/**
* Integrates the particle forward in time by the given amount.
* This function uses a Newton-Euler integration method, which is a
* linear approximation to the correct integral. For this reason it
* may be inaccurate in some cases.
*/
public void Integrate(double duration)
{
// We don't integrate things with zero mass.
if (inverseMass <= 0.0f)
{
return;
}
Debug.Assert(duration > 0.0);
// Update linear position.
position.AddScaledVector(this.velocity, duration);
// Work out the acceleration from the force
MyVector3 resultingAcc = acceleration;
resultingAcc.AddScaledVector(forceAccum, inverseMass);
// Update linear velocity from the acceleration.
velocity.AddScaledVector(resultingAcc, duration);
// Impose drag.
velocity *= System.Math.Pow(damping, duration);
// Clear the forces.
ClearAccumulator();
}
/**
* Integrates the rigid body forward in time by the given amount.
* This function uses a Newton-Euler integration method
*/
public void integrate(real duration)
{
if (!isAwake)
{
return;
}
lastFrameAcceleration = acceleration;
lastFrameAcceleration.AddScaledVector(forceAccum, inverseMass);
MyVector3 angularAcceleration = inverseInertiaTensorWorld.transform(torqueAccum);
velocity.AddScaledVector(lastFrameAcceleration, duration);
rotation.AddScaledVector(angularAcceleration, duration);
velocity *= Mathf.Pow((float)linearDamping, (float)duration);
rotation *= Mathf.Pow((float)angularDamping, (float)duration);
position.AddScaledVector(velocity, duration);
orientation.addScaledVector(rotation, duration);
calculateDerivedData();
clearAccumulators();
if (canSleep)
{
real currentMotion = velocity.ScalarProduct(velocity) +
rotation.ScalarProduct(rotation);
real bias = Mathf.Pow(0.5f, (float)duration);
motion = bias * motion + (1 - bias) * currentMotion;
if (motion < sleepEpsilon)
{
setAwake(false);
}
else if (motion > 10 * sleepEpsilon)
{
motion = 10 * sleepEpsilon;
}
}
}
