org.jbox2d.dynamics.contacts.Contact Java Examples

@Override
public void beginContact(Contact cp) {
    // TODO Auto-generated method stub
    Fixture f1 = cp.getFixtureA();
    Fixture f2 = cp.getFixtureB();

    // Get both bodies
    Body b1 = f1.getBody();
    Body b2 = f2.getBody();

    // Get objects that reference these bodies
    Object o1 = b1.getUserData();
    Object o2 = b2.getUserData();

    if ((o1.getClass() == Maze.class && o2.getClass() == Ball.class) || (o1.getClass() == Ball.class && o2.getClass() == Maze.class)) { //if ball touches maze
        balltosurfacecontact(); //play sound
    }

}
 

@Override
public void preSolve(Contact contact, Manifold oldManifold) {
  super.preSolve(contact, oldManifold);

  Fixture fixtureA = contact.getFixtureA();
  Fixture fixtureB = contact.getFixtureB();

  if (fixtureA != m_platform && fixtureA != m_character) {
    return;
  }

  if (fixtureB != m_character && fixtureB != m_character) {
    return;
  }

  Vec2 position = m_character.getBody().getPosition();

  if (position.y < m_top + m_radius - 3.0f * Settings.linearSlop) {
    contact.setEnabled(false);
  }
}
 

@Override
public void postSolve(Contact contact, ContactImpulse impulse) {
  if (m_broke) {
    // The body already broke.
    return;
  }

  // Should the body break?
  int count = contact.getManifold().pointCount;

  float maxImpulse = 0.0f;
  for (int i = 0; i < count; ++i) {
    maxImpulse = MathUtils.max(maxImpulse, impulse.normalImpulses[i]);
  }

  if (maxImpulse > 40.0f) {
    // Flag the body for breaking.
    m_break = true;
  }
}
 

public void report(ContactVelocityConstraint[] constraints) {
  if (m_listener == null) {
    return;
  }

  for (int i = 0; i < m_contactCount; ++i) {
    Contact c = m_contacts[i];

    ContactVelocityConstraint vc = constraints[i];
    impulse.count = vc.pointCount;
    for (int j = 0; j < vc.pointCount; ++j) {
      impulse.normalImpulses[j] = vc.points[j].normalImpulse;
      impulse.tangentImpulses[j] = vc.points[j].tangentImpulse;
    }

    m_listener.postSolve(c, impulse);
  }
}
 

public void preSolve(Contact contact, Manifold oldManifold) {
  Manifold manifold = contact.getManifold();

  if (manifold.pointCount == 0) {
    return;
  }

  Fixture fixtureA = contact.getFixtureA();
  Fixture fixtureB = contact.getFixtureB();

  Collision.getPointStates(state1, state2, oldManifold, manifold);

  contact.getWorldManifold(worldManifold);

  for (int i = 0; i < manifold.pointCount && pointCount < MAX_CONTACT_POINTS; i++) {
    ContactPoint cp = points[pointCount];
    cp.fixtureA = fixtureA;
    cp.fixtureB = fixtureB;
    cp.position.set(worldManifold.points[i]);
    cp.normal.set(worldManifold.normal);
    cp.state = state2[i];
    cp.normalImpulse = manifold.points[i].normalImpulse;
    cp.tangentImpulse = manifold.points[i].tangentImpulse;
    cp.separation = worldManifold.separations[i];
    ++pointCount;
  }
}
 

@Test
public void testCircleContactStack() {
    System.out.println("A");
    DefaultWorldPool thePool = new DefaultWorldPool(10, 10);
    System.out.println("B");
    IDynamicStack<Contact> theCircleStack = thePool.getCircleContactStack();
    System.out.println("C");
    Contact theContact = theCircleStack.pop();
    System.out.println("D");
    Assert.assertTrue(theContact instanceof CircleContact);
    System.out.println("E");
}
 

@Override
public void preSolve(Contact contact, Manifold oldManifold) {
  super.preSolve(contact, oldManifold);

  Fixture fixtureA = contact.getFixtureA();
  Fixture fixtureB = contact.getFixtureB();

  if (fixtureA == m_platform || fixtureB == m_platform) {
    contact.setTangentSpeed(5.0f);
  }
}
 

public void pushContact(Contact contact) {
  Fixture fixtureA = contact.getFixtureA();
  Fixture fixtureB = contact.getFixtureB();

  if (contact.m_manifold.pointCount > 0 && !fixtureA.isSensor() && !fixtureB.isSensor()) {
    fixtureA.getBody().setAwake(true);
    fixtureB.getBody().setAwake(true);
  }

  ShapeType type1 = fixtureA.getType();
  ShapeType type2 = fixtureB.getType();

  IDynamicStack<Contact> creator = contactStacks[type1.ordinal()][type2.ordinal()].creator;
  creator.push(contact);
}
 

private void addType(IDynamicStack<Contact> creator, ShapeType type1, ShapeType type2) {
  ContactRegister register = new ContactRegister();
  register.creator = creator;
  register.primary = true;
  contactStacks[type1.ordinal()][type2.ordinal()] = register;

  if (type1 != type2) {
    ContactRegister register2 = new ContactRegister();
    register2.creator = creator;
    register2.primary = false;
    contactStacks[type2.ordinal()][type1.ordinal()] = register2;
  }
}
 

/**
 * Call this if you want to establish collision that was previously disabled by
 * ContactFilter::ShouldCollide.
 */
public void refilter() {
  if (m_body == null) {
    return;
  }

  // Flag associated contacts for filtering.
  ContactEdge edge = m_body.getContactList();
  while (edge != null) {
    Contact contact = edge.contact;
    Fixture fixtureA = contact.getFixtureA();
    Fixture fixtureB = contact.getFixtureB();
    if (fixtureA == this || fixtureB == this) {
      contact.flagForFiltering();
    }
    edge = edge.next;
  }

  World world = m_body.getWorld();

  if (world == null) {
    return;
  }

  // Touch each proxy so that new pairs may be created
  BroadPhase broadPhase = world.m_contactManager.m_broadPhase;
  for (int i = 0; i < m_proxyCount; ++i) {
    broadPhase.touchProxy(m_proxies[i].proxyId);
  }
}
 

public void add(Contact contact) {
  assert (m_contactCount < m_contactCapacity);
  m_contacts[m_contactCount++] = contact;
}
 

/**
 * 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) {
    BroadPhase broadPhase = m_world.m_contactManager.m_broadPhase;
    fixture.destroyProxies(broadPhase);
  }

  fixture.destroy();
  fixture.m_body = null;
  fixture.m_next = null;
  fixture = null;

  --m_fixtureCount;

  // Reset the mass data.
  resetMassData();
}
 

public void destroy(Contact c) {
  Fixture fixtureA = c.getFixtureA();
  Fixture fixtureB = c.getFixtureB();
  Body bodyA = fixtureA.getBody();
  Body bodyB = fixtureB.getBody();

  if (m_contactListener != null && c.isTouching()) {
    m_contactListener.endContact(c);
  }

  // Remove from the world.
  if (c.m_prev != null) {
    c.m_prev.m_next = c.m_next;
  }

  if (c.m_next != null) {
    c.m_next.m_prev = c.m_prev;
  }

  if (c == m_contactList) {
    m_contactList = c.m_next;
  }

  // Remove from body 1
  if (c.m_nodeA.prev != null) {
    c.m_nodeA.prev.next = c.m_nodeA.next;
  }

  if (c.m_nodeA.next != null) {
    c.m_nodeA.next.prev = c.m_nodeA.prev;
  }

  if (c.m_nodeA == bodyA.m_contactList) {
    bodyA.m_contactList = c.m_nodeA.next;
  }

  // Remove from body 2
  if (c.m_nodeB.prev != null) {
    c.m_nodeB.prev.next = c.m_nodeB.next;
  }

  if (c.m_nodeB.next != null) {
    c.m_nodeB.next.prev = c.m_nodeB.prev;
  }

  if (c.m_nodeB == bodyB.m_contactList) {
    bodyB.m_contactList = c.m_nodeB.next;
  }

  // Call the factory.
  pool.pushContact(c);
  --m_contactCount;
}
 

@Override
public void endContact(Contact arg0) {
    // TODO Auto-generated method stub

}
 

@Override
public void postSolve(Contact arg0, ContactImpulse arg1) {
    // TODO Auto-generated method stub

}
 

/**
 * Call this to draw shapes and other debug draw data.
 */
public void drawDebugData() {
  if (m_debugDraw == null) {
    return;
  }


  int flags = m_debugDraw.getFlags();
  boolean wireframe = (flags & DebugDraw.e_wireframeDrawingBit) != 0;

  if ((flags & DebugDraw.e_shapeBit) != 0) {
    for (Body b = m_bodyList; b != null; b = b.getNext()) {
      xf.set(b.getTransform());
      for (Fixture f = b.getFixtureList(); f != null; f = f.getNext()) {
        if (b.isActive() == false) {
          color.set(0.5f, 0.5f, 0.3f);
          drawShape(f, xf, color, wireframe);
        } else if (b.getType() == BodyType.STATIC) {
          color.set(0.5f, 0.9f, 0.3f);
          drawShape(f, xf, color, wireframe);
        } else if (b.getType() == BodyType.KINEMATIC) {
          color.set(0.5f, 0.5f, 0.9f);
          drawShape(f, xf, color, wireframe);
        } else if (b.isAwake() == false) {
          color.set(0.5f, 0.5f, 0.5f);
          drawShape(f, xf, color, wireframe);
        } else {
          color.set(0.9f, 0.7f, 0.7f);
          drawShape(f, xf, color, wireframe);
        }
      }
    }
    drawParticleSystem(m_particleSystem);
  }

  if ((flags & DebugDraw.e_jointBit) != 0) {
    for (Joint j = m_jointList; j != null; j = j.getNext()) {
      drawJoint(j);
    }
  }

  if ((flags & DebugDraw.e_pairBit) != 0) {
    color.set(0.3f, 0.9f, 0.9f);
    for (Contact c = m_contactManager.m_contactList; c != null; c = c.getNext()) {
      Fixture fixtureA = c.getFixtureA();
      Fixture fixtureB = c.getFixtureB();
      fixtureA.getAABB(c.getChildIndexA()).getCenterToOut(cA);
      fixtureB.getAABB(c.getChildIndexB()).getCenterToOut(cB);
      m_debugDraw.drawSegment(cA, cB, color);
    }
  }

  if ((flags & DebugDraw.e_aabbBit) != 0) {
    color.set(0.9f, 0.3f, 0.9f);

    for (Body b = m_bodyList; b != null; b = b.getNext()) {
      if (b.isActive() == false) {
        continue;
      }

      for (Fixture f = b.getFixtureList(); f != null; f = f.getNext()) {
        for (int i = 0; i < f.m_proxyCount; ++i) {
          FixtureProxy proxy = f.m_proxies[i];
          AABB aabb = m_contactManager.m_broadPhase.getFatAABB(proxy.proxyId);
          if (aabb != null) {
            Vec2[] vs = avs.get(4);
            vs[0].set(aabb.lowerBound.x, aabb.lowerBound.y);
            vs[1].set(aabb.upperBound.x, aabb.lowerBound.y);
            vs[2].set(aabb.upperBound.x, aabb.upperBound.y);
            vs[3].set(aabb.lowerBound.x, aabb.upperBound.y);
            m_debugDraw.drawPolygon(vs, 4, color);
          }
        }
      }
    }
  }

  if ((flags & DebugDraw.e_centerOfMassBit) != 0) {
    for (Body b = m_bodyList; b != null; b = b.getNext()) {
      xf.set(b.getTransform());
      xf.p.set(b.getWorldCenter());
      m_debugDraw.drawTransform(xf);
    }
  }

  if ((flags & DebugDraw.e_dynamicTreeBit) != 0) {
    m_contactManager.m_broadPhase.drawTree(m_debugDraw);
  }

  m_debugDraw.flush();
}
 

@Override
public void preSolve(Contact arg0, Manifold arg1) {
    // TODO Auto-generated method stub

}
 

@Override
public IDynamicStack<Contact> getChainPolyContactStack() {
  return chpstack;
}
 

@Override
public IDynamicStack<Contact> getChainCircleContactStack() {
  return chcstack;
}
 

@Override
public IDynamicStack<Contact> getEdgePolyContactStack() {
  return epstack;
}
 

@Override
public IDynamicStack<Contact> getEdgeCircleContactStack() {
  return ecstack;
}
 

public final IDynamicStack<Contact> getPolyCircleContactStack() {
  return cpstack;
}
 

public final IDynamicStack<Contact> getCircleContactStack() {
  return ccstack;
}
 

public final IDynamicStack<Contact> getPolyContactStack() {
  return pcstack;
}
 

/**
 * This lets you inspect a contact after the solver is finished. This is useful
 * for inspecting impulses.
 * Note: the contact manifold does not include time of impact impulses, which can be
 * arbitrarily large if the sub-step is small. Hence the impulse is provided explicitly
 * in a separate data structure.
 * Note: this is only called for contacts that are touching, solid, and awake.
 * @param contact
 * @param impulse this is usually a pooled variable, so it will be modified after
 * this call
 */
public void postSolve(Contact contact, ContactImpulse impulse);
 

/**
 * Called when two fixtures begin to touch.
 * @param contact
 */
public void beginContact(Contact contact);
 

/**
 * This is called after a contact is updated. This allows you to inspect a
 * contact before it goes to the solver. If you are careful, you can modify the
 * contact manifold (e.g. disable contact).
 * A copy of the old manifold is provided so that you can detect changes.
 * Note: this is called only for awake bodies.
 * Note: this is called even when the number of contact points is zero.
 * Note: this is not called for sensors.
 * Note: if you set the number of contact points to zero, you will not
 * get an EndContact callback. However, you may get a BeginContact callback
 * the next step.
 * Note: the oldManifold parameter is pooled, so it will be the same object for every callback
 * for each thread.
 * @param contact
 * @param oldManifold
 */
public void preSolve(Contact contact, Manifold oldManifold);
 

/**
 * Called when two fixtures cease to touch.
 * @param contact
 */
public void endContact(Contact contact);
 

/**
 * Get the world contact list. With the returned contact, use Contact.getNext to get the next
 * contact in the world list. A null contact indicates the end of the list.
 * 
 * @return the head of the world contact list.
 * @warning contacts are created and destroyed in the middle of a time step. Use ContactListener
 *          to avoid missing contacts.
 */
public Contact getContactList() {
  return m_contactManager.m_contactList;
}
 

public IDynamicStack<Contact> getPolyContactStack();