private void CalculateOptions(AbstractAIBrain utilityAiBrain)
{
if (utilityAiBrain == null)
{
return;
}
// Setup Contexts
utilityAiBrain.GetNodes <EntryNode>().ForEach(node => node.SetContext(this));
utilityAiBrain.GetNodes <ActionNode>().ForEach(node => node.SetContext(this));
// Add the brain to the option dictionary
if (Options.ContainsKey(utilityAiBrain))
{
Options[utilityAiBrain].Clear();
}
else
{
Options.Add(utilityAiBrain, new List <AIOption>());
}
utilityAiBrain.GetNodes <OptionNode>().ForEach(node => Options[utilityAiBrain]
.AddRange(node.GetOptions()));
// Return if no option found
if (Options[utilityAiBrain].Count == 0)
{
return;
}
// Calculate Probability
foreach (AIOption aiOption in Options[utilityAiBrain])
{
aiOption.Probability = aiOption.Utility / Options[utilityAiBrain]
.Where(option => option.Weight == aiOption.Weight)
.Sum(option => option.Utility);
}
// Order by Weight then Utility
Options[utilityAiBrain] = Options[utilityAiBrain].OrderByDescending(option => option.Weight).ThenByDescending(option => option.Utility).ToList();
}
protected AIOption ChooseOption()
{
if (UtilityAiBrain == null)
{
return(null);
}
UtilityAiBrain.GetNodes <EntryNode>().ForEach(node => node.SetContext(this));
UtilityAiBrain.GetNodes <ActionNode>().ForEach(node => node.SetContext(this));
// Fill the Ranked Options
Options = new List <AIOption>();
UtilityAiBrain.GetNodes <OptionNode>().ForEach(node => Options.AddRange(node.GetOptions()));
// Remove ImpossibleDecisionValue Ranks
Options.RemoveAll(option => option.Rank <= 0f);
if (Options.Count == 0)
{
return(null);
}
// Get max Rank
int maxRank = Options.Max(option => option.Rank);
for (int i = maxRank; i > 0; i--)
{
List <AIOption> options = Options.FindAll(utility => utility.Rank == i);
if (options.Count == 0 || options.Sum(utility => utility.Utility) <= 0)
{
continue;
}
// Calculating Weight
options.ForEach(dualUtility => dualUtility.Weight = dualUtility.Utility / Options.Sum(utility => utility.Utility));
// Rolling probability on weighted random
LastProbabilityResult = Random.Range(0f, 1f);
float weightSum = 0f;
foreach (AIOption dualUtility in options)
{
weightSum += dualUtility.Weight;
if (weightSum >= LastProbabilityResult)
{
return(dualUtility);
}
}
}
return(null);
}