Use mask to check left right top bottom direction of the adjacent chars

[tuanchauict]

Allow direction detector for adjacent characters work with the combined characters Before

┏━┭─╮
┃╔═╗│
┗║┵╟╯
 ╚═╝ 

After

┏━┭─╮
┃╔╪╗│
┗║┵╫╯
 ╚═╝