public override void Overlap(MonotoneChain mc1, int start1, MonotoneChain mc2, int start2)
{
var ss1 = (ISegmentString)mc1.Context;
var ss2 = (ISegmentString)mc2.Context;
_si.ProcessIntersections(ss1, start1, ss2, start2);
}
/// <summary>
/// Return a list of the <c>MonotoneChain</c>s
/// for the given list of coordinates.
/// </summary>
/// <param name="pts"></param>
/// <param name="context"></param>
public static IList<MonotoneChain> GetChains(Coordinate[] pts, object context)
{
var mcList = new List<MonotoneChain>();
var startIndex = GetChainStartIndices(pts);
for (var i = 0; i < startIndex.Length - 1; i++)
{
var mc = new MonotoneChain(pts, startIndex[i], startIndex[i + 1], context);
mcList.Add(mc);
}
return mcList;
}
/// <summary>
///
/// </summary>
/// <param name="start0"></param>
/// <param name="end0"></param>
/// <param name="mc"></param>
/// <param name="start1"></param>
/// <param name="end1"></param>
/// <param name="mco"></param>
private void ComputeOverlaps(int start0, int end0, MonotoneChain mc, int start1, int end1, MonotoneChainOverlapAction mco)
{
Coordinate p00 = _pts[start0];
Coordinate p01 = _pts[end0];
Coordinate p10 = mc._pts[start1];
Coordinate p11 = mc._pts[end1];
// terminating condition for the recursion
if (end0 - start0 == 1 && end1 - start1 == 1)
{
mco.Overlap(this, start0, mc, start1);
return;
}
// nothing to do if the envelopes of these chains don't overlap
mco.TempEnv1.Init(p00, p01);
mco.TempEnv2.Init(p10, p11);
if (! mco.TempEnv1.Intersects(mco.TempEnv2))
return;
// the chains overlap, so split each in half and iterate (binary search)
int mid0 = (start0 + end0) / 2;
int mid1 = (start1 + end1) / 2;
// Assert: mid != start or end (since we checked above for end - start <= 1)
// check terminating conditions before recursing
if (start0 < mid0)
{
if (start1 < mid1)
ComputeOverlaps(start0, mid0, mc, start1, mid1, mco);
if (mid1 < end1)
ComputeOverlaps(start0, mid0, mc, mid1, end1, mco);
}
if (mid0 < end0)
{
if (start1 < mid1)
ComputeOverlaps(mid0, end0, mc, start1, mid1, mco);
if (mid1 < end1)
ComputeOverlaps(mid0, end0, mc, mid1, end1, mco);
}
}
/**
*
* <p>
*
* @param searchEnv the search envelope
* @param mco t
*/
/// <summary>
/// Determine all the line segments in two chains which may overlap, and process them.
/// </summary>
/// <remarks>
/// The monotone chain search algorithm attempts to optimize
/// performance by not calling the overlap action on chain segments
/// which it can determine do not overlap.
/// However, it *may* call the overlap action on segments
/// which do not actually interact.
/// This saves on the overhead of checking intersection
/// each time, since clients may be able to do this more efficiently.
/// </remarks>
/// <param name="mc">The monotone chain</param>
/// <param name="mco">The overlap action to execute on selected segments</param>
public void ComputeOverlaps(MonotoneChain mc, MonotoneChainOverlapAction mco)
{
ComputeOverlaps(_start, _end, mc, mc._start, mc._end, mco);
}
/// <summary>
/// This function can be overridden if the original chains are needed.
/// </summary>
/// <param name="mc1"></param>
/// <param name="start1">The index of the start of the overlapping segment from mc1.</param>
/// <param name="mc2"></param>
/// <param name="start2">The index of the start of the overlapping segment from mc2.</param>
public virtual void Overlap(MonotoneChain mc1, int start1, MonotoneChain mc2, int start2)
{
mc1.GetLineSegment(start1, ref overlapSeg1);
mc2.GetLineSegment(start2, ref overlapSeg2);
Overlap(overlapSeg1, overlapSeg2);
}
/// <summary>
///
/// </summary>
/// <param name="rayEnv"></param>
/// <param name="mcSelecter"></param>
/// <param name="mc"></param>
private static void TestMonotoneChain(Envelope rayEnv, MCSelecter mcSelecter, MonotoneChain mc)
{
mc.Select(rayEnv, mcSelecter);
}
/// <summary>
///
/// </summary>
/// <param name="mc1"></param>
/// <param name="start1"></param>
/// <param name="mc2"></param>
/// <param name="start2"></param>
public override void Overlap(MonotoneChain mc1, int start1, MonotoneChain mc2, int start2)
{
var ss1 = (ISegmentString) mc1.Context;
var ss2 = (ISegmentString) mc2.Context;
_si.ProcessIntersections(ss1, start1, ss2, start2);
}
/// <summary>
/// This method is overridden to process a segment
/// in the context of the parent chain.
/// </summary>
/// <param name="mc">The parent chain</param>
/// <param name="startIndex">The index of the start vertex of the segment being processed</param>
public virtual void Select(MonotoneChain mc, int startIndex)
{
mc.GetLineSegment(startIndex, ref SelectedSegment);
// call this routine in case select(segment) was overridden
Select(SelectedSegment);
}
/// <summary>
/// This function can be overridden if the original chains are needed.
/// </summary>
/// <param name="mc1"></param>
/// <param name="start1">The index of the start of the overlapping segment from mc1.</param>
/// <param name="mc2"></param>
/// <param name="start2">The index of the start of the overlapping segment from mc2.</param>
public virtual void Overlap(MonotoneChain mc1, int start1, MonotoneChain mc2, int start2)
{
mc1.GetLineSegment(start1, ref overlapSeg1);
mc2.GetLineSegment(start2, ref overlapSeg2);
Overlap(overlapSeg1, overlapSeg2);
}
/// <summary>
/// Determine all the line segments in two chains which may overlap, and process them.
/// </summary>
/// <remarks>
/// The monotone chain search algorithm attempts to optimize
/// performance by not calling the overlap action on chain segments
/// which it can determine do not overlap.
/// However, it *may* call the overlap action on segments
/// which do not actually interact.
/// This saves on the overhead of checking intersection
/// each time, since clients may be able to do this more efficiently.
/// </remarks>
/// <param name="mc">The monotone chain</param>
/// <param name="mco">The overlap action to execute on selected segments</param>
public void ComputeOverlaps(MonotoneChain mc, MonotoneChainOverlapAction mco)
{
ComputeOverlaps(_start, _end, mc, mc._start, mc._end, mco);
}
/// <summary>
/// This method is overridden to process a segment
/// in the context of the parent chain.
/// </summary>
/// <param name="mc">The parent chain</param>
/// <param name="startIndex">The index of the start vertex of the segment being processed</param>
public virtual void Select(MonotoneChain mc, int startIndex)
{
mc.GetLineSegment(startIndex, ref SelectedSegment);
// call this routine in case select(segmenet) was overridden
Select(SelectedSegment);
}