getting pixmap from X - Xwindows

This is a discussion on getting pixmap from X - Xwindows ; Hi all, I have a small program that does an XGetImage() to get the pixel values of a pixmap from the X server. Unfortunately, I can't tell the difference between transparent & black pixels - they both have a pixel ...

+ Reply to Thread
Results 1 to 3 of 3

Thread: getting pixmap from X

  1. getting pixmap from X

    Hi all,

    I have a small program that does an XGetImage() to get the
    pixel values of a pixmap from the X server.

    Unfortunately, I can't tell the difference between transparent
    & black pixels - they both have a pixel value of zero!

    Can anyone give me a pointer as to how I can find out what
    the transparent pixels are in such a pixmap?

    For the techies: As part of a WM, I am trying to extract
    EWMH icons that some applications use. eg. GVim.

    SCoTT.


  2. Re: getting pixmap from X

    In comp.windows.x, Scott Smedley

    wrote
    on Thu, 27 May 2004 06:05:37 GMT
    :
    > Hi all,
    >
    > I have a small program that does an XGetImage() to get the
    > pixel values of a pixmap from the X server.
    >
    > Unfortunately, I can't tell the difference between transparent
    > & black pixels - they both have a pixel value of zero!
    >
    > Can anyone give me a pointer as to how I can find out what
    > the transparent pixels are in such a pixmap?
    >
    > For the techies: As part of a WM, I am trying to extract
    > EWMH icons that some applications use. eg. GVim.
    >
    > SCoTT.
    >


    X windows and pixmaps don't have transparent pixels,
    unless there's an extension involved that I don't know
    about offhand.

    --
    #191, ewill3@earthlink.net
    It's still legal to go .sigless.

  3. Re: getting pixmap from X

    The Ghost In The Machine writes:

    > In comp.windows.x, Scott Smedley
    >
    > wrote
    > on Thu, 27 May 2004 06:05:37 GMT
    > :
    >> Hi all,
    >>
    >> I have a small program that does an XGetImage() to get the
    >> pixel values of a pixmap from the X server.
    >>
    >> Unfortunately, I can't tell the difference between transparent
    >> & black pixels - they both have a pixel value of zero!
    >>
    >> Can anyone give me a pointer as to how I can find out what
    >> the transparent pixels are in such a pixmap?
    >>
    >> For the techies: As part of a WM, I am trying to extract
    >> EWMH icons that some applications use. eg. GVim.
    >>
    >> SCoTT.
    >>

    >
    > X windows and pixmaps don't have transparent pixels,
    > unless there's an extension involved that I don't know
    > about offhand.


    The SHAPE extension comes to mind. Maybe XShapeGetRectangles is what
    the OP is looking for.

    --
    Måns Rullgård
    mru@kth.se

+ Reply to Thread