Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!bbn!apple!bloom-beacon!EXPO.LCS.MIT.EDU!jim
From: jim@EXPO.LCS.MIT.EDU (Jim Fulton)
Newsgroups: comp.windows.x
Subject: Re: Reverse-Video
Message-ID: <8902271639.AA01116@expo.lcs.mit.edu>
Date: 27 Feb 89 16:39:06 GMT
References: <8902271458.AA29264@expo.lcs.mit.edu>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: X Consortium, MIT Laboratory for Computer Science
Lines: 15


> Could anyone tell me whether there is an easy way in Xlib to
> reverse-video a window and reverse back again?

Depends on what you mean by "reverse".

If the area in the window only has two pixel values, you can use a filled
rectangle with a GC that has the following fields:

	function:	GXxor
	foreground:	(firstpixelvalue ^ secondpixelvalue)

If you have a more complicated image on the screen, you'll have to look
into allocating color planes (make sure you have a dynamic visual...) and
setting up the color cells so that the arithmetic works out.