[PATCH] small cleanup and "fix" for CreateCircleAction

[naoliv]

Patch below does two things: use functions/methods when possible (instead calculating distances and centers by hand) and "fix" a small issue with circles that have an odd number of nodes.

An odd number of nodes creates an uneven distribution of the nodes in the circle (which we can see by using o to redistribute the nodes)

Since I am not keen to find the problematic part, I am simply adding +1 when the number is odd.
This should also make people with OCD happier (we will always have an even number of nodes now)

We didn't spot this problem before because we were always using a fixed even number of nodes (16).

src/org/openstreetmap/josm/actions/CreateCircleAction.java

@@ -161 +161 @@
 
         if (nodes.size() == 2) {
             // diameter: two single nodes needed or a way with two nodes
-            Node n1 = nodes.get(0);
-            double x1 = n1.getEastNorth().east();
-            double y1 = n1.getEastNorth().north();
-            Node n2 = nodes.get(1);
-            double x2 = n2.getEastNorth().east();
-            double y2 = n2.getEastNorth().north();
+            EastNorth n1 = nodes.get(0).getEastNorth();
+            EastNorth n2 = nodes.get(1).getEastNorth();
 
-            // calculate the center (xc/yc)
-            double xc = 0.5 * (x1 + x2);
-            double yc = 0.5 * (y1 + y2);
-            center = new EastNorth(xc, yc);
+            center = n1.getCenter(n2);
         } else {
             // triangle: three single nodes needed or a way with three nodes
             center = Geometry.getCenter(nodes);
@@ -183 +176 @@
 
         // calculate the radius (r)
         EastNorth n1 = nodes.get(0).getEastNorth();
-        double r = Math.sqrt(Math.pow(center.east()-n1.east(), 2) +
-                Math.pow(center.north()-n1.north(), 2));
+        double r = n1.distance(center);
 
         // see #10777
         LatLon ll1 = Main.getProjection().eastNorth2latlon(n1);
@@ -193 +185 @@
         double radiusInMeters = ll1.greatCircleDistance(ll2);
 
         int numberOfNodesInCircle = (int) Math.ceil(6.0 * Math.pow(radiusInMeters, 0.5));
+        // FIXME an odd number of nodes makes the distribution uneven
+        if ((numberOfNodesInCircle % 2) == 1) {
+            numberOfNodesInCircle += 1;
+        }
         if (numberOfNodesInCircle < 6) {
-           numberOfNodesInCircle = 6;
+            numberOfNodesInCircle = 6;
         }
 
         // Order nodes by angle

[bastiK]

In 12879/josm:

applied #15327 - small cleanup and "fix" for CreateCircleAction (patch by naoliv)