D3DXQuaternionLn

Calculates the natural logarithm.

D3DXQUATERNION * D3DXQuaternionLn(
  D3DXQUATERNION * pOut,
  CONST D3DXQUATERNION * pQ
);

Parameters

pOut

[in, out] Pointer to the D3DXQUATERNION structure that is the result of the operation.

pQ

[in] Pointer to the source D3DXQUATERNION structure.

Return Values

Pointer to a D3DXQUATERNION structure that is the natural logarithm.

Remarks

The D3DXQuaternionLn function works only for unit quaternions.

A unit quaternion, is defined by:
Q == (cos(theta), sin(theta) * v) where |v| = 1
The natural logarithm of Q is, ln(Q) = (0, theta * v)

The return value for this function is the same value returned in the pOut parameter. In this way, the D3DXQuaternionLn function can be used as a parameter for another function.

Use D3DXQuaternionNormalize for any quaternion input that is not already normalized.

Requirements

Header: Declared in D3dx9math.h.

See Also

D3DXQuaternionExp, D3DXQuaternionSquad