Pygame 旋转射击

我和几个朋友一直在编写一种有趣的新射击机制。为了让它发挥作用，我们需要朝玩家面对的方向射击。 Sprite 正在使用 Pygame.Transform.Rotate 进行旋转。我们怎样才能找到一个角度，然后朝那个方向发射子弹呢？

这是我们的精灵旋转代码

 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()

我们怎样才能以玩家面对的角度进行射击呢？

这是一个快速的可执行示例，说明如何使用向量数学来完成您想要的操作。

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()

注意：您似乎每帧都加载播放器的图像。你不应该这样做，因为这是very慢的。只需加载每个图像一次。另外，最好只拥有one在调用的代码中找到pygame.display.update()，因为您应该确保每帧只调用一次。