PK_SKEWBOX_sf_t

struct PK_SKEWBOX_sf_s
     {
     PK_BASIS_SET_sf_t basis_set;    --- coordinate system for box
     PK_BOX_t          box;          --- box
     };
typedef struct PK_SKEWBOX_sf_s PK_SKEWBOX_sf_t;


This data structure is the standard form for a non-orthogonal hexahedronal
skewed box.

Used in:

PK_pattern_cell_t

A skewbox is a non-orthogonal cuboid space defined by an origin, a set of
non-orthogonal axes (normalised direction vectors) and a set of i, j, k
intervals (provided by 'box' and mapped to the min\max X,Y,Z values
respectively).