Artificial Intelligence in Video Games: Towards a Unified Framework

Algorithm 19

Conceptual view code in the onFrame callback function. The RegisterDMController creates a CptBot, which uses the Graven targeting AI to attack enemies, and adds it to the list of controllers of the CptMvAgent2D.

void  GravenAIModule::onFrame()

{

 ⋯

 //For each unit visible to the player

 Unitset units = Broodwar->getAllUnits();

 for  (Unitset::iterator u = units.begin(); u != units.end(); ++u)

 {

  //Ignore neutral units which include mineral fields and critters

  if  (u->getPlayer()->isNeutral())

   continue;

  //Get the projection of the unit in CDS

  CptMvAgent2D  cptUnit =  dynamic_cast <CptMvAgent2D>(cptEntityMgr->GetEntityFromID

   (u->getID()));

  //Projection found, synchronize state and update controllers

  if  (cptUnit)

  {

   syncUnit(cptUnit,  u);

   cptUnit->Update();

  }

  //Projection not found, create one

  else if  (u->exists() && u->isCompleted())

  {

   cptUnit =  new  CptMvAgent2D(cptWorld);

   syncUnit(cptUnit,  u);

   cptWorld->pAddBot(cptUnit);

   cptEntityMgr->RegisterEntity(cptUnit);

   //If the unit can attack, register the targeting AI

   if  (u->getPlayer() == Broodwar->self() && u->canAttack())

   {

    RegisterDMController(cptUnit);

   }

  }

 }

 //Remove projections of units that no longer exist in the game

 std::list<CptMvAgent2D> cptUnits = cptWorld->GetAllBots();

 for  (std::list<CptMvAgent2D>::iterator c = cptUnits.begin(); c != cptUnits.end(); ++c)

 {

  if  (!Broodwar->getUnit((c)->ID())    !Broodwar->getUnit((c)->ID())->exists())

  {

   cptEntityMgr->RemoveEntity(c);

   cptWorld->pRemoveBot((c)->ID());

  }

 }

}