private void solve(TimeStep step) {
m_profile.solveInit = 0;
m_profile.solveVelocity = 0;
m_profile.solvePosition = 0;
// Size the island for the worst case.
island.init(
m_bodyCount,
m_contactManager.m_contactCount,
m_jointCount,
m_contactManager.m_contactListener);
// Clear all the island flags.
for (Body b = m_bodyList; b != null; b = b.m_next) {
b.m_flags &= ~Body.e_islandFlag;
}
for (Contact c = m_contactManager.m_contactList; c != null; c = c.m_next) {
c.m_flags &= ~Contact.ISLAND_FLAG;
}
for (Joint j = m_jointList; j != null; j = j.m_next) {
j.m_islandFlag = false;
}
// Build and simulate all awake islands.
int stackSize = m_bodyCount;
if (stack.length < stackSize) {
stack = new Body[stackSize];
}
for (Body seed = m_bodyList; seed != null; seed = seed.m_next) {
if ((seed.m_flags & Body.e_islandFlag) == Body.e_islandFlag) {
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.m_flags |= Body.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];
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.m_contactList; ce != null; ce = ce.next) {
Contact contact = ce.contact;
// Has this contact already been added to an island?
if ((contact.m_flags & Contact.ISLAND_FLAG) == Contact.ISLAND_FLAG) {
continue;
}
// Is this contact solid and touching?
if (contact.isEnabled() == false || contact.isTouching() == false) {
continue;
}
// Skip sensors.
boolean sensorA = contact.m_fixtureA.m_isSensor;
boolean sensorB = contact.m_fixtureB.m_isSensor;
if (sensorA || sensorB) {
continue;
}
island.add(contact);
contact.m_flags |= Contact.ISLAND_FLAG;
Body other = ce.other;
// Was the other body already added to this island?
if ((other.m_flags & Body.e_islandFlag) == Body.e_islandFlag) {
continue;
}
assert (stackCount < stackSize);
stack[stackCount++] = other;
other.m_flags |= Body.e_islandFlag;
}
// Search all joints connect to this body.
for (JointEdge je = b.m_jointList; je != null; je = je.next) {
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 & Body.e_islandFlag) == Body.e_islandFlag) {
continue;
}
assert (stackCount < stackSize);
stack[stackCount++] = other;
other.m_flags |= Body.e_islandFlag;
}
}
island.solve(islandProfile, step, m_gravity, m_allowSleep);
m_profile.solveInit += islandProfile.solveInit;
m_profile.solveVelocity += islandProfile.solveVelocity;
m_profile.solvePosition += islandProfile.solvePosition;
// Post solve cleanup.
for (int i = 0; i < island.m_bodyCount; ++i) {
// Allow static bodies to participate in other islands.
Body b = island.m_bodies[i];
if (b.getType() == BodyType.STATIC) {
b.m_flags &= ~Body.e_islandFlag;
}
}
}
broadphaseTimer.reset();
// Synchronize fixtures, check for out of range bodies.
for (Body b = m_bodyList; b != null; b = b.getNext()) {
// If a body was not in an island then it did not move.
if ((b.m_flags & Body.e_islandFlag) == 0) {
continue;
}
if (b.getType() == BodyType.STATIC) {
continue;
}
// Update fixtures (for broad-phase).
b.synchronizeFixtures();
}
// Look for new contacts.
m_contactManager.findNewContacts();
m_profile.broadphase = broadphaseTimer.getMilliseconds();
}
