[simspark-devel] ODEImps Plugin

[<ah...@un...>]

Hi,


I am now one step closer to having the ODE classes as a plugin. I use the
PhysicsServer for testing for now, because this is a class that is
actually used, as opposed to the AngularMotor, and thus obviously more
suited for testing. PhysicsServerImp now shows up in the scenegraph; the
key was to build odeimps not as a library, but as a module (which is the
desired method anyway, as building it as a library was merely a
workaround).

I changed spark.rb a bit so that it imports the odeimps bundle at the very
beginning. The relevant part now looks like this:

----- begin excerpt from spark.rb -----
#
# setup spark
#

print "(spark.rb) setup\n"

#import the implementations of the desired physics engine
#currently supported: odeimps (uses Open Dynamics Engine)
importBundle "odeimps"
print "(spark.rb) using ODE, to change the physics engine go to line 559
in spark.rb\n"

#
# set up logging
logServer = get($serverPath+'log')

if (logServer != nil)
  logServer.addStream(':cerr', 'eError')
end


#
# setup the PhysicsServer
sparkGetPhysicsServer()
----- end excerpt from spark.rb -----

Here's a screenshot of rsgedit which proves that the odeimps bundle gets
imported correctly, and also showcases that the PhysicsServerImp shows up
at "/classes/PhysicsServerImp":

http://www.uni-koblenz.de/~aheld/rsgeditscreen.png

Since I can now be 100% sure that PhysicsServerImp is now registered at
/classes/PhysicsServerImp _before_ the PhysicsServer is set up [as
importbundle"odeimps" is called prior to sparkGetPhysicsServer()], I can
now instanciate mPhysicsServerImp in the PhysicsServer's OnLink method
like this:

void PhysicsServer::OnLink(){
    mPhysicsServerImp = shared_dynamic_cast<PhysicsServerInt>
        (GetCore()->New("/classes/PhysicsServerImp"));
}

This leads to the following console output:

----- begin inexplicable console output ----
(ScriptServer) Script ended OK /home/andreas/.simspark/kerosin.rb
(ScriptServer) Running /usr/local/share/simspark//spark.rb...
(spark.rb) setup
(spark.rb) using ODE, to change the physics engine go to line 558 in spark.rb
(Core::New) unkown class '/classes/PhysicsServerImp'
(GeometryServer) MeshImporter 'oxygen/StdMeshImporter' registered
----- end inexplicable console output -----

As even a trained monkey could see, the odeimps bundle is imported, and
thus PhysicsServerImp registered at /classes/PhysicsServerImp immediately
before Zeitgeist complains that PhysicsServerImp is not registered at
/classes/PhysicsServerImp. The RSGEdit screenshot proves that
PhysicsServerImp is registered at /classes/PhysicsServerImp.

Soemhow the PhysicsServer is set up before PhysicsServerImp is registered
even though spark.rb registers PhysicsServerImp before the PhysicsServer
is set up. This is a time paradoxon. Maybe I'm using a quantum computer
without knowing it?

Any ideas would be appreciated.


thanks,

Andreas