DDM Talk Example

A simple talk program which uses DDM.

This program only works in HLA and is closely related to the Talk example.

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//********************************************************************
// Copyright (c) 2005 MaK Technologies, Inc.
// All rights reserved.
//********************************************************************


#include <vlpi/appearance.h>
#include <vl/exerciseConn.h>
#include <vl/exerciseConnInitializer.h>
#include <matrix/geodeticCoord.h>
#include <vl/entityPublisher.h>
#include <vl/entityStateRepository.h>
#include <vlpi/entityTypes.h>
#include <vl/geodeticRegion.h>
#include <vl/topoView.h>
#include <vl/emitterSystemPublisher.h>
#include <vl/emitterSystemRepository.h>

#include <vl/radioTransmitterPublisher.h>

#include <vlutil/vlSmartPointers.h>

int keybrdTick()
{
   char *keyPtr = DtPollBlockingInputLine(); 
   if (keyPtr && (*keyPtr == 'q' || *keyPtr == 'Q'))
      return -1;
   else 
      return 0;
}

int main(int argc, char* argv[])
{
   DtVrlApplicationInitializer appInit(argc, argv, "VR-Link DDM Talk");

   appInit.setExecName("VR-LinkDDM");
#if !DtHLA_1516
   appInit.setFedFileName("VR-LinkDDM.fed");
#else
#if DtHLA_1516_EVOLVED
   appInit.setFedFileName("VR-LinkDDM_evolved.xml");
#else
   appInit.setFedFileName("VR-LinkDDM.xml");
#endif
#endif

   appInit.parseCmdLine();

   DtExerciseConn exConn(appInit);

   // Set use geographic DDM.  Entities will automatically be published
   // in geographic regions sized according to velocity
   exConn.setUseGeographicDdm(true);
   exConn.setDdmPlayBoxLowerBound(DtGeodeticCoord(DtDeg2Rad(30.0), DtDeg2Rad(-130.0), 0));
   exConn.setDdmPlayBoxUpperBound(DtGeodeticCoord(DtDeg2Rad(40.0), DtDeg2Rad(-120.0), 0));

   DtEntityType f18Type(DtPlatform, DtPlatformDomainAir,
      DtUnitedStates, DtFighter, DtF18, 0, 0);

   // Create an entity publisher for the entity we are simulating. 
   DtEntityPublisher entityPub(f18Type, &exConn,
      DtDrDrmRvw, DtForceFriendly, DtEntityPublisher::guiseSameAsType(), 
      "F18 Entity");

   DtEntityStateRepository* esr = entityPub.esr(); 

   // Create an emitter system that uses the F18's region
   DtEmitterSystemPublisher * emitterSys;
      
   try
   {
      emitterSys = new DtEmitterSystemPublisher(&exConn, 0, &(entityPub.publishingRegions()));
   }
#ifdef DtHLA_1516_EVOLVED 
   catch( rti1516e::Exception& )
#elif defined DtHLA_1516 
   catch( rti1516::Exception& )
#elif defined DtHLA
   catch( RTI::Exception& )
#endif
   {
      DtInfo << "Exception Caught: Make sure that DDM is enabled.\n";
      emitterSys = NULL;
      return 0;
   }
      
   DtEmitterSystemRepository* emitSR = emitterSys->esr();
   emitSR->setEmitterNumber(23);

   // Create a topographic view on the state repository, so we 
   // can set position information in topographic coordinates.
   double refLatitude  = DtDeg2Rad(  35.699760);
   double refLongitude = DtDeg2Rad(-121.326577);

   DtTopoView topoView(esr, refLatitude, refLongitude);
   
   // We can use the ESR to set state.
   esr->setMarkingText("VR-Link");

   // Initialize VR-Link time.
   DtClock* clock = exConn.clock();

   DtVector position(0, 0, -100);
   DtVector velocity(40, 0, 0);

   // Main loop
   DtTime dt = 1.0;
   DtTime simTime = 0;
   while (1)
   {
      // Check if user hit 'q' to quit.
      if (keybrdTick() == -1)
         break;

      // Tell VR-Link the current value of simulation time.
      clock->setSimTime(simTime);

      // Process any incoming messages.
      exConn.drainInput();

      // Set the current position information.
      topoView.setLocation(position);
      topoView.setVelocity(velocity);

   
      // Call tick, which insures that any data that needs to be 
      // updated is sent.
      entityPub.tick();
      emitterSys->tick();
      
      // Set up for next iteration.
      position[0] += velocity[0] * dt;

      simTime     += dt;

      // Wait till real time equals simulation time of next step.
      DtSleep(simTime - clock->elapsedRealTime()); 
   }  


   return 0;
}

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