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From: mouse@lightning.mcrcim.mcgill.EDU
Newsgroups: comp.windows.x
Subject: Re:  porting unstructured graphics code to X
Message-ID: <9102261216.AA12279@lightning.McRCIM.McGill.EDU>
Date: 26 Feb 91 12:16:47 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 22

> I have a pile of code that needs to run under X.  It all uses graphic
> primitive calls (lines, dots, crosses) that are PLOT-10 like.

> I'm unenthused about doing a lot of code rewrites to bundle graphics
> code into repaint procedures.

> Is there any easy way to port the code so that I can just draw into a
> window, and *not* have to worry about redrawing from Expose events?

Technically no, but close enough.  You draw into both a pixmap and a
window, and handle Expose events with XCopyArea() from the pixmap to
the window.

Of course, this carries a price: the pixmap (and a relatively slight
speed penalty).  On some servers, pixmaps of reasonable size are more
or less free; on others, even fairly small ones are precious.  You pays
yer money and you takes yer choice....

					der Mouse

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