refactoring of FGFDM parser
replace old helpers with lib functions from <cstring>
remove typecast that kills 'const'
add some comments and clarify variable names
Rewrite the position-init code for carrier starts, to precisely wait
on the carrier model being loaded, before proceeding with FDM init.
This allows the FDM to see the correct carrier model in the ground
cache, and hence avoids starting in the water.
To implement this, the CheckSceneryVisitor is used to force the carrier
model to be loaded while the splash-screen is visible.
In some testing, JSBsim sometimes passed extremely large values into
this function (larger than the radius of the earth). This causes
every tile on the planet to be scheduled if using the standard STG
terrain, effectively blocking startup.
This code allows us a chance to catch this case via logging, but does
not fix the underlying issues.
The wake induced force and moment are computed as an external reaction to the JSBSim model. For these force and moment to be accounted for by JSBSim, the following external reaction needs to be added to FDM XML definition:
<external reaction>
<force name="ai-wake">
...
</force>
<moment name="ai-wake">
...
</moment>
</external reaction>
This is similar to how the hook and wire feature is modeled in JSBSim.
Wake computations are now performed for all AI aircrafts within a range lower or equal to the value indicated by the property /fdm/ai-wake/max-radius-nm.
These computations are triggered by the property /fdm/ai-wake/enabled (it is disabled by default).
The result of the wake computations is not yet used by the FDMs so do not expect the user aircraft to react to the AI wake.
AI wake code is still dead code except that it is now compiled with FG.
Input data for wake computations are extracted from the performance database. The data must be specified as follows (values are for illustration only) :
<geometry>
<wing>
<span-ft> 100. </span-ft>
<chord-ft> 12. <chord-ft>
</wing>
<weight-lbs> 90000. </weight-lbs>
</geometry>
At the moment, this is dead code: only the tests are compiled. FG is still compiled without this code.
A new directory is created that contains all the numerical computations made to estimate the wake induced by AI aircrafts. This is based on the venerable Vortex Lattice Method (VLM) which was all the rage in the 60's Computational Fluid Dynamics (CFD).
Even though quite old, the method is relevant to compute aircrafts wake in real time since 3D Navier-Stokes (NS3D) is out of reach for real time computations even with modern multicore personal computers and their GPUs.
There was a couple of typos in the routine. This code will be used by the AI wake feature.
Also added a test for the matrix code to make sure they will be no regression.
External moments can now be specified in addition to external forces. This feature is needed for the AI wakes.
Headers clean up to reduce the amount of recompilation when modifying an header file.
* Skip the gears when located over water. They will be skipped by the ground reactions anyway making the trim irrelevant.
* Ignore the ground bumpiness during the trim. The trim algorithm seems not to
be robust enough to handle that. This does not make much difference to the
converged solution anyway since the bumpiness is generally low.
* Fixed the WOW status for contacts over water (was 'false' is now 'true').
* All the gear/contact data are now properly reset when WOW==false. The reset
code is now common to all the case where WOW is false.
