Posted 23 March 2024

After a multi-year hiatus, I recently started flying contests again in the Condor Soaring Simulator. As sort of a side project, I have also been working with the XCSoar glider navigation program, to see if I could use XCSoar to help navigate AAT/TAT tasks in Condor (Condor doesn’t support AAT/TAT tasks natively with the in-sim PDA).

After using XCSoar for a while, I became frustrated with XCSoar’s inability to define ‘custom’ turnpoints based on LAT/LON coordinates, which are used quite frequently in Condor contest tasks. After a long-fought and ultimately unsuccessful battle with XCSoar’s source code to see if I could modify the program to facilitate this, I admitted defeat and decided to try another way to skin this cat. XCSoar will accept an ‘Additional Waypoints’ file, so I decided to see if I could create a program to convert the ‘new TP’ blocks in the Condor ‘Task Briefing’ description to XCSoar-compatile .CUP file waypoint lines, which could then be loaded into XCSoar for selection as task waypoints.

Here is the .CUP file format defintion page from the SeeYou (naviter) program website:

The above description is NOT very easy to read. It is full of errors, so some imagination is required to make sense of it. The ‘hardpoints’ in the description are as follows:

• Latitude strings are exactly 9 characters long. Longitude strings are exactly 10 characters long.
• In latitude strings, the decimal point is exactly the 5th character (Char4) . In longitude strings, the decimal point is exactly the 6th character (Char5).
• Both latitude and longitude strings apparently must be zero-padded as necessary to make the string character counts work out. For instance, in the longitude example the ‘degree’ value of ‘014’ must be exactly three characters.

Example Run:

Here’s a recent task briefing from Condor-Club:

As can be seen in the above screengrab, TP2-TP2 are all ‘custom’ turnpoints defined only by Lat/Lon coordinates. Manually adding these to a .CUP formatted file for use in XCSoar would be essentially impossible, given that the turnpoint coordinates only become visible 15 minutes before server start.

To start the process, the turnpoint blocks from the above briefing were copy/pasted one at a time into a text document (I use NotePad++), as follows (note that I manually changed the name of the last turnpoint from ‘Finish’ to TP 6, as my Python script currently only looks for ‘Start’ and ‘TP’ starting strings)

My CondorTPX_to_CupWP.py Python script opens a ‘FileOpen’ dialog where the input file (in this case ‘NewTPs_IN.txt’) can be selected by the user, and a ‘FileSave’ dialog where the output file (in this case ‘NewTPS_OUT.CUP’) can be selected, and then parses through the blocks in the input file, converting them to equivalent .CUP-formatted lines compatible with XCSoar. Here is the console printout from the ‘verbose’ (-v) version of the script:

At the very end of the above printout, the newly-written contents of the output file are read back out again as a verification that the conversion was successful. Here is the actual contents of the ‘NewTPS_OUT.CUP’ file:

This file now has to be transferred to the directory used by XCSoar for waypoints, and then selected in XCSoar (Config->System->Site Files) to load as the ‘More Waypoints’ selection. After this, all the above turnpoints will be available for task construction. Here’s a photo of my Android tablet with the above task turnpoints loaded:

It is clear from the above images that the Condor-Club ‘custom’ task turnpoints have been converted properly from text blocks to SeeYou .CUP format waypoint strings, so now I can use XCSoar to navigate Condor tasks with ‘custom’ turnpoints – Yay!

Here’s the Python script I created to do the conversion:

Enjoy!

Frank