## com.vividsolutions.jts.operation.buffer
Class BufferSubgraph

    java.lang.Object
      com.vividsolutions.jts.operation.buffer.BufferSubgraph

All Implemented Interfaces:
  java.lang.Comparable

public class BufferSubgraph
extends java.lang.Object
implements java.lang.Comparable

A connected subset of the graph of `DirectedEdge`s and `Node`s. Its edges will generate either

- a single polygon in the complete buffer, with zero or more holes, or
- one or more connected holes

Version:
  1.7

Constructor Summary
`BufferSubgraph(CGAlgorithms cga)`

Method Summary
`int` `compareTo(java.lang.Object o)` BufferSubgraphs are compared on the x-value of their rightmost Coordinate.
`void` `computeDepth(int outsideDepth)`
`void` `create(Node node)` Creates the subgraph consisting of all edges reachable from this node.
`void` `findResultEdges()` Find all edges whose depths indicates that they are in the result area(s).
`java.util.List` `getDirectedEdges()`
`Envelope` `getEnvelope()` Computes the envelope of the edges in the subgraph.
`java.util.List` `getNodes()`
`Coordinate` `getRightmostCoordinate()` Gets the rightmost coordinate in the edges of the subgraph

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### BufferSubgraph

    public BufferSubgraph(CGAlgorithms cga)

Method Detail

### getDirectedEdges

    public java.util.List getDirectedEdges()

### getNodes

    public java.util.List getNodes()

### getEnvelope

    public Envelope getEnvelope()

  Computes the envelope of the edges in the subgraph. The envelope is cached after being computed.

  Returns:
    the envelope of the graph.

### getRightmostCoordinate

    public Coordinate getRightmostCoordinate()

  Gets the rightmost coordinate in the edges of the subgraph

### create

    public void create(Node node)

  Creates the subgraph consisting of all edges reachable from this node. Finds the edges in the graph and the rightmost coordinate.

  Parameters:
    `node` - a node to start the graph traversal from

### computeDepth

    public void computeDepth(int outsideDepth)

### findResultEdges

    public void findResultEdges()

  Find all edges whose depths indicates that they are in the result area(s). Since we want polygon shells to be oriented CW, choose dirEdges with the interior of the result on the RHS. Mark them as being in the result. Interior Area edges are the result of dimensional collapses. They do not form part of the result area boundary.

### compareTo

    public int compareTo(java.lang.Object o)

  BufferSubgraphs are compared on the x-value of their rightmost Coordinate. This defines a partial ordering on the graphs such that:

  g1 >= g2 <==> Ring(g2) does not contain Ring(g1)

  where Polygon(g) is the buffer polygon that is built from g.

  This relationship is used to sort the BufferSubgraphs so that shells are guaranteed to be built before holes.

  Specified by:
    `compareTo` in interface `java.lang.Comparable`