geom2d replaced by flat, and structure moved
added flat segment
added some null error to vector and segment
collision detection uses segments
add vertical face helper
find best pair of segments
projected segment calculus
first version working with bugs
add debug functionality (debuggable)
added logger not tested
logger first version
sign error corrected on create_transformation
wall positioning ok
wall extremity lock added
face collision on main side only
anchors composition bug fixed
def collision bug fixed
fixed linear builder
ls reject collided written, need to debug
linear seg < flat seg