How to use

normalizeLocal

method

in

com.ardor3d.math.Vector4

/**
 * Normalize a Vector4 in-buffer.
 * 
 * @param buf
 *            the buffer to find the Vector4 within
 * @param index
 *            the position (in terms of vectors, not floats) of the vector to normalize
 */
public static void normalizeVector4(final FloatBuffer buf, final int index) {
  final Vector4 temp = Vector4.fetchTempInstance();
  populateFromBuffer(temp, buf, index);
  temp.normalizeLocal();
  setInBuffer(temp, buf, index);
  Vector4.releaseTempInstance(temp);
}

/**
 * Normalize a Vector4 in-buffer.
 * 
 * @param buf
 *            the buffer to find the Vector4 within
 * @param index
 *            the position (in terms of vectors, not floats) of the vector to normalize
 */
public static void normalizeVector4(final FloatBuffer buf, final int index) {
  final Vector4 temp = Vector4.fetchTempInstance();
  populateFromBuffer(temp, buf, index);
  temp.normalizeLocal();
  setInBuffer(temp, buf, index);
  Vector4.releaseTempInstance(temp);
}

private void calculateIntersection(final double planeHeight, final ReadOnlyVector2 screenPosition,
    final ReadOnlyMatrix4 modelViewProjectionInverseMatrix) {
  origin.set(screenPosition.getX() * 2 - 1, screenPosition.getY() * 2 - 1, -1, 1);
  direction.set(screenPosition.getX() * 2 - 1, screenPosition.getY() * 2 - 1, 1, 1);
  modelViewProjectionInverseMatrix.applyPre(origin, origin);
  modelViewProjectionInverseMatrix.applyPre(direction, direction);
  direction.subtractLocal(origin);
  // final double t = (planeHeight * origin.getW() - origin.getY())
  // / (direction.getY() - planeHeight * direction.getW());
  if (Math.abs(direction.getY()) > MathUtils.EPSILON) {
    final double t = (planeHeight - origin.getY()) / direction.getY();
    direction.multiplyLocal(t);
  } else {
    direction.normalizeLocal();
    direction.multiplyLocal(mainCamera.getFrustumFar());
  }
  origin.addLocal(direction);
}

private void calculateIntersection(final double planeHeight, final ReadOnlyVector2 screenPosition,
    final ReadOnlyMatrix4 modelViewProjectionInverseMatrix) {
  origin.set(screenPosition.getX() * 2 - 1, screenPosition.getY() * 2 - 1, -1, 1);
  direction.set(screenPosition.getX() * 2 - 1, screenPosition.getY() * 2 - 1, 1, 1);
  modelViewProjectionInverseMatrix.applyPre(origin, origin);
  modelViewProjectionInverseMatrix.applyPre(direction, direction);
  direction.subtractLocal(origin);
  // final double t = (planeHeight * origin.getW() - origin.getY())
  // / (direction.getY() - planeHeight * direction.getW());
  if (Math.abs(direction.getY()) > MathUtils.EPSILON) {
    final double t = (planeHeight - origin.getY()) / direction.getY();
    direction.multiplyLocal(t);
  } else {
    direction.normalizeLocal();
    direction.multiplyLocal(mainCamera.getFrustumFar());
  }
  origin.addLocal(direction);
}

@Test
public void testNormalize() {
  final Vector4 vec1 = new Vector4(2, 1, 3, -1);
  assertTrue(vec1.length() == Math.sqrt(15));
  final Vector4 vec2 = vec1.normalize(null);
  final double invLength = MathUtils.inverseSqrt(2 * 2 + 1 * 1 + 3 * 3 + -1 * -1);
  assertEquals(new Vector4(2 * invLength, 1 * invLength, 3 * invLength, -1 * invLength), vec2);
  vec1.normalizeLocal();
  assertEquals(new Vector4(2 * invLength, 1 * invLength, 3 * invLength, -1 * invLength), vec1);
  vec1.zero();
  vec1.normalize(vec2);
  assertEquals(vec1, vec2);
  // ensure no exception thrown
  vec1.normalizeLocal();
  vec1.normalize(null);
}