Package com.google.common.geometry

Class S2RegionCoverer.ActiveCovering

  • Enclosing class:
    S2RegionCoverer
    final class S2RegionCoverer.ActiveCovering
extends java.lang.Object
    This class tracks the state of a covering while it is underway.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) java.util.PriorityQueue<S2RegionCoverer.QueueEntry> candidateQueue
      Prioritized candidates to explore next.
      (package private) int candidatesCreatedCounter
      Counter of number of candidates created, for performance evaluation.
      (package private) boolean interiorCovering
      True if we're covering the interior.
      (package private) S2Region region
      The region being covered.
      (package private) java.util.ArrayList<S2CellId> result
      Cell ids that have been added to the covering so far.

    • Constructor Summary

      Constructors 
      Constructor Description
      ActiveCovering​(boolean interior, S2Region region)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private void addCandidate​(S2RegionCoverer.Candidate candidate)
      Process a candidate by either adding it to the result list or expanding its children and inserting it into the priority queue.
      private int expandChildren​(S2RegionCoverer.Candidate candidate, S2Cell cell, int numLevels)
      Populate the children of "candidate" by expanding the given number of levels from the given cell.
      private void getCoveringInternal()
      Generates a covering and stores it in result.
      private void getInitialCandidates()
      Computes a set of initial candidates that cover the given region.
      private int maxChildrenShift()
      Return the log base 2 of the maximum number of children of a candidate.
      private S2RegionCoverer.Candidate newCandidate​(S2Cell cell)
      If the cell intersects the given region, return a new candidate with no children, otherwise return null.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • interiorCovering

        final boolean interiorCovering
        True if we're covering the interior.

      • region

        final S2Region region
        The region being covered.

      • candidatesCreatedCounter

        int candidatesCreatedCounter
        Counter of number of candidates created, for performance evaluation.

      • result

        final java.util.ArrayList<S2CellId> result
        Cell ids that have been added to the covering so far.

      • candidateQueue

        final java.util.PriorityQueue<S2RegionCoverer.QueueEntry> candidateQueue
        Prioritized candidates to explore next.

    • Constructor Detail

      • ActiveCovering

        ActiveCovering​(boolean interior,
               S2Region region)

    • Method Detail

      • newCandidate

        private S2RegionCoverer.Candidate newCandidate​(S2Cell cell)
        If the cell intersects the given region, return a new candidate with no children, otherwise return null. Also marks the candidate as "terminal" if it should not be expanded further.

      • maxChildrenShift

        private int maxChildrenShift()
        Return the log base 2 of the maximum number of children of a candidate.

      • addCandidate

        private void addCandidate​(S2RegionCoverer.Candidate candidate)
        Process a candidate by either adding it to the result list or expanding its children and inserting it into the priority queue. Passing a null argument does nothing.

      • expandChildren

        private int expandChildren​(S2RegionCoverer.Candidate candidate,
                           S2Cell cell,
                           int numLevels)
        Populate the children of "candidate" by expanding the given number of levels from the given cell. Returns the number of children that were marked "terminal".

      • getInitialCandidates

        private void getInitialCandidates()
        Computes a set of initial candidates that cover the given region.

      • getCoveringInternal

        private void getCoveringInternal()
        Generates a covering and stores it in result.