Conflict in the formulation of direction rules?

[dansonZhang]

Hi! Thank you very much for your open-source project's contribution to the community!

I have studied the ELSED code in detail and it seems that I have discovered conflicts in terms of direction definition.

On the webpage https://github.com/iago-suarez/ELSED/blob/main/src/ELSED.cpp At line 255（As shown in the following line）, I found a definition conflict.
lastDirection = expandHorizontally ? UPM_RIGHT : UPM_DOWN;

If the gradient direction is horizontal, lastDirection is assigned a value of UPM_ LIGHT (i.e. 2), if the gradient direction is vertical, lastDirection is assigned the value UPM_ DOWN (i.e. 4).This doesn't seem to be a problem, But this direction definition conflicts with annotations on this webpage https://github.com/iago-suarez/ELSED/blob/main/src/ELSED.cpp At line 231（As shown in the following line）.
unsigned char lastDirection; // up = 1, right = 2, down = 3, left = 4;

Best Regards
Danson