Re: [pygame] video synch

[Pete Shinners <pete@shinners.org>]

jabberwocky wrote:
> How can I synchronize video updating with game event? For example, in my 
> game before starting a new level appear the string "Start Level ..." that
>  should disappear after n seconds, allowing the Level start. But the time
>  loading need to appear the screen with the string make the actual number
>  of seconds less than n, since I see the string only for a little time. 
> Is there a way to correct this problem?
This doesn't sound so much like a video sync issue. Check to make sure you 
are calling pygame.display.flip() or pygame.display.update() after showing 
the text. It sounds like your levels load very fast, you may not need to 
show a loading screen?

Video sync is needed to fix "tearing artifacts". These are seen when you 
have large animated objects or changing screens. For a single screen change 
it rarely matters. What happens is the animated screen changes while the 
monitor is halfway through drawing the screen. When it changes you see half 
of the old frame and half of the new frame.

Unfortunately SDL provides no way to control video sync. It has many video 
drivers and they all do what they please in regards to refresh rate and 
video sync.