How do I determine the player's grid position?

Question

My original method for doing this involved taking the player's position, dividing it by the grid cell size, and rounding the result. This works for most cases except when I move my player up above y-axis zero or to the left of x-axis 0. I use the grids to load chunks of procedurally generated tiles into my scene.

it keeps resulting in -0 being a component of the position vectors, which throws my system off. I fixed that by converting each component to integers, but that doesn't solve the greater problem.

There must be a more effective method for this available.

EDIT:

I am using Godot Engine and GDscript for the game I am creating.

This is my code:

    func calculate_grid_position():
    var grid_position = Vector2(int(round(position.x/ 1600)),
                                int(round(position.y/ 1600)))
    return grid_position

Answer 1

It's common for negative zero to behave in unintuitive ways. Complicating things, I wasn't able to find an official doc detailing what sort of behavior a programmer should expect from Godot regarding negative zero.

So the best suggestion I can offer is to special case -0 to behave as needed:

func calculate_grid_position():
    var tempX = int(round(position.x/ 1600)
    if tempX == -0:
        tempX = -1
    var tempY = int(round(position.y/ 1600)
    if tempY == -0:
        tempY = -1
    var grid_position = Vector2(tempX, tempY)
    return grid_position

It would be a good idea not to hard coded the cell size (int this case 1600), but without more knowledge about your code, I can't specifically tell you how to fix that other than suggesting you to move those values into a variable or a constant.

As an end note, the desired mapping as described in the question & comments seems a bit unusual. I generally wouldn't expect -0 to arise under most situations. When I have needed to handle it as a special case, I've either converted it to 0 or treat it as an error / exception.