Method Step

DynamicsB2World.go:890–947

(dt float64, velocityIterations int, positionIterations int)

}

func (world *B2World) Step(dt float64, velocityIterations int, positionIterations int) {
	stepTimer := MakeB2Timer()

	// If new fixtures were added, we need to find the new contacts.
	if (world.M_flags & B2World_Flags.E_newFixture) != 0x0000 {
		world.M_contactManager.FindNewContacts()
		world.M_flags &= ^B2World_Flags.E_newFixture
	}

	world.M_flags |= B2World_Flags.E_locked

	step := MakeB2TimeStep()
	step.Dt = dt
	step.VelocityIterations = velocityIterations
	step.PositionIterations = positionIterations
	if dt > 0.0 {
		step.Inv_dt = 1.0 / dt
	} else {
		step.Inv_dt = 0.0
	}

	step.DtRatio = world.M_inv_dt0 * dt

	step.WarmStarting = world.M_warmStarting

	// Update contacts. This is where some contacts are destroyed.
	{
		timer := MakeB2Timer()
		world.M_contactManager.Collide()
		world.M_profile.Collide = timer.GetMilliseconds()
	}

	// Integrate velocities, solve velocity constraints, and integrate positions.
	if world.M_stepComplete && step.Dt > 0.0 {
		timer := MakeB2Timer()
		world.Solve(step)
		world.M_profile.Solve = timer.GetMilliseconds()
	}

	// Handle TOI events.
	if world.M_continuousPhysics && step.Dt > 0.0 {
		timer := MakeB2Timer()
		world.SolveTOI(step)
		world.M_profile.SolveTOI = timer.GetMilliseconds()
	}

	if step.Dt > 0.0 {
		world.M_inv_dt0 = step.Inv_dt
	}

	if (world.M_flags & B2World_Flags.E_clearForces) != 0x0000 {
		world.ClearForces()
	}

	world.M_flags &= ^B2World_Flags.E_locked

	world.M_profile.Step = stepTimer.GetMilliseconds()
}