如何在Pygame中制作带透明背景的表面。

Question

有人能给我一些在pygame中创建透明背景表面的示例代码吗？

- Paul Eden

Answer 1

这应该可以解决：

image = pygame.Surface([640,480], pygame.SRCALPHA, 32)
image = image.convert_alpha()

确保颜色深度（32）保持明确设置，否则这将无法正常工作。

- Unkwntech

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我赞同这个观点 - image = pygame.Surface([640, 480], pygame.SRCALPHA) 就足够了。 - Jayce

我还想补充一点，现在你可以这样设置颜色：cloud_color = (255, 255, 255, 120)，其中最后一个值的范围是0到255。 - Ethan McRae

Answer 2

您还可以为其设置颜色键，就像GIF文件透明度一样。这是制作精灵的最常见方式。原始位图具有艺术作品，并且具有某种背景色，该背景色不会被绘制，这就是颜色键：

surf.set_colorkey((255,0,255)) // Sets the colorkey to that hideous purple

使用颜色键而不是alpha通道的表面在blit（图像复制）时速度更快，因为它们不需要进行任何混合运算。当SDL表面设置了颜色键时，它使用一个简单的位掩码进行blit，几乎没有任何额外开销。

- Sir Oddfellow

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这是正确的答案。链接：https://riptutorial.com/pygame/example/23788/transparency - Astariul

Answer 3

您有三个选择：

• Set a transparent color key with set_colorkey()

  The color key specifies the color that is treated as transparent. For example, if you have an image with a black background that should be transparent, set a black color key:

  my_surface.set_colorkey((0, 0, 0))
  

• You can enable additional functions when creating a new surface. Set the SRCALPHA flag to create a surface with an image format that includes a per-pixel alpha. The initial value of the pixels is (0, 0, 0, 0):

  my_surface = pygame.Surface((width, height), pygame.SRCALPHA)
  

• Use convert_alpha() to create a copy of the Surface with an image format that provides alpha per pixel.

  However, if you create a new surface and use convert_alpha(), the alpha channels are initially set to maximum. The initial value of the pixels is (0, 0, 0, 255). You need to fill the entire surface with a transparent color before you can draw anything on it:

  my_surface = pygame.Surface((width, height))
  my_surface = my_surface.convert_alpha()
  my_surface.fill((0, 0, 0, 0))
  

- Rabbid76