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Allegro CL version 9.0
Unrevised from 8.2 to 9.0.
8.2 version

with-double-buffering

Arguments: ((window) &body body

This macro should not be needed by most applications. Normally you would achieve double-buffering by enabling the double-buffered property of a window and ensuring that you draw in the window only in a redisplay-window method that Common Graphics calls automatically. See double-buffered for complete information about this property.

But if for some reason you need to draw on a window directly rather than using the usual redisplay-window callback paradigm, and you still want to use double-buffering, then you can do so by wrapping a call to with-double-buffering around the drawing code. This macro will copy the window's memory bitmap to the visible window at the end of its body, just as Common Graphics otherwise does just after it has called redisplay-window.

When using with-double-buffering, the double-buffered property of the window must still be true in order for double-buffering to occur.


Copyright (c) 1998-2012, Franz Inc. Oakland, CA., USA. All rights reserved.
Documentation for Allegro CL version 9.0. This page was not revised from the 8.2 page.
Created 2012.5.30.

ToCDocOverviewCGDocRelNotesFAQIndexPermutedIndex
Allegro CL version 9.0
Unrevised from 8.2 to 9.0.
8.2 version