D3DXQuaternionBaryCentric function (D3dx9math.h)

Note

The D3DX utility library is deprecated. We recommend that you use DirectXMath instead.

Returns a quaternion in barycentric coordinates.

Syntax

D3DXQUATERNION* D3DXQuaternionBaryCentric(
  _Inout_       D3DXQUATERNION *pOut,
  _In_    const D3DXQUATERNION *pQ1,
  _In_    const D3DXQUATERNION *pQ2,
  _In_    const D3DXQUATERNION *pQ3,
  _In_          FLOAT          f,
  _In_          FLOAT          g
);

Parameters

pOut [in, out]

Type: D3DXQUATERNION*

Pointer to the D3DXQUATERNION structure that is the result of the operation.

pQ1 [in]

Type: const D3DXQUATERNION*

Pointer to a source D3DXQUATERNION structure.

pQ2 [in]

Type: const D3DXQUATERNION*

Pointer to a source D3DXQUATERNION structure.

pQ3 [in]

Type: const D3DXQUATERNION*

Pointer to a source D3DXQUATERNION structure.

f [in]

Type: FLOAT

Weighting factor. See Remarks.

g [in]

Type: FLOAT

Weighting factor. See Remarks.

Return value

Type: D3DXQUATERNION*

Pointer to a D3DXQUATERNION structure in Barycentric coordinates.

Remarks

To compute the barycentric coordinates, the D3DXQuaternionBaryCentric function implements the following series of spherical linear interpolation operations:

Slerp(Slerp(Q1, Q2, f+g), Slerp(Q1, Q3, f+g), g/(f+g))

The return value for this function is the same value returned in the pOut parameter. In this way, the D3DXQuaternionBaryCentric function can be used as a parameter for another function.

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

Barycentric coordinates define a point inside a triangle in terms of the triangle's vertices. For a more in-depth description of barycentric coordinates, see Mathworld's Barycentric Coordinates Description.

Requirements

Requirement	Value
Header	D3dx9math.h
Library	D3dx9.lib

See also

Math Functions