/// <summary> /// /// </summary> /// <param name="mce"></param> /// <param name="chainIndex"></param> public MonotoneChain(MonotoneChainEdge mce, int chainIndex) { this.mce = mce; this.chainIndex = chainIndex; }
/// <summary> /// /// </summary> /// <param name="chainIndex0"></param> /// <param name="mce"></param> /// <param name="chainIndex1"></param> /// <param name="si"></param> public virtual 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="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) { Coordinate p00 = _pts[start0]; Coordinate p01 = _pts[end0]; Coordinate p10 = mce._pts[start1]; Coordinate p11 = mce._pts[end1]; // Console.WriteLine("computeIntersectsForChain:" + p00 + p01 + p10 + p11); // 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 _env1.Init(p00, p01); _env2.Init(p10, p11); if (!_env1.Intersects(_env2)) 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); } }
/// <summary> /// /// </summary> /// <param name="mce"></param> /// <param name="si"></param> public virtual void ComputeIntersects(MonotoneChainEdge mce, SegmentIntersector si) { for (int i = 0; i < _startIndex.Length - 1; i++) { for (int j = 0; j < mce._startIndex.Length - 1; j++) { ComputeIntersectsForChain(i, mce, j, si); } } }