Newsgroups: comp.windows.x
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From: twl@cadreri.UUCP (Todd W. Lainhart)
Subject: XGetImage on Sun XServer
Message-ID: <9104042219.AA05949@sun.Eng.Sun.COM>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Date: 4 Apr 91 21:59:48 GMT
Lines: 33


I need some xpert help:

I'm running whatever version of the X Server bundled with OpenWindows 2.0,
running Sun OS 4.1.1 on Sparc.  I've got a pixmap 2016x1584 that I'm reading chunks
of, in 32x32 bit swatches, and ultimately converting that (with the
help of XGetPixel) to another bitmap format for printing.

Here's what the call looks like:

    bitmap_image = XGetImage( xdisplay,
                              my_pixmap,
                              x_offset,
                              y_offset,
                              width,
                              height,
                              AllPlanes,
                              ZPixmap );

As I said, width and height are both 32.  The problem is, once x_offset and
y_offset reach > 1280x1056, XGetImage continually returns NULL.  Clearly, the rectangle
offset into the pixmap does not exceed the bounds of the rectangle.  XGetGeometry
returns 2016x1584 for the width and height of the pixmap, even after XGetImage
returns NULL.  Note that this only seems to happen on the Sun XServer - other
Servers I've tried don't behave this way.

Granted, this is a pretty large pixmap, but it seems that I might have discovered a
bug here.  Does anyone have any knowledge or experience that might shed some light
on this problem?

Thanks.

    -- Todd