Class SimpleMCSweepLineIntersector
- java.lang.Object
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- org.locationtech.jts.geomgraph.index.EdgeSetIntersector
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- org.locationtech.jts.geomgraph.index.SimpleMCSweepLineIntersector
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public class SimpleMCSweepLineIntersector extends EdgeSetIntersector
Finds all intersections in one or two sets of edges, using an x-axis sweepline algorithm in conjunction with Monotone Chains. While still O(n^2) in the worst case, this algorithm drastically improves the average-case time. The use of MonotoneChains as the items in the index seems to offer an improvement in performance over a sweep-line alone.- Version:
- 1.7
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Constructor Summary
Constructors Constructor Description SimpleMCSweepLineIntersector()
A SimpleMCSweepLineIntersector creates monotone chains from the edges and compares them using a simple sweep-line along the x-axis.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description private void
addEdge(Edge edge, java.lang.Object edgeSet)
private void
addEdges(java.util.List edges)
private void
addEdges(java.util.List edges, java.lang.Object edgeSet)
void
computeIntersections(java.util.List edges0, java.util.List edges1, SegmentIntersector si)
Computes all mutual intersections between two sets of edges.void
computeIntersections(java.util.List edges, SegmentIntersector si, boolean testAllSegments)
Computes all self-intersections between edges in a set of edges, allowing client to choose whether self-intersections are computed.private void
computeIntersections(SegmentIntersector si)
private void
prepareEvents()
Because Delete Events have a link to their corresponding Insert event, it is possible to compute exactly the range of events which must be compared to a given Insert event object.private void
processOverlaps(int start, int end, SweepLineEvent ev0, SegmentIntersector si)
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Method Detail
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computeIntersections
public void computeIntersections(java.util.List edges, SegmentIntersector si, boolean testAllSegments)
Description copied from class:EdgeSetIntersector
Computes all self-intersections between edges in a set of edges, allowing client to choose whether self-intersections are computed.- Specified by:
computeIntersections
in classEdgeSetIntersector
- Parameters:
edges
- a list of edges to test for intersectionssi
- the SegmentIntersector to usetestAllSegments
- true if self-intersections are to be tested as well
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computeIntersections
public void computeIntersections(java.util.List edges0, java.util.List edges1, SegmentIntersector si)
Description copied from class:EdgeSetIntersector
Computes all mutual intersections between two sets of edges.- Specified by:
computeIntersections
in classEdgeSetIntersector
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addEdges
private void addEdges(java.util.List edges)
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addEdges
private void addEdges(java.util.List edges, java.lang.Object edgeSet)
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addEdge
private void addEdge(Edge edge, java.lang.Object edgeSet)
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prepareEvents
private void prepareEvents()
Because Delete Events have a link to their corresponding Insert event, it is possible to compute exactly the range of events which must be compared to a given Insert event object.
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computeIntersections
private void computeIntersections(SegmentIntersector si)
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processOverlaps
private void processOverlaps(int start, int end, SweepLineEvent ev0, SegmentIntersector si)
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