solve issue #2023 (getRotationColumn() returns wrong result) (#2024)

* add an automated test for issue #2023

* fix issue #2023

* LightFilterTest:  correct some camera orientations

* update the copyright years to include 2023

jme3-core/src/main/java/com/jme3/math/Quaternion.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2022 jMonkeyEngine
+ * Copyright (c) 2009-2023 jMonkeyEngine
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -651,7 +651,7 @@ public final class Quaternion implements Savable, Cloneable, java.io.Serializabl
 
         float norm = norm();
         if (norm != 1.0f) {
-            norm = FastMath.invSqrt(norm);
+            norm = 1.0f / norm;
         }
 
         float xx = x * x * norm;

jme3-core/src/test/java/com/jme3/light/LightFilterTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2009-2018 jMonkeyEngine
+ * Copyright (c) 2009-2023 jMonkeyEngine
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -134,8 +134,9 @@ public class LightFilterTest {
         checkFilteredLights(1);
         
         // Rotate the camera so it is up, light is outside frustum.
-        cam.lookAtDirection(Vector3f.UNIT_Y, Vector3f.UNIT_Y);
+        cam.lookAtDirection(Vector3f.UNIT_Y, Vector3f.UNIT_X);
         checkFilteredLights(0);
+        cam.lookAtDirection(Vector3f.UNIT_Z, Vector3f.UNIT_Y);
         
         // ==================================
         // Tests for bounding Sphere

jme3-core/src/test/java/com/jme3/math/TestIssue2023.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2023 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package com.jme3.math;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Verify that getRotationColumn() returns correct values for non-normalized
+ * Quaternions. This was issue #2023 at GitHub.
+ *
+ * @author Stephen Gold
+ */
+public class TestIssue2023 {
+
+    /**
+     * Test a couple non-normalized quaternions.
+     */
+    @Test
+    public void testIssue2023() {
+        Quaternion test1 = new Quaternion(2f, 0.5f, 1f, -0.3f);
+
+        Vector3f col0 = test1.getRotationColumn(0);
+        Assert.assertEquals(0.5318352f, col0.x, 1e-6f);
+        Assert.assertEquals(0.26217228f, col0.y, 1e-6f);
+        Assert.assertEquals(0.80524343f, col0.z, 1e-6f);
+
+        Vector3f col1 = test1.getRotationColumn(1);
+        Assert.assertEquals(0.4868914f, col1.x, 1e-6f);
+        Assert.assertEquals(-0.8726592f, col1.y, 1e-6f);
+        Assert.assertEquals(-0.03745319f, col1.z, 1e-6f);
+
+        Vector3f col2 = test1.getRotationColumn(2);
+        Assert.assertEquals(0.6928839f, col2.x, 1e-6f);
+        Assert.assertEquals(0.41198504f, col2.y, 1e-6f);
+        Assert.assertEquals(-0.5917603f, col2.z, 1e-6f);
+
+        Quaternion test2 = new Quaternion(0f, -0.2f, 0f, 0.6f);
+
+        col0 = test2.getRotationColumn(0);
+        Assert.assertEquals(0.8f, col0.x, 1e-6f);
+        Assert.assertEquals(0f, col0.y, 1e-6f);
+        Assert.assertEquals(0.6f, col0.z, 1e-6f);
+
+        col1 = test2.getRotationColumn(1);
+        Assert.assertEquals(0f, col1.x, 1e-6f);
+        Assert.assertEquals(1f, col1.y, 1e-6f);
+        Assert.assertEquals(0f, col1.z, 1e-6f);
+
+        col2 = test2.getRotationColumn(2);
+        Assert.assertEquals(-0.6f, col2.x, 1e-6f);
+        Assert.assertEquals(0f, col2.y, 1e-6f);
+        Assert.assertEquals(0.8f, col2.z, 1e-6f);
+    }
+}