/** Adds a new number range. The range describes a mapping from c to v(c), where
* \f$c \in [cmin,cmax]\f$ and \f$v(cmin):=vmin, v(c):=vmin+c-cmin\f$.
* @param[in] cmin smallest number in the range
* @param[in] cmax largest number in the range
* @param[in] vmin map value of cmin */
void RangeMap::addRange (UInt32 cmin, UInt32 cmax, UInt32 vmin) {
if (cmin > cmax)
swap(cmin, cmax);
Range range(cmin, cmax, vmin);
if (_ranges.empty())
_ranges.push_back(range);
else {
// check for simple cases that can be handled pretty fast
Range &lrange = *_ranges.begin();
Range &rrange = *_ranges.rbegin();
if (cmin > rrange.max()) { // non-overlapping range at end of vector?
if (!rrange.join(range))
_ranges.push_back(range);
}
else if (cmax < lrange.min()) { // non-overlapping range at begin of vector?
if (!lrange.join(range))
_ranges.insert(_ranges.begin(), range);
}
else {
// ranges overlap and/or must be inserted somewhere inside the vector
Ranges::iterator it = lower_bound(_ranges.begin(), _ranges.end(), range);
const bool at_end = (it == _ranges.end());
if (at_end)
--it;
if (!it->join(range) && (it == _ranges.begin() || !(it-1)->join(range))) {
if (it->min() < cmin && it->max() > cmax) { // new range completely inside an existing range?
//split existing range
UInt32 itmax = it->max();
it->max(cmin-1);
it = _ranges.insert(it+1, Range(cmax+1, itmax, it->valueAt(cmax+1)));
}
else if (at_end) // does new range overlap right side of last range in vector?
it = _ranges.end(); // => append new range at end of vector
it = _ranges.insert(it, range);
}
adaptNeighbors(it); // resolve overlaps
}
}
}
/** Adapts the left and right neighbor elements of a newly inserted range.
* The new range could overlap ranges in the neighborhood so that those must be
* adapted or removed. All ranges in the range vector are ordered ascendingly, i.e.
* [min_1, max_1],...,[min_n, max_n] where min_i < min_j for all i < j.
* @param[in] it pointer to the newly inserted range */
void RangeMap::adaptNeighbors (Ranges::iterator it) {
if (it != _ranges.end()) {
// adapt left neighbor
Ranges::iterator lit = it-1; // points to left neighbor
if (it != _ranges.begin() && it->min() <= lit->max()) {
bool left_neighbor_valid = (it->min() > 0 && it->min()-1 >= lit->min());
if (left_neighbor_valid) // is adapted left neighbor valid?
lit->max(it->min()-1); // => assign new max value
if (!left_neighbor_valid || it->join(*lit))
it = _ranges.erase(lit);
}
// remove right neighbors completely overlapped by *it
Ranges::iterator rit = it+1; // points to right neighbor
while (rit != _ranges.end() && it->max() >= rit->max()) { // complete overlap?
_ranges.erase(rit);
rit = it+1;
}
// adapt rightmost range partially overlapped by *it
if (rit != _ranges.end()) {
if (it->max() >= rit->min())
rit->setMinAndAdaptValue(it->max()+1);
// try to merge right neighbor into *this
if (it->join(*rit))
_ranges.erase(rit); // remove merged neighbor
}
}
}
