Various fixes

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

@@ -34,6 +34,17 @@ public ComponentJumpChecker(Collection<TaggedLineString> taggedLines) {
     components = taggedLines;
   }
 
+  /**
+   * Checks if a line section jumps a component if flattened.
+   * 
+   * Assumes start <= end.
+   * 
+   * @param line the line containing the section being flattened
+   * @param start start index of the section
+   * @param end end index of the section
+   * @param seg the flattening segment
+   * @return true if the flattened section jumps a component
+   */
   public boolean hasJump(TaggedLineString line, int start, int end, LineSegment seg) {
     Envelope sectionEnv = computeEnvelope(line, start, end);
     for (TaggedLineString comp : components) {
@@ -51,6 +62,18 @@ public boolean hasJump(TaggedLineString line, int start, int end, LineSegment se
     return false;
   }
 
+  /**
+   * Checks if two consecutive segments jumps a component if flattened.
+   * The segments are assumed to be consecutive.
+   * (so the seg1.p1 = seg2.p0).
+   * The flattening segment must be the segment between seg1.p0 and seg2.p1.
+   * 
+   * @param line the line containing the section being flattened
+   * @param seg1 the first replaced segment
+   * @param seg2 the next replaced segment
+   * @param seg the flattening segment
+   * @return true if the flattened segment jumps a component
+   */
   public boolean hasJump(TaggedLineString line, LineSegment seg1, LineSegment seg2, LineSegment seg) {
     Envelope sectionEnv = computeEnvelope(seg1, seg2);
     for (TaggedLineString comp : components) {

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

@@ -52,13 +52,13 @@ public void remove(LineSegment seg)
     index.remove(new Envelope(seg.p0, seg.p1), seg);
   }
 
-  public List query(LineSegment querySeg)
+  public List<Object> query(LineSegment querySeg)
   {
     Envelope env = new Envelope(querySeg.p0, querySeg.p1);
 
     LineSegmentVisitor visitor = new LineSegmentVisitor(querySeg);
     index.query(env, visitor);
-    List itemsFound = visitor.getItems();
+    List<Object> itemsFound = visitor.getItems();
 
 //    List listQueryItems = index.query(env);
 //    System.out.println("visitor size = " + itemsFound.size()
@@ -78,7 +78,7 @@ class LineSegmentVisitor
 // MD - only seems to make about a 10% difference in overall time.
 
   private LineSegment querySeg;
-  private ArrayList items = new ArrayList();
+  private ArrayList<Object> items = new ArrayList<Object>();
 
   public LineSegmentVisitor(LineSegment querySeg) {
     this.querySeg = querySeg;
@@ -91,5 +91,5 @@ public void visitItem(Object item)
       items.add(item);
   }
 
-  public ArrayList getItems() { return items; }
+  public ArrayList<Object> getItems() { return items; }
 }

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

@@ -32,23 +32,23 @@ class TaggedLineString
 
   private LineString parentLine;
   private TaggedLineSegment[] segs;
-  private List resultSegs = new ArrayList();
+  private List<LineSegment> resultSegs = new ArrayList<LineSegment>();
   private int minimumSize;
-  private boolean isPreserveEndpoint = true;
+  private boolean isKeepEndpoint = true;
 
   public TaggedLineString(LineString parentLine) {
     this(parentLine, 2, true);
   }
 
-  public TaggedLineString(LineString parentLine, int minimumSize, boolean isPreserveEndpoint) {
+  public TaggedLineString(LineString parentLine, int minimumSize, boolean isKeepEndpoint) {
     this.parentLine = parentLine;
     this.minimumSize = minimumSize;
-    this.isPreserveEndpoint = isPreserveEndpoint;
+    this.isKeepEndpoint = isKeepEndpoint;
     init();
   }
 
-  public boolean isPreserveEndpoint() {
-    return isPreserveEndpoint;
+  public boolean isKeepEndpoint() {
+    return isKeepEndpoint;
   }
 
   public int getMinimumSize()  {    return minimumSize;  }
@@ -124,7 +124,7 @@ public LinearRing asLinearRing() {
     return parentLine.getFactory().createLinearRing(extractCoordinates(resultSegs));
   }
 
-  private static Coordinate[] extractCoordinates(List segs)
+  private static Coordinate[] extractCoordinates(List<LineSegment> segs)
   {
     Coordinate[] pts = new Coordinate[segs.size() + 1];
     LineSegment seg = null;

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

@@ -72,7 +72,7 @@ void simplify(TaggedLineString line)
     linePts = line.getParentCoordinates();
     simplifySection(0, linePts.length - 1, 0);
 
-    if (! line.isPreserveEndpoint() && CoordinateArrays.isRing(linePts)) {
+    if (! line.isKeepEndpoint() && CoordinateArrays.isRing(linePts)) {
       simplifyRingEndpoint();
     }
   }
@@ -130,8 +130,8 @@ private void simplifySection(int i, int j, int depth)
 
   /**
    * Simplifies the result segments on either side of a ring endpoint
-   * (which has not been changed by prior simplification).
-   * This ensures that simplification removes flat endpoints.
+   * (which was not processed by the initial simplification).
+   * This ensures that simplification removes flat (collinear) endpoints.
    */
   private void simplifyRingEndpoint()
   {

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

@@ -89,7 +89,7 @@ public static Geometry simplify(Geometry geom, double distanceTolerance)
 
   private Geometry inputGeom;
   private TaggedLinesSimplifier lineSimplifier = new TaggedLinesSimplifier();
-  private Map linestringMap;
+  private Map<LineString, TaggedLineString> linestringMap;
 
   public TopologyPreservingSimplifier(Geometry inputGeom)
   {
@@ -116,7 +116,7 @@ public Geometry getResultGeometry()
     // empty input produces an empty result
     if (inputGeom.isEmpty()) return inputGeom.copy();
 
-    linestringMap = new HashMap();
+    linestringMap = new HashMap<LineString, TaggedLineString>();
     inputGeom.apply(new LineStringMapBuilderFilter(this));
     lineSimplifier.simplify(linestringMap.values());
     Geometry result = (new LineStringTransformer(linestringMap)).transform(inputGeom);
@@ -126,9 +126,9 @@ public Geometry getResultGeometry()
   static class LineStringTransformer
       extends GeometryTransformer
   {
-    private Map linestringMap;
+    private Map<LineString, TaggedLineString> linestringMap;
 
-    public LineStringTransformer(Map linestringMap) {
+    public LineStringTransformer(Map<LineString, TaggedLineString> linestringMap) {
       this.linestringMap = linestringMap;
     }
 
@@ -137,7 +137,7 @@ protected CoordinateSequence transformCoordinates(CoordinateSequence coords, Geo
       if (coords.size() == 0) return null;
     	// for linear components (including rings), simplify the linestring
       if (parent instanceof LineString) {
-        TaggedLineString taggedLine = (TaggedLineString) linestringMap.get(parent);
+        TaggedLineString taggedLine = linestringMap.get(parent);
         return createCoordinateSequence(taggedLine.getResultCoordinates());
       }
       // for anything else (e.g. points) just copy the coordinates
@@ -178,8 +178,8 @@ public void filter(Geometry geom)
         if (line.isEmpty()) return;
 
         int minSize = ((LineString) line).isClosed() ? 4 : 2;
-        boolean isPreserveEndpoint = (line instanceof LinearRing) ? false : true;
-        TaggedLineString taggedLine = new TaggedLineString((LineString) line, minSize, isPreserveEndpoint);
+        boolean isKeepEndpoint = (line instanceof LinearRing) ? false : true;
+        TaggedLineString taggedLine = new TaggedLineString((LineString) line, minSize, isKeepEndpoint);
         tps.linestringMap.put(line, taggedLine);
       }
     }