/**
* Sets the spring frequency.
*
* @param frequency the spring frequency in hz; must be greater than or equal to zero
* @throws IllegalArgumentException if frequency is less than zero
*/
public void setFrequency(double frequency) {
// check for valid value
if (frequency < 0)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.invalidFrequency"));
// set the new value
this.frequency = frequency;
}
/**
* Sets the damping ratio.
*
* @param dampingRatio the damping ratio; in the range [0, 1]
* @throws IllegalArgumentException if damping ration is less than zero or greater than 1
*/
public void setDampingRatio(double dampingRatio) {
// make sure its within range
if (dampingRatio < 0 || dampingRatio > 1)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.invalidDampingRatio"));
// set the new value
this.dampingRatio = dampingRatio;
}
/**
* Minimal constructor.
*
* <p>Creates a fixed distance {@link Joint} where the joined {@link Body}s do not participate in
* collision detection and resolution.
*
* @param body1 the first {@link Body}
* @param body2 the second {@link Body}
* @param anchor1 in world coordinates
* @param anchor2 in world coordinates
* @throws NullPointerException if body1, body2, anchor1, or anchor2 is null
* @throws IllegalArgumentException if body1 == body2
*/
public DistanceJoint(Body body1, Body body2, Vector2 anchor1, Vector2 anchor2) {
super(body1, body2, false);
// verify the bodies are not the same instance
if (body1 == body2)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.sameBody"));
// verify the anchor points are not null
if (anchor1 == null)
throw new NullPointerException(Messages.getString("dynamics.joint.nullAnchor1"));
if (anchor2 == null)
throw new NullPointerException(Messages.getString("dynamics.joint.nullAnchor2"));
// get the local anchor points
this.localAnchor1 = body1.getLocalPoint(anchor1);
this.localAnchor2 = body2.getLocalPoint(anchor2);
// compute the initial distance
this.distance = anchor1.distance(anchor2);
}
/**
* Sets the lower limit in radians.
*
* <p>See the class documentation for more details on the limit ranges.
*
* @param lowerLimit the lower limit in radians
* @throws IllegalArgumentException if lowerLimit is greater than the current upper limit
*/
public void setLowerLimit(double lowerLimit) {
// make sure the minimum is less than or equal to the maximum
if (lowerLimit > this.upperLimit)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.invalidLowerLimit"));
// wake up both bodies
this.body1.setAsleep(false);
this.body2.setAsleep(false);
// set the new target angle
this.lowerLimit = lowerLimit;
}
/**
* Sets both the lower and upper limits.
*
* <p>See the class documentation for more details on the limit ranges.
*
* @param lowerLimit the lower limit in radians
* @param upperLimit the upper limit in radians
* @throws IllegalArgumentException if lowerLimit is greater than upperLimit
*/
public void setLimits(double lowerLimit, double upperLimit) {
// make sure the min < max
if (lowerLimit > upperLimit)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.invalidLimits"));
// wake up the bodies
this.body1.setAsleep(false);
this.body2.setAsleep(false);
// set the limits
this.upperLimit = upperLimit;
this.lowerLimit = lowerLimit;
}
/**
* Sets the rest distance between the two constrained {@link Body}s in meters.
*
* @param distance the distance in meters
* @throws IllegalArgumentException if distance is less than zero
*/
public void setDistance(double distance) {
// make sure the distance is greater than zero
if (distance < 0.0)
throw new IllegalArgumentException(
Messages.getString("dynamics.joint.distance.invalidDistance"));
// wake up both bodies
this.body1.setAsleep(false);
this.body2.setAsleep(false);
// set the new target distance
this.distance = distance;
}
/**
* Full constructor.
*
* @param comparable the comparable object
* @param parent the parent node
* @param left the left node
* @param right the right node
* @throws NullPointerException if comparable is null
*/
public BinarySearchTreeNode(
E comparable,
BinarySearchTreeNode<E> parent,
BinarySearchTreeNode<E> left,
BinarySearchTreeNode<E> right) {
if (comparable == null)
throw new NullPointerException(Messages.getString("binarySearchTree.nullComparable"));
this.comparable = comparable;
this.parent = parent;
this.left = left;
this.right = right;
}
/**
* Minimal constructor.
*
* @param body1 the first {@link Body}
* @param body2 the second {@link Body}
* @throws NullPointerException if body1 or body2 is null
* @throws IllegalArgumentException if body1 == body2
*/
public AngleJoint(Body body1, Body body2) {
// default no collision allowed
super(body1, body2, false);
// verify the bodies are not the same instance
if (body1 == body2)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.sameBody"));
// initialize
this.ratio = 1.0;
this.impulse = 0.0;
// compute the reference angle
this.referenceAngle = body1.getTransform().getRotation() - body2.getTransform().getRotation();
// set both limits
this.upperLimit = this.referenceAngle;
this.lowerLimit = this.referenceAngle;
// set enabled
this.limitEnabled = true;
// default the limit state
this.limitState = LimitState.EQUAL;
}
/**
* Full constructor.
*
* @param transform the transform for the bounds
* @throws NullPointerException if transform is null
*/
public AbstractBounds(Transform transform) {
// check for a null transform
if (transform == null)
throw new NullPointerException(Messages.getString("collision.bounds.abstract.nullTransform"));
this.transform = transform;
}
/**
* Full constructor.
*
* <p>Creates a new {@link Polygon} using the given vertices. The center of the polygon is
* calculated using an area weighted method.
*
* <p>A polygon must have 3 or more vertices, of which one is not colinear with the other two.
*
* <p>A polygon must also be convex and have anti-clockwise winding.
*
* @param vertices the array of vertices
* @throws NullPointerException if vertices is null or contains a null element
* @throws IllegalArgumentException if vertices contains less than 3 points, contains coincident
* points, is not convex, or has clockwise winding
*/
public Polygon(Vector2... vertices) {
super();
// check the vertex array
if (vertices == null)
throw new NullPointerException(Messages.getString("geometry.polygon.nullArray"));
// get the size
int size = vertices.length;
// check the size
if (size < 3)
throw new IllegalArgumentException(Messages.getString("geometry.polygon.lessThan3Vertices"));
// check for null vertices
for (int i = 0; i < size; i++) {
if (vertices[i] == null)
throw new NullPointerException(Messages.getString("geometry.polygon.nullVertices"));
}
// check for convex
double area = 0.0;
double sign = 0.0;
for (int i = 0; i < size; i++) {
Vector2 p0 = (i - 1 < 0) ? vertices[size - 1] : vertices[i - 1];
Vector2 p1 = vertices[i];
Vector2 p2 = (i + 1 == size) ? vertices[0] : vertices[i + 1];
// check for coincident vertices
if (p1.equals(p2)) {
throw new IllegalArgumentException(
Messages.getString("geometry.polygon.coincidentVertices"));
}
// check the cross product for CCW winding
double cross = p0.to(p1).cross(p1.to(p2));
double tsign = Math.signum(cross);
area += cross;
// check for colinear points (for now its allowed)
if (Math.abs(cross) > Epsilon.E) {
// check for convexity
if (sign != 0.0 && tsign != sign) {
throw new IllegalArgumentException(Messages.getString("geometry.polygon.nonConvex"));
}
}
sign = tsign;
}
// check for CCW
if (area < 0.0) {
throw new IllegalArgumentException(Messages.getString("geometry.polygon.invalidWinding"));
}
// set the vertices
this.vertices = vertices;
// create the normals
this.normals = new Vector2[size];
for (int i = 0; i < size; i++) {
// get the edge points
Vector2 p1 = vertices[i];
Vector2 p2 = (i + 1 == size) ? vertices[0] : vertices[i + 1];
// create the edge and get its left perpedicular vector
Vector2 n = p1.to(p2).left();
// normalize it
n.normalize();
this.normals[i] = n;
}
// perform the area weighted center to otain the center
this.center = Geometry.getAreaWeightedCenter(this.vertices);
// find the maximum radius from the center
double r2 = 0.0;
for (int i = 0; i < size; i++) {
double r2t = this.center.distanceSquared(vertices[i]);
// keep the largest
r2 = Math.max(r2, r2t);
}
// set the radius
this.radius = Math.sqrt(r2);
}
