/**
* Take a time step. This performs collision detection, integration, and constraint solution.
*
* @param timeStep the amount of time to simulate, this should not vary.
* @param velocityIterations for the velocity constraint solver.
* @param positionIterations for the position constraint solver.
*/
public void step(float dt, int velocityIterations, int positionIterations) {
stepTimer.reset();
// log.debug("Starting step");
// If new fixtures were added, we need to find the new contacts.
if ((m_flags & NEW_FIXTURE) == NEW_FIXTURE) {
// log.debug("There's a new fixture, lets look for new contacts");
m_contactManager.findNewContacts();
m_flags &= ~NEW_FIXTURE;
}
m_flags |= LOCKED;
step.dt = dt;
step.velocityIterations = velocityIterations;
step.positionIterations = positionIterations;
if (dt > 0.0f) {
step.inv_dt = 1.0f / dt;
} else {
step.inv_dt = 0.0f;
}
step.dtRatio = m_inv_dt0 * dt;
step.warmStarting = m_warmStarting;
// Update contacts. This is where some contacts are destroyed.
tempTimer.reset();
m_contactManager.collide();
m_profile.collide = tempTimer.getMilliseconds();
// Integrate velocities, solve velocity constraints, and integrate positions.
if (m_stepComplete && step.dt > 0.0f) {
tempTimer.reset();
solve(step);
m_profile.solve = tempTimer.getMilliseconds();
}
// Handle TOI events.
if (m_continuousPhysics && step.dt > 0.0f) {
tempTimer.reset();
solveTOI(step);
m_profile.solveTOI = tempTimer.getMilliseconds();
}
if (step.dt > 0.0f) {
m_inv_dt0 = step.inv_dt;
}
if ((m_flags & CLEAR_FORCES) == CLEAR_FORCES) {
clearForces();
}
m_flags &= ~LOCKED;
// log.debug("ending step");
m_profile.step = stepTimer.getMilliseconds();
}