private static void UpdateWindingAngleDelta(WindingData winding)
{
var sin = winding.CurrentDummyWorld.Right.Dot(winding.LastDummyWorld.Up);
var cos = winding.CurrentDummyWorld.Right.Dot(winding.LastDummyWorld.Right);
// Circumference is C=2πr for whole circle (2π) but I'm only interested in part of it (atan(y,x)*π).
winding.AngleDelta = (float)Math.Atan2(sin, cos);
}
private static Vector3 ComputeTorqueFromRopeImpulse(WindingData windingData, InternalRopeData ropeData, Vector3 ropeDirectionVector, Vector3 centerDelta)
{
/*
* /R = rope direction vector (unit length, world space)
* /A = drum axis (unit length, world space)
* /r = displacement vector for torque application (world space) from center of mass
* /tau = torque applied
* /C_d = center delta (center of winding (world space) - center of mass (world space))
* /F = force
* r = drum radius
* I = impulse applied
*
* /r = |/R x /A| * r + C_d
* /F = /R * -I
* /tau = /r x /F
*/
Vector3 A, r, F, tau;
Vector3.Normalize(ref ropeDirectionVector, out ropeDirectionVector);
A = windingData.CurrentDummyWorld.Backward;
Vector3.Cross(ref ropeDirectionVector, ref A, out r);
r = r * windingData.Radius + centerDelta;
F = ropeDirectionVector * ropeData.ImpulseApplied;
Vector3.Cross(ref r, ref F, out tau);
return tau;
}
private static void DeactivateWinding(long hookEntityId, WindingData winding = null)
{
if (winding == null)
{
m_hookIdToActiveWinding.TryGetValue(hookEntityId, out winding);
}
if (winding != null && winding.Emitter != null)
{
winding.Emitter.StopSound(false);
winding.Emitter = null;
winding.Sound = null;
}
m_hookIdToActiveWinding.Remove(hookEntityId);
}
private static void UpdateDummyWorld(MyPositionComponentBase windingEntityPositionComponent, WindingData winding)
{
winding.LastDummyWorld = winding.CurrentDummyWorld;
winding.CurrentDummyWorld = MatrixD.Multiply(winding.LocalDummy, windingEntityPositionComponent.WorldMatrix);
}
private static void ActivateWinding(long hookEntityId, WindingData winding, MyRopeDefinition attachedRope)
{
Debug.Assert(winding != null);
Debug.Assert(!m_hookIdToActiveWinding.ContainsKey(hookEntityId), "Winding already added");
Debug.Assert(m_hookIdToRopeId.ContainsKey(hookEntityId));
m_hookIdToActiveWinding[hookEntityId] = winding;
var hookEntity = MyEntities.GetEntityById(hookEntityId);
UpdateDummyWorld(hookEntity.PositionComp, winding);
if (attachedRope.WindingSound != null)
{
winding.Sound = attachedRope.WindingSound;
winding.Emitter = new MyEntity3DSoundEmitter(hookEntity);
}
}
