[Update REQ 6854]: Geomview - Praise

[munzner at cs.stanford.edu]

> I want to thank for this great tool!! In the last days I learned to
> appreciate its capabilities and its speed. It helped me visualize
> complicated three dimensional structures I created with my
> programme. 

Great, nice to hear :)

> Using a named pipe I can directly feed all the information needed
> into geomview. It working with the binaries for SGI and Sun Ultras,
> both are of version 1.6.1.
>
> At one point I run into a small problem: when my programme starts
> sending information into the pipe, I need to give geomview an X
> event (focus the window or moving mouse pointer is sufficient) in
> order to trigger geomview to read from the pipe. Finally my
> programme stop when geomview does not read from the pipe, but it
> continues after geomview starts reading again. Can I make geomview
> check the pipe regularly, even if the user is not continuously
> sending events to geomview.

Hmm. The stop/start sounds like the pipe is filling up, and then your
program is blocked until the pipe is drained by Geomview. Do you have
a newline on the end of your command printf, and are you using fflush?

The other possiblity is that your pipe is somehow misconfigured, like
maybe somehow you need to set the file descriptors so that it's
nonblocking. But I wouldn't think you'd need to do that in the
situation that you describe. Anyway, if you use the external module
mechanism where your program reads from stdin and writes to stdout,
then Geomview sets up the pipes for you. So one way to test if there's
a problem with the way you're using the named pipes would be to try
using this mechanism instead.

You would start up your external module by clicking on its name in the
Modules part of the main Geomview panel. If your executable is named
"myprog", then you would put a line like
 (emodule-define "My Program" "myprog")
in a file called .geomview in your home directory or in the directory
in which you start Geomview. 

> The feature 'inertia motion' really shows the capabilities of
> geomview, but I would prefer it, if it was switched off by default.
> Is there a gcl command, that I have not found in the manual?

Well, you can manually turn off inertia each time by typing "ui" in a
window, or by using the Motion menu on the main panel. Sadly, it looks
like we didn't ever define a GCL command to control this. But there's
a total hack that you can use in such cases: the GCL command that
simulates an ASCII keyboard event will provide the same effect as if
you'd typed "u" then "i". You'd put this in your .geomview file:

 (rawevent 117 1 0 0 0) (rawevent 105 1 0 0 0)

so that this happens every time you start up Geomview.

Hope this helps,
Tamara

 ---
Tamara Munzner	munzner at cs.stanford.edu
http://www-graphics.stanford.edu/~munzner