Rotating X Fonts?

[Carl Schumann]

Hi,

I am struggling with an application, written by another, that attempts  
to rotate fonts for use on the Y label of a plot.   It uses the  
following font names:
-adobe-helvetica-medium-r-normal--18-180-75-75-p-98-iso8859-1  (the  
non-rotated version)
-adobe-helvetica-medium-r-normal--0-[+0.0+18.0~18.0+0.0]-75-75-p-0- 
iso8859-1 (the rotated 90 degree version)
In my environment this rotation is not uniformly successful.   It  
works on MS Windows machines running Hummingbird Exceed, but fails for  
Linux machines using Xorg.    Failure here means the font is displayed  
just not rotated.  Xorg is able to rotate a font named utopia, so this  
is somewhat specific to the font involved.  So I have a few questions  
whose answer would help me progress please:
1. Is there a way to know at run-time whether or not an X-server will  
actually be able to honor the rotated font request?
2. Is there any documentation/standard for the use of rotated fonts,  
e.g., the name of the rotated font above is mostly a mystery between  
the []?
3. I suspect the issue might be a discrepancy between the installed  
fonts on the two X servers.  Suggestions for how to diagnose and fix  
any such discrepancy?
Thanks for your time.

Sincerely,
Carl Schumann