private void initIter(Shape filter) {
cellNumber = -1;
if (filter instanceof UnitNRShape && ((UnitNRShape) filter).getLevel() == 0)
filter = null; // world means everything -- no filter
iterFilter = filter;
NRCell parent = getShapeAtLevel(getLevel() - 1);
// Initialize iter* members.
// no filter means all subcells
if (filter == null) {
iterFirstCellNumber = 0;
iterFirstIsIntersects = false;
iterLastCellNumber = getNumSubCells(parent) - 1;
iterLastIsIntersects = false;
return;
}
final UnitNRShape minLV;
final UnitNRShape maxLV;
final int lastLevelInCommon; // between minLV & maxLV
if (filter instanceof SpanUnitsNRShape) {
SpanUnitsNRShape spanShape = (SpanUnitsNRShape) iterFilter;
minLV = spanShape.getMinUnit();
maxLV = spanShape.getMaxUnit();
lastLevelInCommon = spanShape.getLevelsInCommon();
} else {
minLV = (UnitNRShape) iterFilter;
maxLV = minLV;
lastLevelInCommon = minLV.getLevel();
}
// fast path optimization that is usually true, but never first level
if (iterFilter == parent.iterFilter
&& (getLevel() <= lastLevelInCommon
|| parent.iterFirstCellNumber != parent.iterLastCellNumber)) {
// TODO benchmark if this optimization pays off. We avoid two comparePrefixLV calls.
if (parent.iterFirstIsIntersects
&& parent.cellNumber == parent.iterFirstCellNumber
&& minLV.getLevel() >= getLevel()) {
iterFirstCellNumber = minLV.getValAtLevel(getLevel());
iterFirstIsIntersects = (minLV.getLevel() > getLevel());
} else {
iterFirstCellNumber = 0;
iterFirstIsIntersects = false;
}
if (parent.iterLastIsIntersects
&& parent.cellNumber == parent.iterLastCellNumber
&& maxLV.getLevel() >= getLevel()) {
iterLastCellNumber = maxLV.getValAtLevel(getLevel());
iterLastIsIntersects = (maxLV.getLevel() > getLevel());
} else {
iterLastCellNumber = getNumSubCells(parent) - 1;
iterLastIsIntersects = false;
}
if (iterFirstCellNumber == iterLastCellNumber) {
if (iterLastIsIntersects) iterFirstIsIntersects = true;
else if (iterFirstIsIntersects) iterLastIsIntersects = true;
}
return;
}
// not common to get here, except for level 1 which always happens
int startCmp = comparePrefix(minLV, parent);
if (startCmp > 0) { // start comes after this cell
iterFirstCellNumber = 0;
iterFirstIsIntersects = false;
iterLastCellNumber = -1; // so ends early (no cells)
iterLastIsIntersects = false;
return;
}
int endCmp = comparePrefix(maxLV, parent); // compare to end cell
if (endCmp < 0) { // end comes before this cell
iterFirstCellNumber = 0;
iterFirstIsIntersects = false;
iterLastCellNumber = -1; // so ends early (no cells)
iterLastIsIntersects = false;
return;
}
if (startCmp < 0 || minLV.getLevel() < getLevel()) {
// start comes before...
iterFirstCellNumber = 0;
iterFirstIsIntersects = false;
} else {
iterFirstCellNumber = minLV.getValAtLevel(getLevel());
iterFirstIsIntersects = (minLV.getLevel() > getLevel());
}
if (endCmp > 0 || maxLV.getLevel() < getLevel()) {
// end comes after...
iterLastCellNumber = getNumSubCells(parent) - 1;
iterLastIsIntersects = false;
} else {
iterLastCellNumber = maxLV.getValAtLevel(getLevel());
iterLastIsIntersects = (maxLV.getLevel() > getLevel());
}
if (iterFirstCellNumber == iterLastCellNumber) {
if (iterLastIsIntersects) iterFirstIsIntersects = true;
else if (iterFirstIsIntersects) iterLastIsIntersects = true;
}
}
