Game logic on its way: tube is closing correctly, only when top and bottom are aligned. No time to make a video today, so i post a serie of 3 pictures showing the connection animation, programmatically validated.

screenshot08152016_170838606

screenshot08152016_170847021

screenshot08152016_170849021

For those who like schema, here is , in a very abstract form, the relations between objects.

class-hierarchy02.pdf