void UHTNPlannerComponent::ProcessExecutionRequest()
{
bRequestedExecutionUpdate = false;
if(!IsRegistered())
{
// it shouldn't be called, component is no longer valid
return;
}
if(bIsPaused)
{
UE_VLOG(GetOwner(), LogHTNPlanner, Verbose, TEXT("Ignoring ProcessExecutionRequest call due to HTNPlannerComponent still being paused"));
return;
}
//GEngine->AddOnScreenDebugMessage(-1, 1.5f, FColor::Yellow, TEXT("UHTNPlannerComponent::ProcessExecutionRequest()"));
if(PendingExecution.IsValid())
{
ProcessPendingExecution();
return;
}
if(NumStackElements == 0)
{
//BestPlan = nullptr;
if(CurrentPlannerAsset->bLoop)
{
// finished execution of plan and we want to loop, so re-start
RestartPlanner();
}
else
{
bIsRunning = false;
}
return;
}
#if HTN_LOG_RUNTIME_STATS
if(StartPlanningTime == FDateTime::MinValue())
{
StartPlanningTime = FDateTime::UtcNow();
}
#endif // HTN_LOG_RUNTIME_STATS
FDateTime PlanningStart = FDateTime::UtcNow();
while(NumStackElements > 0)
{
// our stack is not empty
FTimespan TimePlanned = FDateTime::UtcNow() - PlanningStart;
if(TimePlanned.GetTotalSeconds() >= CurrentPlannerAsset->MaxSearchTime)
{
// we've spent our maximum allowed search time for this tick on planning, so need to continue some other time
ScheduleExecutionUpdate();
#if HTN_LOG_RUNTIME_STATS
CumulativeSearchTimeMs += TimePlanned.GetTotalMilliseconds();
++CumulativeFrameCount;
#endif
return;
}
#if HTN_LOG_RUNTIME_STATS
++NumNodesExpanded;
#endif
if(PreviousPlan.IsValid())
{
UE_LOG(LogHTNPlanner, Warning, TEXT("%d nodes in data structure(s)"), NumStackElements);
}
if(bProbabilisticPlanReuse && bHitLeaf)
{
// we've hit a leaf node, so it's time to re-evaluate whether we're ignoring plan reuse probabilistically
bHitLeaf = false;
if(NumStackElements == PlanningStack.Num())
{
bIgnoringPlanReuse = false; // not ignoring plan reuse if everything's still in the non-prioritized stack
}
else
{
bIgnoringPlanReuse = (FMath::FRand() <= ProbabilityIgnorePlanReuse);
}
}
const FHTNStackElement StackTop = PopStackElement();
if(StackTop.Cost + Cast<UTaskNetwork>(StackTop.TaskNetwork->Task)->
GetHeuristicCost(StackTop.WorldState, StackTop.TaskNetwork->GetMemory()) >= BestCost)
{
if(!bDepthFirstSearch)
{
// everything remaining in the heap will be at least as bad, and maybe worse
PlanningStack.Empty();
NumStackElements = 0;
}
if(PreviousPlan.IsValid()) // we're doing plan reuse
{
// verify that all of our values of maximum streak lengths among unprocessed nodes are still correct
UpdateMaxStreakLengths();
}
continue; // we won't find any improvements down this path
}
UTaskNetwork* TopNetwork = Cast<UTaskNetwork>(StackTop.TaskNetwork->Task);
if(TopNetwork->IsEmpty(StackTop.TaskNetwork->GetMemory()))
{
// we've found a path leading to a legal, complete Plan
#if HTN_LOG_RUNTIME_STATS
CumulativeSearchTimeMsTillLastImprovement = CumulativeSearchTimeMs + (FDateTime::UtcNow() - PlanningStart).GetTotalMilliseconds();
if(BestCost == TNumericLimits<float>::Max()) // this means that this is the first time we find a valid plan
{
CumulativeSearchTimeMsTillFirstPlan = CumulativeSearchTimeMsTillLastImprovement;
FirstPlanCost = StackTop.Cost;
}
#endif
BestPlan = StackTop.Plan;
BestPlan->SetComplete(true);
BestCost = StackTop.Cost;
#if HTN_LOG_RUNTIME_STATS
DataCollector->FoundSolution(BestCost, StackTop.Plan->GetPlanSize(), StackTop.Plan->GetSearchHistory().Num(),
CumulativeSearchTimeMsTillLastImprovement, NumNodesExpanded);
#endif
if(CurrentPlannerAsset->bIgnoreTaskCosts)
{
// the HTN Planner doesn't care about finding optimal plans, only about finding the first one
PlanningStack.Empty();
NumStackElements = 0;
}
else if(!bDepthFirstSearch)
{
// best-first search finds an optimal solution as first solution
PlanningStack.Empty();
NumStackElements = 0;
}
if(PreviousPlan.IsValid()) // we're doing plan reuse
{
if(bProbabilisticPlanReuse)
{
bHitLeaf = true;
}
// verify that all of our values of maximum streak lengths among unprocessed nodes are still correct
UpdateMaxStreakLengths();
}
continue;
}
// find all tasks that share the highest priority amongst the tasks in the task network
TArray<TSharedPtr<FHTNTaskInstance>> TaskInstances = TopNetwork->FindTasksWithoutPredecessors(StackTop.TaskNetwork->GetMemory());
for(const TSharedPtr<FHTNTaskInstance>& TaskInstance : TaskInstances)
{
UHTNTask* Task = TaskInstance->Task;
if(UPrimitiveTask* PrimitiveTask = Cast<UPrimitiveTask>(Task))
{
if(PrimitiveTask->IsApplicable(StackTop.WorldState, TaskInstance->GetMemory()))
{
// prepare a new element for the stack where we'll have applied this primitive task
FHTNStackElement NewStackElement;
NewStackElement.Cost =
FMath::Max(0.f, StackTop.Cost) + PrimitiveTask->GetCost(StackTop.WorldState, TaskInstance->GetMemory());
TSharedPtr<FHTNPlan> Plan = StackTop.Plan->Copy();
Plan->AppendTaskInstance(TaskInstance);
Plan->AppendSearchHistory(TaskInstance);
TSharedPtr<FHTNTaskInstance> TaskNetwork = TopNetwork->Copy(StackTop.TaskNetwork);
Cast<UTaskNetwork>(TaskNetwork->Task)->Remove(TaskInstance, TaskNetwork->GetMemory());
TSharedPtr<FHTNWorldState> WorldState = StackTop.WorldState->Copy();
PrimitiveTask->ApplyTo(WorldState, TaskInstance->GetMemory());
NewStackElement.Plan = Plan;
NewStackElement.TaskNetwork = TaskNetwork;
NewStackElement.WorldState = WorldState;
if(PreviousPlan.IsValid())
{
// we're doing plan reuse
CurrentMatchingStreakLength = Plan->GetMatchingStreak(PreviousPlan, MinMatchingStreakLength);
}
AddStackElement(NewStackElement); // TO DO maybe should explicitly Move the NewStackElement?
}
else if(PreviousPlan.IsValid())
{
if(bProbabilisticPlanReuse)
{
bHitLeaf = true;
}
}
}
else if(UCompoundTask* CompoundTask = Cast<UCompoundTask>(Task))
{
TArray<TSharedPtr<FHTNTaskInstance>> Decompositions = CompoundTask->FindDecompositions(*this, StackTop.WorldState,
TaskInstance->GetMemory());
// regardless of which decomposition we pick, effect on plan will be the same
TSharedPtr<FHTNPlan> Plan = StackTop.Plan->Copy();
Plan->AppendSearchHistory(TaskInstance);
if(PreviousPlan.IsValid())
{
// we're doing plan reuse
if(Decompositions.Num() == 0) // leaf node
{
if(bProbabilisticPlanReuse)
{
bHitLeaf = true;
}
}
CurrentMatchingStreakLength = Plan->GetMatchingStreak(PreviousPlan, MinMatchingStreakLength);
TArray<FHTNStackElement> NewStackElements;
TArray<FHTNStackElement> NewFifoElements;
for(int32 Idx = 0; Idx < Decompositions.Num(); ++Idx)
{
const TSharedPtr<FHTNTaskInstance>& Decomposition = Decompositions[Idx];
// prepare a new element where we'll have decomposed this compound task
FHTNStackElement NewStackElement;
NewStackElement.WorldState = StackTop.WorldState;
NewStackElement.Cost = StackTop.Cost;
TSharedPtr<FHTNTaskInstance> TaskNetwork = TopNetwork->Copy(StackTop.TaskNetwork);
Cast<UTaskNetwork>(TaskNetwork->Task)->Replace(TaskInstance, Decomposition, TaskNetwork->GetMemory());
NewStackElement.Plan = Plan->Copy();
NewStackElement.TaskNetwork = TaskNetwork;
if(bProbabilisticPlanReuse && bIgnoringPlanReuse)
{
// probabilistically ignoring plan reuse, so no need to waste time computing streak lengths
NewStackElements.Push(NewStackElement);
}
else
{
if(MaxCurrentMatchingStreakLength > 0 && CurrentMatchingStreakLength == 0)
{
// this element belongs in a FIFO queue
NewFifoElements.Push(NewStackElement);
}
else
{
// this element belongs in a stack
NewStackElements.Push(NewStackElement);
}
}
}
// first we'll add all the elements that belong in FIFO queues to their FIFO queues (in given order)
for(int32 Idx = 0; Idx < NewFifoElements.Num(); ++Idx)
{
AddStackElement(NewFifoElements[Idx]);
}
// now we'll add all the elements that belong in some stack to those stacks (reverse order)
while(NewStackElements.Num() > 0)
{
AddStackElement(NewStackElements.Pop());
}
}
else
{
// we're not doing plan reuse
// looping through Decompositions in reverse order so that they'll be popped off stack in correct order again
for(int32 Idx = Decompositions.Num() - 1; Idx >= 0; --Idx)
{
const TSharedPtr<FHTNTaskInstance>& Decomposition = Decompositions[Idx];
// prepare a new element for the stack where we'll have decomposed this compound task
FHTNStackElement NewStackElement;
NewStackElement.WorldState = StackTop.WorldState;
NewStackElement.Cost = StackTop.Cost;
TSharedPtr<FHTNTaskInstance> TaskNetwork = TopNetwork->Copy(StackTop.TaskNetwork);
Cast<UTaskNetwork>(TaskNetwork->Task)->Replace(TaskInstance, Decomposition, TaskNetwork->GetMemory());
NewStackElement.Plan = Plan->Copy();
NewStackElement.TaskNetwork = TaskNetwork;
AddStackElement(NewStackElement); // TO DO maybe should explicitly Move the NewStackElement?
}
}
}
else
{
UE_LOG(LogHTNPlanner, Error, TEXT("UHTNPlannerComponent::ProcessExecutionRequest() encountered a Task that was neither Primitive nor Compound!"))
}
}
if(PreviousPlan.IsValid()) // we're doing plan reuse
{
// verify that all of our values of maximum streak lengths among unprocessed nodes are still correct
UpdateMaxStreakLengths();
}
}
if(BestPlan.IsValid())
{
#if HTN_LOG_RUNTIME_STATS
CumulativeSearchTimeMs += (FDateTime::UtcNow() - PlanningStart).GetTotalMilliseconds();
++CumulativeFrameCount;
CumulativeSearchTimespan = FDateTime::UtcNow() - StartPlanningTime;
// print runtime stats
//UE_LOG(LogHTNPlanner, Warning, TEXT("Cumulative Search Timespan = %.2f ms"), CumulativeSearchTimespan.GetTotalMilliseconds());
UE_LOG(LogHTNPlanner, Warning, TEXT("Cumulative Search Time = %.2f ms"), CumulativeSearchTimeMs);
UE_LOG(LogHTNPlanner, Warning, TEXT("Cumulative Search Time Till Last Improvement = %.2f ms"), CumulativeSearchTimeMsTillLastImprovement);
UE_LOG(LogHTNPlanner, Warning, TEXT("Cumulative Search Time First Plan = %.2f ms"), CumulativeSearchTimeMsTillFirstPlan);
//UE_LOG(LogHTNPlanner, Warning, TEXT("Cumulative Frame Count = %d frames"), CumulativeFrameCount);
UE_LOG(LogHTNPlanner, Warning, TEXT("Num Nodes Expanded = %d"), NumNodesExpanded);
UE_LOG(LogHTNPlanner, Warning, TEXT("Cost of first plan found = %.2f"), FirstPlanCost);
if(PreviousPlan.IsValid())
{
UE_LOG(LogHTNPlanner, Warning, TEXT("Longest matching streak = %d"),
BestPlan->GetLongestMatchingStreak(PreviousPlan, MinMatchingStreakLength));
}
DataCollector->OptimalityProven(CumulativeSearchTimeMs, NumNodesExpanded);
#endif
// we have a complete plan, so we'll want to execute the next task in the plan
UE_LOG(LogHTNPlanner, Warning, TEXT("Found Plan with size = %d, cost = %.2f, search history size = %d!"),
BestPlan->GetPlanSize(), BestCost, BestPlan->GetSearchHistory().Num());
if(CurrentPlannerAsset->bExecutePlan)
{
PendingExecution = BestPlan->GetTaskInstanceToExecute();
ProcessPendingExecution();
}
else
{
bIsRunning = false;
}
}
}
