self.direction = direction
        self.pos = pygame.Vector2(self.rect.center)

    def update(self, events, dt):
        self.pos += self.direction * dt
        self.rect.center = self.pos
        if not pygame.display.get_surface().get_rect().contains(self.rect):
            self.kill()

def main():
    pygame.init()
    screen = pygame.display.set_mode((500, 500))
    sprites = pygame.sprite.Group(Player())
    clock = pygame.time.Clock()
    dt = 0

    while True:
        events = pygame.event.get()
        for e in events:
            if e.type == pygame.QUIT:
                return
        sprites.update(events, dt)
        screen.fill((30, 30, 30))
        sprites.draw(screen)
        pygame.display.update()
        dt = clock.tick(60)

if __name__ == '__main__':
    main()

Note: it seems that you're loading the image of your player every frame. You should not do that, as this is very slow. Just load each image once. Also, it's better to have only one spot in your code that calls pygame.display.update(), as you should make sure it's called only once each frame.