public static XMVector SlerpV(XMVector q0, XMVector q1, XMVector t) { Debug.Assert(t.Y == t.X && t.Z == t.X && t.W == t.X, "Reviewed"); //// Result = Q0 * sin((1.0 - t) * Omega) / sin(Omega) + Q1 * sin(t * Omega) / sin(Omega) XMVector oneMinusEpsilon = XMVector.FromFloat(1.0f - 0.00001f, 1.0f - 0.00001f, 1.0f - 0.00001f, 1.0f - 0.00001f); XMVector cosOmega = XMQuaternion.Dot(q0, q1); XMVector zero = XMVector.Zero; XMVector control = XMVector.Less(cosOmega, zero); XMVector sign = XMVector.Select(XMGlobalConstants.One, XMGlobalConstants.NegativeOne, control); cosOmega = XMVector.Multiply(cosOmega, sign); control = XMVector.Less(cosOmega, oneMinusEpsilon); XMVector sinOmega = XMVector .NegativeMultiplySubtract(cosOmega, cosOmega, XMGlobalConstants.One) .Sqrt(); XMVector omega = XMVector.ATan2(sinOmega, cosOmega); XMVector signMask = XMVector.SignMask; XMVector v01 = XMVector.ShiftLeft(t, zero, 2); signMask = XMVector.ShiftLeft(signMask, zero, 3); v01 = XMVector.XorInt(v01, signMask); v01 = XMVector.Add(XMGlobalConstants.IdentityR0, v01); XMVector invSinOmega = sinOmega.Reciprocal(); XMVector s0 = XMVector .Multiply(v01, omega) .Sin(); s0 = XMVector.Multiply(s0, invSinOmega); s0 = XMVector.Select(v01, s0, control); XMVector s1 = XMVector.SplatY(s0); s0 = XMVector.SplatX(s0); s1 = XMVector.Multiply(s1, sign); XMVector result = XMVector.Multiply(q0, s0); result = XMVector.MultiplyAdd(q1, s1, result); return(result); }