Tiled based pathfinding in a 1- or 2-dimensional array

Question

As far as I know all tile based map editors export a JSON object containing one dimensional arrays. While most pathfinding libraries/tutorials are only provided for two dimensional arrays.

Also if for example I would like to do pathfinding in this one dimensional array and this array is huge i'm geussing this would cause performance issues.

So why is it that most tile based map editors output a one dimensional and how should I handle those regarding pathfinding?

example tile editor:

http://elias-schuett.de/git/Online-Tile-Map-Editor/#

Just google pathfinding to find all the two dimensional patfhfinding tutorials

Answer 1

Well, that's a mildly silly way to represent a map.

In order to use path-finding and such on those maps - or to use them for most anything, really - you need a method for addressing the contents using your 2D coordinates. Assuming you know the dimensions of the map (25x19 in the example you linked) you can translate between the [x,y] coordinates and 1D array index fairly simply:

index = y * 25 + x;

Or in reverse:

int x = index % 25;
int y = index / 25;

And once you can do that, you're off and running. Scan the foreground layer's array for blocking (or non-blocking, depending on your path-finding algorithm) items, converting the resulting list of indices to a list of [x,y] nodes

Depending on your path-finding algorithm you can either generate a list of unblocked or block nodes by scanning the 1D array, then converting indices to [x,y] coordinates.