Xjyuk

How do I calculate distance to the closest player and show it via a scoreboard on a vanilla server?

You cannot show the distance closest to the player and show it via scoreboard due to the fact vanilla scoreboards are used for every player. This can be easily done with some bukkit code which will be both more efficient and cleaner to the eye.

Just in case anyone tried to look up how this problem could be accomplished, because this is the first result from google search. And I happened to work it out.


You can do this in 1.13+ now, with the /execute store


The steps are as follows: store player coordinates > calculate the differences > square the differences > sum up > approximate the sqrt values. I'm using euclidean distance as the metric.


1. Store Player Coordinates:

You'd need to define objectives to store the values, I defined them as "X", "Y", and "Z"


execute as @a run execute store result score @s X run data get entity @s Pos[0]

execute as @a run execute store result score @s Y run data get entity @s Pos[1]

execute as @a run execute store result score @s Z run data get entity @s Pos[2]


2. Calculate the Differences:

I defined another set of objectives to store the results "X_difference", "Y_difference", "Z_difference", but you don't have to


execute as @a run scoreboard players operation @s X_difference = @s X

execute at @a run scoreboard players operation @s X_difference -= @p[sort=nearest] X

execute as @a run scoreboard players operation @s Y_difference = @s Y

execute at @a run scoreboard players operation @s Y_difference -= @p[sort=nearest] Y

execute as @a run scoreboard players operation @s Z_difference = @s Z

execute at @a run scoreboard players operation @s Z_difference -= @p[sort=nearest] Z


3. Square the Differences:


execute as @a run scoreboard players operation @s X_difference *= @s X_difference

execute as @a run scoreboard players operation @s Y_difference *= @s Y_difference

execute as @a run scoreboard players operation @s Z_difference *= @s Z_difference


4. Sum Up:

I defined another objective "distance" to store the sum of the squared values from 3.


execute as @a run scoreboard players operation @s distance = @s X_difference

execute as @a run scoreboard players operation @s distance += @s Y_difference

execute as @a run scoreboard players operation @s distance += @s Z_difference


5. Approximate the Square Root Values:

I defined another objective "dist_int" to store the approximations

Here you can expand the list as long as you want, here are a few examples:

execute as @a if score @s distance matches 0.. run scoreboard players set @s dist_int 0

execute as @a if score @s distance matches 1.. run scoreboard players set @s dist_int 1

execute as @a if score @s distance matches 4.. run scoreboard players set @s dist_int 2

execute as @a if score @s distance matches 9.. run scoreboard players set @s dist_int 3

execute as @a if score @s distance matches 16.. run scoreboard players set @s dist_int 4


Generally it's

execute as @a if score @s distance matches n * n.. run scoreboard players set @s dist_int n



The "dist_int" objective contains the answers to your problem.