Below are the 16 possible configurations of details that can be combined to allow one to complete a larger overall drawing.
The detail type is derived from bitwise math in which the adjacency at the North, East, South, or West is given a specific value that when summed provide the detail type. When there are no adjacencies, these cardinal values are given a value of 0.
Up Adjacency = 08
Right Adjacency = 01
Down Adjacency = 02
Left Adjacency = 04
Hence each detail Type Number can be either from 0 – 15.
Below is a further graphical diagram representation of how the types can be combined to finish a larger drawing:
