Extending Box2D-Lite in Javascript: World Class

The properties / members and the key methods associated with the world class of Box2D is shown below. This is by no means a complete list - not by a long way!

STEP

1. very beginning

// If new fixtures were added, we need to find the new contacts.

if (m_newContacts)

{

m_contactManager.FindNewContacts();

m_newContacts = false;

}

2.// Update contacts. This is where some contacts are destroyed.

{

b2Timer timer;

m_contactManager.Collide();

m_profile.collide = timer.GetMilliseconds();

}

3.// Integrate velocities, solve velocity constraints, and integrate positions.

if (m_stepComplete && step.dt > 0.0f)

{

b2Timer timer;

Solve(step);

m_profile.solve = timer.GetMilliseconds();

}

4.if (m_clearForces)

{

ClearForces();

}

SOLVE

// Find islands, integrate and solve constraints, solve position constraints

1. loop through contact / joint graph and rebuild island

2. call island.solve

3. for all bodies, synchornize fixtures

4. m_contactManager.FindNewContacts(); // Look for new contacts.