D3DXMatrixAffineTransformation

Builds a 3D affine transformation matrix. NULL arguments are treated as identity transformations.

D3DXMATRIX * D3DXMatrixAffineTransformation(
  D3DXMATRIX * pOut,
  FLOAT Scaling,
  CONST D3DXVECTOR3 * pRotationCenter,
  CONST D3DXQUATERNION * pRotation,
  CONST D3DXVECTOR3 * pTranslation
);

Parameters

pOut

[in, out] Pointer to the D3DXMATRIX structure that is the result of the operation.

Scaling

[in] Scaling factor.

pRotationCenter

[in] Pointer to a D3DXVECTOR3 structure, a point identifying the center of rotation. If this argument is NULL, an identity M_rc matrix is applied to the formula in Remarks.

pRotation

[in] Pointer to a D3DXQUATERNION structure that specifies the rotation. If this argument is NULL, an identity M_r matrix is applied to the formula in Remarks.

pTranslation

[in] Pointer to a D3DXVECTOR3 structure representing the translation. If this argument is NULL, an identity M_t matrix is applied to the formula in Remarks.

Return Values

Pointer to a D3DXMATRIX structure that is an affine transformation matrix.

Remarks

This function calculates the affine transformation matrix with the following formula, with matrix concatenation evaluated in left-to-right order:

M_out = M_s * (M_rc)^-1 * M_r * M_rc * M_t

where:

M_out = output matrix (pOut)

M_s = scaling matrix (Scaling)

M_rc = center of rotation matrix (pRotationCenter)

M_r = rotation matrix (pRotation)

M_t = translation matrix (pTranslation)

The return value for this function is the same value returned in the pOut parameter. In this way, the D3DXMatrixAffineTransformation function can be used as a parameter for another function.

For 2D affine transformations, use D3DXMatrixAffineTransformation2D.

Requirements

Header: Declared in D3dx9math.h.

See Also

D3DXMatrixTransformation, Transforms