Function tvg_gradient_get_transform 

pub unsafe extern "C" fn tvg_gradient_get_transform(
    grad: Tvg_Gradient,
    m: *mut Tvg_Matrix,
) -> Tvg_Result

@brief Gets the matrix of the affine transformation of the gradient object.

In case no transformation was applied, the identity matrix is set.

@param[in] grad The Tvg_Gradient object of which to get the transformation matrix. @param[out] m The 3x3 augmented matrix.