Post your modding questions here

[maikerumine]

Quick question:

How can I find the undeclared variable in a function?

I receive error in 4.11 not 4.10
ERROR:
14:31:04: ERROR[ServerThread]: Assignment to undeclared global "yaw" inside a function at ...\..\worlds\FIGHTING SURVIVAL\worldmods\badplayer/api.lua:432.

This error comes up a lot with mobs api. I want to fix but don't know where to pinpoint the problem.

See code here: https://github.com/maikerumine/badplayer/blob/master/api.lua#L432

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Code: Select all

if self.state == "stand" then
-- randomly turn
if math.random(1, 4) == 1 then
-- if there is a player nearby look at them
local lp = nil
local s = self.object:getpos()
if self.type == "npc" then
local o = minetest.get_objects_inside_radius(self.object:getpos(), 3)
local yaw = 0
for _,o in ipairs(o) do
if o:is_player() then
lp = o:getpos()
break
end
end
end



if lp ~= nil then
local vec = {x=lp.x-s.x, y=lp.y-s.y, z=lp.z-s.z}
yaw = math.atan(vec.z/vec.x)+math.pi/2
if self.drawtype == "side" then
yaw = yaw+(math.pi/2)
end


if lp.x > s.x then
yaw = yaw+math.pi
end
else
yaw = self.object:getyaw()+((math.random(0,360)-180)/180*math.pi)
end
self.object:setyaw(yaw)
end


Any pointers is greatly appreciated.

[lag01]

Quick question:
...

i think, it is because

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local yaw = 0

is inside if...end statement.
That code don't have any indent at all, so almost impossible to see where one statement is nesting in another! In your place i would start by fixing that :)

[false_chicken]

Yeah that looks like the problem. Also indentation is a must for readability. Of course it is your code so do what you wish but I would suggest applying some. Example:

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Code: Select all

int main(int argc, char *argv[])
{
    ...
    while (x == y) {
        something();
        somethingelse();
 
        if (some_error) {
            do_correct();
        } else {
            continue_as_usual();
        }
    }
 
    finalthing();
    ...
}

It would probably do wonders for your brain. Lol. Tab key is your friend.

http://en.wikipedia.org/wiki/Indent_style

[maikerumine]

Yeah that looks like the problem. Also indentation is a must for readability. Of course it is your code so do what you wish but I would suggest applying some. Example:

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Code: Select all

int main(int argc, char *argv[])
{
    ...
    while (x == y) {
        something();
        somethingelse();
 
        if (some_error) {
            do_correct();
        } else {
            continue_as_usual();
        }
    }
 
    finalthing();
    ...
}

It would probably do wonders for your brain. Lol. Tab key is your friend.

http://en.wikipedia.org/wiki/Indent_style

I totally agree guys. My problem was taking the original code and editing it in word pad! HA! lost all formatting, so I will re do in Lua when I get a chance.

The error was there even before i butchered the code, but only in version 4.11, in 4.10 it is fine. odd.

[false_chicken]

Ah lol. I thought you must have been some sort of wizard to do all that and only have one error.

[rubenwardy]

I think, writing something into depends.txt forces the Engine to load the mod before yours, so your code would be executed after default registered the items.

but if you add a ! after the modname, your mod is loaded after this one l think

lua_api.txt contains nothing about this.

[Hybrid Dog]

I think, writing something into depends.txt forces the Engine to load the mod before yours, so your code would be executed after default registered the items.

but if you add a ! after the modname, your mod is loaded after this one l think

lua_api.txt contains nothing about this.

weird, why did l think that ! after the mod name lets mods become loaded before others
https://github.com/minetest/minetest/bl ... ds.cpp#L67

[maikerumine]

I indented the entire code.

https://github.com/maikerumine/badplayer/blob/master/api.lua#L440

I still cannot figure out why the error comes up in minetest 4.11 and not 4.10.
Something about global and yaw. Should I just ignore it for now?

[ExeterDad]

try changing line 432 from:

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yaw = math.atan(vec.z/vec.x)+math.pi/2

to

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Code: Select all

local yaw = math.atan(vec.z/vec.x)+math.pi/2

Forgive me if I'm wrong. I don't claim to know what I'm doing :P

I forgot what the change was and why, but no more lazy lua coding in recent Minetest without with the engine complaining.

[maikerumine]

try changing line 432 from:

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Code: Select all

yaw = math.atan(vec.z/vec.x)+math.pi/2

to

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

local yaw = math.atan(vec.z/vec.x)+math.pi/2

Forgive me if I'm wrong. I don't claim to know what I'm doing :P

I forgot what the change was and why, but no more lazy lua coding in recent Minetest without with the engine complaining.

Dangit. I added the code (replaced) same error, now in line 441, so i added local to the yaw, then it crashed the engine. I think I will skip the error for now, Thank you for giving me a pointer on local, maybe there is more to it than I can see at the moment.

[ExeterDad]

adding local to yaw on 440 crashed it?

[maikerumine]

adding local to yaw on 440 crashed it?

deleted false comment stating "no"

EDIT. YES I re-checked, 440 bombs the engine.

[rubenwardy]

Adding local to the above lines stops the setyaw from getting yaw, it gets nil instead.

Try

local yaw = 0

Above

if lp ~= nil then

The engine change was by ShadowNinja, and is in builtin/common/strict.lua
If you use the latest dev version of Minetest, then it no longer prints to the chat, due to a pull request I made that was merged.

Edit: the code is indented incorrectly. See for loop above the if statement I specified, end is missing from code inside.

[maikerumine]

Adding local to the above lines stops the setyaw from getting yaw, it gets nil instead.

Try

local yaw = 0

Above

if lp ~= nil then

The engine change was by ShadowNinja, and is in builtin/common/strict.lua
If you use the latest dev version of Minetest, then it no longer prints to the chat, due to a pull request I made that was merged.

Edit: the code is indented incorrectly. See for loop above the if statement I specified, end is missing from code inside.

I am not sure what to do with this. Is this code to replace the current?

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Code: Select all

         --BEGIN MESSED UP CODE
         if self.state == "stand" then
            -- randomly turn
            if math.random(1, 4) == 1 then
               --if there is a player nearby look at them
               local lp = nil
               local s = self.object:getpos()
               if self.type == "npc" then
                  local o = minetest.get_objects_inside_radius(self.object:getpos(), 3)

                  local yaw = 0
                  for _,o in ipairs(o) do
                     if o:is_player() then
                        lp = o:getpos()
                        break
                  end
               end
            end
            if lp ~= nil then
               local vec = {x=lp.x-s.x, y=lp.y-s.y, z=lp.z-s.z}
               yaw = math.atan(vec.z/vec.x)+math.pi/2
               if self.drawtype == "side" then
                  yaw = yaw+(math.pi/2)
               end
               if lp.x > s.x then
                  yaw = yaw+math.pi
               end
            else
               yaw = self.object:getyaw()+((math.random(0,360)-180)/180*math.pi)
            end
            self.object:setyaw(yaw)
         end

[maikerumine]

IT WORKED! Thank you, Ruben!

Now I need to make sure the indenting is correct and it should be good.

[TenPlus1]

if it helps Mobs Redo mod is using the latest mob api with the majority of the bugs fixed, as well as new features...

https://forum.minetest.net/viewtopic.php?f=9&t=9917

[Nathan.S]

Is there any significance to the order of item drops, as in this code.

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Code: Select all

drop = {
      max_items = 1,
      items = {
         {
         items = {'default:gravel'},
         rarity = 3,
         },
         {
         items = {'default:gold_lump'},
         rarity = 100,
         },
         {
         items = {'default:dirt_with_grass'},
         },


I'm wondering if it makes any difference which items I declare first. Should they run in any certain order, or shouldn't order make any difference.
Thanks in advance.

[TenPlus1]

It doesn't matter which order you add the drops, the routine that handles mob death will go through each and chose a random drop according to rarity and number...

[Nathan.S]

Thanks TenPlus1, this is for a node not a mob, but I'll assume that it doesn't make a difference, correct me if I'm wrong please.

[BrunoMine]

How to wear a tool that is in the inventory?
But without using the tool. Example. Every 3 seconds, wearing a little.
Anyone me a help on this.

[false_chicken]

I cannot seem to get tool callbacks working. They never seem to get called. Here is what I have:

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minetest.register_tool("testhammer:testhammer", { -- Register the hammer.
   description = "The Hammer",
   inventory_image = "hammer.png",
   tool_capabilities = {
      full_punch_interval = 0.7,
      max_drop_level=1,
      groupcaps={
         snappy={times={[1]=1.90, [2]=0.90, [3]=0.30}, uses=40, maxlevel=3},
      },
   
   damage_groups = {fleshy=8},
      
   on_punch = function(pos, node, puncher, pointed_thing)
      LogMan:sendMessageToPlayer (puncher, "Punched!") -- Print message to console and player.
      LogMan:logMessage("HAMMER", 1, "PUNCHED!")
   end,
   
   on_use = function(itemstack, user, pointed_thing)
      LogMan:sendMessageToPlayer (user, "Used!")
      LogMan:logMessage("HaMMER", 1, "USED!")
   end,
   
   on_rightclick = function(pos, node, player, itemstack, pointed_thing)
      LogMan:sendMessageToPlayer (player, "Right clicked!")
                LogMan:sendMessageToPlayer (player, "Right clicked!")
   end,

   on_place = function(pos, node, player, itemstack, pointed_thing)
      LogMan:sendMessageToPlayer (player, "Rightclicked!")
      return
   end,
   }
})

Is there something I am missing? Using version 0.4.11.

EDIT: Figured it out. Seems like I put a spare } in there that screwed things up. Thanks anyway.

[false_chicken]

How do you use pointed_thing? My goal is to get the player hit with a tool. I know how to find a node using the position returned with the pointed_thing but how do I get the player/entity at that location using the same idea?

EDIT: It doesn't seem to return any sort of actual 'object' you are pointing at. Just the type and position. Is there something similar to get a player at a position like how you would get node data at a position? Is minetest.get_objects_inside_radius the proper/only way?

[HeroOfTheWinds]

@false_chicken: If you only intend for your mod to have an effect if a player is hit by the tool, try experimenting with

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Code: Select all

punch(puncher, time_from_last_punch, tool_capabilities, direction)

If I'm not mistaken, player:punch() is actually a call of on_punch(), meaning puncher is the one punching the player. So, when you use the tool, use get_objects_inside_radius(), check each object if it is a player, and call punch() on each one that is a player.

Good luck!

[Hybrid Dog]

How to wear a tool that is in the inventory?
But without using the tool. Example. Every 3 seconds, wearing a little.
Anyone me a help on this.

Do you mean something like the technic flashlight?
https://github.com/minetest-technic/tec ... ht.lua#L74
https://github.com/minetest-technic/tec ... er.lua#L47

[Anonymous_moose]

how to make a function happen on punching a node
I am making a mod where when you punch a node, it spawns a monster on it with

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Code: Select all

add_entity(pos, "monster")

, changes the time to midnight through

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set_timeofday(0000)

and becomes a different node using

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set_node(pos, "traps:used_monster_portal")

[false_chicken]

how to make a function happen on punching a node
I am making a mod where when you punch a node, it spawns a monster on it with

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

add_entity(pos, "monster")

, changes the time to midnight through

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

set_timeofday(0000)

and becomes a different node using

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set_node(pos, "traps:used_monster_portal")

Use callbacks. Idk how to define it for the fists. I suppose you should override them. Something like:

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minetest.override_item(":", { -- I think that is the name fists have. That is the name in the source.
        on_punch = function(pos, node, puncher, pointed_thing)
            -- Do stuff here.
            add_entity(pos, "monster")
            set_timeofday(0000)
            set_node(pos, "traps:used_monster_portal")
        end,   
})

http://dev.minetest.net/minetest.register_node#on_punch

http://dev.minetest.net/minetest.override_item

[rubenwardy]

how to make a function happen on punching a node
I am making a mod where when you punch a node, it spawns a monster on it with

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

add_entity(pos, "monster")

, changes the time to midnight through

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Code: Select all

set_timeofday(0000)

and becomes a different node using

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Code: Select all

set_node(pos, "traps:used_monster_portal")

If you're adding a tool, you will want to use the on_use callback of the tool.

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Code: Select all

minetest.register_craftitem("asasas:asasas", {
    on_use = function(itemstack, user, pointed_thing)
        if pointed_thing.type == "node" then
            local pos = pointed_thing.above
            -- spawn the monster at 'pos'
        end
    end
})


untested.

[false_chicken]

If you're adding a tool, you will want to use the on_use callback of the tool.

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Code: Select all

minetest.register_craftitem("asasas:asasas", {
    on_use = function(itemstack, user, pointed_thing)
        if pointed_thing.type == "node" then
            local pos = pointed_thing.above
            -- spawn the monster at 'pos'
        end
    end
})


untested.

Are the hands considered a tool? I noticed that in the source for minetest_game they are identified by ":". That doesnt seem to follow the normal convention. Why?

[rubenwardy]

If you aren't registering a custom tool/craftitem to spawn it, use minetest.register_on_punch_node instead.

[Kilarin]

Hello folks! I've got an ore generation question.
So a normal register_ore looks something like this:

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minetest.register_ore({
   ore_type       = "scatter",
   ore            = "default:stone_with_iron",
   wherein        = "default:stone",
   clust_scarcity = 11 * 11 * 11,
   clust_num_ores = 3,
   clust_size     = 2,
   height_min     = -15,
   height_max     = 2,
})

cluster_scarcity indicates how likely the ore is to generate, the smaller the number, the better odds. If I'm understanding correctly, it is generally coded as a cube because the odds are that the ore will show up once in that size of cube?

But, now for the serious question. I would like to make ore generation vary according to your location on the map. By height is obvious, since I can set height min and max and can just register the ore with different scarcity numbers at different heights. BUT, I would like to make ore scarcity vary depending on X and Z coords. For example, I might like to make iron ore more likely to generate the further you get from spawn. The math for this would not be at all difficult, I might use

clust_scarcity = 11 * 11 * 11*(1/(abs(x)+abs(z)+1)) (not necessarily a good formula, but gets the idea across)

But this would depend on two factors:
1: Is the value of clust_scarity calculated once at runtime and never again, in which case this approach wouldn't work at all.

2: IF this approach is valid at all, how would I specify the values of the x and z coords?

Thank you very much for any help in correcting my vast oceans of ignorance about minetest mapgen. :)