public GroundConstraint(Body body, Fixture bodyFixture, SurfaceMovementControl surfaceMovementControl)
{
_body = body;
_surfaceMovementControl = surfaceMovementControl;
Add(bodyFixture.CreateContactHandler(HexPhysicTypes.Ground, EnterGroundContact, ExitGroundContact));
// sensor
var sensor = _body.AttachCircle(10f, 0);
sensor.IsSensor = true;
sensor.SetCollisionType(HexPhysicTypes.GroundSensor);
_closeHexList = Add(new FixtureContactList(sensor));
// ground constraint
_groundConstraintUpdate = new UpdateComponent(UpdateGroundConstraint, UpdateTime.Sim);
Add(_groundConstraintUpdate);
// state
Add(new StateRecorder("groundConstraint",
state => { },
state =>
{
_isOnGround = false;
_currentHex = null;
}));
}