python-pygame之旋转图像

• 利用pygame.transform.ratate(Surface, angle)

• angle为正，逆时针旋转；为负，顺时针旋转
  方法一:
  (用库函数写一个自定义函数)

   The below example is a bit redundant (and forgets that pygame.transform.rotate returns the rotated surface, it doesn't transform in place)
        
        You can simply write it thusly:
        
        def __init__(self, image, startangle):
            ...
            self.original = image
            self.rotate(startangle)
        def rotate(self, angle):
            self.image = pygame.transform.rotate(self.original, angle)
  

方法二：
（直接用，但是需要赋值更新）

A good idea in rotating in small angles is to restore the image or sprite to its
original picture for example:

def __init__(self)
    ...
    self.original=self.image
    self.image=pygame.transform.rotate(self.image,self.angle)
def rotate(self,angle)
    self.image=self.original
    pygame.transform.rotate(self.image,angle)

but in exchange it will eat more pc usage and memory usage but youll have 
almost 90% better than rotating the image again and again so you have to choose
whether speed or quality