/// Set the active state of the body. An inactive body is not
/// simulated and cannot be collided with or woken up.
/// If you pass a flag of true, all fixtures will be added to the
/// broad-phase.
/// If you pass a flag of false, all fixtures will be removed from
/// the broad-phase and all contacts will be destroyed.
/// Fixtures and joints are otherwise unaffected. You may continue
/// to create/destroy fixtures and joints on inactive bodies.
/// Fixtures on an inactive body are implicitly inactive and will
/// not participate in collisions, ray-casts, or queries.
/// Joints connected to an inactive body are implicitly inactive.
/// An inactive body is still owned by a b2World object and remains
/// in the body list.
public void SetActive(bool flag)
{
Debug.Assert(m_world.IsLocked() == false);
if (flag == IsActive())
{
return;
}
if (flag)
{
m_flags |= BodyFlags.e_activeFlag;
// Create all proxies.
b2BroadPhase broadPhase = m_world.m_contactManager.m_broadPhase;
for (b2Fixture f = m_fixtureList; f != null; f = f.m_next)
{
f.CreateProxies(broadPhase, m_xf);
}
// Contacts are created the next time step.
}
else
{
m_flags &= ~BodyFlags.e_activeFlag;
// Destroy all proxies.
b2BroadPhase broadPhase = m_world.m_contactManager.m_broadPhase;
for (b2Fixture f = m_fixtureList; f != null; f = f.m_next)
{
f.DestroyProxies(broadPhase);
}
// Destroy the attached contacts.
b2ContactEdge ce = m_contactList;
while (ce != null)
{
b2ContactEdge ce0 = ce;
ce = ce.next;
m_world.m_contactManager.Destroy(ce0.contact);
}
m_contactList = null;
}
}
/// Creates a fixture and attach it to this body. Use this function if you need
/// to set some fixture parameters, like friction. Otherwise you can create the
/// fixture directly from a shape.
/// If the density is non-zero, this function automatically updates the mass of the body.
/// Contacts are not created until the next time step.
/// @param def the fixture definition.
/// @warning This function is locked during callbacks.
public b2Fixture CreateFixture(b2FixtureDef def)
{
Debug.Assert(m_world.IsLocked() == false);
if (m_world.IsLocked() == true)
{
return(null);
}
b2Fixture fixture = new b2Fixture();
fixture.Create(this, def);
if ((m_flags & BodyFlags.e_activeFlag) != 0)
{
b2BroadPhase broadPhase = m_world.m_contactManager.m_broadPhase;
fixture.CreateProxies(broadPhase, m_xf);
}
fixture.m_next = m_fixtureList;
m_fixtureList = fixture;
++m_fixtureCount;
fixture.m_body = this;
// Adjust mass properties if needed.
if (fixture.m_density > 0.0f)
{
ResetMassData();
}
// Let the world know we have a new fixture. This will cause new contacts
// to be created at the beginning of the next time step.
m_world.m_flags |= b2World.WorldFlags.e_newFixture;
return(fixture);
}