Question Locate points along perimeter of gridshape (island) in correct order

Hey,

I have a island I've procedurally generated using a grid, and I now need to find all the points along the perimeter (corners and edges), however they have to be in order, as in, one by one. Like shown below



The only solution i can think of is to have a bot in the update loop jumping from tile to tile along the perimeter until it comes back to itself, and adding each tile into a list.

However, I'm wondering if there is a more efficient way to do this, maybe using for loops or something?
If there's something i'm explaining poorly just let me know!

 

If the rule is never-diagonal (ie, always north, south, east, west transitions), it's easy to write a bot that steps around it until it arrives at the beginning again, keeping a list of places it has been.

I don't think the choice of loop construct would affect efficiency significantly.

 

Thanks for your reply! Yes, the rule is never diagonal. I guess that's the way to go then