Post your modding questions here

[Byakuren]

Do players keep their velocity after being detached from an entity?

[stu]

Do players keep their velocity after being detached from an entity?

If you mean the velocity of the entity they were attached to then no, they do not. They will, however, suffer the effects of gravity if detaching from a height ;-)

[Byakuren]

Do players keep their velocity after being detached from an entity?

If you mean the velocity of the entity they were attached to then no, they do not. They will, however, suffer the effects of gravity if detaching from a height ;-)

Alright, thank you.

[stu]

Do players keep their velocity after being detached from an entity?

If you mean the velocity of the entity they were attached to then no, they do not. They will, however, suffer the effects of gravity if detaching from a height ;-)

Alright, thank you.

You're welcome, what was it you were trying to achieve anyway? maybe there is another way to accomplish that.

[iangp]

Hey guys,
Is there some way to a mod cause some error like that?

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

*** Error in `minetest': double free or corruption (fasttop): 0x0000000001239c60 ***
Abortado (imagem do núcleo gravada)


Or Is just my minetest build? I just retype and then it runs but it's a strange issue

[Byakuren]

Does minetest.get_gametime() return the number of seconds the world has been active? As in, it doesn't count up when the world is not being played. Also, is it dependent on simulation speed, i.e. will it slow down if not enough ticks are being processed quickly enough?

[Nathan.S]

Question about best practices, I am changing the speed that a player gets thirsty in the thirst mod based off the month from the mymonths mod. Would it be better to make the changes in the thirst mod and have that read the month, or would it be better to do the changes in the mymonths mod and have that modify the thirst mod, or would there probably not be any difference.

[kaeza]

Your thirst depends on the month, not the other way around, so the best thing to do would be to translate that into code and modify thirst.

This also makes it easier in case you want to distribute the modified mod, or offer a patch for thirst.

[Don]

@Nathan - Just my opinion - I think changes should be in the thirst mod since the changes only effect the thirst mod. Either way would work but keeping the code with thirst would make it so if mymonths was forked and changed then thirst could easily be changed to work with the fork. I have no objections to adding it to mymonths if that is what you choose.

[kaeza]

Does minetest.get_gametime() return the number of seconds the world has been active? As in, it doesn't count up when the world is not being played. Also, is it dependent on simulation speed, i.e. will it slow down if not enough ticks are being processed quickly enough?

It returns the time in seconds since you created the world, and is only incremented while the server is running.

It apparently discards the fractions of a second when the server shuts down, so it's not 100% precise. Depending on what you need the time for, and your precision needs, you'd be better with updating your own timer and saving/restoring from a file in the world directory.

[Nathan.S]

Thanks guys.

[rubenwardy]

Does minetest.get_gametime() return the number of seconds the world has been active? As in, it doesn't count up when the world is not being played. Also, is it dependent on simulation speed, i.e. will it slow down if not enough ticks are being processed quickly enough?

It returns the time in seconds since you created the world, and is only incremented while the server is running.

It apparently discards the fractions of a second when the server shuts down, so it's not 100% precise. Depending on what you need the time for, and your precision needs, you'd be better with updating your own timer and saving/restoring from a file in the world directory.

Also note that game time isn't reliable as env_data.txt is often corrupted (so gametime may be reset after a shutdown)

[Byakuren]

Does minetest.get_gametime() return the number of seconds the world has been active? As in, it doesn't count up when the world is not being played. Also, is it dependent on simulation speed, i.e. will it slow down if not enough ticks are being processed quickly enough?

It returns the time in seconds since you created the world, and is only incremented while the server is running.

It apparently discards the fractions of a second when the server shuts down, so it's not 100% precise. Depending on what you need the time for, and your precision needs, you'd be better with updating your own timer and saving/restoring from a file in the world directory.

Does minetest.get_gametime() return the number of seconds the world has been active? As in, it doesn't count up when the world is not being played. Also, is it dependent on simulation speed, i.e. will it slow down if not enough ticks are being processed quickly enough?

It returns the time in seconds since you created the world, and is only incremented while the server is running.

It apparently discards the fractions of a second when the server shuts down, so it's not 100% precise. Depending on what you need the time for, and your precision needs, you'd be better with updating your own timer and saving/restoring from a file in the world directory.

Also note that game time isn't reliable as env_data.txt is often corrupted (so gametime may be reset after a shutdown)

Okay, thank you both!

[RREDesigns]

Hello everyone. I seem to have a huge problem trying to write scripts for a mod. I did my best trying to follow what the API reference says, but I get nothing but errors. Check this code:

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Code: Select all

minetest.register_chatcommand("getpname",function(player)
                              local user = player:get_player_name()   
                              if user ~= nil then
                                 minetest.chat_send_player(user, tostring(user))
                                return     
                              else
                                 minetest.chat_send_player(user, "No name retrieved.")
                                return
                              end
                              end)


I'm just trying to retrieve the player name and can't even do that. MT will complain about everything, no matter of what. So, this minetest.* methods has to be used under certain scopes or what? How is it that var = minetest.get_player_name() won't leave me with a string in my var (I tried that way too)?

[iangp]

Hello everyone. I seem to have a huge problem trying to write scripts for a mod. I did my best trying to follow what the API reference says, but I get nothing but errors. Check this code:

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

minetest.register_chatcommand("getpname",function(player)
                              local user = player:get_player_name()   
                              if user ~= nil then
                                 minetest.chat_send_player(user, tostring(user))
                                return     
                              else
                                 minetest.chat_send_player(user, "No name retrieved.")
                                return
                              end
                              end)


I'm just trying to retrieve the player name and can't even do that. MT will complain about everything, no matter of what. So, this minetest.* methods has to be used under certain scopes or what? How is it that var = minetest.get_player_name() won't leave me with a string in my var (I tried that way too)?

What are you doing (exactly)?
minetest.register_chatcommand("cmd", {chatcommand definition})
{chatcommand definition} isn't a function, it's a table.
see:
http://dev.minetest.net/minetest.register_chatcommand

You must put this function inside the table

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Code: Select all

{
   params = "<name>",
   description = "Some desc",
        func = function( name , param) -- name: player name, param: name passed
                              local player = minetest.get_player_by_name(param)
                              if param ~= nil then
                                   minetest.chat_send_player(player, tostring(player))
                                   return
                              else
                                   minetest.chat_send_player(player, "No name retrieved.")
                                   return
                              end
        end)
}


[rubenwardy]

Also see this chapter: http://rubenwardy.com/minetest_modding_ ... t-commands

[RREDesigns]

I tried to do that about 20 times, in different ways, including a funtion defined outside the list. It just doesn't work. I think I forgot to make a list this last time, so I fixed it, but it doesn't work. Then I tried to copy the code provided by "iangp" and that doesn't work either, the error:

ServerError: Lua: Runtime error from mod 'testmod' in callback on_chat_message():***/init.lua:11: bad argument #1 to 'chat_send_player' (string expected, got nil)

I clearly said I wanted to retrieve the player's name. All I need is to store it's name in a var to use it later in other strings operations. I used the chat to print it, just to check wheter it was working or not.

[RREDesigns]

Also, I was reading the mods scripts, and noticed that in most of them they make use of undefined/undeclared vars and arguments, like in the teleport mod, where "sender" and "receiver" are used all over the file, but never initialised. What's up with that?

[rubenwardy]

I can't find a teleport mod.

Please take the time to read that chapter. The code should be this:

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Code: Select all

minetest.register_chatcommand("getpname", {
       description = "Some desc",
       func = function(name , param)
                if name ~= nil then
                       return true, name
               else
                       -- this will never run, as far as I know.
                       return false, "No name retrieved."
               end
        end)
})


When player1 runs /getpname blah blah, func will be called with
name == "player1"
param == "blah blah".

The reason that a player name rather than a player object is passed is because the player might not actually be online, but may be running commands from IRC. So don't assume that minetest.get_player_by_name will work in a chat command call back.

[RREDesigns]

Ok, cool. I'm trying that now.

How is it that "name" and "param" get their values?

[RREDesigns]

Why "playerName = minetest.get_player_name()" doesn't work alone?

[RREDesigns]

Ok, it works now, with func(name), since all I wanted was the player name, no parameters has to be passed.



Big thanks for the help.

[RREDesigns]

This is the code in init.lua for the teleport requests I was talking earlier:

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Code: Select all

local timeout_delay = 60

-- Set to true to register tpr_admin priv
local regnewpriv = false

local version = "1.1"

local tpr_list = {}
local tphr_list = {}

--Teleport Request System
local function tpr_send(sender, receiver)
   if receiver == "" then
      minetest.chat_send_player(sender, "Usage: /tpr <Player name>")
      return
   end

   --If paremeter is valid, Send teleport message and set the table.
   if not minetest.get_player_by_name(receiver) then
      return
   end

   minetest.chat_send_player(receiver, sender ..' is requesting to teleport to you. /tpy to accept.')
   minetest.chat_send_player(sender, 'Teleport request sent! It will time out in '.. timeout_delay ..' seconds.')

   --Write name values to list and clear old values.
   tpr_list[receiver] = sender
   --Teleport timeout delay
   minetest.after(timeout_delay, function(name)
      if tpr_list[name] then
         tpr_list[name] = nil
      end
   end, sender)
end

local function tphr_send(sender, receiver)
   if receiver == "" then
      minetest.chat_send_player(sender, "Usage: /tphr <Player name>")
      return
   end

   --If paremeter is valid, Send teleport message and set the table.
   if not minetest.get_player_by_name(receiver) then
      return
   end

   minetest.chat_send_player(receiver, sender ..' is requesting that you teleport to them. /tpy to accept; /tpn to deny')
   minetest.chat_send_player(sender, 'Teleport request sent! It will time out in '.. timeout_delay ..' seconds.')

   --Write name values to list and clear old values.
   tphr_list[receiver] = sender
   --Teleport timeout delay
   minetest.after(timeout_delay, function(name)
      if tphr_list[name] then
         tphr_list[name] = nil
      end
   end, sender)
end

local function tpr_deny(name)
   if tpr_list[name] then
      minetest.chat_send_player(tpr_list[name], 'Teleport request denied.')
      tpr_list[name] = nil
   end
   if tphr_list[name] then
      minetest.chat_send_player(tphr_list[name], 'Teleport request denied.')
      tphr_list[name] = nil
   end
end

-- Copied from Celeron-55's /teleport command. Thanks Celeron!
local function find_free_position_near(pos)
   local tries = {
      {x=1,y=0,z=0},
      {x=-1,y=0,z=0},
      {x=0,y=0,z=1},
      {x=0,y=0,z=-1},
   }
   for _,d in pairs(tries) do
      local p = vector.add(pos, d)
      if not minetest.registered_nodes[minetest.get_node(p).name].walkable then
         return p, true
      end
   end
   return pos, false
end


--Teleport Accept Systems
local function tpr_accept(name, param)

   --Check to prevent constant teleporting.
   if not tpr_list[name]
   and not tphr_list[name] then
      minetest.chat_send_player(name, "Usage: /tpy allows you to accept teleport requests sent to you by other players")
      return
   end

   local chatmsg, source, target, name2

   if tpr_list[name] then
      name2 = tpr_list[name]
      source = minetest.get_player_by_name(name)
      target = minetest.get_player_by_name(name2)
      chatmsg = name2 .. " is teleporting to you."
      tpr_list[name] = nil
   elseif tphr_list[name] then
      name2 = tphr_list[name]
      source = minetest.get_player_by_name(name2)
      target = minetest.get_player_by_name(name)
      chatmsg = "You are teleporting to " .. name2 .. "."
      tphr_list[name] = nil
   else
      return
   end

   -- Could happen if either player disconnects (or timeout); if so just abort
   if not source
   or not target then
      return
   end

   minetest.chat_send_player(name2, "Request Accepted!")
   minetest.chat_send_player(name, chatmsg)

   target:setpos(find_free_position_near(source:getpos()))
end

--Initalize Permissions.

if regnewpriv then
   minetest.register_privilege("tpr_admin", {
      description = "Permission to override teleport to other players. UNFINISHED",
      give_to_singleplayer = true
   })
end

--Initalize Commands.

minetest.register_chatcommand("tpr", {
   description = "Request teleport to another player",
   params = "<playername> | leave playername empty to see help message",
   privs = {interact=true},
   func = tpr_send
})

minetest.register_chatcommand("tphr", {
   description = "Request player to teleport to you",
   params = "<playername> | leave playername empty to see help message",
   privs = {interact=true},
   func = tphr_send
})

minetest.register_chatcommand("tpy", {
   description = "Accept teleport requests from another player",
   func = tpr_accept
})

minetest.register_chatcommand("tpn", {
   description = "Deny teleport requests from another player",
   func = tpr_deny
})

minetest.log("info", "[Teleport Request] Teleport Request v" .. version .. " Loaded.")


[rubenwardy]

Minetest does that for you.

In the following code:

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Code: Select all

function foo(param1, param2)

end


param1 and param2 are local variables in that function.
Think of it a little like this, although this code won't work:

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Code: Select all

function foo()
    local param1
    local param2

   -- both can be accessed here
end

-- there is no param1 or param2 here.


The caller sets the value of the params like so:

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Code: Select all

function foo(param1, param2)

end

foo("one value", 123)


It's minetest that calls the function for you and gives it that value. So somewhere there will be code like this:

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Code: Select all

local cmd = somehowGetTheCommandFromItsName(cmd_name)
local ret, msg = cmd.func(callername, parampassed)
if ret then
   print("command was successful")
else
    print("command was unsuccessful")
end
print(msg)


That about code is example code, and won't work.

[Hybrid Dog]

Hey guys,
Is there some way to a mod cause some error like that?

Your phone or window isn't wide enough to display the code box. If it's a phone, try rotating it to landscape mode.

Code: Select all

*** Error in `minetest': double free or corruption (fasttop): 0x0000000001239c60 ***
Abortado (imagem do núcleo gravada)


Or Is just my minetest build? I just retype and then it runs but it's a strange issue

l don't think a mod causes such an error message.
viewforum.php?f=6

[iangp]

I tried to do that about 20 times, in different ways, including a funtion defined outside the list. It just doesn't work. I think I forgot to make a list this last time, so I fixed it, but it doesn't work. Then I tried to copy the code provided by "iangp" and that doesn't work either, the error:

ServerError: Lua: Runtime error from mod 'testmod' in callback on_chat_message():***/init.lua:11: bad argument #1 to 'chat_send_player' (string expected, got nil)

I clearly said I wanted to retrieve the player's name. All I need is to store it's name in a var to use it later in other strings operations. I used the chat to print it, just to check wheter it was working or not.

try replace tostring() to dump() on my code...

[rubenwardy]

Why "playerName = minetest.get_player_name()" doesn't work alone?

Where would minetest be getting the name from? Mods are ran on the serverside, not the client side. Therefore there can be more than one player, so minetest.get_player_name() won't know which one.

If you have a player object, you can do player:get_player_name()

Also, make sure you use local:

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Code: Select all

local playerName = player:get_player_name()


See here for more info: http://rubenwardy.com/minetest_modding_ ... and-global

This is the code in init.lua for the teleport requests I was talking earlier:

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Code: Select all

local timeout_delay = 60

-- Set to true to register tpr_admin priv
local regnewpriv = false

local version = "1.1"

local tpr_list = {}
local tphr_list = {}

--Teleport Request System
local function tpr_send(sender, receiver)
   if receiver == "" then
      minetest.chat_send_player(sender, "Usage: /tpr <Player name>")
      return
   end

   --If paremeter is valid, Send teleport message and set the table.
   if not minetest.get_player_by_name(receiver) then
      return
   end

   minetest.chat_send_player(receiver, sender ..' is requesting to teleport to you. /tpy to accept.')
   minetest.chat_send_player(sender, 'Teleport request sent! It will time out in '.. timeout_delay ..' seconds.')

   --Write name values to list and clear old values.
   tpr_list[receiver] = sender
   --Teleport timeout delay
   minetest.after(timeout_delay, function(name)
      if tpr_list[name] then
         tpr_list[name] = nil
      end
   end, sender)
end

local function tphr_send(sender, receiver)
   if receiver == "" then
      minetest.chat_send_player(sender, "Usage: /tphr <Player name>")
      return
   end

   --If paremeter is valid, Send teleport message and set the table.
   if not minetest.get_player_by_name(receiver) then
      return
   end

   minetest.chat_send_player(receiver, sender ..' is requesting that you teleport to them. /tpy to accept; /tpn to deny')
   minetest.chat_send_player(sender, 'Teleport request sent! It will time out in '.. timeout_delay ..' seconds.')

   --Write name values to list and clear old values.
   tphr_list[receiver] = sender
   --Teleport timeout delay
   minetest.after(timeout_delay, function(name)
      if tphr_list[name] then
         tphr_list[name] = nil
      end
   end, sender)
end

local function tpr_deny(name)
   if tpr_list[name] then
      minetest.chat_send_player(tpr_list[name], 'Teleport request denied.')
      tpr_list[name] = nil
   end
   if tphr_list[name] then
      minetest.chat_send_player(tphr_list[name], 'Teleport request denied.')
      tphr_list[name] = nil
   end
end

-- Copied from Celeron-55's /teleport command. Thanks Celeron!
local function find_free_position_near(pos)
   local tries = {
      {x=1,y=0,z=0},
      {x=-1,y=0,z=0},
      {x=0,y=0,z=1},
      {x=0,y=0,z=-1},
   }
   for _,d in pairs(tries) do
      local p = vector.add(pos, d)
      if not minetest.registered_nodes[minetest.get_node(p).name].walkable then
         return p, true
      end
   end
   return pos, false
end


--Teleport Accept Systems
local function tpr_accept(name, param)

   --Check to prevent constant teleporting.
   if not tpr_list[name]
   and not tphr_list[name] then
      minetest.chat_send_player(name, "Usage: /tpy allows you to accept teleport requests sent to you by other players")
      return
   end

   local chatmsg, source, target, name2

   if tpr_list[name] then
      name2 = tpr_list[name]
      source = minetest.get_player_by_name(name)
      target = minetest.get_player_by_name(name2)
      chatmsg = name2 .. " is teleporting to you."
      tpr_list[name] = nil
   elseif tphr_list[name] then
      name2 = tphr_list[name]
      source = minetest.get_player_by_name(name2)
      target = minetest.get_player_by_name(name)
      chatmsg = "You are teleporting to " .. name2 .. "."
      tphr_list[name] = nil
   else
      return
   end

   -- Could happen if either player disconnects (or timeout); if so just abort
   if not source
   or not target then
      return
   end

   minetest.chat_send_player(name2, "Request Accepted!")
   minetest.chat_send_player(name, chatmsg)

   target:setpos(find_free_position_near(source:getpos()))
end

--Initalize Permissions.

if regnewpriv then
   minetest.register_privilege("tpr_admin", {
      description = "Permission to override teleport to other players. UNFINISHED",
      give_to_singleplayer = true
   })
end

--Initalize Commands.

minetest.register_chatcommand("tpr", {
   description = "Request teleport to another player",
   params = "<playername> | leave playername empty to see help message",
   privs = {interact=true},
   func = tpr_send
})

minetest.register_chatcommand("tphr", {
   description = "Request player to teleport to you",
   params = "<playername> | leave playername empty to see help message",
   privs = {interact=true},
   func = tphr_send
})

minetest.register_chatcommand("tpy", {
   description = "Accept teleport requests from another player",
   func = tpr_accept
})

minetest.register_chatcommand("tpn", {
   description = "Deny teleport requests from another player",
   func = tpr_deny
})

minetest.log("info", "[Teleport Request] Teleport Request v" .. version .. " Loaded.")


Those variables are function parameters, and are defined when the function is defined, here:

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Code: Select all

local function tphr_send(sender, receiver)

try replace tostring() to dump() on my code...

No. Your code is not the correct solution, he's trying to find out the name of the caller not the param passed.

Anyway, it would be player:get_player_name() not tostring or dump.
dump(player) will return <userdata>.

[RREDesigns]

Ok, that explains a lot. I was missing some of that.

In the code for the telport requests, sender and receiver are declared, but never defined. That's one of my biggest issues, I don't know how those vars get their value, or how the engine sorts them. Can I change those vars with, let's say paka and paka2, and get the same value assigned to those by the engine?

[rubenwardy]

Yes. Both these will work:

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Code: Select all

function foo(one, two)
    print(one, two)
end


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Code: Select all

function foo(dog, cat)
    print(dog, cat)
end


What matters is the order, not the names.

Somewhere is in the code gives it their value, see above.

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Code: Select all

foo("something", "happened")


Runs the code in foo, starts with
one = dog = "something"
two = cat = "happened"

[everamzah]

Why doesn't this work? Or, more specifically, why would this make minetest run at 100% CPU and become unresponsive?

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Code: Select all

minetest.register_node("kalite:plastic_grass", {
        tiles = "default_grass.png"
})

minetest.register_on_generated(function(minp, maxp, seed)
        if minp.y >= 14360 and minp.y <= 14440 then
                for x = minp.x, maxp.x do
                for z = minp.z, maxp.z do
                        minetest.set_node({x = x, y = 14400, z = z}, {name="default:cloud"})--[[
                        minetest.set_node({x = x, y = 14401, z = z}, {name="kalite:plastic_grass"})--]]
                end
                end
        end
end)


https://github.com/cornernote/minetest- ... it.lua#L25