FSX XML coding help needed - array?

[ti_dabbelju]

Hi folks,
I have managed to get an XML gauge to work that uses the fs9gps TrafficInfo to retrieve AI positions. All it needs to do is to write bearing, distance, altitude to L: Vars. The gauge has no visible output.
Can anybody tell me how I can modify the code to allow for e.g. 15 aircraft to be polled (without paste & copy), I'm thinking of an array.
It seems arrays are a difficult topic in XML?
Thanks!

<Gauge Name="TrafficInfoTW" Version="1.0">
<Size X="400" Y="300" />
        <Update Frequency="2" Hidden="No">
                16 (&gt;C:ITrafficInfo:Filter, enum)  <!-- Bit 4: TRAFFIC_FILTER_IN_AIR
-->
                15 (&gt;C:ITrafficInfo:Radius,nmiles)
                20 (>C:ITrafficInfo:MaxVehicles)
                0 d (&gt;C:ITrafficInfo:CurrentVehicle,enum)
                    (&gt;C:ITrafficInfo:SelectedVehicle,enum) 

                (A:PLANE LATITUDE,degrees) (&gt;C:fs9gps:GeoCalcLatitude1,degrees) 
                (A:PLANE LONGITUDE,degrees) (&gt;C:fs9gps:GeoCalcLongitude1,degrees) 
                (C:ITrafficInfo:S:PLANE LATITUDE,degrees)  (&gt;L:temp_lat,degrees) 
                (L:temp_lat) (&gt;C:fs9gps:GeoCalcLatitude2,degrees) 
                (C:ITrafficInfo:S:PLANE LONGITUDE,degrees) (&gt;L:temp_lon,degrees) 
                (L:temp_lon,degrees) (&gt;C:fs9gps:GeoCalcLongitude2,degrees) 
                (C:fs9gps:GeoCalcBearing,degrees) (&gt;L:TCAS_bearing_0,degrees)
                (C:fs9gps:GeoCalcDistance,nmiles) (&gt;L:TCAS_distance_0,nmiles)
                (C:ITrafficInfo:S:PLANE ALTITUDE, feet) (&gt;L:TCAS_altitude_0, feet)                       
            
        </Update>
 </Gauge>

 

[rcbarend]

Use Tom's XMLTools (available here in the library).
Great for using tables/arrays in XML gauges ...

Rob

 

[Ronald]

Here are a number of articles about XML and Array's to get you started:

XML Serialisation:
- https://msdn.microsoft.com/en-us/library/182eeyhh(v=vs.110).aspx
- https://msdn.microsoft.com/en-us/library/58a18dwa(v=vs.110).aspx

XML (array) Schema patterns:
- https://www.w3.org/2005/07/xml-schema-patterns.html
- http://simple.sourceforge.net/download/stream/doc/tutorial/tutorial.php

 

[rpmc]

I agree with Rob's recommendation to use XMLTools (specifically, the XMLVars class) to create your arrays for ITraffic information.

As an additional reference, you might take a look at the ExampleMovingMap1.xml gauge bundled with FSMAP Guidebook. Download the Example XML Map Gauges.zip file.

Among other things, it contains a fully functional XML TCAS gauge that uses XMLVars for the necessary AI Traffic info arrays. It will also provide some insight as to use of the ITrafficInfo variable SelectedVehicleID to keep track of specific AI Traffic as you cycle through CurrentVehicle. Actually, as currently written, your Update section doesn't loop through 20 vehicles, but, instead, returns information only on the closest traffic, CurrentVehicle 0.

Hope this helps,

Bob

 

[ti_dabbelju]

Thanks for your tips. I will look into it.

FYI the actual gauge will be "stupid". It must only provide the altitude, bearing and distance of AI in LVars. These will be accessed through Air Manager where the actual TCAS functionality will be programmed.

 

[rpmc]

A few items regarding TCAS simulation:

1. An ItrafficInfo search returns traffic in ascending distance from the reference (the User's) aircraft. In one Update cycle, the order may be Aircraft A, Aircraft B, Aircraft C, Aircraft D. The next Update cycle, it could be Aircraft B, Aircraft A, Aircraft C, Aircraft D. TCAS calculations are aircraft specific, not distance from the reference aircraft specific. Therefore, one must pass information to a TCAS calculator based on specific aircraft, and that is done using SelectedVehicleID as part of the information array.

2. TCAS alarm thresholds are based on time separation, not distance. That forces you to keep track of a specific traffic aircraft from one Update cycle to the next, so that rate of change information can be determined. Again, that aircraft's order in the ItrafficInfo search output often changes from one cycle to the next, so keep track of the aircraft's SelectedVehicleID, not its CurrentVehicle order.

3. You are correct to view this as an array issue. I use XMLVars to create the aircraft-specific arrays in my TCAS alarm calculations, but bear in mind that XMLVar variables are C:Vars, not L:Vars. If, for some reason, your TCAS manager program cannot read C:Vars, then you may be in trouble. And, you can't assign your XMLVar array into say, 15 L:Vars because you will lose the aircraft-specific information that TCAS relies on.

Regards,

Bob