[squeak-dev] Re: Double-buffering using Display and BitBlt

Andreas Raab andreas.raab at gmx.de
Tue Mar 17 08:00:48 UTC 2009


Michael van der Gulik wrote:
> Is there a trick related to deferUpdates:? Or is it not really supported 
> or supported using some other plug-in?

Yes, there is a trick. Compare these two:

1 to: 1000 do:[:i|
	Display getCanvas line: i at 0 to: i at 500 width: 1 color: Color black.
].

vs. (after doing a restore display):

Display deferUpdates: true.
1 to: 1000 do:[:i|
	Display getCanvas line: i at 0 to: i at 500 width: 1 color: Color black.
].
Display forceToScreen: Display boundingBox. "way too much but hey..."

Cheers,
   - Andreas



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