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; }