} // public void Select( Envelope searchEnv, MonotoneChainSelectAction mcs )
private void ComputeSelect(
Envelope searchEnv,
int start0, int end0,
MonotoneChainSelectAction mcs )
{
Coordinate p0 = _pts[start0];
Coordinate p1 = _pts[end0];
_env1.Initialize( p0, p1 );
//Trace.WriteLine( "trying:" + p0.ToString() + p1.ToString() + " [ " + start0.ToString() + ", " + end0.ToString() + " ]");
// terminating condition for the recursion
if (end0 - start0 == 1)
{
//Trace.WriteLine("ComputeSelect:" + p0.ToString() + p1.ToString() );
mcs.Select( this, start0 );
return;
}
// nothing to do if the envelopes don't overlap
if ( !searchEnv.Intersects( _env1 ) )
{
return;
}
// the chains overlap, so split each in half and iterate (binary search)
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 );
}
} // private void ComputeSelect(...
