Re: [ferret_users] wHDF not supported on this platform

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Martin,

| > Thanks for the suggestion.  It sounds really promising and must be
| > the way to go.  But, it doesn't work for unknown reasons, even though
| > Backing Store is enabled.  The first frame is briefly displayed and
| > is followed by white (empty) frames.  I tested Ferret 6.30 and 6.61 .
| > I use the "testing" distribution of Debian.
| >   
| This is what we see with Suse linux, when backing store is not
| enabled. For Suse 9 and 10 it works fine, if
| backing store is switched on. The kde version is kde 3
| The process looks like
| 
| /usr/X11R6/bin/X -br +bs vt7 -auth /var ......
| 
| +bs is the key! I suggest to check your X server. Use "ps -ef | grep
| X"

I'm quite positive that Backing Store is enabled.
(I have, or rather, the Linux distribution I use has, moved to
 xorg from XF86 .  I don't think that makes much difference in this
 discussion, though.) 

The command line options to the X server (/usr/bin/X in my case)
overrides the setting in the configuration file.  I don't have
"+bs" or "-bs" on the command line, so the setting in the
configuration file must be being honored.

And the configuration file (/etc/X11/xorg.conf) has

   Option          "BackingStore"          "true"

in the "Device" section, and the log file /var/log/Xorg.0.log says

  (**) NV(0): Option "BackingStore" "true"
  (**) NV(0): Backing store enabled

Moreover, 

  $ xdpyinfo | egrep save
  options:    backing-store YES, save-unders NO
  $

In addition, I know GrADS 1.9 doesn't work correctly without
backing store.  It's much worse than Ferret:  Without backing store,
whenever its graphics window is overlapped by other windows,
the overlapped portion is wiped out.  My GrADS doesn't behave that
way.

So, this is something weired.

| > Familiar to me, but I don't know those things well enough to
| > understand why backing store isn't an important feature any longer
| > to most applications.
|
| Please note backing store works through the net. I am running ferret
| from time to time in a remote compute center. There the machine does
| not run with backing store switched on. The key is my home machine
| that has this feature enabled. X generates an animation through the
| web without knowing anything about the remote system, the
| graphics adapter ... for me a great tool.

So, you work quite similarly to me.  No wonder we both have seen
similar issues.

| May be kde-programmers think in terms of a PC and do not really care
| about the original ideas of X as a tool for unified remote work.

Exactly my impression.  Not only KDE people.  For most modern
developers of desktop apps, remote X-Window communication is
not something that requires attention.  (By the way, I switched
to LXDE from KDE some time ago.)

The information I have given above about Backing Store is all
local only and doesn't involve any remote login.

Regards,
Ryo