Overview

This example shows how to create a plug-in that adds updaters for a GL Studio cockpit (HUD) display. It adds two new updaters: one is VR-Link protocol-specific and is used in the network thread; one is used in the render thread and is considered to use the object protocol.

Expected Result

M1A2 Hud Result

A-10 Hud Result

ArmordVehicleCockpit change

FixedWingCockpit change

Example details

As seen in exampleHatchStateUpdater.h and exampleMetersPerSecondUpdater.h, all updaters return a string that is used by the GL Studio object to update the display.

virtual void init(DtVrlinkEntityStateListener* listener);

virtual std::string value();

Each of the updaters also has a creator that is registered with the updater factory.

      class DT_DLL_EXAMPLEHUDUPDATERPLUGIN DtGlStudioHatchStateUpdaterCreator : public DtGlStudioAttributeUpdaterCreator
      {
      public:
         DtGlStudioHatchStateUpdaterCreator();
         virtual ~DtGlStudioHatchStateUpdaterCreator();
         virtual DtGlStudioAttributeUpdater* create() const;
      protected:
      };

In exampleHudUpdaterPluginInit.cxx the Plugin loader needs to make sure that GL Studio plugin has been initialized and then register a post-initialize function with the display engine to add the new updaters to the updater factory.

         DT_DE_INIT_ONCE(de);
         try
         {
            //make sure GlStudio is initialized
            DtGlStudio::init(de);
            //connect to post-initialize signal to setup updaters
            de.signal_postInitialize.connect(boost::bind(&addUpdaters, &de));
         }
         DtCATCH_AND_PROPAGATE(DtCorruptedState)

In the post-initialize function the updater factory is populated with new updaters. The updater factory is owned by the DtSharedCockpitSettings object. Updater creators are registered with the factory. If an updater creator has the same protocol and name as an existing creator, it will replace the creator.

void addUpdaters(makVrv::DtDe* de)
{
   //create the settings manager and get access to it
   DtSharedCockpitSettingsManager::instance(*de);
   {
      //get the updater factory
      DtWriteSettingsLock<DtSharedCockpitSettings> settings(DtSharedSettingsManager::instance(*de));
      DtGlStudioAttributeUpdaterFactory& factory=settings->updaterFactory();
      //visualizer side updater using entity state repository data directly at network update rate
       factory.registerUpdater(new vrvDis::DtGlStudioHatchStateUpdaterCreator());
      //object side updater uses TSPI data stored in HUD renderable to generate smooth updates at frame rate
      factory.registerUpdater(new DtExampleMetersPerSecondUpdaterCreator());
   }
   de->signal_postInitialize.disconnect(boost::bind(&addUpdaters, de));

All updater creators have a name and a protocol that are set in their constructor. The factory uses these to do lookups when a HUD object is created.

      :DtGlStudioAttributeUpdaterCreator()
   {
      myName="MetersPerSecond";
      myProtocol="Object";
   }

TheDtExampleMetersPerSecondUpdater is derived from a DtGlStudioObjectAttributeUpdater since it is going to live on the object (GL Studio object) side, or in the render thread.

All updaters that are of the "object" protocol have access to a smoother object which is able to get the smoothed values for position, velocity and accelleration at the specific time called.

   std::string DtExampleMetersPerSecondUpdater::value(double time)
   {
      if(mySmoother!=NULL)
      {
         myVelocity = DtVector32To64(mySmoother->approxVelocity(time));
         std::stringstream ss;
         double magnitude= sqrt(myVelocity.magnitudeSquared());
         ss << magnitude;
         return ss.str();
      }
   
      return "0.0";

The DtGlStudioHatchStateUpdater is a VR-Link protocol updater that is derived from the DtGlStudioVrlAttributeUpdater. This class uses the shared source technique common in VR-Vantage. The protocol specific updaters also return a string value and have a creator exactly like the object protocol updaters. VR-Link protocol updaters are placed in a protocol-specific namespace to keep from conflicting with the same updater for other protocols.

The VR-Link protocol updater is initialized with a DtVrlinkEntityStateListener. This listener provides access to the VR-Link entity state repository and allows for signals to be sent when attributes change.

      void DtGlStudioHatchStateUpdater::init(DtVrlinkEntityStateListener* listener )
      {
         myEntityConnections += listener->signal_appearanceBitSet.connect(
            boost::bind(&DtGlStudioHatchStateUpdater::setAppearanceBit, this, _1, _2));
          //initialize with current data
          setAppearanceBit(0, listener->esr().appearance());
      }

Building the Example

VR-Vantage includes pre-built versions of the example plug-in. To build it yourself, follow the instructions at Building VR-Vantage Examples, Applications, and Plug-ins.

Running the Example

This example is a plug-in. You can run it by running ./bin64/exampleHudUpdater_stealth.bat (on Windows) or ./bin64/exampleHudUpdater_stealth.sh (on Linux). For more information about running examples, please see Running Applications and Examples.

Running the example with VRForces

To see the effects of the plugin, start VR Forces. Load a terrain like Makland.mtf. Create an entity with a hatch (ex., M1A2Abrams MBT) and one fixed wing (ex., A-10 Thunderbolt). Run exampleHudUpdater_stealth.bat to start Vantage. Load Makland.mtf. Connect Vantage to VR Forces. You should see your tank and plane. In Vantage, go to Visual Model Editors. Select the tab for Model Definition Editor. Use the yellow funnel to filter on "Cockpit Display". Select ArmoredVehicleCockpit. Select Attribute:ToDVis. This attributed corresponds to a UI element on the tank hud as specified in the docs at <vantage dir>="">. In the hud pdf, we see that ToDVis controls the visibility of the time of day display. Change the value of AttributeToDVis to HatchState which is the name of the state given in exampleHatchStateUpdater.inl (in DtGlStudioHatchStateUpdaterCreator) Right click on the tank and choose Attach Mimic. You should see the tank hud. Now go to VR Forces. Right click on the tank. select "Set -> Appearance -> Appearance" . On the UI that comes up, select Primary Hatch and change it to Open. Click Apply. You should see a digital clock in the upper right corner which says 88:88:88 Time Of Day. Change the Primary Hatch to Closed and click Apply. The UI element in VR Vantage should go away.

For the plane in VRF Right click on the tank and choose Attach Mimic than in VR Vantage, go to Settings -> Visual Model Editors -> Model Definition Editor and use the filter funnel to select Cockpit Display Select the FixedWingCockpit and change the Attribute:Airspeed to MetersPerSecond. Now the needle on the air speed gauge should start to move.

Overall, in the cockpit model definitions, the Attribute:Airspeed, Attribute:XYZ corresponds to fields described in the doc. For example, in the ArmoredVehicleCockpit, it has a parameter Attribute:ToDVis. If we look at - 2D Armored Vehicle Reticle.pdf we can see that on page 11, it says that ToDVis is true/false and controls the visibility of the time of day display. To set an attribute to true, change the model definition for that parameter to the value Value:true. For false, use Value:false. By setting the value to HatchState, this means that we are telling Vantage that we are driving this component of the UI through a named variable in code. In this case, we were driving Attribute:Airspeed with a value MeterPerSecond created in the exampleHudUpdater.

Example Source Files

exampleHatchStateUpdater.h

/****************************************************************************** 
** Copyright (c) 2019 MAK Technologies, Inc. 
** All rights reserved. 
******************************************************************************/ 
#ifndef DT_PROTOCOL_NAMESPACE
#error Namespace Protocol Macro DT_PROTOCOL_NAMESPACE not defined.
#endif
#ifndef DtExampleHudUpdater_H_ 
#define DtExampleHudUpdater_H_ 
#include "exampleHudUpdaterPlugin.h"
#include <vrvGlStudioShared/DtGlStudioVrlAttributeUpdater.h>
namespace makVrv 
{ 
   namespace DT_PROTOCOL_NAMESPACE
   {
      
      class DtGlStudioHatchStateUpdater : public DtGlStudioVrlAttributeUpdater
      {
         public: 
            DtGlStudioHatchStateUpdater();
            virtual ~DtGlStudioHatchStateUpdater();
            virtual void init(DtVrlinkEntityStateListener* listener);
            virtual std::string value();
         protected:
            virtual void setAppearanceBit(unsigned int oldVal, unsigned int newVal);
            unsigned int myHatchState;
      };
      class DT_DLL_EXAMPLEHUDUPDATERPLUGIN DtGlStudioHatchStateUpdaterCreator : public DtGlStudioAttributeUpdaterCreator
      {
      public:
         DtGlStudioHatchStateUpdaterCreator();
         virtual ~DtGlStudioHatchStateUpdaterCreator();
         virtual DtGlStudioAttributeUpdater* create() const;
      protected:
      };
   } //DT_PROTOCOL_NAMESPACE::
} //makVrv::
#endif

exampleHatchStateUpdater.inl

/*******************************************************************************
** Copyright (c) 2019 MAK Technologies, Inc.
** All rights reserved.
*******************************************************************************/
#include "exampleHatchStateUpdater.h"
#include <vrvVrl/DtVrlinkEntityStateListener.h>
#include <vl/entityStateRepository.h>
#include <boost/bind.hpp>
namespace makVrv
{
   namespace DT_PROTOCOL_NAMESPACE
   {
      DtGlStudioHatchStateUpdater::DtGlStudioHatchStateUpdater()
         :DtGlStudioVrlAttributeUpdater()
         , myHatchState( 0 )
      {
      }
      DtGlStudioHatchStateUpdater::~DtGlStudioHatchStateUpdater()
      {
      }
      void DtGlStudioHatchStateUpdater::init(DtVrlinkEntityStateListener* listener )
      {
         myEntityConnections += listener->signal_appearanceBitSet.connect(
            boost::bind(&DtGlStudioHatchStateUpdater::setAppearanceBit, this, _1, _2));
          //initialize with current data
          setAppearanceBit(0, listener->esr().appearance());
      }
      std::string DtGlStudioHatchStateUpdater::value()
      {
         //reset dirty flag
         myIsDirty=false;
         if(myHatchState==DtHatchOpenBitVal)
         {
            return "true";
         }
         return "false";
      }
      void DtGlStudioHatchStateUpdater::setAppearanceBit(unsigned int oldBits, unsigned int newBits)
      {
         //change in the state we care about
         unsigned oldHatch = oldBits & DtAppHatch;
         unsigned newHatch = newBits & DtAppHatch;
         if(oldHatch != newHatch)
         {
            myIsDirty=true;
            myHatchState = newHatch;
         }
      }
      DtGlStudioHatchStateUpdaterCreator::DtGlStudioHatchStateUpdaterCreator()
         :DtGlStudioAttributeUpdaterCreator()
      {
         myName="HatchState";
#ifdef DtDIS
         myProtocol="DtDis";
#else
#ifdef DtHLA_1516
   #ifdef DtHLA_1516_EVOLVED
         myProtocol="DtHla1516e";
   #else
         myProtocol="DtHla1516";
   #endif
#else
         myProtocol="DtHla13";
#endif
#endif
      }
      DtGlStudioHatchStateUpdaterCreator::~DtGlStudioHatchStateUpdaterCreator()
      {
      }
      DtGlStudioAttributeUpdater* DtGlStudioHatchStateUpdaterCreator::create() const
      {
         return new DtGlStudioHatchStateUpdater();
      }
   }//DT_PROTOCOL_NAMESPACE::
} //makVrv::

exampleMetersPerSecondUpdater.cxx

/*******************************************************************************
** Copyright (c) 2019 MAK Technologies, Inc.
** All rights reserved.
*******************************************************************************/
#include "exampleMetersPerSecondUpdater.h"
#include <vlpi/trigonometricSmoother.h>
namespace makVrv
{
   DtExampleMetersPerSecondUpdater::DtExampleMetersPerSecondUpdater()
      :DtGlStudioObjectAttributeUpdater()
   {
   }
   DtExampleMetersPerSecondUpdater::~DtExampleMetersPerSecondUpdater()
   {
   }
   std::string DtExampleMetersPerSecondUpdater::value(double time)
   {
      if(mySmoother!=NULL)
      {
         myVelocity = DtVector32To64(mySmoother->approxVelocity(time));
         std::stringstream ss;
         double magnitude= sqrt(myVelocity.magnitudeSquared());
         ss << magnitude;
         return ss.str();
      }
   
      return "0.0";
   }
   DtExampleMetersPerSecondUpdaterCreator::DtExampleMetersPerSecondUpdaterCreator()
      :DtGlStudioAttributeUpdaterCreator()
   {
      myName="MetersPerSecond";
      myProtocol="Object";
   }
   DtExampleMetersPerSecondUpdaterCreator::~DtExampleMetersPerSecondUpdaterCreator()
   {
   }
   DtGlStudioAttributeUpdater* DtExampleMetersPerSecondUpdaterCreator::create() const
   {
      return new DtExampleMetersPerSecondUpdater();
   }
} //makVrv::

exampleMetersPerSecondUpdater.h

/*******************************************************************************
** Copyright (c) 2019 MAK Technologies, Inc.
** All rights reserved.
*******************************************************************************/
#ifndef DtExampleMetersPerSecondUpdater_h
#define DtExampleMetersPerSecondUpdater_h
#include "exampleHudUpdaterPlugin.h"
#include <vrvGlStudioShared/DtGlStudioObjectAttributeUpdater.h>
#include <matrix/vlVector.h>
namespace makVrv
{
   class DtExampleMetersPerSecondUpdater : public DtGlStudioObjectAttributeUpdater
   {
   public: 
      DtExampleMetersPerSecondUpdater();
      virtual ~DtExampleMetersPerSecondUpdater();
      virtual std::string value(double time);
   protected:
      DtVector myVelocity;
   };
   class DT_DLL_EXAMPLEHUDUPDATERPLUGIN DtExampleMetersPerSecondUpdaterCreator : public DtGlStudioAttributeUpdaterCreator
   {
   public:
      DtExampleMetersPerSecondUpdaterCreator();
      virtual ~DtExampleMetersPerSecondUpdaterCreator();
      virtual DtGlStudioAttributeUpdater* create() const;
   protected:
   };
} //makVrv::
#endif

exampleHudUpdaterPluginInit.cxx

/******************************************************************************
** Copyright (c) 2019 MAK Technologies, Inc.
** All rights reserved.
******************************************************************************/
#include "exampleHudUpdaterPlugin.h"
#include "exampleHudUpdaterPluginInit.h"
#include <vrvCore/DtDe.h>
#include <vrvGlStudio/DtGlStudio.h>
#include <vrvGlStudioShared/DtSharedCockpitSettings.h>
#include <vrvGlStudioShared/DtSharedCockpitSettingsManager.h>
#include <boost/bind.hpp>
//shared source implementation 
#define DT_PROTOCOL_NAMESPACE vrvDis
#include <vl/globalObjectDesignator.h>
#include <vrvGlStudioDIS/DtGlStudioDIS.h>
#include <vrvDis/vrvDis.h>
#include <vrvVrl/vrvVrl.h>
#include <vl/entityStateRepository.h>
#include <vlpi/entityIdentifier.h>
#include <vrvVrl/DtVrlinkConnection.h>
#include "exampleHatchStateUpdater.h"
#include "exampleHatchStateUpdater.inl"
#undef DT_PROTOCOL_NAMESPACE
#include "exampleMetersPerSecondUpdater.h"
using namespace makVrv;
bool initDeModule(makVrv::DtDe* de)
{
   if (de->deInitializer().featureSupported( makVrv::DtDeInitializer::Features_3D ) )
   {
      vrvExampleHudUpdaterPlugin::init(*de);
      return true;
   }
   return false;
}
void addUpdaters(makVrv::DtDe* de)
{
   //create the settings manager and get access to it
   DtSharedCockpitSettingsManager::instance(*de);
   {
      //get the updater factory
      DtWriteSettingsLock<DtSharedCockpitSettings> settings(DtSharedSettingsManager::instance(*de));
      DtGlStudioAttributeUpdaterFactory& factory=settings->updaterFactory();
      //visualizer side updater using entity state repository data directly at network update rate
       factory.registerUpdater(new vrvDis::DtGlStudioHatchStateUpdaterCreator());
      //object side updater uses TSPI data stored in HUD renderable to generate smooth updates at frame rate
      factory.registerUpdater(new DtExampleMetersPerSecondUpdaterCreator());
   }
   de->signal_postInitialize.disconnect(boost::bind(&addUpdaters, de));
}
namespace makVrv
{
   namespace vrvExampleHudUpdaterPlugin
   {
      void init(DtDe& de)
      {
         DT_DE_INIT_ONCE(de);
         try
         {
            //make sure GlStudio is initialized
            DtGlStudio::init(de);
            //connect to post-initialize signal to setup updaters
            de.signal_postInitialize.connect(boost::bind(&addUpdaters, &de));
         }
         DtCATCH_AND_PROPAGATE(DtCorruptedState)
      }
   }
}

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