games/minimal/mods/default/textures/default_tnt_top.png

--atc.lua
--registers and controls the ATC system

local atc={}

local eval_conditional

-- ATC persistence table. advtrains.atc is created by init.lua when it loads the save file.
atc.controllers = {}
function atc.load_data(data)
	local temp = data and data.controllers or {}
	--transcode atc controller data to node hashes: table access times for numbers are far less than for strings
	for pts, data in pairs(temp) do
		if type(pts)=="number" then
			pts=minetest.pos_to_string(minetest.get_position_from_hash(pts))
		end
		atc.controllers[pts] = data
	end
end
function atc.save_data()
	return {controllers = atc.controllers}
end
--contents: {command="...", arrowconn=0-15 where arrow points}

--general
function atc.train_set_command(train, command, arrow)
	atc.train_reset_command(train, true)
	train.atc_delay = 0
	train.atc_arrow = arrow
	train.atc_command = command
end

function atc.send_command(pos, par_tid)
	local pts=minetest.pos_to_string(pos)
	if atc.controllers[pts] then
		--atprint("Called send_command at "..pts)
		local train_id = par_tid or advtrains.get_train_at_pos(pos)
		if train_id then
			if advtrains.trains[train_id] then
				--atprint("send_command inside if: "..sid(train_id))
				if atc.controllers[pts].arrowconn then
					atlog("ATC controller at",pts,": This controller had an arrowconn of", atc.controllers[pts].arrowconn, "set. Since this field is now deprecated, it was removed.")
					atc.controllers[pts].arrowconn = nil
				end
				
				local train = advtrains.trains[train_id]
				local index = advtrains.path_lookup(train, pos)
				
				local iconnid = 1
				if index then
					iconnid = train.path_cn[index]
				else
					atwarn("ATC rail at", pos, ": Rail not on train's path! Can't determine arrow direction. Assuming +!")
				end
				
				local command = atc.controllers[pts].command				
				command = eval_conditional(command, iconnid==1, train.velocity)
				if not command then command="" end
				command=string.match(command, "^%s*(.*)$")
				
				if command == "" then
					atprint("Sending ATC Command to", train_id, ": Not modifying, conditional evaluated empty.")
					return true
				end
				
				atc.train_set_command(train, command, iconnid==1)
				atprint("Sending ATC Command to", train_id, ":", command, "iconnid=",iconnid)
				return true
				
			else
				atwarn("ATC rail at", pos, ": Sending command failed: The train",train_id,"does not exist. This seems to be a bug.")
			end
		else
			atwarn("ATC rail at", pos, ": Sending command failed: There's no train at this position. This seems to be a bug.")
		end
	else
		atwarn("ATC rail at", pos, ": Sending command failed: Entry for controller not found.")
		atwarn("ATC rail at", pos, ": Please visit controller and click 'Save'")
	end
	return false
end

-- Resets any ATC commands the train is currently executing, including the target speed (tarvelocity) it is instructed to hold
-- if keep_tarvel is set, does not clear the tarvelocity
function atc.train_reset_command(train, keep_tarvel)
	train.atc_command=nil
	train.atc_delay=nil
	train.atc_brake_target=nil
	train.atc_wait_finish=nil
	train.atc_arrow=nil
	if not keep_tarvel then
		train.tarvelocity=nil
	end
end

--nodes
local idxtrans={static=1, mesecon=2, digiline=3}
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