void
MonotoneChain::computeSelect(const Envelope& searchEnv,
size_t start0, size_t end0,
MonotoneChainSelectAction& mcs)
{
const Coordinate& p0 = pts[start0];
const Coordinate& p1 = pts[end0];
// terminating condition for the recursion
if(end0 - start0 == 1) {
mcs.select(*this, start0);
return;
}
// nothing to do if the envelopes don't overlap
if(!searchEnv.intersects(p0, p1)) {
return;
}
// the chains overlap,so split each in half and iterate (binary search)
size_t mid = (start0 + end0) / 2;
// Assert: mid != start or end (since we checked above for end-start <= 1)
// check terminating conditions before recursing
if(start0 < mid) {
computeSelect(searchEnv, start0, mid, mcs);
}
if(mid < end0) {
computeSelect(searchEnv, mid, end0, mcs);
}
}
void
MonotoneChain::computeSelect(const Envelope& searchEnv,
size_t start0, size_t end0,
MonotoneChainSelectAction& mcs )
{
const Coordinate& p0=pts[start0];
const Coordinate& p1=pts[end0];
mcs.tempEnv1.init(p0,p1);
//Debug.println("trying:"+p0+p1+" [ "+start0+","+end0+" ]");
// terminating condition for the recursion
if(end0-start0==1)
{
//Debug.println("computeSelect:"+p0+p1);
mcs.select(*this,start0);
return;
}
// nothing to do if the envelopes don't overlap
if (!searchEnv.intersects(mcs.tempEnv1))
return;
// the chains overlap,so split each in half and iterate (binary search)
unsigned int mid=(start0+end0)/2;
// Assert: mid != start or end (since we checked above for end-start <= 1)
// check terminating conditions before recursing
if (start0 < mid)
{
computeSelect(searchEnv,start0,mid,mcs);
}
if (mid < end0)
{
computeSelect(searchEnv,mid,end0,mcs);
}
}