AER-4255 Extended HexagonUtil to add custom rounding parameter for hexagon coordinates.

source/imaer-shared/src/main/java/nl/overheid/aerius/shared/domain/geo/HexagonUtil.java

@@ -16,6 +16,8 @@
  */
 package nl.overheid.aerius.shared.domain.geo;
 
+import java.util.function.DoubleUnaryOperator;
+
 import nl.overheid.aerius.shared.MathUtil;
 import nl.overheid.aerius.shared.domain.v2.geojson.Point;
 import nl.overheid.aerius.shared.domain.v2.geojson.Polygon;
@@ -27,6 +29,15 @@ public final class HexagonUtil {
 
   private HexagonUtil() {}
 
+  /**
+   * Returns a Geometry with a hexagon conforming to the given Point, and rounds the points of the hexagon
+   *
+   * @see #createHexagon(Point, HexagonZoomLevel, DoubleUnaryOperator)
+   */
+  public static Polygon createHexagon(final Point point, final HexagonZoomLevel config) {
+    return createHexagon(point, config, MathUtil::round);
+  }
+
   /**
    * Returns a Geometry with a hexagon conforming to the given Point and
    * HexagonConfiguration. The points of the hexagon are given in the following
@@ -43,9 +54,10 @@ private HexagonUtil() {}
    *
    * @param point Center of the hexagon
    * @param config the hexagon zoom level for level 1
+   * @param roundFunction function to round the coordinates of the hexagon with
    * @return Returns the hexagon as an AERIUS polygon
    */
-  public static Polygon createHexagon(final Point point, final HexagonZoomLevel config) {
+  public static Polygon createHexagon(final Point point, final HexagonZoomLevel config, final DoubleUnaryOperator roundFunction) {
     // Store hexagon values
     final double[] horizontal = config.getHorizontal();
     final double[] vertical = config.getVertical();
@@ -54,16 +66,16 @@ public static Polygon createHexagon(final Point point, final HexagonZoomLevel co
     // Iterate over the number of corners in a hexagon
     for (int i = 0; i < HexagonZoomLevel.HEXAGON_CORNERS; i++) {
       final double[] coordinate = new double[] {
-          MathUtil.round(point.getX() + horizontal[i]),
-          MathUtil.round(point.getY() + vertical[i])
+          roundFunction.applyAsDouble(point.getX() + horizontal[i]),
+          roundFunction.applyAsDouble(point.getY() + vertical[i])
       };
       coordinates[i] = coordinate;
     }
 
     // Polygon first and last point need to be the same
     final double[] lastCoordinate = new double[] {
-        MathUtil.round(point.getX() + horizontal[0]),
-        MathUtil.round(point.getY() + vertical[0])
+        roundFunction.applyAsDouble(point.getX() + horizontal[0]),
+        roundFunction.applyAsDouble(point.getY() + vertical[0])
     };
     coordinates[HexagonZoomLevel.HEXAGON_CORNERS] = lastCoordinate;
     final Polygon polygon = new Polygon();

source/imaer-shared/src/test/java/nl/overheid/aerius/shared/domain/geo/HexagonUtilTest.java

@@ -16,31 +16,49 @@
  */
 package nl.overheid.aerius.shared.domain.geo;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.List;
+
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 import nl.overheid.aerius.shared.domain.v2.geojson.Point;
 import nl.overheid.aerius.shared.domain.v2.geojson.Polygon;
 
 /**
  * Test class for {@link HexagonUtil}.
  */
-public class HexagonUtilTest {
+class HexagonUtilTest {
 
   private static final HexagonZoomLevel ZOOM_LEVEL_1 = new HexagonZoomLevel(1, 10000);
 
-  @Test
-  public void testCreateHexagon() {
-    assertCreateHexagon();
-    // Run twice to test if cache works.
-    assertCreateHexagon();
+  @ParameterizedTest
+  @MethodSource("createHexagon")
+  void testCreateHexagon(final boolean useDefaultMethod, final double[][][] results) {
+    final Point point = new Point(ZOOM_LEVEL_1.getHexagonRadius(), ZOOM_LEVEL_1.getHexagonHeight() / 2);
+    // When round use the default createHexagon method to test, otherwise the version with roundingFunction
+    final Polygon polygon = useDefaultMethod
+        ? HexagonUtil.createHexagon(point, ZOOM_LEVEL_1)
+        : HexagonUtil.createHexagon(point, ZOOM_LEVEL_1, d -> BigDecimal.valueOf(d).setScale(3, RoundingMode.HALF_UP).doubleValue());
+
+    Assertions.assertArrayEquals(results, polygon.getCoordinates(), "createHexagon zoom level 1");
   }
 
-  private void assertCreateHexagon() {
-    final Point point = new Point(ZOOM_LEVEL_1.getHexagonRadius(), ZOOM_LEVEL_1.getHexagonHeight() / 2);
-    final Polygon polygon = HexagonUtil.createHexagon(point, ZOOM_LEVEL_1);
+  private static List<Arguments> createHexagon() {
+    return List.of(
+        Arguments.of(false,
+            new double[][][] {{{93.06, 107.457}, {124.081, 53.728}, {93.06, 0.0}, {31.02, 0.0}, {0.0, 53.728}, {31.02, 107.457}, {93.06, 107.457}}}),
+        Arguments.of(true, new double[][][] {{{93, 107}, {124, 54}, {93, 0}, {31, 0}, {0, 54}, {31, 107}, {93, 107}}}));
+  }
 
-    Assertions.assertArrayEquals(new double[][][] {{{93, 107}, {124, 54}, {93, 0}, {31, 0}, {0, 54}, {31, 107}, {93, 107}}}, polygon.getCoordinates(),
-        "createHexagon zoom level 1");
+  @Test
+  void testGetDistanceLevelForCircle() {
+    assertEquals(2.0, HexagonUtil.getDistanceLevelForCircle(100, ZOOM_LEVEL_1), 1E-7, "Not the expected distance level for circle");
   }
 }