private CollisionDataNative GetCollisionData(b2Contact contact)
{
int colliderAId = contact.GetFixtureA().GetUserData().data;
int colliderBId = contact.GetFixtureB().GetUserData().data;
int physicsObjectAId = contact.GetFixtureA().GetBody().GetUserData().data;
int physicsObjectBId = contact.GetFixtureB().GetBody().GetUserData().data;
int childIndexA = contact.GetChildIndexA();
int childIndexB = contact.GetChildIndexB();
IPhysicsObject physicsObjectA = _Physics2D.GetPhysicsObject(physicsObjectAId);
ICollider colliderA = physicsObjectA.GetCollider(colliderAId);
IPhysicsObject physicsObjectB = _Physics2D.GetPhysicsObject(physicsObjectBId);
ICollider colliderB = physicsObjectB.GetCollider(colliderBId);
return(new CollisionDataNative(contact, physicsObjectA, colliderA, childIndexA, physicsObjectB, colliderB, childIndexB));
}
// Find TOI contacts and solve them.
public void SolveTOI(b2TimeStep step)
{
b2Island island = new b2Island(2 * b2Settings.b2_maxTOIContacts, b2Settings.b2_maxTOIContacts, 0, m_contactManager.ContactListener);
if (m_stepComplete)
{
for (b2Body b = m_bodyList; b; b = b.Next)
{
b.BodyFlags &= ~b2Body.e_islandFlag;
b.m_sweep.alpha0 = 0.0f;
}
for (b2Contact c = m_contactManager.ContactList; c; c = c.Next)
{
// Invalidate TOI
c.ContactFlags &= ~(b2ContactType.e_toiFlag | b2ContactType.e_islandFlag);
c.m_toiCount = 0;
c.m_toi = 1.0f;
}
}
// Find TOI events and solve them.
for (; ;)
{
// Find the first TOI.
b2Contact minContact = null;
float minAlpha = 1.0f;
for (b2Contact c = m_contactManager.ContactList; c != null; c = c.Next)
{
// Is this contact disabled?
if (c.IsEnabled() == false)
{
continue;
}
// Prevent excessive sub-stepping.
if (c.m_toiCount > b2Settings.b2_maxSubSteps)
{
continue;
}
float alpha = 1.0f;
if (c.ContactFlags.HasFlag(b2ContactFlags.e_toiFlag))
{
// This contact has a valid cached TOI.
alpha = c.m_toi;
}
else
{
b2Fixture fA = c.GetFixtureA();
b2Fixture fB = c.GetFixtureB();
// Is there a sensor?
if (fA.IsSensor || fB.IsSensor)
{
continue;
}
b2Body bA = fA.Body;
b2Body bB = fB.Body;
b2BodyType typeA = bA.BodyType;
b2BodyType typeB = bB.BodyType;
bool activeA = bA.IsAwake() && typeA != b2BodyType.b2_staticBody;
bool activeB = bB.IsAwake() && typeB != b2BodyType.b2_staticBody;
// Is at least one body active (awake and dynamic or kinematic)?
if (activeA == false && activeB == false)
{
continue;
}
bool collideA = bA.IsBullet() || typeA != b2BodyType.b2_dynamicBody;
bool collideB = bB.IsBullet() || typeB != b2BodyType.b2_dynamicBody;
// Are these two non-bullet dynamic bodies?
if (collideA == false && collideB == false)
{
continue;
}
// Compute the TOI for this contact.
// Put the sweeps onto the same time interval.
float alpha0 = bA.Sweep.alpha0;
if (bA.Sweep.alpha0 < bB.Sweep.alpha0)
{
alpha0 = bB.Sweep.alpha0;
bA.Sweep.Advance(alpha0);
}
else if (bB.Sweep.alpha0 < bA.Sweep.alpha0)
{
alpha0 = bA.Sweep.alpha0;
bB.Sweep.Advance(alpha0);
}
int indexA = c.GetChildIndexA();
int indexB = c.GetChildIndexB();
// Compute the time of impact in interval [0, minTOI]
b2TOIInput input = new b2TOIInput();
input.proxyA.Set(fA.Shape, indexA);
input.proxyB.Set(fB.Shape, indexB);
input.sweepA = bA.Sweep;
input.sweepB = bB.Sweep;
input.tMax = 1.0f;
b2TOIOutput output = b2TimeOfImpact(input);
// Beta is the fraction of the remaining portion of the .
float beta = output.t;
if (output.state == b2TOIOutputType.e_touching)
{
alpha = b2Math.b2Min(alpha0 + (1.0f - alpha0) * beta, 1.0f);
}
else
{
alpha = 1.0f;
}
c.m_toi = alpha;
c.ContactFlags |= b2ContactFlags.e_toiFlag;
}
if (alpha < minAlpha)
{
// This is the minimum TOI found so far.
minContact = c;
minAlpha = alpha;
}
}
if (minContact == null || 1.0f - 10.0f * b2Settings.b2_epsilon < minAlpha)
{
// No more TOI events. Done!
m_stepComplete = true;
break;
}
{
// Advance the bodies to the TOI.
b2Fixture fA = minContact.GetFixtureA();
b2Fixture fB = minContact.GetFixtureB();
b2Body bA = fA.Body;
b2Body bB = fB.Body;
b2Sweep backup1 = bA.Sweep;
b2Sweep backup2 = bB.Sweep;
bA.Advance(minAlpha);
bB.Advance(minAlpha);
// The TOI contact likely has some new contact points.
minContact.Update(m_contactManager.ContactListener);
minContact.ContactFlags &= ~b2ContactFlags.e_toiFlag;
++minContact.m_toiCount;
// Is the contact solid?
if (minContact.IsEnabled() == false || minContact.IsTouching() == false)
{
// Restore the sweeps.
minContact.SetEnabled(false);
bA.Sweep = backup1;
bB.Sweep = backup2;
bA.SynchronizeTransform();
bB.SynchronizeTransform();
continue;
}
bA.SetAwake(true);
bB.SetAwake(true);
// Build the island
island.Clear();
island.Add(bA);
island.Add(bB);
island.Add(minContact);
bA.BodyFlags |= b2BodyFlags.e_islandFlag;
bB.BodyFlags |= b2BodyFlags.e_islandFlag;
minContact.ContentType |= b2ContactFlags.e_islandFlag;
// Get contacts on bodyA and bodyB.
b2Body[] bodies = new b2Body[] { bA, bB };
for (int i = 0; i < 2; ++i)
{
b2Body body = bodies[i];
if (body.BodyType == b2BodyType.b2_dynamicBody)
{
for (b2ContactEdge ce = body.ContactList; ce != null; ce = ce.next)
{
if (island.BodyCount == island.BodyCapacity)
{
break;
}
if (island.ContactCount == island.ContactCapacity)
{
break;
}
b2Contact contact = ce.contact;
// Has this contact already been added to the island?
if (contact.ContactType & b2ContactType.e_islandFlag)
{
continue;
}
// Only add static, kinematic, or bullet bodies.
b2Body other = ce.other;
if (other.BodyType == b2BodyType.b2_dynamicBody &&
body.IsBullet() == false && other.IsBullet() == false)
{
continue;
}
// Skip sensors.
bool sensorA = contact.m_fixtureA.m_isSensor;
bool sensorB = contact.m_fixtureB.m_isSensor;
if (sensorA || sensorB)
{
continue;
}
// Tentatively advance the body to the TOI.
b2Sweep backup = other.Sweep;
if (other.BodyFlags.HasFlag(b2BodyFlags.e_islandFlag))
{
other.Advance(minAlpha);
}
// Update the contact points
contact.Update(m_contactManager.ContactListener);
// Was the contact disabled by the user?
if (contact.IsEnabled() == false)
{
other.Sweep = backup;
other.SynchronizeTransform();
continue;
}
// Are there contact points?
if (contact.IsTouching() == false)
{
other.Sweep = backup;
other.SynchronizeTransform();
continue;
}
// Add the contact to the island
contact.ContactFlags |= b2ContactFlags.e_islandFlag;
island.Add(contact);
// Has the other body already been added to the island?
if (other.BodyFlags.HasFlag(b2BodyFlags.e_islandFlag))
{
continue;
}
// Add the other body to the island.
other.BodyFlags |= b2BodyFlags.e_islandFlag;
if (other.BodyType != b2BodyType.b2_staticBody)
{
other.SetAwake(true);
}
island.Add(other);
}
}
}
b2TimeStep subStep;
subStep.dt = (1.0f - minAlpha) * step.dt;
subStep.inv_dt = 1.0f / subStep.dt;
subStep.dtRatio = 1.0f;
subStep.positionIterations = 20;
subStep.velocityIterations = step.velocityIterations;
subStep.warmStarting = false;
island.SolveTOI(subStep, bA.m_islandIndex, bB.m_islandIndex);
// Reset island flags and synchronize broad-phase proxies.
for (int i = 0; i < island.m_bodyCount; ++i)
{
b2Body body = island.m_bodies[i];
body.BodyFlags &= ~b2BodyFlags.e_islandFlag;
if (body.BodyType != b2BodyType.b2_dynamicBody)
{
continue;
}
body.SynchronizeFixtures();
// Invalidate all contact TOIs on this displaced body.
for (b2ContactEdge ce = body.ContactList; ce != null; ce = ce.next)
{
ce.Contact.ContactFlags &= ~(b2ContactFlags.e_toiFlag | b2ContactFlags.e_islandFlag);
}
}
// Commit fixture proxy movements to the broad-phase so that new contacts are created.
// Also, some contacts can be destroyed.
m_contactManager.FindNewContacts();
if (m_subStepping)
{
m_stepComplete = false;
break;
}
}
}
}
public void AddPair(object proxyUserDataA, object proxyUserDataB)
{
b2FixtureProxy proxyA = (b2FixtureProxy)proxyUserDataA;
b2FixtureProxy proxyB = (b2FixtureProxy)proxyUserDataB;
b2Fixture fixtureA = proxyA.fixture;
b2Fixture fixtureB = proxyB.fixture;
int indexA = proxyA.childIndex;
int indexB = proxyB.childIndex;
b2Body bodyA = fixtureA.GetBody();
b2Body bodyB = fixtureB.GetBody();
// Are the fixtures on the same body?
if (bodyA == bodyB)
{
return;
}
// TODO_ERIN use a hash table to remove a potential bottleneck when both
// bodies have a lot of contacts.
// Does a contact already exist?
b2ContactEdge edge = bodyB.GetContactList();
while (edge)
{
if (edge.other == bodyA)
{
b2Fixture fA = edge.contact.GetFixtureA();
b2Fixture fB = edge.contact.GetFixtureB();
int iA = edge.contact.GetChildIndexA();
int iB = edge.contact.GetChildIndexB();
if (fA == fixtureA && fB == fixtureB && iA == indexA && iB == indexB)
{
// A contact already exists.
return;
}
if (fA == fixtureB && fB == fixtureA && iA == indexB && iB == indexA)
{
// A contact already exists.
return;
}
}
edge = edge.next;
}
// Does a joint override collision? Is at least one body dynamic?
if (bodyB.ShouldCollide(bodyA) == false)
{
return;
}
// Check user filtering.
if (m_contactFilter && m_contactFilter.ShouldCollide(fixtureA, fixtureB) == false)
{
return;
}
// Call the factory.
b2Contact c = b2Contact.Create(fixtureA, indexA, fixtureB, indexB, m_allocator);
if (c == null)
{
return;
}
// Contact creation may swap fixtures.
fixtureA = c.GetFixtureA();
fixtureB = c.GetFixtureB();
indexA = c.GetChildIndexA();
indexB = c.GetChildIndexB();
bodyA = fixtureA.GetBody();
bodyB = fixtureB.GetBody();
// Insert into the world.
c.m_prev = null;
c.m_next = m_contactList;
if (m_contactList != null)
{
m_contactList.m_prev = c;
}
m_contactList = c;
// Connect to island graph.
// Connect to body A
c.m_nodeA.contact = c;
c.m_nodeA.other = bodyB;
c.m_nodeA.prev = null;
c.m_nodeA.next = bodyA.m_contactList;
if (bodyA.m_contactList != null)
{
bodyA.m_contactList.prev = &c.m_nodeA;
}
bodyA.m_contactList = &c.m_nodeA;
// Connect to body B
c.m_nodeB.contact = c;
c.m_nodeB.other = bodyA;
c.m_nodeB.prev = null;
c.m_nodeB.next = bodyB.m_contactList;
if (bodyB.m_contactList != null)
{
bodyB.m_contactList.prev = &c.m_nodeB;
}
bodyB.m_contactList = &c.m_nodeB;
// Wake up the bodies
bodyA.SetAwake(true);
bodyB.SetAwake(true);
++m_contactCount;
}
// This is the top level collision call for the time step. Here
// all the narrow phase collision is processed for the world
// contact list.
public void Collide()
{
// Update awake contacts.
b2Contact c = m_contactList;
while (c)
{
b2Fixture fixtureA = c.GetFixtureA();
b2Fixture fixtureB = c.GetFixtureB();
int indexA = c.GetChildIndexA();
int indexB = c.GetChildIndexB();
b2Body bodyA = fixtureA.GetBody();
b2Body bodyB = fixtureB.GetBody();
// Is this contact flagged for filtering?
if (c.m_flags & b2Contact.e_filterFlag)
{
// Should these bodies collide?
if (bodyB.ShouldCollide(bodyA) == false)
{
b2Contact cNuke = c;
c = cNuke.GetNext();
Destroy(cNuke);
continue;
}
// Check user filtering.
if (m_contactFilter && m_contactFilter.ShouldCollide(fixtureA, fixtureB) == false)
{
b2Contact cNuke = c;
c = cNuke.GetNext();
Destroy(cNuke);
continue;
}
// Clear the filtering flag.
c.m_flags &= ~b2Contact.e_filterFlag;
}
bool activeA = bodyA.IsAwake() && bodyA.m_type != b2BodyType.b2_staticBody;
bool activeB = bodyB.IsAwake() && bodyB.m_type != b2BodyType.b2_staticBody;
// At least one body must be awake and it must be dynamic or kinematic.
if (activeA == false && activeB == false)
{
c = c.GetNext();
continue;
}
int proxyIdA = fixtureA.m_proxies[indexA].proxyId;
int proxyIdB = fixtureB.m_proxies[indexB].proxyId;
bool overlap = m_broadPhase.TestOverlap(proxyIdA, proxyIdB);
// Here we destroy contacts that cease to overlap in the broad-phase.
if (overlap == false)
{
b2Contact cNuke = c;
c = cNuke.GetNext();
Destroy(cNuke);
continue;
}
// The contact persists.
c.Update(m_contactListener);
c = c.GetNext();
}
}
public void SolveTOI(b2TimeStep subStep, int toiIndexA, int toiIndexB)
{
Debug.Assert(toiIndexA < m_bodyCount);
Debug.Assert(toiIndexB < m_bodyCount);
// Initialize the body state.
for (int i = 0; i < m_bodyCount; ++i)
{
b2Body b = m_bodies[i];
m_positions[i].c = b.Sweep.c;
m_positions[i].a = b.Sweep.a;
m_velocities[i].v = b.LinearVelocity;
m_velocities[i].w = b.AngularVelocity;
}
b2ContactSolverDef contactSolverDef;
contactSolverDef.contacts = m_contacts;
contactSolverDef.count = m_contactCount;
contactSolverDef.step = subStep;
contactSolverDef.positions = m_positions;
contactSolverDef.velocities = m_velocities;
b2ContactSolver contactSolver = new b2ContactSolver(contactSolverDef);
// Solve position constraints.
for (int i = 0; i < subStep.positionIterations; ++i)
{
bool contactsOkay = contactSolver.SolveTOIPositionConstraints(toiIndexA, toiIndexB);
if (contactsOkay)
{
break;
}
}
#if false
// Is the new position really safe?
for (int i = 0; i < m_contactCount; ++i)
{
b2Contact c = m_contacts[i];
b2Fixture fA = c.GetFixtureA();
b2Fixture fB = c.GetFixtureB();
b2Body bA = fA.Body;
b2Body bB = fB.Body;
int indexA = c.GetChildIndexA();
int indexB = c.GetChildIndexB();
b2DistanceInput input = new b2DistanceInput();
input.proxyA.Set(fA.Shape, indexA);
input.proxyB.Set(fB.Shape, indexB);
input.transformA = bA.Transform;
input.transformB = bB.Transform;
input.useRadii = false;
b2DistanceOutput output;
b2SimplexCache cache = new b2SimplexCache();
cache.count = 0;
output = b2Distance(cache, input);
if (output.distance == 0 || cache.count == 3)
{
cache.count += 0;
}
}
#endif
// Leap of faith to new safe state.
m_bodies[toiIndexA].Sweep.c0 = m_positions[toiIndexA].c;
m_bodies[toiIndexA].Sweep.a0 = m_positions[toiIndexA].a;
m_bodies[toiIndexB].Sweep.c0 = m_positions[toiIndexB].c;
m_bodies[toiIndexB].Sweep.a0 = m_positions[toiIndexB].a;
// No warm starting is needed for TOI events because warm
// starting impulses were applied in the discrete solver.
contactSolver.InitializeVelocityConstraints();
// Solve velocity constraints.
for (int i = 0; i < subStep.velocityIterations; ++i)
{
contactSolver.SolveVelocityConstraints();
}
// Don't store the TOI contact forces for warm starting
// because they can be quite large.
float h = subStep.dt;
// Integrate positions
for (int i = 0; i < m_bodyCount; ++i)
{
b2Vec2 c = m_positions[i].c;
float a = m_positions[i].a;
b2Vec2 v = m_velocities[i].v;
float w = m_velocities[i].w;
// Check for large velocities
b2Vec2 translation = h * v;
if (b2Math.b2Dot(translation, translation) > b2Settings.b2_maxTranslationSquared)
{
float ratio = b2Settings.b2_maxTranslation / translation.Length;
v *= ratio;
}
float rotation = h * w;
if (rotation * rotation > b2Settings.b2_maxRotationSquared)
{
float ratio = b2Settings.b2_maxRotation / Math.Abs(rotation);
w *= ratio;
}
// Integrate
c += h * v;
a += h * w;
m_positions[i].c = c;
m_positions[i].a = a;
m_velocities[i].v = v;
m_velocities[i].w = w;
// Sync bodies
b2Body body = m_bodies[i];
body.Sweep.c = c;
body.Sweep.a = a;
body.LinearVelocity = v;
body.AngularVelocity = w;
body.SynchronizeTransform();
}
Report(contactSolver.m_velocityConstraints);
}