[Discuss-gnuradio] Persistence causes glAccum exception

[Marcus D. Leech]

So, I did a quick "audit" this evening of four different machines in my 
house, running both Ubuntu recent and Fedora recent, but with
  different generations of video hardware/motherboards, and tried the 
"Persistence" control on all of them.

EVERY SINGLE ONE OF THEM failed, provoking an OpenGL exception from 
glAccum, which, it turns out, is an optional feature, and at least in
  this little survey, not a single piece of my hardware supported that op.

How many people actually use "persistence"?  (As opposed, I must be 
clear, to "Peak Hold").  I suspect that a workable approach is to,
  for now, remove that feature entirely, but I don't have a good feel 
for who uses it.

Near as I can tell, the "persistence" feature is intended to give a kind 
of storage-scope effect, or high-persistence phosphor effect.
  But the "effect" uses a non-mandatory OpenGL feature (the accumulator 
buffer) which appears, at least on the garden-variety
  video hardware I use, not to be supported.  And to be clear, I'm 
running modern motherboards on two of my systems, but using
  the on-board video, since I'm not a gamer, and really, the simple 2D 
effects Gnu Radio uses aren't particularly taxing.


--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org