Class S2ShapeUtil.S2EdgeVectorShape

  • All Implemented Interfaces:
    S2Shape, java.lang.Iterable<S2Edge>, java.util.Collection<S2Edge>, java.util.List<S2Edge>
    Enclosing class:
    S2ShapeUtil

    static class S2ShapeUtil.S2EdgeVectorShape
    extends java.util.AbstractList<S2Edge>
    implements S2Shape
    S2EdgeVectorShape is an S2Shape representing a set of unrelated edges. It contains no area and has no interior. Although it implements List, only the add(S2Point, S2Point) method can mutate the list of edges.

    It is mainly used for testing, but it can also be useful if you have, say, a collection of polylines and don't care about memory efficiency (since this class would store most of the vertices twice.) If the vertices are already stored somewhere else, you would be better off writing your own subclass of S2Shape that points to the existing vertex data rather than copying it.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.util.List<S2Edge> edges  
      • Fields inherited from class java.util.AbstractList

        modCount
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void add​(S2Point a, S2Point b)
      Adds an edge to the vector.
      boolean containsOrigin()
      Returns true if this shape contains S2.origin().
      int dimension()
      Returns the dimension of the geometry represented by this shape.
      S2Edge get​(int index)  
      void getChainEdge​(int chainId, int offset, S2Shape.MutableEdge result)
      Returns the edge for the given chain id and offset in result.
      int getChainLength​(int chainId)
      Returns the number of edge ids corresponding to the edge chain for the given chain id.
      int getChainStart​(int chainId)
      Returns the first edge id corresponding to the edge chain for the given chain id.
      S2Point getChainVertex​(int chainId, int edgeOffset)
      Returns the start point of the edge that would be returned by S2Shape.getChainEdge(int, int, com.google.common.geometry.S2Shape.MutableEdge), or the endpoint of the last edge if edgeOffset==getChainLength(chainId).
      void getEdge​(int index, S2Shape.MutableEdge result)
      Returns the edge for the given index in result.
      boolean hasInterior()
      Returns true if this shape has an interior, i.e.
      int numChains()
      Returns the number of contiguous edge chains in the shape.
      int numEdges()
      Returns the number of edges in this shape.
      int size()  
      • Methods inherited from class java.util.AbstractList

        add, add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList
      • Methods inherited from class java.util.AbstractCollection

        addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface java.util.Collection

        parallelStream, removeIf, stream, toArray
      • Methods inherited from interface java.lang.Iterable

        forEach
      • Methods inherited from interface java.util.List

        addAll, contains, containsAll, isEmpty, remove, removeAll, replaceAll, retainAll, sort, spliterator, toArray, toArray
    • Field Detail

      • edges

        private final java.util.List<S2Edge> edges
    • Constructor Detail

      • S2EdgeVectorShape

        public S2EdgeVectorShape()
        Default constructor creates a vector with no edges.
      • S2EdgeVectorShape

        public S2EdgeVectorShape​(S2Point a,
                                 S2Point b)
        Convenience constructor for creating a vector of length 1.
    • Method Detail

      • add

        public void add​(S2Point a,
                        S2Point b)
        Adds an edge to the vector.
      • getEdge

        public void getEdge​(int index,
                            S2Shape.MutableEdge result)
        Description copied from interface: S2Shape
        Returns the edge for the given index in result. Must not return zero-length edges.
        Specified by:
        getEdge in interface S2Shape
        Parameters:
        index - which edge to set into result, from 0 to S2Shape.numEdges() - 1
      • hasInterior

        public boolean hasInterior()
        Description copied from interface: S2Shape
        Returns true if this shape has an interior, i.e. the shape consists of one or more closed non-intersecting loops.
        Specified by:
        hasInterior in interface S2Shape
      • containsOrigin

        public boolean containsOrigin()
        Description copied from interface: S2Shape
        Returns true if this shape contains S2.origin(). Should return false for shapes that do not have an interior.
        Specified by:
        containsOrigin in interface S2Shape
      • numEdges

        public int numEdges()
        Description copied from interface: S2Shape
        Returns the number of edges in this shape.
        Specified by:
        numEdges in interface S2Shape
      • numChains

        public int numChains()
        Description copied from interface: S2Shape
        Returns the number of contiguous edge chains in the shape. For example, a shape whose edges are [AB, BC, CD, AE, EF] may consist of two chains [A, B, C, D] and [A, E, F]. Every chain is assigned a chain id numbered sequentially starting from zero.

        An empty shape has no chains. A full shape (which contains the entire globe) has one chain with no edges. Other shapes should have at least one chain, and the sum of all valid chain lengths should equal S2Shape.numEdges() (that is, edges may only be used by a single chain).

        Note that it is always acceptable to implement this method by returning S2Shape.numEdges() (i.e. every chain consists of a single edge), but this may reduce the efficiency of some algorithms.

        Specified by:
        numChains in interface S2Shape
      • getChainStart

        public int getChainStart​(int chainId)
        Description copied from interface: S2Shape
        Returns the first edge id corresponding to the edge chain for the given chain id. The edge chains must form contiguous, non-overlapping ranges that cover the entire range of edge ids.
        Specified by:
        getChainStart in interface S2Shape
        Parameters:
        chainId - which edge chain to return its start, from 0 to S2Shape.numChains() - 1
      • getChainLength

        public int getChainLength​(int chainId)
        Description copied from interface: S2Shape
        Returns the number of edge ids corresponding to the edge chain for the given chain id. The edge chains must form contiguous, non-overlapping ranges that cover the entire range of edge ids.
        Specified by:
        getChainLength in interface S2Shape
        Parameters:
        chainId - which edge chain to return its length, from 0 to S2Shape.numChains() - 1
      • getChainEdge

        public void getChainEdge​(int chainId,
                                 int offset,
                                 S2Shape.MutableEdge result)
        Description copied from interface: S2Shape
        Returns the edge for the given chain id and offset in result. Must not return zero-length edges.
        Specified by:
        getChainEdge in interface S2Shape
        Parameters:
        chainId - which chain contains the edge to return, from 0 to S2Shape.numChains() - 1
        offset - position from chain start for the edge to return, from 0 to S2Shape.getChainLength(int) - 1
      • dimension

        public int dimension()
        Description copied from interface: S2Shape
        Returns the dimension of the geometry represented by this shape.
        • 0 - Point geometry. Each point is represented as a degenerate edge.
        • 1 - Polyline geometry. Polyline edges may be degenerate. A shape may represent any number of polylines. Polylines edges may intersect.
        • 2 - Polygon geometry. Edges should be oriented such that the polygon interior is always on the left. In theory the edges may be returned in any order, but typically the edges are organized as a collection of edge chains where each chain represents one polygon loop. Polygons may have degeneracies, e.g., degenerate edges or sibling pairs consisting of an edge and its corresponding reversed edge. A polygon loop may also be full (containing all points on the sphere); by convention this is represented as a chain with no edges.

        Note that this method allows degenerate geometry of different dimensions to be distinguished, e.g., it allows a point to be distinguished from a polyline or polygon that has been simplified to a single point.

        Specified by:
        dimension in interface S2Shape
      • get

        public S2Edge get​(int index)
        Specified by:
        get in interface java.util.List<S2Edge>
        Specified by:
        get in class java.util.AbstractList<S2Edge>
      • size

        public int size()
        Specified by:
        size in interface java.util.Collection<S2Edge>
        Specified by:
        size in interface java.util.List<S2Edge>
        Specified by:
        size in class java.util.AbstractCollection<S2Edge>