[xcrysden] XCrySDen on Linux, X-Server on Windows

[Ulrich Wedig]

Dear XCrySDen user,

in times of Covid-19 and home-office you sometimes have to proceed
unconventionally.

I'm running XCrySDen (1.6.2) on a Linux node in the institute, using the
X-Server on my Windows-PC at home (Xming).

This is of course not the most efficient way to display 3D-graphics. A
local Cygwin installations is surely faster. However the remote
execution as described above may be reasonable, if e.g. the CRYSTAL
integration is needed, e.g. with the properties menu.

Using the standard distribution of XCrySDen does not work in this way.
It is known, that the accumulation buffer has to be disabled, if
XCrySDen is running on Windows. This is captured in the file
$XCRYSDEN_TOPDIR/Tcl/toglOpt.tcl. However in the above case, XCrySDen
runs on Linux with accumulation buffer enabled, only the x-server on
Windows, giving the error 'Couldn't configure togl widget'.

In order to cure this behaviour, I added the following lines to toglOpt.tcl:

    # XCrysden running in Linux with X-Server (like Xming) on Windows
    # toglOpt(accum) = false (set environment variable IF_XMING to Xming)

    if { [info exists env(IF_XMING)] } {
        if { [string match -nocase *Xming* $env(IF_XMING)] } {
                # disable accumulation buffer
                set toglOpt(accum) false
                puts stderr "   accumulation buffer disabled"
        }
    }

If I now define (and export) the environment variable IF_XMING=Xming,
the accumulation buffer will be disabled, and XCrySDen is running
properly with my local Windows X-server.

Best regards,

Ulrich

-- 
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Dr. Ulrich Wedig                              Tel. 0711/6891535
Max-Planck-Institut fuer Festkoerperforschung FAX  0711/6891502
Heisenbergstr. 1
70569 Stuttgart                               U.Wedig at fkf.mpg.de
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