Fix for loss of precision issues. (#15)

Enables rounding in cases where a distance in radians calc is converted
to the internal degrees representation.
This should fix test case failures.

Author: Tyler

src/main/java/com/javadocmd/simplelatlng/window/CircularWindow.java

@@ -21,10 +21,11 @@
 import java.util.List;
 
 import com.javadocmd.simplelatlng.LatLng;
-import com.javadocmd.simplelatlng.LatLngTool;
 import com.javadocmd.simplelatlng.util.LatLngConfig;
 import com.javadocmd.simplelatlng.util.LengthUnit;
 
+import static com.javadocmd.simplelatlng.LatLngTool.distanceInRadians;
+
 /**
  * <p>
  * A circular window. Has the benefit of performing well around poles and
@@ -105,30 +106,34 @@ public <E> void filterCopySort(Collection<E> source, Collection<E> destination,
 		}
 	}
 
+	private long toDegreesInternal(Double radians) {
+		// When converting a radian distance to the internal degrees representation
+		// for the sake of comparison, rounding the result seems to be appropriate.
+		return Math.round(Math.toDegrees(radians) / LatLngConfig.DEGREE_TOLERANCE);
+	}
+
 	/**
 	 * A specialized implementation of the {@link #contains(LatLng)} check which
 	 * returns the distance from the center of the window if the window contains
 	 * the point and null if it does not. Used in
 	 * {@link #filterCopySort(Collection, Collection, FilterHelper)}.
 	 */
 	private Double containsForSort(LatLng point) {
-		double d = Math.toDegrees(LatLngTool.distanceInRadians(center, point));
-		if (LatLngConfig.doubleToLong(d) <= radius)
+		double d = distanceInRadians(center, point);
+		if (toDegreesInternal(d) <= radius)
 			return d;
 		else
 			return null;
 	}
 
 	@Override
 	public boolean contains(LatLng point) {
-		return LatLngConfig
-				.doubleToLong(Math.toDegrees(LatLngTool.distanceInRadians(center, point))) <= radius;
+		return toDegreesInternal(distanceInRadians(center, point)) <= radius;
 	}
 
 	@Override
 	public boolean overlaps(CircularWindow window) {
-		long angle = LatLngConfig.doubleToLong(Math.toDegrees(LatLngTool.distanceInRadians(
-				this.center, window.getCenter())));
+		long angle = toDegreesInternal(distanceInRadians(this.center, window.getCenter()));
 		return angle <= (this.radius + window.radius);
 	}
 

src/test/java/com/javadocmd/simplelatlng/LatLngToolTest.java

@@ -143,8 +143,7 @@ public void testDistanceInRadians() {
 	}
 
 	private static void distRadTest(double expected, LatLng point1, LatLng point2) {
-		assertEquals(expected, Math.toDegrees(distanceInRadians(point1, point2)),
-				.00001);
+		assertEquals(expected, Math.toDegrees(distanceInRadians(point1, point2)), .000001);
 	}
 
 	@Test