path: root/advtrains/nodedb.lua

--nodedb.lua
--database of all nodes that have 'save_in_at_nodedb' field set to true in node definition


--serialization format:
--(2byte z) (2byte y) (2byte x) (2byte contentid)
--contentid := (14bit nodeid, 2bit param2)

local function int_to_bytes(i)
	local x=i+32768--clip to positive integers
	local cH = math.floor(x /           256) % 256;
	local cL = math.floor(x                ) % 256;
	return(string.char(cH, cL));
end
local function bytes_to_int(bytes)
	local t={string.byte(bytes,1,-1)}
	local n = 
		t[1] *           256 +
		t[2]
    return n-32768
end
local function l2b(x)
	return x%4
end
local function u14b(x)
	return math.floor(x/4)
end
local ndb={}

--local variables for performance
local ndb_nodeids={}
local ndb_nodes={}

local function ndbget(x,y,z)
	local ny=ndb_nodes[y]
	if ny then
		local nx=ny[x]
		if nx then
			return nx[z]
		end
	end
	return nil
end
local function ndbset(x,y,z,v)
	if not ndb_nodes[y] then
		ndb_nodes[y]={}
	end
	if not ndb_nodes[y][x] then
		ndb_nodes[y][x]={}
	end
	ndb_nodes[y][x][z]=v
end


local path=minetest.get_worldpath()..DIR_DELIM.."advtrains_ndb2"
--load
--nodeids get loaded by advtrains init.lua and passed here
function ndb.load_data(data)
	ndb_nodeids = data and data.nodeids or {}
	local file, err = io.open(path, "rb")
	if not file then
		atwarn("Couldn't load the node database: ", err or "Unknown Error")
	else
		local cnt=0
		local hst_z=file:read(2)
		local hst_y=file:read(2)
		local hst_x=file:read(2)
		local cid=file:read(2)
		while hst_z and hst_y and hst_x and cid and #hst_z==2 and #hst_y==2 and #hst_x==2 and #cid==2 do
			ndbset(bytes_to_int(hst_x), bytes_to_int(hst_y), bytes_to_int(hst_z), bytes_to_int(cid))
			cnt=cnt+1
			hst_z=file:read(2)
			hst_y=file:read(2)
			hst_x=file:read(2)
			cid=file:read(2)
		end
		atlog("nodedb: read", cnt, "nodes.")
		file:close()
	end
end

--save
function ndb.save_data()
	local file, err = io.open(path, "wb")
	if not file then
		atwarn("Couldn't save the node database: ", err or "Unknown Error")
	else
		for y, ny in pairs(ndb_nodes) do
			for x, nx in pairs(ny) do
				for z, cid in pairs(nx) do
					file:write(int_to_bytes(z))
					file:write(int_to_bytes(y))
					file:write(int_to_bytes(x))
					file:write(int_to_bytes(cid))
				end
			end
		end
		file:close()
	end
	return {nodeids = ndb_nodeids}
end

--function to get node. track database is not helpful here.
function ndb.get_node_or_nil(pos)
	-- FIX for bug found on linuxworks server:
	-- a loaded node might get read before the LBM has updated its state, resulting in wrongly set signals and switches
	-- -> Using the saved node prioritarily.
	local node = ndb.get_node_raw(pos)
	if node then
		return node
	else
		--try reading the node from the map
		return minetest.get_node_or_nil(pos)
	end
end
function ndb.get_node(pos)
	local n=ndb.get_node_or_nil(pos)
	if not n then
		return {name="ignore", param2=0}
	end
	return n
end
function ndb.get_node_raw(pos)
	local cid=ndbget(pos.x, pos.y, pos.z)
	if cid then
		local nodeid = ndb_nodeids[u14b(cid)]
		if nodeid then
			return {name=nodeid, param2 = l2b(cid)}
		end
	end
	return nil
end


function ndb.swap_node(pos, node, no_inval)
	if minetest.get_node_or_nil(pos) then
		minetest.swap_node(pos, node)
	end
	ndb.update(pos, node)
end

function ndb.update(pos, pnode)
	local node = pnode or minetest.get_node_or_nil(pos)
	if not node or node.name=="ignore" then return end
	if minetest.registered_nodes[node.name] and minetest.registered_nodes[node.name].groups.save_in_at_nodedb then
		local nid
		for tnid, nname in pairs(ndb_nodeids) do
			if nname==node.name then
				nid=tnid
			end
		end
		if not nid then
			nid=#ndb_nodeids+1
			ndb_nodeids[nid]=node.name
		end
		ndbset(pos.x, pos.y, pos.z, (nid * 4) + (l2b(node.param2 or 0)) )
		--atprint("nodedb: updating node", pos, "stored nid",nid,"assigned",ndb_nodeids[nid],"resulting cid",ndb_nodes[hash])
	else
		--at this position there is no longer a node that needs to be tracked.
		ndbset(pos.x, pos.y, pos.z, nil)
	end
end

function ndb.clear(pos)
	ndbset(pos.x, pos.y, pos.z, nil)
end


--get_node with pseudoload. now we only need track data, so we can use the trackdb as second fallback
--nothing new will be saved inside the trackdb.
--returns:
--true, conn1, conn2, rely1, rely2, railheight   in case everything's right.
--false  if it's not a rail or the train does not drive on this rail, but it is loaded or
--nil    if the node is neither loaded nor in trackdb
--the distraction between false and nil will be needed only in special cases.(train initpos)
function advtrains.get_rail_info_at(pos, drives_on)
	local rdp=advtrains.round_vector_floor_y(pos)
	
	local node=ndb.get_node_or_nil(rdp)
	if not node then return end
	
	local nodename=node.name
	if(not advtrains.is_track_and_drives_on(nodename, drives_on)) then
		return false
	end
	local conns, railheight, tracktype=advtrains.get_track_connections(node.name, node.param2)
	
	return true, conns, railheight
end

ndb.run_lbm = function(pos, node)
	return advtrains.pcall(function()
		local cid=ndbget(pos.x, pos.y, pos.z)
		if cid then
			--if in database, detect changes and apply.
			local nodeid = ndb_nodeids[u14b(cid)]
			local param2 = l2b(cid)
			if not nodeid then
				--something went wrong
				atwarn("Node Database corruption, couldn't determine node to set at", pos)
				ndb.update(pos, node)
			else
				if (nodeid~=node.name or param2~=node.param2) then
					atprint("nodedb: lbm replaced", pos, "with nodeid", nodeid, "param2", param2, "cid is", cid)
					minetest.swap_node(pos, {name=nodeid, param2 = param2})
					local ndef=minetest.registered_nodes[nodeid]
					if ndef and ndef.on_updated_from_nodedb then
						ndef.on_updated_from_nodedb(pos, node)
					end
					return true
				end
			end
		else
			--if not in database, take it.
			--atlog("Node Database:", pos, "was not found in the database, have you used worldedit?")
			ndb.update(pos, node)
		end
		return false
	end)
end


minetest.register_lbm({
        name = "advtrains:nodedb_on_load_update",
        nodenames = {"group:save_in_at_nodedb"},
        run_at_every_load = true,
        run_on_every_load = true,
        action = ndb.run_lbm,
        interval=30,
        chance=1,
    })

--used when restoring stuff after a crash
ndb.restore_all = function()
	--atlog("Updating the map from the nodedb, this may take a while")
	local cnt=0
	local dcnt=0
	for y, ny in pairs(ndb_nodes) do
		for x, nx in pairs(ny) do
			for z, _ in pairs(nx) do
				local pos={x=x, y=y, z=z}
				local node=minetest.get_node_or_nil(pos)
				if node then
					local ori_ndef=minetest.registered_nodes[node.name]
					local ndbnode=ndb.get_node_raw(pos)
					if ori_ndef and ori_ndef.groups.save_in_at_nodedb then --check if this node has been worldedited, and don't replace then
						if (ndbnode.name~=node.name or ndbnode.param2~=node.param2) then
							minetest.swap_node(pos, ndbnode)
							--atlog("Replaced",node.name,"@",pos,"with",ndbnode.name)
							cnt=cnt+1
						end
					else
						ndb.clear(pos)
						dcnt=dcnt+1
						--atlog("Found ghost node (former",ndbnode and ndbnode.name,") @",pos,"deleting")
					end
				end
			end
		end
	endspan class="hl opt">["swlcr"]="swrcr",
		["swlst"]="swrst",
	},
	rotation={"", "_30", "_45", "_60"},
}
advtrains.trackpresets = advtrains.ap

--definition format: ([] optional)
--[[{
	nodename_prefix
	texture_prefix
	[shared_texture]
	models_prefix
	models_suffix (with dot)
	[shared_model]
	formats={
		st,cr,swlst,swlcr,swrst,swrcr,vst1,vst2
		(each a table with indices 0-3, for if to register a rail with this 'rotation' table entry. nil is assumed as 'all', set {} to not register at all)
	}
	common={} change something on common rail appearance
}
[18.12.17] Note on new connection system:
In order to support real rail crossing nodes and finally make the trackplacer respect switches, I changed the connection system.
There can be a variable number of connections available. These are specified as tuples {c=<connection>, y=<rely>}
The table "at_conns" consists of {<conn1>, <conn2>...}
the "at_rail_y" property holds the value that was previously called "railheight"
Depending on the number of connections:
2 conns: regular rail
3 conns: switch:
	- when train passes in at conn1, will move out of conn2
	- when train passes in at conn2 or conn3, will move out of conn1
4 conns: cross (or cross switch, depending on arrangement of conns):
	- conn1 <> conn2
	- conn3 <> conn4
]]

function advtrains.register_tracks(tracktype, def, preset)
	advtrains.trackplacer.register_tracktype(def.nodename_prefix, preset.tpdefault)
	if preset.regtp then
		advtrains.trackplacer.register_track_placer(def.nodename_prefix, def.texture_prefix, def.description, def)			
	end
	if preset.regsp then
		advtrains.slope.register_placer(def, preset)			
	end
	for suffix, var in pairs(preset.variant) do
		for rotid, rotation in ipairs(preset.rotation) do
			if not def.formats[suffix] or def.formats[suffix][rotid] then
				local img_suffix = suffix..rotation
				local ndef = advtrains.merge_tables({
					description=def.description.."("..(var.desc or "any")..rotation..")",
					drawtype = "mesh",
					paramtype="light",
					paramtype2="facedir",
					walkable = false,
					selection_box = {
						type = "fixed",
						fixed = {-1/2, -1/2, -1/2, 1/2, -1/2+1/16, 1/2},
					},
					
					mesh = def.shared_model or (def.models_prefix.."_"..img_suffix..def.models_suffix),
					tiles = {def.shared_texture or (def.texture_prefix.."_"..img_suffix..".png"), def.second_texture},
					
					groups = {
						attached_node=1,
						advtrains_track=1,
						["advtrains_track_"..tracktype]=1,
						save_in_at_nodedb=1,
						dig_immediate=2,
						not_in_creative_inventory=1,
						not_blocking_trains=1,
					},
						
					can_dig=function(pos)
						return not advtrains.get_train_at_pos(pos)
					end,
					after_dig_node=function(pos)
						advtrains.ndb.update(pos)
					end,
					after_place_node=function(pos)
						advtrains.ndb.update(pos)
					end,
					at_nnpref = def.nodename_prefix,
					at_suffix = suffix,
					at_rotation = rotation,
					at_rail_y = var.rail_y
				}, def.common or {})
				
				if preset.regtp then
					ndef.drop = def.nodename_prefix.."_placer"
				end
				if preset.regsp and var.slope then
					ndef.drop = def.nodename_prefix.."_slopeplacer"
				end
				
				--connections
				ndef.at_conns = advtrains.rotate_conn_by(var.conns, (rotid-1)*preset.regstep)
				
				local ndef_avt_table
				
				if var.switchalt and var.switchst then
					local switchfunc=function(pos, node, newstate)
						-- this code is only called from the internal setstate function, which
						-- ensures that it is safe to switch the turnout
						if newstate~=var.switchst then
							advtrains.ndb.swap_node(pos, {name=def.nodename_prefix.."_"..var.switchalt..rotation, param2=node.param2})
							advtrains.invalidate_all_paths(pos)
						end
					end
					ndef.on_rightclick = function(pos, node, player)
						if advtrains.check_turnout_signal_protection(pos, player:get_player_name()) then
							advtrains.setstate(pos, newstate, node)
							advtrains.log("Switch", player:get_player_name(), pos)
						end
					end
					if var.switchmc then
						ndef.mesecons = {effector = {
							["action_"..var.switchmc] = function(pos, node) 
								advtrains.setstate(pos, nil, node)
							end,
							rules=advtrains.meseconrules
						}}
					end
					ndef_avt_table = {
						getstate = var.switchst,
						setstate = switchfunc,
					}
				end
				
				local adef={}
				if def.get_additional_definiton then
					adef=def.get_additional_definiton(def, preset, suffix, rotation)
				end
				ndef = advtrains.merge_tables(ndef, adef)
				
				-- insert getstate/setstate functions after merging the additional definitions
				if ndef_avt_table then
					ndef.advtrains = advtrains.merge_tables(ndef.advtrains or {}, ndef_avt_table)
				end

				minetest.register_node(":"..def.nodename_prefix.."_"..suffix..rotation, ndef)
				--trackplacer
				if preset.regtp then
					local tpconns = {conn1=ndef.at_conns[1].c, conn2=ndef.at_conns[2].c}
					if var.tpdouble then
						advtrains.trackplacer.add_double_conn(def.nodename_prefix, suffix, rotation, tpconns)
					end
					if var.tpsingle then
						advtrains.trackplacer.add_single_conn(def.nodename_prefix, suffix, rotation, tpconns)
					end
				end
				advtrains.trackplacer.add_worked(def.nodename_prefix, suffix, rotation, var.trackworker)
			end
		end
	end
	advtrains.all_tracktypes[tracktype]=true
end

function advtrains.is_track_and_drives_on(nodename, drives_on_p)
	local drives_on = drives_on_p
	if not drives_on then drives_on = advtrains.all_tracktypes end
	local hasentry = false
	for _,_ in pairs(drives_on) do
		hasentry=true
	end
	if not hasentry then drives_on = advtrains.all_tracktypes end
	
	if not minetest.registered_nodes[nodename] then
		return false
	end
	local nodedef=minetest.registered_nodes[nodename]
	for k,v in pairs(drives_on) do
		if nodedef.groups["advtrains_track_"..k] then
			return true
		end
	end
	return false
end

function advtrains.get_track_connections(name, param2)
	local nodedef=minetest.registered_nodes[name]
	if not nodedef then atprint(" get_track_connections couldn't find nodedef for nodename "..(name or "nil")) return nil end
	local noderot=param2
	if not param2 then noderot=0 end
	if noderot > 3 then atprint(" get_track_connections: rail has invaild param2 of "..noderot) noderot=0 end
	
	local tracktype
	for k,_ in pairs(nodedef.groups) do
		local tt=string.match(k, "^advtrains_track_(.+)$")
		if tt then
			tracktype=tt
		end
	end
	return advtrains.rotate_conn_by(nodedef.at_conns, noderot*AT_CMAX/4), (nodedef.at_rail_y or 0), tracktype
end

-- slope placer. Defined in register_tracks.
--crafted with rail and gravel
local sl={}
function sl.register_placer(def, preset)
	minetest.register_craftitem(":"..def.nodename_prefix.."_slopeplacer",{
		description = attrans("@1 Slope", def.description),
		inventory_image = def.texture_prefix.."_slopeplacer.png",
		wield_image = def.texture_prefix.."_slopeplacer.png",
		groups={},
		on_place = sl.create_slopeplacer_on_place(def, preset)
	})
end
--(itemstack, placer, pointed_thing)
function sl.create_slopeplacer_on_place(def, preset)
	return function(istack, player, pt)
		if not pt.type=="node" then 
			minetest.chat_send_player(player:get_player_name(), attrans("Can't place: not pointing at node"))
			return istack 
		end
		local pos=pt.above
		if not pos then 
			minetest.chat_send_player(player:get_player_name(), attrans("Can't place: not pointing at node"))
			return istack
		end
		local node=minetest.get_node(pos)
		if not minetest.registered_nodes[node.name] or not minetest.registered_nodes[node.name].buildable_to then
			minetest.chat_send_player(player:get_player_name(), attrans("Can't place: space occupied!"))
			return istack
		end
		if not advtrains.check_track_protection(pos, player:get_player_name()) then 
			minetest.record_protection_violation(pos, player:get_player_name())
			return istack
		end
		--determine player orientation (only horizontal component)
		--get_look_horizontal may not be available
		local yaw=player.get_look_horizontal and player:get_look_horizontal() or (player:get_look_yaw() - math.pi/2)
		
		--rounding unit vectors is a nice way for selecting 1 of 8 directions since sin(30°) is 0.5.
		dirvec={x=math.floor(math.sin(-yaw)+0.5), y=0, z=math.floor(math.cos(-yaw)+0.5)}
		--translate to direction to look up inside the preset table
		local param2, rot45=({
			[-1]={
				[-1]=2,
				[0]=3,
				[1]=3,
				},
			[0]={
				[-1]=2,
				[1]=0,
				},
			[1]={
				[-1]=1,
				[0]=1,
				[1]=0,
				},
		})[dirvec.x][dirvec.z], dirvec.x~=0 and dirvec.z~=0
		local lookup=preset.slopeplacer
		if rot45 then lookup=preset.slopeplacer_45 end
		
		--go unitvector forward and look how far the next node is
		local step=1
		while step<=lookup.max do
			local node=minetest.get_node(vector.add(pos, dirvec))
			--next node solid?
			if not minetest.registered_nodes[node.name] or not minetest.registered_nodes[node.name].buildable_to or advtrains.is_protected(pos, player:get_player_name()) then 
				--do slopes of this distance exist?
				if lookup[step] then
					if minetest.settings:get_bool("creative_mode") or istack:get_count()>=step then
						--start placing
						local placenodes=lookup[step]
						while step>0 do
							minetest.set_node(pos, {name=def.nodename_prefix.."_"..placenodes[step], param2=param2})
							if not minetest.settings:get_bool("creative_mode") then
								istack:take_item()
							end
							step=step-1
							pos=vector.subtract(pos, dirvec)
						end
					else
						minetest.chat_send_player(player:get_player_name(), attrans("Can't place: Not enough slope items left (@1 required)", step))
					end
				else
					minetest.chat_send_player(player:get_player_name(), attrans("Can't place: There's no slope of length @1",step))
				end
				return istack
			end
			step=step+1
			pos=vector.add(pos, dirvec)
		end
		minetest.chat_send_player(player:get_player_name(), attrans("Can't place: no supporting node at upper end."))
		return itemstack
	end
end

advtrains.slope=sl

--END code, BEGIN definition
--definition format: ([] optional)
--[[{
	nodename_prefix
	texture_prefix
	[shared_texture]
	models_prefix
	models_suffix (with dot)
	[shared_model]
	formats={
		st,cr,swlst,swlcr,swrst,swrcr,vst1,vst2
		(each a table with indices 0-3, for if to register a rail with this 'rotation' table entry. nil is assumed as 'all', set {} to not register at all)
	}
	common={} change something on common rail appearance
}]]