Enable ring-endpoint-handling for LineString with isRing() == true

modules/core/src/main/java/org/locationtech/jts/simplify/DouglasPeuckerLineSimplifier.java

@@ -33,7 +33,7 @@ public static Coordinate[] simplify(Coordinate[] pts, double distanceTolerance,
     return simp.simplify();
   }
 
-  private Coordinate[] pts;
+  private final Coordinate[] pts;
   private boolean[] usePt;
   private double distanceTolerance;
   private boolean isPreserveEndpoint = false;
@@ -56,21 +56,21 @@ public void setDistanceTolerance(double distanceTolerance) {
   private void setPreserveEndpoint(boolean isPreserveEndpoint) {
     this.isPreserveEndpoint  = isPreserveEndpoint;
   }
-  
+
   public Coordinate[] simplify()
   {
     usePt = new boolean[pts.length];
     for (int i = 0; i < pts.length; i++) {
       usePt[i] = true;
     }
     simplifySection(0, pts.length - 1);
-    
+
     CoordinateList coordList = new CoordinateList();
     for (int i = 0; i < pts.length; i++) {
       if (usePt[i])
         coordList.add(new Coordinate(pts[i]));
     }
-    
+
     if (! isPreserveEndpoint && CoordinateArrays.isRing(pts)) {
       simplifyRingEndpoint(coordList);
     }
@@ -84,7 +84,7 @@ private void simplifyRingEndpoint(CoordinateList pts) {
       return;
     //-- base segment for endpoint
     seg.p0 = pts.get(1);
-    seg.p1 = pts.get(pts.size() - 2); 
+    seg.p1 = pts.get(pts.size() - 2);
     double distance = seg.distance(pts.get(0));
     if (distance <= distanceTolerance) {
       pts.remove(0);
@@ -93,7 +93,7 @@ private void simplifyRingEndpoint(CoordinateList pts) {
     }
   }
 
-  private LineSegment seg = new LineSegment();
+  private final LineSegment seg = new LineSegment();
 
   private void simplifySection(int i, int j)
   {

modules/core/src/main/java/org/locationtech/jts/simplify/DouglasPeuckerSimplifier.java

@@ -24,7 +24,7 @@
  * Simplifies a {@link Geometry} using the Douglas-Peucker algorithm.
  * Ensures that any polygonal geometries returned are valid.
  * Simple lines are not guaranteed to remain simple after simplification.
- * All geometry types are handled. 
+ * All geometry types are handled.
  * Empty and point geometries are returned unchanged.
  * Empty geometry components are deleted.
  * <p>
@@ -49,7 +49,7 @@ public class DouglasPeuckerSimplifier
 
   /**
    * Simplifies a geometry using a given tolerance.
-   * 
+   *
    * @param geom geometry to simplify
    * @param distanceTolerance the tolerance to use
    * @return a simplified version of the geometry
@@ -61,13 +61,13 @@ public static Geometry simplify(Geometry geom, double distanceTolerance)
     return tss.getResultGeometry();
   }
 
-  private Geometry inputGeom;
+  private final Geometry inputGeom;
   private double distanceTolerance;
   private boolean isEnsureValidTopology = true;
-  
+
   /**
    * Creates a simplifier for a given geometry.
-   * 
+   *
    * @param inputGeom the geometry to simplify
    */
   public DouglasPeuckerSimplifier(Geometry inputGeom)
@@ -79,7 +79,7 @@ public DouglasPeuckerSimplifier(Geometry inputGeom)
    * Sets the distance tolerance for the simplification.
    * All vertices in the simplified geometry will be within this
    * distance of the original geometry.
-   * The tolerance value must be non-negative. 
+   * The tolerance value must be non-negative.
    *
    * @param distanceTolerance the approximation tolerance to use
    */
@@ -98,46 +98,46 @@ public void setDistanceTolerance(double distanceTolerance) {
    * <li>fixing topology is a relative expensive operation
    * <li>in some pathological cases the topology fixing operation may either fail or run for too long
    * </ul>
-   * 
+   *
    * The default is to fix polygon topology.
-   * 
+   *
    * @param isEnsureValidTopology
    */
   public void setEnsureValid(boolean isEnsureValidTopology)
   {
   	this.isEnsureValidTopology = isEnsureValidTopology;
   }
-  
+
   /**
    * Gets the simplified geometry.
-   * 
+   *
    * @return the simplified geometry
    */
   public Geometry getResultGeometry()
   {
     // empty input produces an empty result
     if (inputGeom.isEmpty()) return inputGeom.copy();
-    
+
     return (new DPTransformer(isEnsureValidTopology, distanceTolerance)).transform(inputGeom);
   }
 
 static class DPTransformer
     extends GeometryTransformer
 {
-  private boolean isEnsureValidTopology = true;
-  private double distanceTolerance;
+  private final boolean isEnsureValidTopology;
+  private final double distanceTolerance;
 
 	public DPTransformer(boolean isEnsureValidTopology, double distanceTolerance)
 	{
 		this.isEnsureValidTopology = isEnsureValidTopology;
 		this.distanceTolerance = distanceTolerance;
 	}
-	
+
   protected CoordinateSequence transformCoordinates(CoordinateSequence coords, Geometry parent)
   {
     boolean isPreserveEndpoint = ! (parent instanceof LinearRing);
     Coordinate[] inputPts = coords.toCoordinateArray();
-    Coordinate[] newPts = null;
+    Coordinate[] newPts;
     if (inputPts.length == 0) {
       newPts = new Coordinate[0];
     }
@@ -163,22 +163,20 @@ protected Geometry transformPolygon(Polygon geom, Geometry parent) {
   }
 
   /**
-   * Simplifies a LinearRing.  If the simplification results 
+   * Simplifies a LinearRing.  If the simplification results
    * in a degenerate ring, remove the component.
-   * 
+   *
    * @return null if the simplification results in a degenerate ring
    */
-  //*
-  protected Geometry transformLinearRing(LinearRing geom, Geometry parent) 
+  protected Geometry transformLinearRing(LinearRing geom, Geometry parent)
   {
   	boolean removeDegenerateRings = parent instanceof Polygon;
   	Geometry simpResult = super.transformLinearRing(geom, parent);
   	if (removeDegenerateRings && ! (simpResult instanceof LinearRing))
   		return null;
   	return simpResult;
   }
-  //*/
-
+
   /**
    * Simplifies a MultiPolygon, fixing it if required.
    */
@@ -195,8 +193,8 @@ protected Geometry transformMultiPolygon(MultiPolygon geom, Geometry parent) {
    * topology.
    * Note this only works for area geometries, since buffer always returns
    * areas.  This also may return empty geometries, if the input
-   * has no actual area.  
-   * If the input is empty or is not polygonal, 
+   * has no actual area.
+   * If the input is empty or is not polygonal,
    * this ensures that POLYGON EMPTY is returned.
    *
    * @param rawAreaGeom an area geometry possibly containing self-intersections

modules/core/src/main/java/org/locationtech/jts/simplify/TaggedLineString.java

@@ -21,20 +21,20 @@
 import org.locationtech.jts.geom.LinearRing;
 
 /**
- * Represents a {@link LineString} which can be modified to a simplified shape.  
+ * Represents a {@link LineString} which can be modified to a simplified shape.
  * This class provides an attribute which specifies the minimum allowable length
  * for the modified result.
- * 
+ *
  * @version 1.7
  */
 class TaggedLineString
 {
 
-  private LineString parentLine;
+  private final LineString parentLine;
   private TaggedLineSegment[] segs;
-  private List<LineSegment> resultSegs = new ArrayList<LineSegment>();
-  private int minimumSize;
-  private boolean isRing = true;
+  private final List<LineSegment> resultSegs = new ArrayList<LineSegment>();
+  private final int minimumSize;
+  private final boolean isRing;
 
   public TaggedLineString(LineString parentLine, int minimumSize, boolean isRing) {
     this.parentLine = parentLine;
@@ -46,8 +46,8 @@ public TaggedLineString(LineString parentLine, int minimumSize, boolean isRing)
   public boolean isRing() {
     return isRing;
   }
-  
-  public int getMinimumSize()  {    return minimumSize;  }
+
+  public int getMinimumSize()  { return minimumSize; }
   public LineString getParent() { return parentLine; }
   public Coordinate[] getParentCoordinates() { return parentLine.getCoordinates(); }
   public Coordinate[] getResultCoordinates() { return extractCoordinates(resultSegs); }
@@ -59,11 +59,11 @@ public Coordinate getCoordinate(int i) {
   public int size() {
     return parentLine.getNumPoints();
   }
-  
+
   public Coordinate getComponentPoint() {
     return getParentCoordinates()[1];
   }
-  
+
   public int getResultSize()
   {
     int resultSegsSize = resultSegs.size();
@@ -78,12 +78,11 @@ public int getResultSize()
    * @param i the segment index to retrieve
    * @return the result segment
    */
-  public LineSegment getResultSegment(int i) { 
-    int index = i;
+  public LineSegment getResultSegment(int i) {
     if (i < 0) {
-      index = resultSegs.size() + i;
+      i = resultSegs.size() + i;
     }
-    return (LineSegment) resultSegs.get(index);
+    return resultSegs.get(i);
   }
 
   private void init()
@@ -103,7 +102,7 @@ private void init()
    * Add a simplified segment to the result.
    * This assumes simplified segments are computed in the order
    * they occur in the line.
-   * 
+   *
    * @param seg the result segment to add
    */
   public void addToResult(LineSegment seg)
@@ -125,7 +124,7 @@ private static Coordinate[] extractCoordinates(List<LineSegment> segs)
     Coordinate[] pts = new Coordinate[segs.size() + 1];
     LineSegment seg = null;
     for (int i = 0; i < segs.size(); i++) {
-      seg = (LineSegment) segs.get(i);
+      seg = segs.get(i);
       pts[i] = seg.p0;
     }
     // add last point
@@ -135,8 +134,8 @@ private static Coordinate[] extractCoordinates(List<LineSegment> segs)
 
   void removeRingEndpoint()
   {
-    LineSegment firstSeg = (LineSegment) resultSegs.get(0);
-    LineSegment lastSeg = (LineSegment) resultSegs.get(resultSegs.size() - 1);
+    LineSegment firstSeg = resultSegs.get(0);
+    LineSegment lastSeg = resultSegs.get(resultSegs.size() - 1);
 
     firstSeg.p0 = lastSeg.p0;
     resultSegs.remove(resultSegs.size() - 1);