No context and missing information. No way anyone could make more than a guess as to what it is for other than something to do with manipulating some text.
Pretty pointless post
Can you please add more context to the OP? Even I have absolutely no idea where you got this from.
Looks like maybe something to do with drawing ASCII line art using a set of coordinates.
But there are variables referenced that are out of scope of what is presented.
What gives that away to me are the references to odd and even elements in the array (j modulus 2), the - | and + type symbology and the references to lines and gradients/coordinates (i think thatās what m.x and m.y are).
Itās fucking hideous code though and whoever wrote it needs to be fired.
part of a riddle bot someone wrote. i canāt make anything out of it personally. pretty pointless post i guess. sorry to bother u all and thanks for your insight.
Its a join message array for an ascii image.
Since the variables are all one letter, I hope this was minified.
No it if was minified there would be no whitespace or formatting.
Unless the code was minified and then prettifiyed by OP to make it readable 
doubt that, its a screen shot and not a paste.
Probably some tool to generate a random map design in a RTS game. Or some way to write sequential data to a tape, output might suggest different (yet similar by pattern) things.
If you knew from the off without searching, Iām impressed.
The use of ASCII symbol 197 ā¼ (coupled with the use of j and k as indexes) was a dead giveaway that the code was drawing a two-dimensional text maze. I remember doing that on a Commodore 64 in the early 1980s.
As far as Iām aware .verti isnāt a method/function in any computing language, so I figured it must be a custom array name. āvertiā is also a very unusual contraction of āverticalā ā far more-so that āhorizā ā so that made for a nice/rare search term.
Plug āā¼ maze vertiā into DuckDuckGo and the Stack Overflow page was literally the second hit.
Goes to show how badly that code needed comments.
Because most of us didnāt understand the intent unless we had prior experience.
They should make IDE assistant you explain your code to and it comment it for you. Imagineā¦ āOK, rubber duck, hereās what this method is doingā¦ā