/// <summary>
///
/// </summary>
/// <param name="chainIndex0"></param>
/// <param name="mce"></param>
/// <param name="chainIndex1"></param>
/// <param name="si"></param>
public void ComputeIntersectsForChain(int chainIndex0, MonotoneChainEdge mce, int chainIndex1, SegmentIntersector si)
{
ComputeIntersectsForChain(startIndex[chainIndex0], startIndex[chainIndex0 + 1], mce,
mce.startIndex[chainIndex1], mce.startIndex[chainIndex1 + 1], si);
}
/// <summary>
///
/// </summary>
/// <param name="edges0"></param>
/// <param name="edges1"></param>
/// <param name="si"></param>
public override void ComputeIntersections(IList <Edge> edges0, IList <Edge> edges1, SegmentIntersector si)
{
foreach (var edge0 in edges0)
{
foreach (var edge1 in edges1)
{
ComputeIntersects(edge0, edge1, si);
}
}
}
/// <summary>
///
/// </summary>
/// <param name="start0"></param>
/// <param name="end0"></param>
/// <param name="mce"></param>
/// <param name="start1"></param>
/// <param name="end1"></param>
/// <param name="ei"></param>
private void ComputeIntersectsForChain(int start0, int end0, MonotoneChainEdge mce, int start1, int end1, SegmentIntersector ei)
{
// terminating condition for the recursion
if (end0 - start0 == 1 && end1 - start1 == 1)
{
ei.AddIntersections(e, start0, mce.e, start1);
return;
}
// nothing to do if the envelopes of these chains don't overlap
if (!Overlaps(start0, end0, mce, start1, end1))
{
return;
}
// the chains overlap, so split each in half and iterate (binary search)
int mid0 = (start0 + end0) / 2;
int mid1 = (start1 + end1) / 2;
// check terminating conditions before recursing
if (start0 < mid0)
{
if (start1 < mid1)
{
ComputeIntersectsForChain(start0, mid0, mce, start1, mid1, ei);
}
if (mid1 < end1)
{
ComputeIntersectsForChain(start0, mid0, mce, mid1, end1, ei);
}
}
if (mid0 < end0)
{
if (start1 < mid1)
{
ComputeIntersectsForChain(mid0, end0, mce, start1, mid1, ei);
}
if (mid1 < end1)
{
ComputeIntersectsForChain(mid0, end0, mce, mid1, end1, ei);
}
}
}