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有一个精灵在以屏幕中心为中心的圆上移动，半径 = 30 像素。运动或多或少还可以，但精灵根本不旋转。我尝试了一些教程（例如，如何使用 rotozoom 在 pygame 中设置缩放和旋转动画），当精灵沿着一条线移动或随机改变其轨迹时 - 没有问题。那么当它沿着圆圈移动时有什么问题呢？这是代码：

class EnemiesStrong(pygame.sprite.Sprite):
    
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)     
        self.image = pygame.image.load("enemy3.png").convert_alpha()
        self.image2 = self.image        
        self.rect = self.image2.get_rect()  
        self.angle = 0
        
    def initLoc(self, pos, x_pos, y_pos):
        
        self.rect.x = pos[0]/2 + x_pos
        self.rect.y = y_pos
        
    
    def update(self, pos, x_pos, y_pos, quadrant, newcoord):
        #print(quadrant)
        
        self.rect.y = y_pos
        
        
        if (quadrant==1 and newcoord==0):
            self.rect.x-=1            
        elif (quadrant==1 and newcoord==1):
            self.rect.x=x_pos
                    
        elif (quadrant==2):           
                        
            oldcenter = self.rect.center
            **self.image2 = pygame.transform.rotate(self.image, self.angle)**
            self.rect = self.image2.get_rect()
            self.rect.center = oldcenter  
            self.rect.x+=1
                        
            
        elif (quadrant==3 and newcoord==0):
            self.rect.x+=1   
                                
        elif (quadrant==4 and newcoord==0):
            self.rect.x-=1
        elif (quadrant==4 and newcoord==1):
            self.rect.x=x_pos                   
                
    def turnLeft(self, pos):

        self.angle = (self.angle + 10) % 360
        print(self.angle)
        
    def whereEnemy(self):
        return (self.rect.x, self.rect.y)    

def OrbitalCoordinates(loc, xpos, radius, quadrant):

    #do lots of stuff to determine the location of the ship in the screen
    #and return its Y-coordinate
    disc = np.power(radius,2) - np.power(xpos - loc[0]/2,2)
    ypos = loc[1]/2 - np.sqrt(disc)                
    return ypos

enemy_s = EnemiesStrong()
ypos = OrbitalCoordinates(screenpar, xpos + screenpar[0]/2, radius,2)
enemy_s.initLoc(screenpar, xpos, ypos)
enemiesupdate.add(enemy_s)
where_strong_enemy = enemy_s.whereEnemy()
bg = pygame.image.load("outer_space.jpg")
screenpar = [bg.get_width(), bg.get_height()]

def main():
    #various useless crap
    for enemy_s in enemiesupdate:
            #do lots of stuff to determine the x- position and direction of movement of the ship 
            #and pass these values to OrbitalCoordinates  
            enemy_s.turnLeft(screenpar) 
            ypos = OrbitalCoordinates(screenpar, where_strong_enemy[0], radius, quadrant)
            enemy_s.update(screenpar, where_strong_enemy[0], ypos, quadrant, 0)
            where_strong_enemy = list(enemy_s.whereEnemy())
            #then check if the y-coordinates are close to the middle of the screen to tweak them a                          
            #little bit
screen.blit(bg, [0, 0])   
enemiesupdate.draw(screen)
pygame.display.flip()

我省略了我认为不必要的代码块。我确定我犯了一些愚蠢的错误。

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1 回答 1

0

阅读以下文档pygame.sprite.Group.draw：

将包含的 Sprite 绘制到 Surface 参数。这将Sprite.image属性用于源表面和Sprite.rect位置。

因此，旋转后的图像必须存储在image属性中。您将看不到任何旋转，因为您将旋转后的图像保存在image2属性中，而是image最初旋转的图像。将原始图像存储在 中original_image，将旋转后的图像存储在 中image：

class EnemiesStrong(pygame.sprite.Sprite):

    def __init__(self):
        pygame.sprite.Sprite.__init__(self)     
        self.image = pygame.image.load("enemy3.png").convert_alpha()
        self.image = self.original_image        
        self.rect = self.image.get_rect()  
        self.angle = 0

    def update(self):
        # [...]

        self.image = pygame.transform.rotate(self.original_image, self.angle)
        self.rect = self.image.get_rect(center = oldcenter)

        # [...]

另请参见移动和旋转。

最小的例子：

import pygame

class EnemiesStrong(pygame.sprite.Sprite):

    def __init__(self):
        pygame.sprite.Sprite.__init__(self)     
        self.original_image = pygame.image.load(r"arrow_up.png").convert_alpha()
        self.image = self.original_image        
        self.rect = self.image.get_rect()  
        self.angle = 0

    def initLoc(self, pos, radius):
        self.pos = pos
        self.radius = radius

    def update(self):
        center = pygame.math.Vector2(self.pos) + pygame.math.Vector2(0, -self.radius).rotate(-self.angle) 
        self.image = pygame.transform.rotate(self.original_image, self.angle)
        self.rect = self.image.get_rect(center = (round(center.x), round(center.y)))            

    def turnLeft(self):
        self.angle = (self.angle + 1) % 360
   
pygame.init()
window = pygame.display.set_mode((500, 500))
clock = pygame.time.Clock()

enemy_s = EnemiesStrong()
enemy_s.initLoc(window.get_rect().center, 100)
all_sprites = pygame.sprite.Group(enemy_s)

run = True
while run:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    enemy_s.turnLeft()
    all_sprites.update()

    window.fill(0)
    pygame.draw.circle(window, (127, 127, 127), window.get_rect().center, 100, 1)
    all_sprites.draw(window)
    pygame.display.flip()

pygame.quit()
exit()
于 2020-12-16T22:37:59.753 回答