How to use

multiplyLocal

method

in

com.ardor3d.math.Vector4

/**
 * @return same as multiplyLocal(-1)
 */
public Vector4 negateLocal() {
  return multiplyLocal(-1);
}

/**
 * @return same as multiplyLocal(-1)
 */
public Vector4 negateLocal() {
  return multiplyLocal(-1);
}

/**
 * Converts this vector into a unit vector by dividing it internally by its length. If the length is 0, (ie, if the
 * vector is 0, 0, 0, 0) then no action is taken.
 * 
 * @return this vector for chaining
 */
public Vector4 normalizeLocal() {
  final double lengthSq = lengthSquared();
  if (Math.abs(lengthSq) > MathUtils.EPSILON) {
    return multiplyLocal(MathUtils.inverseSqrt(lengthSq));
  }
  return this;
}

/**
 * Converts this vector into a unit vector by dividing it internally by its length. If the length is 0, (ie, if the
 * vector is 0, 0, 0, 0) then no action is taken.
 * 
 * @return this vector for chaining
 */
public Vector4 normalizeLocal() {
  final double lengthSq = lengthSquared();
  if (Math.abs(lengthSq) > MathUtils.EPSILON) {
    return multiplyLocal(MathUtils.inverseSqrt(lengthSq));
  }
  return this;
}

/**
 * Multiply and store a Vector3 in-buffer.
 * 
 * @param toMult
 *            the vector to multiply against
 * @param buf
 *            the buffer to find the Vector3 within
 * @param index
 *            the position (in terms of vectors, not floats) of the vector to multiply
 */
public static void multInBuffer(final ReadOnlyVector4 toMult, final FloatBuffer buf, final int index) {
  final Vector4 temp = Vector4.fetchTempInstance();
  populateFromBuffer(temp, buf, index);
  temp.multiplyLocal(toMult);
  setInBuffer(temp, buf, index);
  Vector4.releaseTempInstance(temp);
}

/**
 * Multiply and store a Vector3 in-buffer.
 * 
 * @param toMult
 *            the vector to multiply against
 * @param buf
 *            the buffer to find the Vector3 within
 * @param index
 *            the position (in terms of vectors, not floats) of the vector to multiply
 */
public static void multInBuffer(final ReadOnlyVector4 toMult, final FloatBuffer buf, final int index) {
  final Vector4 temp = Vector4.fetchTempInstance();
  populateFromBuffer(temp, buf, index);
  temp.multiplyLocal(toMult);
  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);
}

public Vector3 getNormalizedDeviceCoordinates(final ReadOnlyVector3 worldPosition, Vector3 store) {
  if (store == null) {
    store = new Vector3();
  }
  checkModelViewProjection();
  final Vector4 position = Vector4.fetchTempInstance();
  position.set(worldPosition.getX(), worldPosition.getY(), worldPosition.getZ(), 1);
  _modelViewProjection.applyPre(position, position);
  position.multiplyLocal(1.0 / position.getW());
  store.setX(position.getX());
  store.setY(position.getY());
  store.setZ(position.getZ());
  Vector4.releaseTempInstance(position);
  return store;
}

public Vector3 getNormalizedDeviceCoordinates(final ReadOnlyVector3 worldPosition, Vector3 store) {
  if (store == null) {
    store = new Vector3();
  }
  checkModelViewProjection();
  final Vector4 position = Vector4.fetchTempInstance();
  position.set(worldPosition.getX(), worldPosition.getY(), worldPosition.getZ(), 1);
  _modelViewProjection.applyPre(position, position);
  position.multiplyLocal(1.0 / position.getW());
  store.setX(position.getX());
  store.setY(position.getY());
  store.setZ(position.getZ());
  Vector4.releaseTempInstance(position);
  return store;
}

    zDepth * 2 - 1, 1);
_modelViewProjectionInverse.applyPre(position, position);
position.multiplyLocal(1.0 / position.getW());
store.setX(position.getX());
store.setY(position.getY());

    zDepth * 2 - 1, 1);
_modelViewProjectionInverse.applyPre(position, position);
position.multiplyLocal(1.0 / position.getW());
store.setX(position.getX());
store.setY(position.getY());

@Test
public void testMultiply() {
  final Vector4 vec1 = new Vector4(1, -1, 2, -2);
  final Vector4 vec2 = vec1.multiply(2.0, null);
  final Vector4 vec2B = vec1.multiply(2.0, new Vector4());
  assertEquals(new Vector4(2.0, -2.0, 4.0, -4.0), vec2);
  assertEquals(new Vector4(2.0, -2.0, 4.0, -4.0), vec2B);
  vec2.multiplyLocal(0.5);
  assertEquals(new Vector4(1.0, -1.0, 2.0, -2.0), vec2);
  final Vector4 vec3 = vec1.multiply(vec2, null);
  final Vector4 vec3B = vec1.multiply(vec2, new Vector4());
  assertEquals(new Vector4(1, 1, 4, 4), vec3);
  assertEquals(new Vector4(1, 1, 4, 4), vec3B);
  final Vector4 vec4 = vec1.multiply(2, 3, 2, 3, null);
  final Vector4 vec4B = vec1.multiply(2, 3, 2, 3, new Vector4());
  assertEquals(new Vector4(2, -3, 4, -6), vec4);
  assertEquals(new Vector4(2, -3, 4, -6), vec4B);
  vec1.multiplyLocal(0.5, 0.5, 0.5, 0.5);
  assertEquals(new Vector4(0.5, -0.5, 1.0, -1.0), vec1);
  vec1.multiplyLocal(vec2);
  assertEquals(new Vector4(0.5, 0.5, 2.0, 2.0), vec1);
}