void Solve(ref TimeStep step)
{
// Size the island for the worst case.
_island.Reset(_bodyCount,
_contactManager._contactCount,
_jointCount,
_contactManager.ContactListener);
// Clear all the island flags.
for (Body b = _bodyList; b != null; b = b._next)
{
b._flags &= ~BodyFlags.Island;
}
for (Contact c = _contactManager._contactList; c != null; c = c._next)
{
c._flags &= ~ContactFlags.Island;
}
for (Joint j = _jointList; j != null; j = j._next)
{
j._islandFlag = false;
}
// Build and simulate all awake islands.
int stackSize = _bodyCount;
if (stackSize > stack.Length)
{
stack = new Body[Math.Max(stack.Length * 2, stackSize)];
}
for (Body seed = _bodyList; seed != null; seed = seed._next)
{
if ((seed._flags & (BodyFlags.Island)) != BodyFlags.None)
{
continue;
}
if (seed.IsAwake() == false || seed.IsActive() == false)
{
continue;
}
// The seed can be dynamic or kinematic.
if (seed.GetType() == BodyType.Static)
{
continue;
}
// Reset island and stack.
_island.Clear();
int stackCount = 0;
stack[stackCount++] = seed;
seed._flags |= BodyFlags.Island;
// Perform a depth first search (DFS) on the raint graph.
while (stackCount > 0)
{
// Grab the next body off the stack and add it to the island.
Body b = stack[--stackCount];
//Debug.Assert(b.IsActive() == true);
_island.Add(b);
// Make sure the body is awake.
b.SetAwake(true);
// To keep islands as small as possible, we don't
// propagate islands across static bodies.
if (b.GetType() == BodyType.Static)
{
continue;
}
// Search all contacts connected to this body.
for (ContactEdge ce = b._contactList; ce != null; ce = ce.Next)
{
Contact contact = ce.Contact;
// Has this contact already been added to an island?
if ((contact._flags & ContactFlags.Island) != ContactFlags.None)
{
continue;
}
// Is this contact solid and touching?
if (!ce.Contact.IsEnabled() || !ce.Contact.IsTouching())
{
continue;
}
// Skip sensors.
bool sensorA = contact._fixtureA._isSensor;
bool sensorB = contact._fixtureB._isSensor;
if (sensorA || sensorB)
{
continue;
}
_island.Add(contact);
contact._flags |= ContactFlags.Island;
Body other = ce.Other;
// Was the other body already added to this island?
if ((other._flags & BodyFlags.Island) != BodyFlags.None)
{
continue;
}
//Debug.Assert(stackCount < stackSize);
stack[stackCount++] = other;
other._flags |= BodyFlags.Island;
}
// Search all joints connect to this body.
for (JointEdge je = b._jointList; je != null; je = je.Next)
{
if (je.Joint._islandFlag == true)
{
continue;
}
Body other = je.Other;
// Don't simulate joints connected to inactive bodies.
if (other.IsActive() == false)
{
continue;
}
_island.Add(je.Joint);
je.Joint._islandFlag = true;
if ((other._flags & BodyFlags.Island) != BodyFlags.None)
{
continue;
}
//Debug.Assert(stackCount < stackSize);
stack[stackCount++] = other;
other._flags |= BodyFlags.Island;
}
}
_island.Solve(ref step, Gravity, _allowSleep);
// Post solve cleanup.
for (int i = 0; i < _island._bodyCount; ++i)
{
// Allow static bodies to participate in other islands.
Body b = _island._bodies[i];
if (b.GetType() == BodyType.Static)
{
b._flags &= ~BodyFlags.Island;
}
}
}
// Synchronize fixtures, check for out of range bodies.
for (Body b = _bodyList; b != null; b = b.GetNext())
{
// If a body was not in an island then it did not move.
if ((b._flags & BodyFlags.Island) != BodyFlags.Island)
{
continue;
}
if (b.GetType() == BodyType.Static)
{
continue;
}
// Update fixtures (for broad-phase).
b.SynchronizeFixtures();
}
// Look for new contacts.
_contactManager.FindNewContacts();
}
private void Solve(TimeStep step)
{
m_profile.solveInit = 0.0f;
m_profile.solveVelocity = 0.0f;
m_profile.solvePosition = 0.0f;
// Size the island for the worst case.
Island island = new Island(m_contactManager.m_contactListener);
// Clear all the island flags.
foreach (Body b in m_bodyList)
{
b.m_flags &= ~Body.BodyFlags.e_islandFlag;
}
foreach (Contact c in m_contactManager.m_contactList)
{
c.m_flags &= ~ContactFlags.e_islandFlag;
}
foreach (Joint j in m_jointList)
{
j.m_islandFlag = false;
}
// Build and simulate all awake islands.
List <Body> stack = new List <Body>(m_bodyList.Count());
foreach (Body seed in m_bodyList)
{
if (seed.m_flags.HasFlag(Body.BodyFlags.e_islandFlag))
{
continue;
}
if (seed.IsAwake() == false || seed.IsActive() == false)
{
continue;
}
// The seed can be dynamic or kinematic.
if (seed.GetBodyType() == BodyType._staticBody)
{
continue;
}
// Reset island and stack.
island.Clear();
int stackCount = 0;
stack.Add(seed); stackCount++;
seed.m_flags |= Body.BodyFlags.e_islandFlag;
// Perform a depth first search (DFS) on the constraint graph.
while (stackCount > 0)
{
// Grab the next body off the stack and add it to the island.
Body b = stack[--stackCount];
Utilities.Assert(b.IsActive() == true);
island.Add(b);
// Make sure the body is awake.
b.SetAwake(true);
// To keep islands as small as possible, we don't
// propagate islands across static bodies.
if (b.GetBodyType() == BodyType._staticBody)
{
continue;
}
// Search all contacts connected to this body.
foreach (ContactEdge ce in b.m_contactList)
{
Contact contact = ce.contact;
// Has this contact already been added to an island?
if (contact.m_flags.HasFlag(ContactFlags.e_islandFlag))
{
continue;
}
// Is this contact solid and touching?
if (contact.IsEnabled() == false ||
contact.IsTouching() == false)
{
continue;
}
// Skip sensors.
bool sensorA = contact.m_fixtureA.m_isSensor;
bool sensorB = contact.m_fixtureB.m_isSensor;
if (sensorA || sensorB)
{
continue;
}
island.Add(contact);
contact.m_flags |= ContactFlags.e_islandFlag;
Body other = ce.other;
// Was the other body already added to this island?
if (other.m_flags.HasFlag(Body.BodyFlags.e_islandFlag))
{
continue;
}
Utilities.Assert(stackCount < m_bodyList.Count());
stack.Add(other); stackCount++;
other.m_flags |= Body.BodyFlags.e_islandFlag;
}
// Search all joints connect to this body.
foreach (JointEdge je in b.m_jointList)
{
if (je.joint.m_islandFlag == true)
{
continue;
}
Body other = je.other;
// Don't simulate joints connected to inactive bodies.
if (other.IsActive() == false)
{
continue;
}
island.Add(je.joint);
je.joint.m_islandFlag = true;
if (other.m_flags.HasFlag(Body.BodyFlags.e_islandFlag))
{
continue;
}
stack.Add(other); stackCount++;
other.m_flags |= Body.BodyFlags.e_islandFlag;
}
}
Profile profile = new Profile();
island.Solve(profile, step, m_gravity, m_allowSleep);
m_profile.solveInit += profile.solveInit;
m_profile.solveVelocity += profile.solveVelocity;
m_profile.solvePosition += profile.solvePosition;
// Post solve cleanup.
for (int i = 0; i < island.m_bodies.Count(); ++i)
{
// Allow static bodies to participate in other islands.
Body b = island.m_bodies[i];
if (b.GetBodyType() == BodyType._staticBody)
{
b.m_flags &= ~Body.BodyFlags.e_islandFlag;
}
}
}
{
Timer timer = new Timer();
// Synchronize fixtures, check for out of range bodies.
foreach (Body b in m_bodyList)
{
// If a body was not in an island then it did not move.
if ((b.m_flags & Body.BodyFlags.e_islandFlag) == 0)
{
continue;
}
if (b.GetBodyType() == BodyType._staticBody)
{
continue;
}
// Update fixtures (for broad-phase).
b.SynchronizeFixtures();
}
// Look for new contacts.
m_contactManager.FindNewContacts();
m_profile.broadphase = timer.GetMilliseconds();
}
}
