"Sorting" coordinates?

[mekasha]

Hi all,

This is my first foray into modding. I've put together a super simple mod that list that just prints out a list of the new rare mobs/one-time-loot world objects in WoD. Here's a sample of what I have so far:

if (((zoneName == "Frostfire Ridge") and msg == "") or msg == "ff") then
        print("Items in Frostfire")
    
        if (IsQuestFlaggedCompleted(34132) == false) then
        print("Scout Goreseeker[76.5, 63.5]")
        end
        if (IsQuestFlaggedCompleted(34931) == false) then
        print("Pale Loot Sack[21.7, 50.8]")
        end
        if (IsQuestFlaggedCompleted(34133) == false) then
        print("The Beater[26.9, 31.9]")
        end
         end

I have the above working for every zone using data I scraped from Wowpedia. My question is, is there any way to kind of sort the items based on a relative closeness to player position? I don't need to find "distance", I was just thinking something simple like ((player X coord - item X coord) or (item X coord - player X coord)) based on whichever is higher, then sorting based on the lower result.

Are there any examples of how I would store my values into an array/table and sort that, then write that out to the screen? I'm mainly an SQL guy, so I've been learning the basics of lua/non-scripted programming as I go.

[semlar]

Originally Posted by mekasha My question is, is there any way to kind of sort the items based on a relative closeness to player position? I don't need to find "distance", I was just thinking something simple like ((player X coord - item X coord) or (item X coord - player X coord)) based on whichever is higher, then sorting based on the lower result.

Distance is pretty much exactly what you're trying to sort by.

If you have a table like

{
  {34132, 76.5, 63.5},
  {34931, 21.7, 50.8},
  {34133, 26.9, 31.9},
}

And you only want to sort by the X coordinate, you would get the player's coordinates and then sort the table..

local coords = {
  {34132, 76.5, 63.5},
  {34931, 21.7, 50.8},
  {34133, 26.9, 31.9},
}
local playerX, playerY = GetPlayerMapPosition('player')
table.sort(coords, function(a, b)
  return (a[2] - playerX) < (b[2] - playerX)
end)

For actual distance you'd sort like this

table.sort(coords, function(a, b)
  return ((a[2] - playerX)^2 + (a[3] - playerY)^2) < ((b[2] - playerX)^2 + (b[3] - playerY)^2)
end)

[Mazzop]

nvm, semlar edited

[mekasha]

That is quite helpful. I understand how the table.sort is working, and how you populate the initial table, but I'm having a lot of trouble adding subsequent items to the table.

I'm especially having trouble getting it to work since I'll have 4 values per line in the table, and almost every example I've come across just shows how to handle a key and single value.

I'm assuming that using my initial code, I'll be changing each Print to some method of inserting a new row into my table, then doing the sort at the end, then printing the sorted table.

edit: I think I have it working, here is my concept code:

local coords = {}
 
table.insert (coords , {34132, 70.5, 63.5, "scout"})
table.insert (coords , {34931, 21.7, 50.8, "warrior"})
table.insert (coords , {34133, 26.9, 31.9, "hunter"})
table.insert (coords , {34134, 1000, 1000, "unknown location"})
 
 local playerX = 2
 local playerY = 1
 
    table.sort(coords, function(a, b)
      return ((a[2] - playerX)^2 + (a[3] - playerY)^2) > ((b[2] - playerX)^2 + (b[3] - playerY)^2)
    end)
 
    for i,line in ipairs(coords) do
      print(line[1], line[2], line[3], "npc", line[4], "near place")
    end

Is the "for ipairs" the best way for printing out my sorted table? Also, for the items I do not have the coordinates for, is there a more elegant method than setting their coordinates to 1000, 1000?

[Lombra]

I don't know how much of this you already figured out, but

Originally Posted by mekasha I'm especially having trouble getting it to work since I'll have 4 values per line in the table, and almost every example I've come across just shows how to handle a key and single value.

You shouldn't be thinking of it like that. You have only one value, which is the table.

local value = {34132, 70.5, 63.5, "scout"}
table.insert(coords, value)

Originally Posted by mekasha Is the "for ipairs" the best way for printing out my sorted table?

If you're going to do stuff with a table very frequently there is another way of doing it than ipairs, but for a single or just a few iterations there's really no reason to complicate things. ipairs is fine.

Originally Posted by mekasha Also, for the items I do not have the coordinates for, is there a more elegant method than setting their coordinates to 1000, 1000?

Probably. Depends on how you want to treat those items.