public override void Initialize()
{
if (_world != null && Texture != null)
{
var data = new uint[Texture.Width * Texture.Height];
Texture.GetData(data);
var verts = PolygonTools.CreatePolygon(data, Texture.Width, true);
var scale = ConvertUnits.ToSimUnits(new Vector2(1, 1));
verts.Scale(ref scale);
var list = BayazitDecomposer.ConvexPartition(verts);
var compound = BodyFactory.CreateCompoundPolygon(_world, list, 1);
compound.BodyType = BodyType.Dynamic;
Body = compound;
Body.Restitution = 1;
SetStartPosition();
var joint = new FixedPrismaticJoint(Body, Body.Position, new Vector2(1, 0));
joint.LimitEnabled = true;
joint.LowerLimit = -ConvertUnits.ToSimUnits((_screenBounds.Width - Texture.Width) / 2f);
joint.UpperLimit = ConvertUnits.ToSimUnits((_screenBounds.Width - Texture.Width) / 2f);
joint.Enabled = true;
joint.MaxMotorForce = 70f;
_world.AddJoint(joint);
}
base.Initialize();
}
public static FixedPrismaticJoint CreateFixedPrismaticJoint(World world, Body body, Vector2 worldAnchor,
Vector2 axis)
{
FixedPrismaticJoint joint = new FixedPrismaticJoint(body, worldAnchor, axis);
world.AddJoint(joint);
return joint;
}
public Paddle(Texture2D texture,
Vector2 position,
World world,
DebugViewXNA debugViewXNA,
ContentManager content,
GraphicsDeviceManager graphics)
: base(world, debugViewXNA, content, graphics)
{
this.mTexture = texture;
this.mWidth = ConvertUnits.ToSimUnits(this.mTexture.Width);
this.mHeight = ConvertUnits.ToSimUnits(this.mTexture.Height);
this.mOrigin = new Vector2(this.mWidth / 2f, this.mHeight / 2f);
this.mSpriteEffects = SpriteEffects.None;
this.mPosition = ConvertUnits.ToSimUnits(position);
this.mBody = BodyFactory.CreateRectangle(this.mWorld,
this.mWidth,
this.mHeight,
1f,
this.mPosition);
this.mBody.BodyType = BodyType.Dynamic;
this.mJointWorldAnchor = this.mPosition;
this.mFixedPrismJoint = new FixedPrismaticJoint(this.mBody,
this.mJointWorldAnchor,
this.mJointAxis);
this.mFixedPrismJoint.LimitEnabled = true;
this.mFixedPrismJoint.LowerLimit = this.mJointLowerLimit;
this.mFixedPrismJoint.UpperLimit = this.mJointUpperLimit;
this.mFixedPrismJoint.Enabled = true;
this.mWorld.AddJoint(this.mFixedPrismJoint);
this.mBody.OnCollision += new OnCollisionEventHandler(OnCollision);
this.mBody.OnSeparation += new OnSeparationEventHandler(OnSeparation);
this.mBody.FixtureList[0].AfterCollision += new AfterCollisionEventHandler(OnAfterCollision);
this.mParticleRenderer = new SpriteBatchRenderer
{
GraphicsDeviceService = this.mGraphics
};
this.mParticleEffect = new ParticleEffect();
this.mParticleRenderer.LoadContent(this.mContent);
this.mParticleEffect = this.mContent.Load<ParticleEffect>(@"Effects\basicSparks");
this.mParticleEffect.LoadContent(this.mContent);
this.mParticleEffect.Initialise();
}
private PrismaticTest()
{
Body ground;
{
ground = BodyFactory.CreateBody(World);
PolygonShape shape3 = new PolygonShape(0);
shape3.SetAsEdge(new Vector2(-40.0f, 0.0f), new Vector2(40.0f, 0.0f));
ground.CreateFixture(shape3);
}
PolygonShape shape = new PolygonShape(5);
shape.SetAsBox(2.0f, 0.5f);
Body body = BodyFactory.CreateBody(World);
body.BodyType = BodyType.Dynamic;
body.Position = new Vector2(0.0f, 10.0f);
body.CreateFixture(shape);
_fixedJoint = new FixedPrismaticJoint(body, body.Position, new Vector2(0.5f, 1.0f));
_fixedJoint.MotorSpeed = 5.0f;
_fixedJoint.MaxMotorForce = 1000.0f;
_fixedJoint.MotorEnabled = true;
_fixedJoint.LowerLimit = -10.0f;
_fixedJoint.UpperLimit = 20.0f;
_fixedJoint.LimitEnabled = true;
World.AddJoint(_fixedJoint);
PolygonShape shape2 = new PolygonShape(5);
shape2.SetAsBox(2.0f, 0.5f);
Body body2 = BodyFactory.CreateBody(World);
body2.BodyType = BodyType.Dynamic;
body2.Position = new Vector2(10.0f, 10.0f);
body2.CreateFixture(shape2);
_joint = new PrismaticJoint(ground, body2, ground.GetLocalPoint(body2.Position), Vector2.Zero,
new Vector2(0.5f, 1.0f));
_joint.MotorSpeed = 5.0f;
_joint.MaxMotorForce = 1000.0f;
_joint.MotorEnabled = true;
_joint.LowerLimit = -10.0f;
_joint.UpperLimit = 20.0f;
_joint.LimitEnabled = true;
World.AddJoint(_joint);
}
private GearsTest()
{
{
// First circle
CircleShape circle1 = new CircleShape(1.0f, 5);
Body body1 = BodyFactory.CreateBody(World);
body1.BodyType = BodyType.Dynamic;
body1.Position = new Vector2(-3.0f, 12.0f);
body1.CreateFixture(circle1);
// Second circle
CircleShape circle2 = new CircleShape(2.0f, 5);
Body body2 = BodyFactory.CreateBody(World);
body2.BodyType = BodyType.Dynamic;
body2.Position = new Vector2(0.0f, 12.0f);
body2.CreateFixture(circle2);
// Rectangle
Vertices box = PolygonTools.CreateRectangle(0.5f, 5.0f);
PolygonShape polygonBox = new PolygonShape(box, 5);
Body body3 = BodyFactory.CreateBody(World);
body3.BodyType = BodyType.Dynamic;
body3.Position = new Vector2(2.5f, 12.0f);
body3.CreateFixture(polygonBox);
// Fix first circle
_joint1 = new FixedRevoluteJoint(body1, Vector2.Zero, body1.Position);
World.AddJoint(_joint1);
// Fix second circle
_joint2 = new FixedRevoluteJoint(body2, Vector2.Zero, body2.Position);
World.AddJoint(_joint2);
// Fix rectangle
_joint3 = new FixedPrismaticJoint(body3, body3.Position, new Vector2(0.0f, 1.0f));
_joint3.LowerLimit = -5.0f;
_joint3.UpperLimit = 5.0f;
_joint3.LimitEnabled = true;
World.AddJoint(_joint3);
// Attach first and second circle together with a gear joint
_joint4 = new GearJoint(_joint1, _joint2, circle2.Radius / circle1.Radius);
World.AddJoint(_joint4);
// Attach second and rectangle together with a gear joint
_joint5 = new GearJoint(_joint2, _joint3, -1.0f / circle2.Radius);
World.AddJoint(_joint5);
}
}
private BodyTypesTest()
{
//Ground
BodyFactory.CreateEdge(World, new Vector2(-40.0f, 0.0f), new Vector2(40.0f, 0.0f));
// Define attachment
{
_attachment = BodyFactory.CreateBody(World);
_attachment.BodyType = BodyType.Dynamic;
_attachment.Position = new Vector2(0.0f, 3.0f);
Vertices box = PolygonTools.CreateRectangle(0.5f, 2.0f);
PolygonShape shape = new PolygonShape(box, 2);
_attachment.CreateFixture(shape);
}
// Define platform
{
_platform = BodyFactory.CreateBody(World);
_platform.BodyType = BodyType.Dynamic;
_platform.Position = new Vector2(0.0f, 5.0f);
Vertices box = PolygonTools.CreateRectangle(4.0f, 0.5f);
PolygonShape shape = new PolygonShape(box, 2);
Fixture fixture = _platform.CreateFixture(shape);
fixture.Friction = 0.6f;
RevoluteJoint rjd = new RevoluteJoint(_attachment, _platform,
_attachment.GetLocalPoint(_platform.Position),
Vector2.Zero);
rjd.MaxMotorTorque = 50.0f;
rjd.MotorEnabled = true;
World.AddJoint(rjd);
FixedPrismaticJoint pjd = new FixedPrismaticJoint(_platform, new Vector2(0.0f, 5.0f),
new Vector2(1.0f, 0.0f));
pjd.MaxMotorForce = 1000.0f;
pjd.MotorEnabled = true;
pjd.LowerLimit = -10.0f;
pjd.UpperLimit = 10.0f;
pjd.LimitEnabled = true;
World.AddJoint(pjd);
_speed = 3.0f;
}
// Create a payload
{
Body body = BodyFactory.CreateBody(World);
body.BodyType = BodyType.Dynamic;
body.Position = new Vector2(0.0f, 8.0f);
Vertices box = PolygonTools.CreateRectangle(0.75f, 0.75f);
PolygonShape shape = new PolygonShape(box, 2);
Fixture fixture = body.CreateFixture(shape);
fixture.Friction = 0.6f;
}
}
/// <summary>
/// Requires two existing revolute or prismatic joints (any combination will work).
/// The provided joints must attach a dynamic body to a static body.
/// </summary>
/// <param name="jointA">The first joint.</param>
/// <param name="jointB">The second joint.</param>
/// <param name="ratio">The ratio.</param>
public GearJoint(Joint jointA, Joint jointB, float ratio)
: base(jointA.BodyA, jointA.BodyB)
{
JointType = JointType.Gear;
JointA = jointA;
JointB = jointB;
Ratio = ratio;
JointType type1 = jointA.JointType;
JointType type2 = jointB.JointType;
// Make sure its the right kind of joint
Debug.Assert(type1 == JointType.Revolute ||
type1 == JointType.Prismatic ||
type1 == JointType.FixedRevolute ||
type1 == JointType.FixedPrismatic);
Debug.Assert(type2 == JointType.Revolute ||
type2 == JointType.Prismatic ||
type2 == JointType.FixedRevolute ||
type2 == JointType.FixedPrismatic);
// In the case of a prismatic and revolute joint, the first body must be static.
if (type1 == JointType.Revolute || type1 == JointType.Prismatic)
{
Debug.Assert(jointA.BodyA.Type == BodyType.Static);
}
if (type2 == JointType.Revolute || type2 == JointType.Prismatic)
{
Debug.Assert(jointB.BodyA.Type == BodyType.Static);
}
float coordinate1 = 0.0f, coordinate2 = 0.0f;
switch (type1)
{
case JointType.Revolute:
BodyA = jointA.BodyB;
_revolute1 = (RevoluteJoint)jointA;
LocalAnchor1 = _revolute1.LocalAnchorB;
coordinate1 = _revolute1.JointAngle;
break;
case JointType.Prismatic:
BodyA = jointA.BodyB;
_prismatic1 = (PrismaticJoint)jointA;
LocalAnchor1 = _prismatic1.LocalAnchorB;
coordinate1 = _prismatic1.JointTranslation;
break;
case JointType.FixedRevolute:
BodyA = jointA.BodyA;
_fixedRevolute1 = (FixedRevoluteJoint)jointA;
LocalAnchor1 = _fixedRevolute1.LocalAnchorA;
coordinate1 = _fixedRevolute1.JointAngle;
break;
case JointType.FixedPrismatic:
BodyA = jointA.BodyA;
_fixedPrismatic1 = (FixedPrismaticJoint)jointA;
LocalAnchor1 = _fixedPrismatic1.LocalAnchorA;
coordinate1 = _fixedPrismatic1.JointTranslation;
break;
}
switch (type2)
{
case JointType.Revolute:
BodyB = jointB.BodyB;
_revolute2 = (RevoluteJoint)jointB;
LocalAnchor2 = _revolute2.LocalAnchorB;
coordinate2 = _revolute2.JointAngle;
break;
case JointType.Prismatic:
BodyB = jointB.BodyB;
_prismatic2 = (PrismaticJoint)jointB;
LocalAnchor2 = _prismatic2.LocalAnchorB;
coordinate2 = _prismatic2.JointTranslation;
break;
case JointType.FixedRevolute:
BodyB = jointB.BodyA;
_fixedRevolute2 = (FixedRevoluteJoint)jointB;
LocalAnchor2 = _fixedRevolute2.LocalAnchorA;
coordinate2 = _fixedRevolute2.JointAngle;
break;
case JointType.FixedPrismatic:
BodyB = jointB.BodyA;
_fixedPrismatic2 = (FixedPrismaticJoint)jointB;
LocalAnchor2 = _fixedPrismatic2.LocalAnchorA;
coordinate2 = _fixedPrismatic2.JointTranslation;
break;
}
_ant = coordinate1 + Ratio * coordinate2;
}
/// <summary>
/// Requires two existing revolute or prismatic joints (any combination will work).
/// The provided joints must attach a dynamic body to a static body.
/// </summary>
/// <param name="jointA">The first joint.</param>
/// <param name="jointB">The second joint.</param>
/// <param name="ratio">The ratio.</param>
public GearJoint(Joint jointA, Joint jointB, float ratio)
: base(jointA.BodyA, jointA.BodyB)
{
JointType = JointType.Gear;
JointA = jointA;
JointB = jointB;
Ratio = ratio;
JointType type1 = jointA.JointType;
JointType type2 = jointB.JointType;
// Make sure its the right kind of joint
Debug.Assert(type1 == JointType.Revolute ||
type1 == JointType.Prismatic ||
type1 == JointType.FixedRevolute ||
type1 == JointType.FixedPrismatic);
Debug.Assert(type2 == JointType.Revolute ||
type2 == JointType.Prismatic ||
type2 == JointType.FixedRevolute ||
type2 == JointType.FixedPrismatic);
// In the case of a prismatic and revolute joint, the first body must be static.
if (type1 == JointType.Revolute || type1 == JointType.Prismatic)
Debug.Assert(jointA.BodyA.BodyType == BodyType.Static);
if (type2 == JointType.Revolute || type2 == JointType.Prismatic)
Debug.Assert(jointB.BodyA.BodyType == BodyType.Static);
float coordinate1 = 0.0f, coordinate2 = 0.0f;
switch (type1)
{
case JointType.Revolute:
BodyA = jointA.BodyB;
_revolute1 = (RevoluteJoint)jointA;
LocalAnchor1 = _revolute1.LocalAnchorB;
coordinate1 = _revolute1.JointAngle;
break;
case JointType.Prismatic:
BodyA = jointA.BodyB;
_prismatic1 = (PrismaticJoint)jointA;
LocalAnchor1 = _prismatic1.LocalAnchorB;
coordinate1 = _prismatic1.JointTranslation;
break;
case JointType.FixedRevolute:
BodyA = jointA.BodyA;
_fixedRevolute1 = (FixedRevoluteJoint)jointA;
LocalAnchor1 = _fixedRevolute1.LocalAnchorA;
coordinate1 = _fixedRevolute1.JointAngle;
break;
case JointType.FixedPrismatic:
BodyA = jointA.BodyA;
_fixedPrismatic1 = (FixedPrismaticJoint)jointA;
LocalAnchor1 = _fixedPrismatic1.LocalAnchorA;
coordinate1 = _fixedPrismatic1.JointTranslation;
break;
}
switch (type2)
{
case JointType.Revolute:
BodyB = jointB.BodyB;
_revolute2 = (RevoluteJoint)jointB;
LocalAnchor2 = _revolute2.LocalAnchorB;
coordinate2 = _revolute2.JointAngle;
break;
case JointType.Prismatic:
BodyB = jointB.BodyB;
_prismatic2 = (PrismaticJoint)jointB;
LocalAnchor2 = _prismatic2.LocalAnchorB;
coordinate2 = _prismatic2.JointTranslation;
break;
case JointType.FixedRevolute:
BodyB = jointB.BodyA;
_fixedRevolute2 = (FixedRevoluteJoint)jointB;
LocalAnchor2 = _fixedRevolute2.LocalAnchorA;
coordinate2 = _fixedRevolute2.JointAngle;
break;
case JointType.FixedPrismatic:
BodyB = jointB.BodyA;
_fixedPrismatic2 = (FixedPrismaticJoint)jointB;
LocalAnchor2 = _fixedPrismatic2.LocalAnchorA;
coordinate2 = _fixedPrismatic2.JointTranslation;
break;
}
_ant = coordinate1 + Ratio * coordinate2;
}
private SliderCrankTest()
{
Body ground;
{
ground = BodyFactory.CreateBody(World);
EdgeShape shape = new EdgeShape(new Vector2(-40.0f, 0.0f), new Vector2(40.0f, 0.0f));
ground.CreateFixture(shape);
}
{
Body prevBody = ground;
// Define crank.
{
PolygonShape shape = new PolygonShape(2);
shape.SetAsBox(0.5f, 2.0f);
Body body = BodyFactory.CreateBody(World);
body.BodyType = BodyType.Dynamic;
body.Position = new Vector2(0.0f, 7.0f);
body.CreateFixture(shape);
Vector2 anchor = new Vector2(0.0f, -2.0f);
_joint1 = new RevoluteJoint(prevBody, body, prevBody.GetLocalPoint(body.GetWorldPoint(anchor)),
anchor);
_joint1.MotorSpeed = 1.0f * Settings.Pi;
_joint1.MaxMotorTorque = 10000.0f;
_joint1.MotorEnabled = true;
World.AddJoint(_joint1);
prevBody = body;
}
// Define follower.
{
PolygonShape shape = new PolygonShape(2);
shape.SetAsBox(0.5f, 4.0f);
Body body = BodyFactory.CreateBody(World);
body.BodyType = BodyType.Dynamic;
body.Position = new Vector2(0.0f, 13.0f);
body.CreateFixture(shape);
Vector2 anchor = new Vector2(0.0f, -4.0f);
RevoluteJoint rjd3 = new RevoluteJoint(prevBody, body,
prevBody.GetLocalPoint(body.GetWorldPoint(anchor)), anchor);
rjd3.MotorEnabled = false;
World.AddJoint(rjd3);
prevBody = body;
}
// Define piston
{
PolygonShape shape = new PolygonShape(2);
shape.SetAsBox(1.5f, 1.5f);
Body body = BodyFactory.CreateBody(World);
body.BodyType = BodyType.Dynamic;
body.Position = new Vector2(0.0f, 17.0f);
body.CreateFixture(shape);
Vector2 anchor = Vector2.Zero;
RevoluteJoint rjd2 = new RevoluteJoint(prevBody, body,
prevBody.GetLocalPoint(body.GetWorldPoint(anchor)), anchor);
World.AddJoint(rjd2);
_joint2 = new FixedPrismaticJoint(body, new Vector2(0.0f, 17.0f), new Vector2(0.0f, 1.0f));
_joint2.MaxMotorForce = 1000.0f;
_joint2.MotorEnabled = true;
World.AddJoint(_joint2);
}
// Create a payload
{
PolygonShape shape = new PolygonShape(2);
shape.SetAsBox(1.5f, 1.5f);
Body body = BodyFactory.CreateBody(World);
body.BodyType = BodyType.Dynamic;
body.Position = new Vector2(0.0f, 23.0f);
body.CreateFixture(shape);
}
}
}
/// <summary>
/// Call during the method in which you create the body for the object.
/// Make sure it's used afterwards otherwise you'll have issues.
/// </summary>
/// <param name="world"></param>
protected virtual void SetUpJoint(World world)
{
#if EDITOR
#else
this._currentMovingDirection = false;
Vector2 axis = Vector2.Zero;
if (_movementDirection == Direction.Horizontal)
{
if (_endPosition.X < _position.X)
{
axis = new Vector2(-1, 0);
}
else
{
axis = new Vector2(1, 0);
}
}
else
{
if (_endPosition.Y < _position.Y)
{
axis = new Vector2(0, -1);
}
else
{
axis = new Vector2(0, 1);
}
}
this._prismaticJoint = JointFactory.CreateFixedPrismaticJoint(world, this.Body, ConvertUnits.ToSimUnits(this.Position), axis);
if (_movementDirection == Direction.Horizontal)
{
this._prismaticJoint.UpperLimit = Math.Abs(ConvertUnits.ToSimUnits(_endPosition.X - Position.X));
}
else
{
this._prismaticJoint.UpperLimit = Math.Abs(ConvertUnits.ToSimUnits(_endPosition.Y - Position.Y));
}
this._prismaticJoint.LowerLimit = 0.0f;
this._prismaticJoint.LimitEnabled = true;
this._prismaticJoint.MotorEnabled = true;
this._prismaticJoint.MaxMotorForce = float.MaxValue;
if (_startsMoving)
{
this._isMoving = true;
this._prismaticJoint.MotorSpeed = _motorSpeed;
}
#endif
}
void HandleJoint(float delta, FixedPrismaticJoint joint, float i )
{
#if !EDITOR
if ((joint.JointTranslation >= joint.UpperLimit && !this.MovingToStart) ||
(joint.JointTranslation <= joint.LowerLimit && this.MovingToStart))
{
if (joint.MotorSpeed != 0)
{
joint.MotorSpeed = 0.0f;
}
}
else
{
if (_motorSpeed < 0)
{
i *= -1.0f;
}
if (joint.MotorSpeed != this._motorSpeed)
{
joint.MotorSpeed = this._motorSpeed;
}
}
#endif
}
public static Joint CopyJoint(Joint joint, Body bodyA, Body bodyB, World world)
{
Joint newJoint = null;
switch (joint.JointType)
{
case JointType.Angle:
newJoint = JointFactory.CreateAngleJoint(world, bodyA, bodyB);
break;
case JointType.Distance:
newJoint = new DistanceJoint(bodyA, bodyB, bodyA.WorldCenter, bodyB.WorldCenter);
break;
case JointType.FixedAngle:
newJoint = new FixedAngleJoint(bodyA);
break;
case JointType.FixedDistance:
newJoint = new FixedDistanceJoint(bodyA, bodyA.WorldCenter, Vector2.Zero);
break;
case JointType.FixedFriction:
newJoint = new FixedFrictionJoint(bodyA, bodyA.WorldCenter);
break;
case JointType.FixedPrismatic:
var fpJoint = joint as FixedPrismaticJoint;
var fpAxis = fpJoint.LocalXAxis1;
newJoint = new FixedPrismaticJoint(bodyA, bodyA.WorldCenter, fpAxis);
break;
case JointType.FixedRevolute:
newJoint = new FixedRevoluteJoint(bodyA, bodyA.WorldCenter, Vector2.Zero);
break;
case JointType.Friction:
newJoint = new FrictionJoint(bodyA, bodyB, bodyA.WorldCenter, bodyB.WorldCenter);
break;
case JointType.Line:
var lineJoint = joint as LineJoint;
var axis = lineJoint.LocalXAxis;
newJoint = new LineJoint(bodyA, bodyB, bodyA.WorldCenter, axis);
break;
case JointType.Prismatic:
var pJoint = joint as PrismaticJoint;
var pAxis = pJoint.LocalXAxis1;
newJoint = new PrismaticJoint(bodyA, bodyB, bodyA.WorldCenter, bodyB.WorldCenter, pAxis);
((PrismaticJoint)newJoint).LimitEnabled = pJoint.LimitEnabled;
((PrismaticJoint)newJoint).MotorEnabled = pJoint.MotorEnabled;
((PrismaticJoint)newJoint).MaxMotorForce = pJoint.MaxMotorForce;
((PrismaticJoint)newJoint).MotorSpeed = pJoint.MotorSpeed;
((PrismaticJoint)newJoint).LowerLimit = pJoint.LowerLimit;
((PrismaticJoint)newJoint).UpperLimit = pJoint.UpperLimit;
((PrismaticJoint)newJoint).ReferenceAngle = pJoint.ReferenceAngle;
((PrismaticJoint)newJoint).LocalXAxis1 = pJoint.LocalXAxis1;
break;
case JointType.Pulley:
var pulleyJoint = joint as PulleyJoint;
var ratio = pulleyJoint.Ratio;
newJoint = new PulleyJoint(bodyA, bodyB, Vector2.Zero, Vector2.Zero, bodyA.WorldCenter, bodyB.WorldCenter, ratio);
break;
case JointType.Revolute:
newJoint = new RevoluteJoint(bodyA, bodyB, bodyA.WorldCenter, bodyB.WorldCenter);
break;
case JointType.Slider:
var sliderJoint = joint as SliderJoint;
var minLength = sliderJoint.MinLength;
var maxLength = sliderJoint.MaxLength;
newJoint = new SliderJoint(bodyA, bodyB, bodyA.WorldCenter, bodyB.WorldCenter, minLength, maxLength);
break;
case JointType.Weld:
newJoint = new WeldJoint(bodyA, bodyB, bodyA.WorldCenter, bodyB.WorldCenter);
break;
}
var data = new FarseerJointUserData();
data.BodyAName = ((FarseerJointUserData) joint.UserData).BodyAName;
data.BodyBName = ((FarseerJointUserData) joint.UserData).BodyBName;
joint.UserData = data;
return newJoint;
}