industrialtest/machines/magnetizer.lua

-- IndustrialTest
-- Copyright (C) 2025 mrkubax10

-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.

-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.

-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.

local S=minetest.get_translator("industrialtest")

local function findFenceRailEnd(initialPosition,direction)
	local y=initialPosition.y
	local railNode=minetest.get_node(vector.new(initialPosition.x,y,initialPosition.z))
	while minetest.get_item_group(railNode.name,"_industrialtest_metalFence")>0 and math.abs(initialPosition.y-y)<=19 do
		y=y+direction
		railNode=minetest.get_node(vector.new(initialPosition.x,y,initialPosition.z))
	end
	return y-direction
end

local function hasMetalBoots(player)
	local inv
	if industrialtest.mtgAvailable then
		_,inv=armor:get_valid_player(player,"")
	elseif industrialtest.mclAvailable then
		inv=player:get_inventory()
	end

	if inv then
		local armorList=inv:get_list("armor")
		assert(armorList)
		local requiredGroups={
			"armor_iron",
			"armor_gold",
			"armor_bronze",
			"_industrialtest_electricArmor"
		}
		-- 3D armor boots have to be hardcoded here because they don't provide any group depending on material
		local requiredNames={
			"3d_armor:boots_steel",
			"3d_armor:boots_gold",
			"3d_armor:boots_bronze"
		}
		for _,itemstack in ipairs(armorList) do
			local def=itemstack:get_definition()
			if def and def.groups and def.groups.armor_feet then
				for _,group in ipairs(requiredGroups) do
					if def.groups[group] then
						-- Matching group succeeded
						return true
					end
				end
			end
			for _,itemname in ipairs(requiredNames) do
				if itemname==itemstack:get_name() then
					-- Matching itemname succeeded
					return true
				end
			end
		end
	end

	return false
end

industrialtest.Magnetizer=table.copy(industrialtest.ElectricMachine)
industrialtest.internal.unpackTableInto(industrialtest.Magnetizer,{
	name="industrialtest:magnetizer",
	description=S("Magnetizer"),
	tiles={
		"industrialtest_machine_block.png",
		"industrialtest_machine_block.png",
		"industrialtest_machine_block.png",
		"industrialtest_machine_block.png",
		"industrialtest_machine_block.png",
		"industrialtest_machine_block.png^industrialtest_magnetizer_front.png"
	},
	sounds="metal",
	facedir=true,
	storageLists={
		"powerStorage"
	},
	powerLists={
		{
			list="powerStorage",
			direction="i"
		}
	},
	capacity=industrialtest.api.lvPowerFlow*2,
	flow=industrialtest.api.lvPowerFlow,
	ioConfig="iiiiii",
	requiresWrench=true,
	hasPowerInput=true,
	_capacityPerFence=15,
	_opPower=4
})

function industrialtest.Magnetizer.onConstruct(self,pos)
	local meta=minetest.get_meta(pos)
	local inv=meta:get_inventory()
	inv:set_size("powerStorage",1)
	self:determineFenceRail(pos)
	self:determinePowerCapacity(pos)
	industrialtest.ElectricMachine.onConstruct(self,pos)
end

function industrialtest.Magnetizer.onDestruct(self,pos)
	self.detachFenceRail(pos)
	industrialtest.ElectricMachine.onDestruct(self,pos)
end

function industrialtest.Magnetizer.onDig(self,pos,node,digger)
	self.detachFenceRail(pos)
	return industrialtest.ElectricMachine.onDig(self,pos,node,digger)
end

function industrialtest.Magnetizer.getFormspec(self,pos)
	local parentFormspec=industrialtest.ElectricMachine.getFormspec(self,pos)
	local meta=minetest.get_meta(pos)
	local powerPercent=meta:get_int("industrialtest.powerAmount")/meta:get_int("industrialtest.powerCapacity")*100
	local formspec={
		(powerPercent>0 and "image[4.7,2.7;1,1;industrialtest_gui_electricity_bg.png^[lowpart:"..powerPercent..":industrialtest_gui_electricity_fg.png]"
		 or "image[4.7,2.7;1,1;industrialtest_gui_electricity_bg.png]"),
		"list[context;powerStorage;4.7,3.7;1,1]",
		"listring[context;powerStorage]"
	}
	return parentFormspec..table.concat(formspec,"")
end

function industrialtest.Magnetizer.determinePowerCapacity(self,pos)
	local meta=minetest.get_meta(pos)
	if meta:contains("lowY") and meta:contains("highY") then
		local lowY=meta:get_int("lowY")
		local highY=meta:get_int("highY")
		local capacity=self.capacity+(highY-lowY)*self._capacityPerFence
		meta:set_int("industrialtest.powerCapacity",capacity)
	end
end

-- Checks all sides on the same Y level if there is rail made from metal fences attached
function industrialtest.Magnetizer.determineFenceRail(self,pos)
	local neighbourPositions={
		vector.offset(pos,-1,0,0),
		vector.offset(pos,1,0,0),
		vector.offset(pos,0,0,-1),
		vector.offset(pos,0,0,1)
	}
	local railPosition
	for _,neighbourPosition in ipairs(neighbourPositions) do
		local neighbourNode=minetest.get_node(neighbourPosition)
		if minetest.get_item_group(neighbourNode.name,"_industrialtest_metalFence")>0 then
			railPosition=neighbourPosition
			break
		end
	end
	if not railPosition then
		return
	end

	local direction=vector.subtract(railPosition,pos)
	minetest.swap_node(pos,{
		name=self.name,
		-- Some cryptic code that converts direction vector to param2
		param2=direction.z+1*math.abs(direction.z)+direction.x+2*math.abs(direction.x)
	})

	-- Find low and high points of fence rail
	local lowY=findFenceRailEnd(railPosition,-1)
	local highY=findFenceRailEnd(railPosition,1)

	-- Keep magnetizer position in fence metadata so new fences can be attached easily
	for y=lowY,highY,1 do
		local meta=minetest.get_meta(vector.new(railPosition.x,y,railPosition.z))
		meta:set_string("magnetizerPosition",minetest.serialize(pos))
	end

	local meta=minetest.get_meta(pos)
	meta:set_string("railPosition",minetest.serialize(railPosition))
	meta:set_int("lowY",lowY)
	meta:set_int("highY",highY)
end

function industrialtest.Magnetizer.detachFenceRail(pos)
	local meta=minetest.get_meta(pos)
	if not meta:contains("railPosition") or not meta:contains("lowY") or not meta:contains("highY") then
		return
	end

	local railPosition=minetest.deserialize(meta:get_string("railPosition"))
	local lowY=meta:get_int("lowY")
	local highY=meta:get_int("highY")
	for y=lowY,highY,1 do
		local fenceMeta=minetest.get_meta(vector.new(railPosition.x,y,railPosition.z))
		fenceMeta:set_string("magnetizerPosition","")
	end
	meta:set_string("railPosition","")
end

industrialtest.Magnetizer:register()

minetest.register_craft({
	type="shaped",
	output="industrialtest:magnetizer",
	recipe={
		{industrialtest.elementKeys.powerCarrier,"industrialtest:iron_fence",industrialtest.elementKeys.powerCarrier},
		{industrialtest.elementKeys.powerCarrier,"industrialtest:machine_block",industrialtest.elementKeys.powerCarrier},
		{industrialtest.elementKeys.powerCarrier,"industrialtest:iron_fence",industrialtest.elementKeys.powerCarrier}
	}
})

-- Players to which Y velocity should be added
local validatedPlayers={}
-- Time since last check to which players the effect should be applied
local validationDelta=0.2
minetest.register_globalstep(function(dtime)
	validationDelta=validationDelta+dtime
	if validationDelta>=0.2 then
		validatedPlayers={}
		local players=minetest.get_connected_players()
		for _,player in ipairs(players) do
			local control=player:get_player_control()
			if (control.jump or control.sneak) and hasMetalBoots(player) then
				local props=player:get_properties()
				local pos=player:get_pos()
				local offsets={
					vector.new(props.collisionbox[1],0,0),
					vector.new(props.collisionbox[4],0,0),
					vector.new(0,0,props.collisionbox[3]),
					vector.new(0,0,props.collisionbox[6])
				}
				for _,offset in ipairs(offsets) do
					local targetPos=vector.add(pos,offset)
					local targetNode=minetest.get_node(targetPos)
					if minetest.get_item_group(targetNode.name,"_industrialtest_metalFence")>0 then
						local fenceMeta=minetest.get_meta(targetPos)
						if fenceMeta:contains("magnetizerPosition") then
							table.insert(validatedPlayers,{
								playerName=player:get_player_name(),
								magnetizerPosition=minetest.deserialize(fenceMeta:get_string("magnetizerPosition")),
								multiplier=(control.sneak and 0.55 or 1)
							})
							break
						end
					end
				end
			end
		end
	end

	for _,validatedPlayer in ipairs(validatedPlayers) do
		local player=minetest.get_player_by_name(validatedPlayer.playerName)
		if player then
			local magnetizerMeta=minetest.get_meta(validatedPlayer.magnetizerPosition)
			local physicsOverride=player:get_physics_override()
			local requiredPower=industrialtest.Magnetizer._opPower*physicsOverride.gravity
			if magnetizerMeta:get_int("industrialtest.powerAmount")>=requiredPower then
				industrialtest.api.addPower(magnetizerMeta,-requiredPower)
				industrialtest.Magnetizer:requestPower(validatedPlayer.magnetizerPosition)
				industrialtest.Magnetizer:updateFormspec(validatedPlayer.magnetizerPosition)
				industrialtest.internal.addYVelocityClamped(player,30*dtime*physicsOverride.gravity*validatedPlayer.multiplier,5*physicsOverride.gravity)
			end
		end
	end
end)