Amount of steps from one field in a grid to another, orthogonally?

Question

How do I calculate the amount of "steps" there is from one field to another in a grid, moving orthogonally?

I am implementing an A* pathfinding system for a game that I am developing, and this simple mathematical operation is in my way.

I should probably re-attend third grade. Haha.

Answer 1

If I understand correctly, I think you just add up the x,y movements necessary. Given two points (x1,y1) and (x2,y2), then the distance (assuming "moving orthogonally" means moving only horizontally and/or vertically) then it is:

abs(x1-x2) + abs(y1-y2)

For example, moving from position (1,1) to (3,4) means moving 2 spaces to the right and 3 spaces up for a total of 5. abs(1-3)+abs(1-4) = 2 + 3 = 5

Answer 2

I do believe this is a matter of simple math.

Surely, you know your starting x / y values, and your ending x / y values. To get the distance between the two, you do this:

dist = sqrt(dx^2 + dy^2 )

Where dx is the difference between the x-coordinates of the points Where dy is the difference between y-coordinates of the points.

So, for example. Lets say co-ordinate A is A(15,20) and co-ordinate B is B(35,5);

dx = 35 - 15 = 20; dy = 20-5 = 15;

Therefore;

dist between AB = sqrt(20^2 + 15^2) = 25.0 units.

Now for your final answer, this depends how many units a "step" is in your program. If a step is 5 units, (25/5) than there is 5 steps needed to get from point A to B.