Class S2Edge

java.lang.Object
com.google.common.geometry.S2Edge
All Implemented Interfaces:
S2Shape, Serializable

@GwtCompatible(serializable=true) public final class S2Edge extends Object implements Serializable, S2Shape
An abstract directed edge from one S2Point to another S2Point.
See Also:
  • Field Details

  • Constructor Details

  • Method Details

    • getStart

      public S2Point getStart()
    • getEnd

      public S2Point getEnd()
    • toString

      public String toString()
      Overrides:
      toString in class Object
    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object
    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object
    • numEdges

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

      public S2Point getChainVertex(int chainId, int edgeOffset)
      Description copied from interface: S2Shape
      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).
      Specified by:
      getChainVertex in interface S2Shape
    • 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