registerInput(_componentTree, "component tree");

registerInput(_maxHeight, "max height");

registerOutput(_pruned, "component tree");

if (!_pruned)

_pruned = new ComponentTree();

prune();

// the new root will be a clone of the old root

_root = boost::make_shared<ComponentTree::Node>(_componentTree->getRoot()->getComponent());

// copy and prune on-the-fly, starting with the root node

int rootLevel;

boost::shared_ptr<ComponentTree::Node> pruned = prune(_componentTree->getRoot(), rootLevel);

// the whole tree did not exceed the threshold

if (pruned)

_root = pruned;

_pruned->setRoot(_root);

boost::shared_ptr<ComponentTree::Node> node,

int& level) {

// copies of all children of node that do not exceed the threshold

std::vector<boost::shared_ptr<ComponentTree::Node> > validChildren;

// prune the trees under every child and add them to the clone

int maxChildLevel = -1;

foreach (boost::shared_ptr<ComponentTree::Node> child, node->getChildren()) {

// copy the child nodes and get their level

int childLevel;

boost::shared_ptr<ComponentTree::Node> childClone = prune(child, childLevel);

if (childLevel > maxChildLevel)

maxChildLevel = childLevel;

// collect the child clones temporarily (if there was no child clone

// returned, child was already exceeding the threshold)

if (childClone)

validChildren.push_back(childClone);

}

// update our level (zero if we have no children)

level = maxChildLevel + 1;

// we are exceeding the threshold

if (level > *_maxHeight) {

// connect our children (that are not exceeding the threshold) directly

// to the root node

foreach (boost::shared_ptr<ComponentTree::Node> child, validChildren)

_root->addChild(child);

// return nothing to indicate we are done in this branch

return boost::shared_ptr<ComponentTree::Node>();

}

// we are good, create a copy...

boost::shared_ptr<ComponentTree::Node> nodeClone = boost::make_shared<ComponentTree::Node>(node->getComponent());

// ...connect our children to it...

foreach (boost::shared_ptr<ComponentTree::Node> child, validChildren)

nodeClone->addChild(child);

// ...and return it

return nodeClone;