//---------------------------------------------------------------------------
// Description: Highlights the routes with the heigher pheromone intesity
// starting from the Nest. If the Food source is not reached
// after a given number of tries, stop the search and draw the
// result.
bool __fastcall Civilization::FindMainRoads(int Ntries, TImage *ImageBox, const int RWidth, const float Scale)
{
// Start from the Anthill...
City *CurrentCity = Nest;
TList *MainRoads = new TList();
while(CurrentCity!=FoodSourceCity && Ntries>0)
{
int PheroLevel = -MAXINT;
Route *CurrentRoad = NULL;
City* NextCity;
Route* thisRoad;
// the following loop select the best road acording to the pheromone level
for(int j=0; j<Roads->Count; j++)
{
thisRoad = (Route*)Roads->Items[j];
// if the road has a conection with the current city...
NextCity = thisRoad->GetConection(CurrentCity);
// Test the highest Pheromone level among the possible roads...
// if 'thisRoad' was not used before...
if(NextCity!=NULL && MainRoads->IndexOf(thisRoad)==-1)
{
if(thisRoad->GetPheromone() > PheroLevel)
{
CurrentRoad = thisRoad;
PheroLevel = thisRoad->GetPheromone();
}
}
}
// Go to next city using the selected road...
if(CurrentCity!=NULL && CurrentRoad!=NULL)
{
CurrentCity = CurrentRoad->GetConection(CurrentCity);
MainRoads->Add(CurrentRoad);
}
Ntries--;
}
// Draw the MainRoad
Rebuild(ImageBox,Scale);
// Draw all the roads
for(int i=0; i<MainRoads->Count; i++)
{
ImageBox->Canvas->Pen->Width = RWidth;
((Route*)MainRoads->Items[i])->DrawRoad(ImageBox,clRed,Scale);
ImageBox->Canvas->Pen->Width = 1;
}
return (Ntries>0)?true:false;
}
//---------------------------------------------------------------------------
// Description: Evaluates the next move of all agents in the population.
//
// For all ants in the colony...
// - if traveling, walk one more step
// - if in the food source not carrying food, pick food
// - if in the nest carrying food, leave food
// - else (in another city), choose next route
int Civilization::NextTurn()
{
TurnsRemaining--;
if(TurnsRemaining==0) // If it's time to evolve the population...
{
NaturalSelection(); // ...perform Natural Selection
}
Epoch++; // Update next turn number
// For all ants in the colony...
for(int i=0; i<Ants->Count; i++)
{
// Select an Ant...
Ant* thisAnt = (Ant*)Ants->Items[i];
// If it's traveling, walk a little more...
if(thisAnt->IsOnTheRoad()) thisAnt->Walk();
else { //... else, if the ant is on a city, ...
// See if the ant reached the Civilization's Food Souce...
if( (thisAnt->TargetCity==FoodSourceCity) && !thisAnt->CarryingFood() )
{
thisAnt->PickFood();
thisAnt->PrepareTrail();
}
else
// ... or in the Nest carrying food, ...
if( (thisAnt->TargetCity==Nest) && thisAnt->CarryingFood() )
{
thisAnt->LeaveFood(); // ... leave food
FoodCollected++; // ... add one more food to the colony
thisAnt->RememberCity(); // ... start again ...
int *ThisYear = new int;
*ThisYear = Epoch;
DeliveryTime->Add(ThisYear);
}
else
// if the ant is carring food, follow its own trail back to the Anthill
if( thisAnt->CarryingFood() )
{
City *CurrentCity = thisAnt->TargetCity;
City *BackCity = thisAnt->GetNextCity();
for(int j=0; j<Roads->Count; j++)
{
Route* thisRoad = (Route*)Roads->Items[j];
// if the road has a conection with the current city...
City* NextCity = thisRoad->GetConection(CurrentCity);
if(NextCity!=NULL && NextCity==BackCity)
{
thisAnt->SetDistance((int)NextCity->GetDistance(CurrentCity));
thisAnt->TargetCity = NextCity;
thisAnt->Road = thisRoad;
if(thisAnt->Road!=NULL) thisAnt->PutPheromone();
break;
}
}
}
else
{
// ... or select a new way to go.
// Search all cities that have a road to this one
float CurrentLevel = -MaxInt;
// Save the TargetCity for comparisons...
City *CurrentCity = thisAnt->TargetCity;
for(int j=0; j<Roads->Count; j++)
{
Route* thisRoad = (Route*)Roads->Items[j];
// if the road has a conection with the current city...
City* NextCity = thisRoad->GetConection(CurrentCity);
// ... test the Will Level
if(NextCity!=NULL)
{
float Level = thisAnt->GetTendency(thisRoad->GetPheromone());
if(Level > CurrentLevel)
{
CurrentLevel = Level;
// Set the distance to the next target city
thisAnt->SetDistance((int)NextCity->GetDistance(CurrentCity));
// Select a new Target City and Route:
thisAnt->TargetCity = NextCity;
thisAnt->Road = thisRoad;
}
}
thisRoad->UpdateStatusInfo();
} // end of Road Search
if(thisAnt->Road!=NULL) thisAnt->PutPheromone();
// After a target city was selected, remember it...
thisAnt->RememberCity();
} // end of new path selection
}
// Draw Ants...
thisAnt->DrawAnt(VirtualCiv);
} // end of Ants Movements
// Pheromone Evaporation...
for(int j=0; j<Roads->Count; j++)
{
((Route*)Roads->Items[j])->EvaporatePheromone();
}
// Show Current Status on the main window
LabelEpoch->Caption = "Turn: " + IntToStr(Epoch) + '\n' + "Population: " + IntToStr(Ants->Count) + '\n' +
"Food Collected: " + IntToStr(FoodCollected);
return Epoch;
}
