Path: utzoo!attcan!uunet!cs.utexas.edu!usc!apple!snorkelwacker!bloom-beacon!LARRY.MCRCIM.MCGILL.EDU!mouse
From: mouse@LARRY.MCRCIM.MCGILL.EDU (der Mouse)
Newsgroups: comp.windows.x
Subject: Re:  pixmaps
Message-ID: <9006091006.AA11777@Larry.McRCIM.McGill.EDU>
Date: 9 Jun 90 10:06:57 GMT
Sender: root@athena.mit.edu (Wizard A. Root)
Organization: The Internet
Lines: 32

> I need to create a pair of pixmaps( sensitive and insensensitive) for
> a Motif button.  The second pixmap will be just like the first,
> except it should be stippled using the background color.  To
> accomplish this, I am calling XCreatePixmapFromBitmapData twice, with
> the same data.  Then I call XFillRectangle with the appropriate gc to
> stipple the second pixmap.

That's perfectly reasonable, though as you imply you've noticed,
slightly inefficient (very inefficient if the thing is large).

> I think I should be able to copy the first pixmap to the second (
> using memcpy or some other low level routine ) and then call
> XFillRectangle on the new pixmap.  The problem here is I don't really
> know how much memory the pixmap occupies.

There is a much more serious problem: in general, you, the client, do
not have access to the memory occupied by the pixmap.  All you have is
an ID by which you identify the pixmap to the server in X requests.  (I
said "in general" because someone probably has a system where the
client and server can use shared memory if they're on the same machine.)

> It has also been suggested that I use XCreatePixmap and XCopyArea to
> create the second pixmap.

This is a much better way of doing it.  It's the method I'd recommend.
(Ie, XCreatePixmapFromBitmapData, XCreatePixmap, XCopyArea,
XFillRectangle (plus some GC setup calls).)

					der Mouse

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