I've been messing with pygame for awhile and am having a blast! Thanks for
a great site, pygame.org people! And, I just got on this list and already
its been very helpful!
I ran into a performance snag trying to blit a surface with surface-alpha to
a fullscreen display surface (trying to do a fade-to-black for the screen).
It works great (realtime) when the display is windowed. Lotsa fun! But,
when the display is fullscreen, each blit takes almost a second to complete
in 640x480 on a beefy machine.
Now, I've read the pygame docs on surfaces and displays and searched this
list (finding some related discussions) and can't quite nail down what my
problem is.
So, my question is: why does it take me so long to blit in fullscreen mode?
And, how can I create the surfaces in such a way that the blit performs at
realtime in both windowed and fullscreen mode?
Here's some snatches of my code. I grabbed the important bits, as it would
be too much code to post all my classes in their entirety.
…Set up windowed mode:
pygame.display.set_mode((640, 480))
...or set up fullscreen mode:
pygame.display.set_mode((640, 480), pygame.FULLSCREEN | pygame.HWSURFACE)
...creating the surface to do the fade:
self._fadeSurface = pygame.Surface(size)
self._fadeSurface.fill(color)
self._fadeSurface.set_alpha(alpha)
self._fadeSurface = self._fadeSurface.convert()
...blitting the fade surface to the display:
self._targetSurface.blit(self._fadeSurface, (0, 0))
In windowed mode, pygame.display.Info() returns:
<VideoInfo(hw = 1, wm = 1,video_mem = 238032
blit_hw = 1, blit_hw_CC = 1, blit_hw_A = 0,
blit_sw = 1, blit_sw_CC = 1, blit_sw_A = 0,
bitsize = 32, bytesize = 4,
masks = (16711680, 65280, 255, 0),
shifts = (16, 8, 0, 0),
losses = (0, 0, 0, 8)>
In fullscreen mode, pygame.display.Info() returns:
<VideoInfo(hw = 1, wm = 1,video_mem = 244688
blit_hw = 1, blit_hw_CC = 1, blit_hw_A = 0,
blit_sw = 1, blit_sw_CC = 1, blit_sw_A = 0,
bitsize = 32, bytesize = 4,
masks = (16711680, 65280, 255, 0),
shifts = (16, 8, 0, 0),
losses = (0, 0, 0, 8)>
So, the alpha HW acceleration capabilities of the display in either mode are
the same. I do a convert() on the surface before blitting so it's format
should match the display's. Why is the blit so slow in one case (fullscreen
surface) and realtime in the other (windowed surface)? I'm sure this has
something to do with mismatches in surface modes, but I haven't been able to
get a handle on the details.
Thanks in advance...
-Scott