public static void Prestep(ref Vector3Wide tangentX, ref Vector3Wide tangentY, ref Vector3Wide offsetA, ref BodyInertias inertiaA,
out Projection projection)
{
ComputeJacobians(ref tangentX, ref tangentY, ref offsetA, out var jacobians);
//Compute effective mass matrix contributions.
Symmetric2x2Wide.SandwichScale(jacobians.LinearA, inertiaA.InverseMass, out var linearContributionA);
Symmetric3x3Wide.MatrixSandwich(jacobians.AngularA, inertiaA.InverseInertiaTensor, out var angularContributionA);
//No softening; this constraint is rigid by design. (It does support a maximum force, but that is distinct from a proper damping ratio/natural frequency.)
Symmetric2x2Wide.Add(linearContributionA, angularContributionA, out var inverseEffectiveMass);
Symmetric2x2Wide.InvertWithoutOverlap(inverseEffectiveMass, out projection.EffectiveMass);
projection.OffsetA = offsetA;
//Note that friction constraints have no bias velocity. They target zero velocity.
}
public void Do()
{
Symmetric3x3Wide.MatrixSandwich(m, triangular, out result);
}