PK_TOPOL_fctab_strip_zigzag_t

struct  PK_TOPOL_fcstr_strip_zigzag_s
       {
       int     strip;
       int       fin;
       };
typedef struct PK_TOPOL_fcstr_strip_zigzag_s
               PK_TOPOL_fcstr_strip_zigzag_t;

struct PK_TOPOL_fctab_strip_zigzag_s
       {
       PK_TOPOL_fcstr_strip_zigzag_t *data;
       int                            length;
       };

typedef struct PK_TOPOL_fctab_strip_zigzag_s
               PK_TOPOL_fctab_strip_zigzag_t;

Used in:

PK_TOPOL_facet_table_t

This is a support structure for PK_TOPOL_facet_2_r_t. It is a lookup
table which 'groups' the fins in the facet strip together so that their head
vertices follow a zigzag ordering along the strip.

NOTE: The first three fins bound the first facet in anti-clockwise order, the
      following facet is in clockwise order and so on.

Example:

            v0--f0---v2-------v4-------v6-------v8-------v10
            |       /|       /|       /|       /|       /|
            |      / |      / |      / |      / |      / |
            |     /  |     /  |     /  |     /  |     /  |
           f1   f2  f3   f4  f5   f6  f7   f8  f9   f10  |
            |   /    |   /    |   /    |   /    |   /    |
            |  /     |  /     |  /     |  /     |  /     |
            | /      | /      | /      | /      | /      |
            |/       |/       |/       |/       |/       |
            v1-------v3-------v5-------v7-------v9--f11--v11

            v0--f0---v2-------v4-------v6-------v8-------v10
            |       /|       /|       /|       /|       /
            |      / |      / |      / |      / |      /
            |     /  |     /  |     /  |     /  |     /
           f1   f2  f3   f4  f5   f6  f7   f8  f9   f10
            |   /    |   /    |   /    |   /    |   /
            |  /     |  /     |  /     |  /     |  /
            | /      | /      | /      | /      | /
            |/       |/       |/       |/       |/
            v1-------v3-------v5-------v7-------v9

The first facet strip contains an even number of facets, its 'strip_zigzag' is
represented by the sequence:

                f0  f1  f2  f3  f4  f5  f6  f7  f8  f9  f10 and f11

The second facet strip contains an odd number of facets, its 'strip_zigzag' is
represented by the sequence:

                f0  f1  f2  f3  f4  f5  f6  f7  f8  f9  and f10


Where f0  is the fin starting at v2 and ending at v0,
      f1  is the fin starting at v0 and ending at v1,
      f2  is the fin starting at v1 and ending at v2,
      .                          .                .
      .                          .                .
      .                          .                .
      f9  is the fin starting at v8 and ending at v9,
      f10 is the fin starting at v9 and ending at v10 and
      f11 is the fin starting at v9 and ending at v11

Each facet_strip is assigned an integer value from 0 to
('number_of_strips' - 1).