add checkbox for drawing axis or not
add checkbox for drawing projections or not
fix: check if we must draw axis after each generation

    put checkbox as member of main_view to peek the state at generation
change eligible test when extract edges from points

    do it on segments, check every cases, works fine
extend adjacent edges when generating 3D intervals
remove broken data and add two pretty interval3D
move generation of intervals in separate module
add : store "squares" in Interval2D

    find them while generating a random Interval2D
    will be used to find in O(log(n)) if a point lies in this interval2D
move _is_in method to Interval2D.__contains__()

    call _points3d_from_projections() directly with Interval2Ds
    remove 'close' parameter from __contains__, assume it's always True
add: use squares of Interval2Ds for __contains__()

    with a binary search