cdef struct point_c:
double x
double y
double z
cdef struct face_c:
int n
int* vertices
cdef class Transformation:
cdef matrix
cdef double _matrix_data[12]
cdef object _svd
cpdef transform_point(self, x)
cpdef transform_vector(self, v)
cpdef transform_bounding_box(self, box)
cdef void transform_point_c(self, point_c* res, point_c P)
cdef void transform_vector_c(self, point_c* res, point_c P)
