/**
* 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 final Fixture createFixture(FixtureDef def) {
assert (m_world.isLocked() == false);
if (m_world.isLocked() == true) {
return null;
}
// djm TODO from pool?
Fixture fixture = new Fixture();
fixture.create(this, def);
if ((m_flags & e_activeFlag) == e_activeFlag) {
BroadPhase broadPhase = m_world.m_contactManager.m_broadPhase;
fixture.createProxy(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 |= World.NEW_FIXTURE;
return fixture;
}
/**
* Destroy a fixture. This removes the fixture from the broad-phase and destroys all contacts
* associated with this fixture. This will automatically adjust the mass of the body if the body
* is dynamic and the fixture has positive density. 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 final void destroyFixture(Fixture fixture) {
assert (m_world.isLocked() == false);
if (m_world.isLocked() == true) {
return;
}
assert (fixture.m_body == this);
// Remove the fixture from this body's singly linked list.
assert (m_fixtureCount > 0);
Fixture node = m_fixtureList;
Fixture last = null; // java change
boolean found = false;
while (node != null) {
if (node == fixture) {
node = fixture.m_next;
found = true;
break;
}
last = node;
node = node.m_next;
}
// You tried to remove a shape that is not attached to this body.
assert (found);
// java change, remove it from the list
if (last == null) {
m_fixtureList = fixture.m_next;
} else {
last.m_next = fixture.m_next;
}
// Destroy any contacts associated with the fixture.
ContactEdge edge = m_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.
m_world.m_contactManager.destroy(c);
}
}
if ((m_flags & e_activeFlag) == e_activeFlag) {
assert (fixture.m_proxy != null);
BroadPhase broadPhase = m_world.m_contactManager.m_broadPhase;
fixture.destroyProxy(broadPhase);
} else {
assert (fixture.m_proxy == null);
}
fixture.destroy();
fixture.m_body = null;
fixture.m_next = null;
fixture = null;
--m_fixtureCount;
// Reset the mass data.
resetMassData();
}