[comp.sys.sgi] zbuffer lrectread w/lsetdepth

randy@tessa.iaf.uiowa.edu (randy frank) (06/18/91)

	I have been reading a couple of mesages about attempting to 
analyze a Zbuffer (In my code I generate a Zbuffer in SW and use it
to prime the Zbuffer instead of clearing it).  The problem on some
machines is the signed 24bit integer.  This problem can be avoided
by using lsetdepth() in such a way that the negative numbers are
never used.  I use it in my code so that all machines use the same
depths as a GTX and I don't have to write multiple versions of my
Zbuffer generator.  The problems can arise if your application needs
the extra Zbuffer depth of the PI.  Generally this is not a large
problem.

--
rjf.
Randy Frank, Engineer                       |  (319) 335-6712       
University of Iowa, Image Analysis Facility |  73 EMRB              
randy@tessa.iaf.uiowa.edu                   |  Iowa City, IA 52242