I have developed the attached program source from GPS4PPC, hopefully to be of use when yachting. Hence it deals with "waypoints" which are the basis of marine navigation.
This program will probably not be useful to anyone directly in this form. I am almost hoping this is the case since I would have to write a manual! However chunks of the code that deal with inputting and outputting KML and GPX data might be of use for cannibalisation.
Raster charts have limitations on such a small screen, and having little power to deal with multiple zoom levels, I chose to use vector outline “charts”. I can construct these from freely-available coastline data and they can be zoomed down to the level of line segments.
In the process I discovered that the UK Ordnance Survey make their road vector data, with a subset of road names, freely available too, and that a small adaptation of my program could draw roads instead of coastlines. It does not attempt to draw the road names. Instead, one road name can be picked (from an alphabetic list) and that road highlighted on the road map.
BTW The zoom is done via a rectangle drawn on the screen per
http://www.basic4ppc.com/forum/quest...html#post34008. A new rectangle can be drawn on the zoomed screen and thus any number of successive zooms can be performed. When un-zooming, the previous rectangle is re-drawn and can be adjusted. The current location, by GPS, can be indicated at all zoom levels if wished. Tap-and-hold on the map will bring up an edit screen for creating a waypoint at that location. But I have not attempted, in my additions, to incorporate the ability to show coordinates in UTM grid and in alternative datums, that exists in the original program.
In line with the marine alignment of functionality I substituted GPS4PPC’s small compass-bearing pointer display with a large swinging compass card like that in a boat’s binnacle. Where the original compass display was shown is now a view of the satellite IDs in the sky, with colour-coded relative signal strengths.
Because yachts move so slowly, the speed values that a GPS shows are too variable to be directly useful. So I added a running-average feature using up to ten past values. This also feeds the display of “velocity made good” (VMG) towards the next waypoint.
I haven’t really solved the problem of how best to move between the various forms that can be shown, other than a few specific buttons (like the ones to switch between “waypoints” and “routes”). Maybe an extra menu would be appropriate.
The three GPS*.sbp files differ only in the way that they use the GPS DLLs (see
http://www.basic4ppc.com/forum/addit...html#post34993). They all use the same modules in the same way. Those modules do the real work.
If anyone wants to know how to get the coastlines or UK roads into GPX/KML (using 3rd-party programs) then I can explain that too.
Regards, Mike.
Edit: see
http://www.basic4ppc.com/forum/open-...html#post36754 for an Auto-scale executable CAB file of this program.