Correct use of xy array

Author: bjornharrtell

modules/core/src/main/java/org/locationtech/jts/geom/impl/PackedCoordinateSequence.java

@@ -464,9 +464,8 @@ public Double2(Coordinate[] coordinates, int dimension, int measures) {
 
       xy = new double[coordinates.length];
       for (int i = 0; i < coordinates.length; i++) {
-        int offset = i * 2;
-        xy[offset] = coordinates[i].x;
-        xy[offset + 1] = coordinates[i].y;
+        xy[i * 2] = coordinates[i].x;
+        xy[i * 2 + 1] = coordinates[i].y;
         if (dimension == 3)
           z[i] = coordinates[i].getOrdinate(2);
         if (measures == 1)
@@ -502,8 +501,8 @@ public Double2(int size, int dimension, int measures) {
      * @see PackedCoordinateSequence#getCoordinate(int)
      */
     public Coordinate getCoordinateInternal(int i) {
-      double x = xy[i * dimension];
-      double y = xy[i * dimension + 1];
+      double x = xy[i * 2];
+      double y = xy[i * 2 + 1];
       if( dimension == 2 && measures == 0 ) {
         return new CoordinateXY(x,y);
       }