internal Fixture()
{
_userData = null;
_body = null;
_next = null;
_proxyId = BroadPhase.NullProxy;
_shape = null;
}
internal PolygonAndCircleContact(Fixture fixtureA, Fixture fixtureB)
: base(fixtureA, fixtureB)
{
Debug.Assert(_fixtureA.ShapeType == ShapeType.Polygon);
Debug.Assert(_fixtureB.ShapeType == ShapeType.Circle);
}
// Broad-phase callback.
internal void AddPair(Fixture proxyUserDataA, Fixture proxyUserDataB)
{
Fixture fixtureA = proxyUserDataA;
Fixture fixtureB = proxyUserDataB;
Body bodyA = fixtureA.GetBody();
Body bodyB = fixtureB.GetBody();
// Are the fixtures on the same body?
if (bodyA == bodyB)
{
return;
}
// Are both bodies static?
if (bodyA.IsStatic && bodyB.IsStatic)
{
return;
}
// Does a contact already exist?
ContactEdge edge = bodyB.GetConactList();
while (edge != null)
{
if (edge.Other == bodyA)
{
Fixture fA = edge.Contact.GetFixtureA();
Fixture fB = edge.Contact.GetFixtureB();
if (fA == fixtureA && fB == fixtureB)
{
// A contact already exists.
return;
}
if (fA == fixtureB && fB == fixtureA)
{
// A contact already exists.
return;
}
}
edge = edge.Next;
}
// Does a joint override collision?
if (bodyB.IsConnected(bodyA))
{
return;
}
// Check user filtering.
if (ContactFilter.ShouldCollide(fixtureA, fixtureB) == false)
{
return;
}
// Call the factory.
Contact c = Contact.Create(fixtureA, fixtureB);
// Contact creation may swap fixtures.
fixtureA = c.GetFixtureA();
fixtureB = c.GetFixtureB();
bodyA = fixtureA.GetBody();
bodyB = fixtureB.GetBody();
// Insert into the world.
c._prev = null;
c._next = _contactList;
if (_contactList != null)
{
_contactList._prev = c;
}
_contactList = c;
// Connect to island graph.
// Connect to body A
c._nodeA.Contact = c;
c._nodeA.Other = bodyB;
c._nodeA.Prev = null;
c._nodeA.Next = bodyA._contactList;
if (bodyA._contactList != null)
{
bodyA._contactList.Prev = c._nodeA;
}
bodyA._contactList = c._nodeA;
// Connect to body B
c._nodeB.Contact = c;
c._nodeB.Other = bodyA;
c._nodeB.Prev = null;
c._nodeB.Next = bodyB._contactList;
if (bodyB._contactList != null)
{
bodyB._contactList.Prev = c._nodeB;
}
bodyB._contactList = c._nodeB;
++_contactCount;
}
// We need separation create/destroy functions from the ructor/destructor because
// the destructor cannot access the allocator or broad-phase (no destructor arguments allowed by C++).
internal void Create(BroadPhase broadPhase, Body body, ref XForm xf, FixtureDef def)
{
_userData = def.userData;
_friction = def.friction;
_restitution = def.restitution;
_density = def.density;
_body = body;
_next = null;
_filter = def.filter;
_isSensor = def.isSensor;
_shape = def.shape.Clone();
// Create proxy in the broad-phase.
AABB aabb;
_shape.ComputeAABB(out aabb, ref xf);
_proxyId = broadPhase.CreateProxy(ref aabb, this);
}
internal XForm _xf; // the body origin transform
#endregion Fields
#region Constructors
internal Body(BodyDef bd, World world)
{
_flags = 0;
if (bd.isBullet)
{
_flags |= BodyFlags.Bullet;
}
if (bd.fixedRotation)
{
_flags |= BodyFlags.FixedRotation;
}
if (bd.allowSleep)
{
_flags |= BodyFlags.AllowSleep;
}
if (bd.isSleeping)
{
_flags |= BodyFlags.Sleep;
}
_world = world;
_xf.Position = bd.position;
_xf.R.Set(bd.angle);
_sweep.localCenter = bd.massData.center;
_sweep.t0 = 1.0f;
_sweep.a0 = _sweep.a = bd.angle;
_sweep.c0 = _sweep.c = MathUtils.Multiply(ref _xf, _sweep.localCenter);
_jointList = null;
_contactList = null;
_prev = null;
_next = null;
_linearVelocity = bd.linearVelocity;
_angularVelocity = bd.angularVelocity;
_linearDamping = bd.linearDamping;
_angularDamping = bd.angularDamping;
_force = new Vector2(0.0f, 0.0f);
_torque = 0.0f;
_linearVelocity = Vector2.Zero;
_angularVelocity = 0.0f;
_sleepTime = 0.0f;
_invMass = 0.0f;
_I = 0.0f;
_invI = 0.0f;
_mass = bd.massData.mass;
if (_mass > 0.0f)
{
_invMass = 1.0f / _mass;
}
_I = bd.massData.i;
if (_I > 0.0f && (_flags & BodyFlags.FixedRotation) == 0)
{
_invI = 1.0f / _I;
}
if (_invMass == 0.0f && _invI == 0.0f)
{
_type = BodyType.Static;
}
else
{
_type = BodyType.Dynamic;
}
_userData = bd.userData;
_fixtureList = null;
_fixtureCount = 0;
}
/// Destroy a fixture. This removes the fixture from the broad-phase and
/// therefore destroys any contacts associated with this fixture. All fixtures
/// attached to a body are implicitly destroyed when the body is destroyed.
/// @param fixture the fixture to be removed.
/// @warning This function is locked during callbacks.
public void DestroyFixture(Fixture fixture)
{
Debug.Assert(_world.IsLocked == false);
if (_world.IsLocked == true)
{
return;
}
Debug.Assert(fixture._body == this);
// Remove the fixture from this body's singly linked list.
Debug.Assert(_fixtureCount > 0);
Fixture node = _fixtureList;
bool found = false;
while (node != null)
{
if (node == fixture)
{
_fixtureList = fixture._next;
found = true;
break;
}
node = node._next;
}
// You tried to remove a shape that is not attached to this body.
Debug.Assert(found);
// Destroy any contacts associated with the fixture.
ContactEdge edge = _contactList;
while (edge != null)
{
Contact c = edge.Contact;
edge = edge.Next;
Fixture fixtureA = c.GetFixtureA();
Fixture fixtureB = c.GetFixtureB();
if (fixture == fixtureA || fixture == fixtureB)
{
// This destroys the contact and removes it from
// this body's contact list.
_world._contactManager.Destroy(c);
}
}
BroadPhase broadPhase = _world._contactManager._broadPhase;
fixture.Destroy(broadPhase);
fixture._body = null;
fixture._next = null;
--_fixtureCount;
}
/// Creates a fixture from a shape and attach it to this body.
/// This is a convenience function. Use FixtureDef if you need to set parameters
/// like friction, restitution, user data, or filtering.
/// @param shape the shape to be cloned.
/// @param density the shape density (set to zero for static bodies).
/// @warning This function is locked during callbacks.
public Fixture CreateFixture(Shape shape, float density)
{
Debug.Assert(_world.IsLocked == false);
if (_world.IsLocked == true)
{
return null;
}
BroadPhase broadPhase = _world._contactManager._broadPhase;
FixtureDef def = new FixtureDef();
def.shape = shape;
def.density = density;
Fixture fixture = new Fixture();
fixture.Create(broadPhase, this, ref _xf, def);
fixture._next = _fixtureList;
_fixtureList = fixture;
++_fixtureCount;
fixture._body = this;
// Let the world know we have a new fixture.
_world._flags |= WorldFlags.NewFixture;
return fixture;
}
void DrawShape(Fixture fixture, XForm xf, Color color)
{
Color coreColor = ColorEx.FromScRgb(0.9f, 0.6f, 0.6f);
switch (fixture.ShapeType)
{
case ShapeType.Circle:
{
CircleShape circle = (CircleShape)fixture.GetShape();
Vector2 center = MathUtils.Multiply(ref xf, circle._p);
float radius = circle._radius;
Vector2 axis = xf.R.col1;
DebugDraw.DrawSolidCircle(center, radius, axis, color);
}
break;
case ShapeType.Polygon:
{
PolygonShape poly = (PolygonShape)fixture.GetShape();
int vertexCount = poly._vertexCount;
Debug.Assert(vertexCount <= Settings.b2_maxPolygonVertices);
FixedArray8<Vector2> vertices = new FixedArray8<Vector2>();
for (int i = 0; i < vertexCount; ++i)
{
vertices[i] = MathUtils.Multiply(ref xf, poly._vertices[i]);
}
DebugDraw.DrawSolidPolygon(ref vertices, vertexCount, color);
}
break;
}
}
