On 1/4/06, Jenkins, Bart (NE) <Bart.Jenkins@...> wrote:
> I really like what I see in OpenEV, however...
> I'm concerned about the performance implications of using an interpreted
> language like Python. So, can someone quantify how much of OpenEV is
> written in Python and how much is in C/C++? If I need to, can I write
> performance intensive pieces in C/C++ and link that in as a library? Wha=
> are the issues? It sounds like I need to have a good understanding of GT=
A quick count shows 50000 lines of C code, and 40000 lines of
python code in OpenEV. Yes, you can provide extensions in
C/C++ with appropriate python bindings and then load them
dynamically. This was done for some compute intensive
portions of CIETmap for instance.
> Specifically, I want to be able to drop an icon with lat/long/altitude in=
> onto a vector map that represents a moving object (say, a ship) and anima=
> the movement of that onto the OpenEV display. I would need to be able to
> update the location of that ship every 2 seconds to 3 minutes (not a
> real-time issue, but time sensitive). I would also appreciate it if some=
> who has done such a thing could point me to any how-to's for such an effo=
> (and how long it took them to integrate that with OpenEV)
This shouldn't be a problem from a compute intensive point of
view. You might want to look at the GvManager.queue_task()
method in gview.py for one mechanism of queueing up low
priority work. The main issue I see with using this for your task
is that it doesn't understand how to wait a while before doing
the task. So you would end up busy-waiting for your next
update. This should only be a problem if you are concerned
about CPU usage in OpenEV.
If you desparately need a specific example implementing
what you want then let me know and I could prepare one,
but perhaps someone else will already have something handy.
I set the clouds in motion - turn up | Frank Warmerdam, warmerdam@...=
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | Geospatial Programmer for Rent