The number of tiles is the maximum of the distance in the X or Y direction. If you have two points (x1,y1) and (x2,y2), then the number of tiles is max(abs(x2-x1), abs(y2-y1)).

There are a few variants to how to treat the values you have to be aware of though. Depending on if you want to, say, count both the start and end tiles, or only count the start or end tile but not he other, or if you want the number of tiles bwteen the two points, and how you want to handle fractional coordinates, you may have to round the values differently and at different places and add or subtract one at some places.

Combinations includes round(), floor(), ceil() of either the individual coordinates, the difference between them, of absolute values or of the maximum value.

The number of tiles is the maximum of the distance in the X or Y direction. If you have two points (x1,y1) and (x2,y2), then the number of tiles is max(abs(x2-x1), abs(y2-y1)).

There are a few variants to how to treat the values you have to be aware of though. Depending on if you want to, say, count both the start and end tiles, or only count the start or end tile but not he other, or if you want the number of tiles bwteen the two points, and how you want to handle fractional coordinates, you will have to round the values differently and at different places.

Combinations includes round(), floor(), ceil() of either the individual coordinates, the difference between them, of absolute values or of the maximum value.