OctreeElementPointer OctreeElement::getOrCreateChildElementContaining(const AABox& box) {
OctreeElementPointer child = NULL;
int childIndex = getMyChildContaining(box);
// If getMyChildContaining() returns CHILD_UNKNOWN then it means that our level
// is the correct level for this cube
if (childIndex == CHILD_UNKNOWN) {
return shared_from_this();
}
// Now, check if we have a child at that location
child = getChildAtIndex(childIndex);
if (!child) {
child = addChildAtIndex(childIndex);
}
// if we've made a really small child, then go ahead and use that one.
if (child->getScale() <= SMALLEST_REASONABLE_OCTREE_ELEMENT_SCALE) {
return child;
}
// Now that we have the child to recurse down, let it answer the original question...
return child->getOrCreateChildElementContaining(box);
}
OctreeElementPointer UpdateEntityOperator::possiblyCreateChildAt(OctreeElementPointer element, int childIndex) {
// If we're getting called, it's because there was no child element at this index while recursing.
// We only care if this happens while still searching for the new entity location.
// Check to see if
if (!_foundNew) {
float childElementScale = element->getScale() / 2.0f; // all of our children will be half our scale
// Note: because the entity's bounds might have been clamped to the domain. We want to check if the
// bounds of the clamped box would fit in our child elements. It may be the case that the actual
// bounds of the element would hang outside of the child elements cells.
bool entityWouldFitInChild = _newEntityBox.getLargestDimension() <= childElementScale;
// if the scale of our desired cube is smaller than our children, then consider making a child
if (entityWouldFitInChild) {
int indexOfChildContainingNewEntity = element->getMyChildContaining(_newEntityBox);
if (childIndex == indexOfChildContainingNewEntity) {
return element->addChildAtIndex(childIndex);;
}
}
}
return NULL;
}
