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();
}
private void solveTOI(final TimeStep step) {
final Island island = toiIsland;
island.init(
2 * Settings.maxTOIContacts,
Settings.maxTOIContacts,
0,
m_contactManager.m_contactListener);
if (m_stepComplete) {
for (Body b = m_bodyList; b != null; b = b.m_next) {
b.m_flags &= ~Body.e_islandFlag;
b.m_sweep.alpha0 = 0.0f;
}
for (Contact c = m_contactManager.m_contactList; c != null; c = c.m_next) {
// Invalidate TOI
c.m_flags &= ~(Contact.TOI_FLAG | Contact.ISLAND_FLAG);
c.m_toiCount = 0;
c.m_toi = 1.0f;
}
}
// Find TOI events and solve them.
for (; ; ) {
// Find the first TOI.
Contact minContact = null;
float minAlpha = 1.0f;
for (Contact c = m_contactManager.m_contactList; c != null; c = c.m_next) {
// Is this contact disabled?
if (c.isEnabled() == false) {
continue;
}
// Prevent excessive sub-stepping.
if (c.m_toiCount > Settings.maxSubSteps) {
continue;
}
float alpha = 1.0f;
if ((c.m_flags & Contact.TOI_FLAG) != 0) {
// This contact has a valid cached TOI.
alpha = c.m_toi;
} else {
Fixture fA = c.getFixtureA();
Fixture fB = c.getFixtureB();
// Is there a sensor?
if (fA.isSensor() || fB.isSensor()) {
continue;
}
Body bA = fA.getBody();
Body bB = fB.getBody();
BodyType typeA = bA.m_type;
BodyType typeB = bB.m_type;
assert (typeA == BodyType.DYNAMIC || typeB == BodyType.DYNAMIC);
boolean activeA = bA.isAwake() && typeA != BodyType.STATIC;
boolean activeB = bB.isAwake() && typeB != BodyType.STATIC;
// Is at least one body active (awake and dynamic or kinematic)?
if (activeA == false && activeB == false) {
continue;
}
boolean collideA = bA.isBullet() || typeA != BodyType.DYNAMIC;
boolean collideB = bB.isBullet() || typeB != BodyType.DYNAMIC;
// 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.m_sweep.alpha0;
if (bA.m_sweep.alpha0 < bB.m_sweep.alpha0) {
alpha0 = bB.m_sweep.alpha0;
bA.m_sweep.advance(alpha0);
} else if (bB.m_sweep.alpha0 < bA.m_sweep.alpha0) {
alpha0 = bA.m_sweep.alpha0;
bB.m_sweep.advance(alpha0);
}
assert (alpha0 < 1.0f);
int indexA = c.getChildIndexA();
int indexB = c.getChildIndexB();
// Compute the time of impact in interval [0, minTOI]
final TOIInput input = toiInput;
input.proxyA.set(fA.getShape(), indexA);
input.proxyB.set(fB.getShape(), indexB);
input.sweepA.set(bA.m_sweep);
input.sweepB.set(bB.m_sweep);
input.tMax = 1.0f;
pool.getTimeOfImpact().timeOfImpact(toiOutput, input);
// Beta is the fraction of the remaining portion of the .
float beta = toiOutput.t;
if (toiOutput.state == TOIOutputState.TOUCHING) {
alpha = MathUtils.min(alpha0 + (1.0f - alpha0) * beta, 1.0f);
} else {
alpha = 1.0f;
}
c.m_toi = alpha;
c.m_flags |= Contact.TOI_FLAG;
}
if (alpha < minAlpha) {
// This is the minimum TOI found so far.
minContact = c;
minAlpha = alpha;
}
}
if (minContact == null || 1.0f - 10.0f * Settings.EPSILON < minAlpha) {
// No more TOI events. Done!
m_stepComplete = true;
break;
}
// Advance the bodies to the TOI.
Fixture fA = minContact.getFixtureA();
Fixture fB = minContact.getFixtureB();
Body bA = fA.getBody();
Body bB = fB.getBody();
backup1.set(bA.m_sweep);
backup2.set(bB.m_sweep);
bA.advance(minAlpha);
bB.advance(minAlpha);
// The TOI contact likely has some new contact points.
minContact.update(m_contactManager.m_contactListener);
minContact.m_flags &= ~Contact.TOI_FLAG;
++minContact.m_toiCount;
// Is the contact solid?
if (minContact.isEnabled() == false || minContact.isTouching() == false) {
// Restore the sweeps.
minContact.setEnabled(false);
bA.m_sweep.set(backup1);
bB.m_sweep.set(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.m_flags |= Body.e_islandFlag;
bB.m_flags |= Body.e_islandFlag;
minContact.m_flags |= Contact.ISLAND_FLAG;
// Get contacts on bodyA and bodyB.
tempBodies[0] = bA;
tempBodies[1] = bB;
for (int i = 0; i < 2; ++i) {
Body body = tempBodies[i];
if (body.m_type == BodyType.DYNAMIC) {
for (ContactEdge ce = body.m_contactList; ce != null; ce = ce.next) {
if (island.m_bodyCount == island.m_bodyCapacity) {
break;
}
if (island.m_contactCount == island.m_contactCapacity) {
break;
}
Contact contact = ce.contact;
// Has this contact already been added to the island?
if ((contact.m_flags & Contact.ISLAND_FLAG) != 0) {
continue;
}
// Only add static, kinematic, or bullet bodies.
Body other = ce.other;
if (other.m_type == BodyType.DYNAMIC
&& body.isBullet() == false
&& other.isBullet() == false) {
continue;
}
// Skip sensors.
boolean sensorA = contact.m_fixtureA.m_isSensor;
boolean sensorB = contact.m_fixtureB.m_isSensor;
if (sensorA || sensorB) {
continue;
}
// Tentatively advance the body to the TOI.
backup1.set(other.m_sweep);
if ((other.m_flags & Body.e_islandFlag) == 0) {
other.advance(minAlpha);
}
// Update the contact points
contact.update(m_contactManager.m_contactListener);
// Was the contact disabled by the user?
if (contact.isEnabled() == false) {
other.m_sweep.set(backup1);
other.synchronizeTransform();
continue;
}
// Are there contact points?
if (contact.isTouching() == false) {
other.m_sweep.set(backup1);
other.synchronizeTransform();
continue;
}
// Add the contact to the island
contact.m_flags |= Contact.ISLAND_FLAG;
island.add(contact);
// Has the other body already been added to the island?
if ((other.m_flags & Body.e_islandFlag) != 0) {
continue;
}
// Add the other body to the island.
other.m_flags |= Body.e_islandFlag;
if (other.m_type != BodyType.STATIC) {
other.setAwake(true);
}
island.add(other);
}
}
}
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) {
Body body = island.m_bodies[i];
body.m_flags &= ~Body.e_islandFlag;
if (body.m_type != BodyType.DYNAMIC) {
continue;
}
body.synchronizeFixtures();
// Invalidate all contact TOIs on this displaced body.
for (ContactEdge ce = body.m_contactList; ce != null; ce = ce.next) {
ce.contact.m_flags &= ~(Contact.TOI_FLAG | Contact.ISLAND_FLAG);
}
}
// 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;
}
}
}