/**
* Creates a BTExecutor that handles the execution of a behaviour tree. The behaviour tree is
* represented by a ModelTask (the root of the tree).
* <p>
* A new empty context for the tree is created. This context is passed to the root of the tree,
* and, in general, it will be shared by all the nodes in the tree (it will be passed down the
* hierarchy of the tree). Note however that, depending on the semantics of the tree itself,
* some nodes may not use the context context.
*
* @param modelBT
* the root of the behaviour tree to run.
*/
public BTExecutor(ModelTask modelBT)
{
if (modelBT == null)
{
throw new ArgumentException("The input ModelTask cannot be null");
}
_modelBT = modelBT;
_modelBT.ComputePositions();
_context = new BasicContext();
_tickableTasks = new List<ExecutionTask>();
_openTasks = new List<ExecutionTask>();
_currentOpenInsertions = new List<ExecutionTask>();
_currentOpenRemovals = new List<ExecutionTask>();
_currentTickableInsertions = new List<ExecutionTask>();
_currentTickableRemovals = new List<ExecutionTask>();
_interrupters = new Dictionary<ModelInterrupter, ExecutionInterrupter>();
_tasksStates = new Dictionary<Position, ITaskState>();
}
/**
* This method first retrieve from the context the tree (ModelTask) that is
* going to be emulated by this task. Then, it creates its corresponding
* executor and finally spawns it. If the tree cannot be found in the
* context, does nothing.
*
* @see jbt.execution.core.ExecutionTask#internalSpawn()
*/
protected override void InternalSpawn()
{
/* Retrieve the tree to run from the context. */
treeToRun = Context.GetBT(
((ModelSubtreeLookup)ModelTask).TreeName);
if (treeToRun == null)
{
treeRetrieved = false;
/*
* Must request to be inserted into the list of tickable nodes,
* since no tree has been retrieved and as a result it must be the
* task the one continuin the work.
*/
Executor.RequestInsertionIntoList(BTExecutor.BTExecutorList.Tickable, this);
// System.err.println("Could not retrieve tree "
// + ((ModelSubtreeLookup) this.getModelTask()).getTreeName()
// + " from the context. Check if the context has been properly initialized.");
}
else
{
treeRetrieved = true;
/* Compute positions for the retrieved tree. */
treeToRun.ComputePositions();
executionTree = treeToRun.CreateExecutor(Executor, this);
executionTree.AddTaskListener(this);
executionTree.Spawn(Context);
}
}
