Post your modding questions here

[Hybrid Dog]

It doesn't work:

Code: Select all

local function getb(d)
	return math.log(2*d) / (1 - d)
end

local function geta(b)
	return 1/(1-math.exp(-b))
end

local function v(d)
	print("d = " .. d)
	local b = getb(d)
	print("b = " .. b)
	local a = geta(b)
	print("a = " .. a)
	-- col should be 0.5
	local col = a*(1-math.exp(-b*d))
	print("col = " .. col)
	return col
end

for i = 0,10 do
	v(i/10)
	print("\r")
end

Spoiler

d = 0
b = -inf
a = -0
col = nan

d = 0.1
b = -1.788264347149
a = -0.20084088574179
col = 0.039327291406572

d = 0.2
b = -1.1453634148427
a = -0.46650851967355
col = 0.12009488819587

d = 0.3
b = -0.72975089109427
a = -0.93061021188818
col = 0.22775591524473

d = 0.4
b = -0.37190591885702
a = -2.2197730208415
col = 0.3560453958317

d = 0.5
b = 0
a = inf
col = nan

d = 0.6
b = 0.45580389198489
a = 2.7317787610291
col = 0.65364424779417

d = 0.7
b = 1.1215741220707
a = 1.48316590624
col = 0.80673363750398

d = 0.8
b = 2.3500181462287
a = 1.1054211786931
col = 0.93674729278413

d = 0.9
b = 5.8778666490212
a = 1.0028086201511
col = 0.99775310387913

d = 1
b = inf
a = 1
col = 1

deriving is a nice idea but
call the left side l(b) and the right side r(b)
l(b) = r(b)
the derivation gives the pitch of the function, but l and r are just equal at b, which is fixed, so l'(b) doesn't need to be r'(b)

Maybe you need to use the W function to shift it for b

[Hybrid Dog]

l made it get b approximately:

Code: Select all

local function geta(b)
	return 1/(1-math.exp(-b))
end

local minb = -1002
local maxb = 30001

local function v(d)
	local b
	io.write("d = " .. d.."\n")
	for i = 0,100 do
		b = (minb+maxb)/2
		io.write("b = " .. b.."; ")
		local a = geta(b)
		--print("a = " .. a)
		local col = a*(1-math.exp(-b*d))
		io.write("col = " .. col.."\n")

		if math.log(col-0.5)/math.log(10) < -9
		or tostring(col) == "nan" then
			break
		elseif col < 0.5 then
			minb = b
		else
			maxb = b
		end
	end
end

v(0.8)

Spoiler

d = 0.8
b = 14499.5; col = 1
b = 6748.75; col = 1
b = 2873.375; col = 1
b = 935.6875; col = 1
b = -33.15625; col = 0.0013185139131068
b = 451.265625; col = 1
b = 209.0546875; col = 1
b = 87.94921875; col = 1
b = 27.396484375; col = 0.99999999969823
b = -2.8798828125; col = 0.53611234532014
b = -18.01806640625; col = 0.02722515775512
b = -10.448974609375; col = 0.12368711017427
b = -6.6644287109375; col = 0.26277482855574
b = -4.7721557617188; col = 0.37978275468918
b = -3.8260192871094; col = 0.45332360670287
b = -3.3529510498047; col = 0.49369563299398
b = -3.1164169311523; col = 0.51467348487931
b = -3.2346839904785; col = 0.50412338618094
b = -3.2938175201416; col = 0.49889380994757
b = -3.2642507553101; col = 0.50150472233792
b = -3.2790341377258; col = 0.50019829096251
b = -3.2864258289337; col = 0.49954580588774
b = -3.2827299833298; col = 0.49987198737943
b = -3.2808820605278; col = 0.5000351239216
b = -3.2818060219288; col = 0.49995355183667
b = -3.2813440412283; col = 0.49999433692586
b = -3.281113050878; col = 0.50001473018543
b = -3.2812285460532; col = 0.50000453349607
b = -3.2812862936407; col = 0.49999943519607
b = -3.281257419847; col = 0.50000198434235
b = -3.2812718567438; col = 0.50000070976828
b = -3.2812790751923; col = 0.50000007248194
b = -3.2812826844165; col = 0.49999975383895
b = -3.2812808798044; col = 0.49999991316043
b = -3.2812799774983; col = 0.49999999282118
b = -3.2812795263453; col = 0.50000003265156
b = -3.2812797519218; col = 0.50000001273637
b = -3.2812798647101; col = 0.50000000277878
b = -3.2812799211042; col = 0.49999999779998
b = -3.2812798929072; col = 0.50000000028938

This makes a list of bs:

Code: Select all

local function geta(b)
	return 1/(1-math.exp(-b))
end

local function v(d)
	local minb = -1002
	local maxb = 30001

	local b
	--io.write("d = " .. d.."\n")
	for i = 0,100 do
		b = (minb+maxb)/2
		--io.write("b = " .. b.."; ")
		local a = geta(b)
		--print("a = " .. a)
		local col = a*(1-math.exp(-b*d))
		--io.write("col = " .. col.."\n")

		if math.log(col-0.5)/math.log(10) < -9
		or tostring(col) == "nan" then
			break
		elseif col < 0.5 then
			minb = b
		else
			maxb = b
		end
	end
	return b
end

for i = 0,10 do
	local d = i/10
	io.write("d = " .. d..";"..(" "):rep(5-#tostring(d)).."b = "..v(d).."\n")
end

To use it for automatic brightness adjusting, the bs can be stored in a table and to get a b, interpolation can be used

Code: Select all

d = 0;    b = 30001
d = 0.1;  b = 6.921614307927
d = 0.2;  b = 3.2812798977898
d = 0.3;  b = 1.8010717819961
d = 0.4;  b = 0.82216324127785
d = 0.5;  b = 9.4905772130005e-09
d = 0.6;  b = -0.82216322934596
d = 0.7;  b = -1.8010717700643
d = 0.8;  b = -3.2812798929072
d = 0.9;  b = -6.9216142889459
d = 1;    b = -759.7890625

[Hybrid Dog]

Code: Select all

-- code including much unused

local load_time_start = os.clock()
math.randomseed(os.time()+tonumber(io.popen("date +%N"):read("*all")))

--$ luajit parab.lua | pnmtopng > dsa.png && optipng -o7 -quiet dsa.png
local s = 2^10
local col = 255

local tab = {"P3", s, s, col}
local num = 5

local function info(msg)
	os.execute("notify-send '"..msg.."'")
end

local function round(n)
	return math.floor(n+0.5)
end

local function gcol(c)
	if c == math.huge
	or tostring(c) == "-nan" then
		c = 0
	end
	return round(c)%(col+1)
end

local function set(r,g,b)
	tab[num] = gcol(r)
	tab[num+1] = gcol(g)
	tab[num+2] = gcol(b)
	num = num+3
end

local sts = {}
local minc, maxc
local function tset(c)
	if not minc then
		minc = c
		maxc = c
	end
	minc = math.min(c, minc)
	maxc = math.max(c, maxc)
	table.insert(sts, c)
end


local function geta(b)
	return 1/(1-math.exp(-b))
end

local function v(d)
	local minb = -1002
	local maxb = 30001

	local b
	--io.write("d = " .. d.."\n")
	for i = 0,100 do
		b = (minb+maxb)/2
		--io.write("b = " .. b.."; ")
		local a = geta(b)
		--print("a = " .. a)
		local col = a*(1-math.exp(-b*d))
		--io.write("col = " .. col.."\n")

		if math.log(col-0.5)/math.log(10) < -9
		or tostring(col) == "nan" then
			break
		elseif col < 0.5 then
			minb = b
		else
			maxb = b
		end
	end
	return b
end

local function f(x)
	return v((x+s/2)/s)*s/100--math.sqrt(math.abs(10000-x*x))
end


local crds = {}
local a,b = -s/2+1, s/2
for x = a,b do
	if x == 0 then
		for y = a,b do
			crds[y] = crds[y] or {}
			crds[y][x] = 0.5
		end
	else
		local yf = f(x)
		if yf > b then
			for y = a,b do
				crds[y] = crds[y] or {}
				crds[y][x] = 0
			end
		elseif yf < a then
			for y = a,b do
				crds[y] = crds[y] or {}
				crds[y][x] = 1
			end
		else
			for y = a,math.floor(yf) do
				crds[y] = crds[y] or {}
				crds[y][x] = 0
			end
			for y = math.ceil(yf),b do
				crds[y] = crds[y] or {}
				crds[y][x] = 1
			end
			local y = math.ceil(yf)
			crds[y] = crds[y] or {}
			crds[y][x] = math.max(0, math.min(1, y-yf))
		end
	end
end

-- [[
for y = s/2,-s/2+1,-1 do
	for x = 1,s do
		x = x-s/2
		tset(crds[y][x])
	end
end--]]
--[[
for x = 1,s do
	x = x-1--s/2
	tset(do_ws_func(2, x))
end--]]


--[[
local crn = {x1=0,y1=0, x2=0,y2=0}
local hs = {}
local function seth(x,y)
	if not hs[y] then
		hs[y] = {}
	end
	if not hs[y][x] then
		hs[y][x] = 1
	else
		hs[y][x] = hs[y][x]+1
	end
	crn.x1 = math.min(x, crn.x1)
	crn.y1 = math.min(y, crn.y1)
	crn.x2 = math.max(x, crn.x2)
	crn.y2 = math.max(y, crn.y2)
end

local function geth(x,y)
	if not hs[y] then
		return 0
	end
	return hs[y][x] or 0
end

local cx = 0
local cy = 0
local dirs = {
	{1,0},
	{0,1},
	{-1,0},
	{0,-1},
}

local dif = maxc-minc
for i = 1,#sts do
	local v = sts[i]
	v = (v-minc)/dif
	sts[i] = v
	-- [ [
	v = v*255
	v = v*math.pi
	set(v,v,v)-- ] ]

	seth(cx,cy)
	--info(round(v*3)+1)
	--local dir = (v*300)%1
	local dir = (round(v*math.pi*100))%4+1
	local ndir = dirs[dir]
	cx = cx+ndir[1]
	cy = cy+ndir[2]
end

crn.x1 = crn.x1-5
crn.y1 = crn.y1-5
crn.x2 = crn.x2+5
crn.y2 = crn.y2+5

local s = {crn.x2-crn.x1, crn.y2-crn.y1}
tab[2] = s[1]+1
tab[3] = s[2]+1

maxc = 0
for y,xs in pairs(hs) do
	for _,h in pairs(xs) do
		maxc = math.max(maxc, h)
	end
end

for y = crn.y1,crn.y2 do
	for x = crn.x1,crn.x2 do
		local c = 0
		local v = hs[y]
		if v then
			c = hs[y][x] or 0
		end
		c = c*255/maxc
		--c = c%2*255
		set(c,c,c)
	end
end--]]

local dif = maxc-minc
for i = 1,#sts do
	local v = sts[i]
	v = (v-minc)/dif
	--sts[i] = v
	-- [[
	v = v*255
	--v = v*math.pi
	set(v,v,v)--]]

	--[[
	seth(cx,cy)
	--info(round(v*3)+1)
	--local dir = (v*300)%1
	local dir = (round(v*math.pi*100))%4+1
	local ndir = dirs[dir]
	cx = cx+ndir[1]
	cy = cy+ndir[2]--]]
end

info("fi")

print(table.concat(tab, " "))

local time = math.floor(tonumber(os.clock()-load_time_start)*100+0.5)/100
local msg = "fertig nach ca. "..time.."s"
if time > 0.05 then
	info(msg)
end

l think 1 y is 50 x on the picture

[iangp]

Well, nice results for your approximation :D

I just had this idea cause the (-1) was pissing me off after a while trying shift the equation hehe and d/dx(constant) = 0, a perfect murder hehe, unfortunately doesn't work in this case.

I just learned Calculus I (limits, derivatives and integrals, with just one variable and at IR) and I need more practice, but I'll try understand W function in somewhere else.

[Hybrid Dog]

l didn't know derivations with more than one variable are possible.

[iangp]

partial derivatives of functions that have more than one variable.
https://en.wikipedia.org/wiki/Partial_derivative
And derivatives of vectors, I see that like "more than one variable" (in this case axis), gradient and others operations
https://en.wikipedia.org/wiki/Gradient

the point is I'm just getting started at this new stage of mathematics :P
This is probably getting off-topic it's better we finish it here.

[Foghrye4]

I have a question!
I want to override ore generation of other mods. Thus i can use "minetest.clear_registered_ores()". But how i can control mod load order? Does it depends from mod name?

[paramat]

the 'depends.txt' file controls mod order.

[Foghrye4]

Thank, paramat.

[Hybrid Dog]

Do mesh objects have a cuboid collision box or a complex one?

[Don]

You set the collision box like a nodebox.

[xeranas]

Hi,
I'm trying to create block similar to furnace but more like "item converter". Due this reason I cannot use regular "fuel" recipes (I want that items as "fuel" would work only on my block).

So far I decided go ABM route which would check item in "fuel" slot and add it as fuel time manually according some predefined rules. To do so I need "extract" fuel name from fuel slot (it will be multiple custom "fuels").

I take furnace as example

Code: Select all

minetest.register_abm({
  action = function(pos, node, active_object_count, active_object_count_wider)
    local meta = minetest.get_meta(pos)
    local inv = meta:get_inventory()
    local fuellist = inv:get_list("fuel")

Seems I getting list of userdata objects. I do not know how to extract properties from them rather than guessing. Unfortunately minetest dev wiki and lua api documentation does not provide explanation about userdata (or I missed?).

Code: Select all

{ <userdata 1> }

Maybe I did completely wrong and I need go another direction?

[xeranas]

guessing over

Code: Select all

userdata:get_name()

Still where I could find which properties I can get from userdata? Maybe we can add some notes in dev wiki or lua api to help newbies like me?

[Byakuren]

They are a list of ItemStack. You can find the methods available in the mod API doc.

[xeranas]

They are a list of ItemStack. You can find the methods available in the mod API doc.

Thanks!, I was bit confused because lua.api documentation does not explicity says which type of objects from list I should expect. InvRef get_list

get_list(listname): return full list

[garywhite]

I am trying to set up a server, but I cannot get unified_inventory to work. Attached is the in-game load error.

Here is what debug says:

Code: Select all

2016-03-17 10:44:46: ERROR[main]: Failed to load and run script from 
2016-03-17 10:44:46: ERROR[main]: D:\FlipShare Data\mt\minetest-0.4.13\bin\..\mods\unifiedinventory\init.lua:
2016-03-17 10:44:46: ERROR[main]: ...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:60: Name unified_inventory:bag_small does not follow naming conventions: "modname:" or ":" prefix required
2016-03-17 10:44:46: ERROR[main]: stack traceback:
2016-03-17 10:44:46: ERROR[main]: 	[C]: in function 'error'

Does anyone know? I tried installing bags mod, to no avail. Please reply.

garywhite

mt error.png (59.14 KiB) Viewed 913 times

Code: Select all

2016-03-17 10:44:46: ERROR[main]: 	...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:60: in function 'check_modname_prefix'
2016-03-17 10:44:46: ERROR[main]: 	...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:98: in function 'register_item'
2016-03-17 10:44:46: ERROR[main]: 	...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:216: in function 'really_register_tool'
2016-03-17 10:44:46: ERROR[main]: 	...t-0.4.13\bin\..\mods\Technic\technic_worldgen/crafts.lua:162: in function 'register_tool'
2016-03-17 10:44:46: ERROR[main]: 	...mt\minetest-0.4.13\bin\..\mods\unifiedinventory/bags.lua:173: in main chunk
2016-03-17 10:44:46: ERROR[main]: 	[C]: in function 'dofile'
2016-03-17 10:44:46: ERROR[main]: 	...mt\minetest-0.4.13\bin\..\mods\unifiedinventory\init.lua:63: in main chunk
2016-03-17 10:44:46: ERROR[main]: ======= END OF ERROR FROM LUA ========
2016-03-17 10:44:46: ERROR[main]: Server: Failed to load and run D:\FlipShare Data\mt\minetest-0.4.13\bin\..\mods\unifiedinventory\init.lua
2016-03-17 10:44:46: ERROR[main]: ModError: ModError: Failed to load and run D:\FlipShare Data\mt\minetest-0.4.13\bin\..\mods\unifiedinventory\init.lua
2016-03-17 10:44:46: ERROR[main]: Error from Lua:
2016-03-17 10:44:46: ERROR[main]: ...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:60: Name unified_inventory:bag_small does not follow naming conventions: "modname:" or ":" prefix required
2016-03-17 10:44:46: ERROR[main]: stack traceback:
2016-03-17 10:44:46: ERROR[main]: 	[C]: in function 'error'
2016-03-17 10:44:46: ERROR[main]: 	...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:60: in function 'check_modname_prefix'
2016-03-17 10:44:46: ERROR[main]: 	...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:98: in function 'register_item'
2016-03-17 10:44:46: ERROR[main]: 	...Data\mt\minetest-0.4.13\bin\..\builtin\game\register.lua:216: in function 'really_register_tool'
2016-03-17 10:44:46: ERROR[main]: 	...t-0.4.13\bin\..\mods\Technic\technic_worldgen/crafts.lua:162: in function 'register_tool'
2016-03-17 10:44:46: ERROR[main]: 	...mt\minetest-0.4.13\bin\..\mods\unifiedinventory/bags.lua:173: in main chunk
2016-03-17 10:44:46: ERROR[main]: 	[C]: in function 'dofile'
2016-03-17 10:44:46: ERROR[main]: 	...mt\minetest-0.4.13\bin\..\mods\unifiedinventory\init.lua:63: in main chunk
2016-03-17 10:44:46: ERROR[main]: Check debug.txt for details.

[Hybrid Dog]

you called the mod folder unifiedinventory, but you need to call it unified_inventory

"read before asking for help"
http://wiki.minetest.net/Troubleshootin ... a.E2.80.9D

[BrunoMine]

About the method:

Code: Select all

minetest.register_decoration()

How I can set a quantity of generated items?

[MineYoshi]

Exactly how i can stop this function with other use?

Code: Select all

minetest.register_tool("headphones:1headphones", {
	description = "Headphones Test Song",
	inventory_image = "testh.bmp",

   on_use = function()
      minetest.sound_play("test")
   end,
   
		
})

I mean i click one time, plays the sound, i click other time, the song plays again with the other.
I want to do this, i click one time, plays the sound, i click again and the stops the sound, how i do that?

[iangp]

Exactly how i can stop this function with other use?

Code: Select all

minetest.register_tool("headphones:1headphones", {
	description = "Headphones Test Song",
	inventory_image = "testh.bmp",

   on_use = function()
      minetest.sound_play("test")
   end,
   
		
})

I mean i click one time, plays the sound, i click other time, the song plays again with the other.
I want to do this, i click one time, plays the sound, i click again and the stops the sound, how i do that?

What if you:

Code: Select all

--Put a global var here
sound = 'no'
minetest.register_tool("headphones:1headphones", {
	description = "Headphones Test Song",
	inventory_image = "testh.bmp",

   on_use = function()
        if sound == 'no' then
            sound = minetest.sound_play("test") --keep the "reference" of the sound
        else
            minestes.sound_stop(sound)
           sound = 'no'
       end
   end,
   
		
})

[Byakuren]

Except you probably want to make sound a local var instead.

[rubenwardy]

You should rarely use global variables as they will be present in other mods. You should only create global variables with the same name as your mod.

[Hybrid Dog]

VaE adds a vector.dot and people may think it's added by builtin, so they don't notice that their mod crashes if pipeworks isn't installed

[iangp]

You should rarely use global variables as they will be present in other mods. You should only create global variables with the same name as your mod.

hmm This is a convention ? I understand the fact, avoid using global vars, because they can conflict with other mods but if I use something like that, would it be ok?:
nameofmymod_sound = 'no'
or local sound = 'no' also works inside the func?

another Q: This is documented on wiki or on somewhere?, I'm just can't remember...
That was just a "speed coding"...
Reading this I think I should review some code on my mods... XD

[rubenwardy]

It's just good practice not to. Instead of nameofmymod_sound you should do nameofmymod.sound or a local variable.
Global variables are the best way to communicate between files. The alternative is passing parameters between files is a bit weird.

Code: Select all

-- You can do this if you want want to make a global variable,
-- but I usually use nameofmod.sound as I prefer that personally.
local sound = "no"
dofile(minetest.get_modpath() .. "/other.lua", sound)

This doesn't seem to be mentioned anyway, except a little bit by me here: http://rubenwardy.com/minetest_modding_ ... and-global