suggestion for lens distorsion : creating an alignment line

[pierrelabreche]

In any image, some lines are vertical, some are horizontal, some are slanted.
Currently the transform shows a 5-point horizontal line near the top side.
Would it be possible to let the user create two end-points for creating an alignment set, whereby three initial intermediate points would be added automatically in-between the two endoints. The user would then fine-adjust all 5 points.