[Xastir-dev] args to data_add()

[Curt, WE7U]

On Fri, 9 Apr 2004, Wendell Turner wrote:

> > You could use some of the empty symbol slots to define new symbols,
> > but you'd have to define a lot of them in order to have fine-control
> > over the direction, plus if we added new APRS symbols in the future
> > it might conflict with where you placed yours.  We wouldn't want
> > your symbols in the main Xastir code in that case either, as they
> > wouldn't carry across APRS clients.
>
> Would I want to define my own symbol, which wasn't really an
> icon symbol, but a graphic?  If I wrote a graphics routine that
> is called to draw this symbol, then that routine could rotate
> the graphics symbol.

Problem is, if you picked a particular standard APRS symbol slot,
there's a good chance it might be used for APRS in the future.  I
probably shouldn't have brought it up for that reason.

Better would be to define a user-defined packet format which was
similar to one of the existing formats (perhaps NMEA?), but gave you
some special symbol capability as well.  You could then parse out
that special info for your symbol drawing uses, then toss the rest
of the packet through the standard decoding.  We a bunch of
extract_this() and extract_that() routines all through db.c.  You'd
just need to write an extract_flightgear() routine or similar to
extract your special symbol info, then of course tie into something
later in the drawing code which could draw that special symbol for
you.  draw_symbol() could be extended I suppose.


> > You could tie in to the code which draws to pixmap_final before it
> > gets copied to the screen, and do your own graphics drawing to that
> > pixmap.
>
> Maybe that is the same as my idea above?  Would something
> like this be not-too-intrusive into the Xastir/APRS way of
> things?  I certainly don't want to take up much of the APRS
> symbol space just for the rotation.

Well, your questions are good, because I have use for more symbols
beyond the standard APRS symbol set, for SAR purposes.  A way of
mapping user-defined symbols onto the map would be useful.

--
Curt, WE7U			    archer at eskimo dot com
Arlington, WA, USA		http://www.eskimo.com/~archer
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