Generate all possible bounded polygons for a fixed number of lines with equal lenght that have only 90 degree angles.
First all possible shapes with fixed number of lines and 90 degree angles are generated. Then we filter useless polygons by mapping the drawing on coordinates and checking if end line lands on (0,0) and trace point history and eliminate on repetition except for (0,0).
Example for 12 lines, 744 shapes generated:
