Re: Animating bitmaps on openmap

I recommend not using a timer, but rather somehow storing or buffering
the gps data, then using the UTC timestamp on the GPS data to
make the plotting smooth. I send my GPS data to a database, which
solves lots of problems communicating with a variable number of remote
wireless gps devices. Then my applet talks to the database. If there
isn't any data, nothing gets plotted. if there is lots of data, a chunk of
time (I think 1minute for real time, or more if it is historic data being
plotted at faster than real time) is requested from the db, and
is plotted when the animator time is greater than the UTC timestamp. different
gps units are stored in different vectors but handled in the same animator
loop/db request.

I copied the swing worker stuff from the earthquake layer code to set up
my db request (actually, I call a cgi program on my web server....) I fire
off a new swing worker when the current vector of reserve data is being
plotted (I have 1+ minute of data in reserve or being requested at all
times when i am plotting historical data, but for live data the reserve
vector in practice is usually empty, waiting for the remote units to send
in their positions.)

james marca

>From Mark Bucciarelli, received Wed, Jun 20, 2001 at 12:28:54PM -0700:
> You could add a thread to a location layer handler that goes back and
> requeries for the location(s) position(s) every so-many milliseconds.
>
> --
> Mark Bucciarelli Peregrine Systems, Inc. R&D, Boston
> (413) 253-0020 mbucciarelli@peregrine.com Yahoo: m_bucciarelli
> http://www.peregrine.com
>
> > -----Original Message-----
> > From: John Mairs [mailto:mairsj@oso.nrl.navy.mil]
> > Sent: Wednesday, June 20, 2001 1:59 PM
> > To: openmap-users@bbn.com
> > Subject: Animating bitmaps on openmap
> >
> >
> > Hi Folks,
> >
> > I'm trying to setup a simple experiment using Openmap.
> > Imagine a scenario
> > where you are using Openmap to track a GPS receiver, say in
> > someone's car or
> > in an airplane. My first step is to simply display a bitmap.
> > I already
> > have a Windows bitmap; i.e. bmp file, that I would like to
> > use. I noticed
> > some JPEG helpers in the API but nothing explicity stating
> > bitmap or bmp.
> > Seems to me this code would make up a "layer" and that
> > somebody else must
> > have done this already.
> >
> >
> > Next question is how do you animate it moving on the map? Most of the
> > examples I have seen have been with "static" data. From an object
> > orientated sense I have a couple of different objects that
> > all know their
> > current location and they need to draw themselves. I guess
> > my question is
> > what is the trigger that would model an icon/bitmap slowly or
> > quickly moving
> > along a road on a digital map? Any code fragments or
> > examples out there?
> >
> > Thanks,
> >
> > John
> >
> >
> >

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