From 2ff8f5fd4649cff554cc6afab3d92ac7efedb809 Mon Sep 17 00:00:00 2001
From: orwell96 <orwell@bleipb.de>
Date: Wed, 19 Dec 2018 17:16:13 +0100
Subject: Initial version

---
 nodedb.lua | 163 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 163 insertions(+)
 create mode 100644 nodedb.lua

(limited to 'nodedb.lua')

diff --git a/nodedb.lua b/nodedb.lua
new file mode 100644
index 0000000..f79dbbd
--- /dev/null
+++ b/nodedb.lua
@@ -0,0 +1,163 @@
+--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="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
+		print("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
+		print("nodedb: read", cnt, "nodes.")
+		file:close()
+	end
+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
+		-- no minetest here
+		return nil
+	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.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)
+	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
+	
+	local conns, railheight, tracktype=advtrains.get_track_connections(node.name, node.param2)
+	
+	if not conns then
+		return false
+	end
+	
+	return true, conns, railheight
+end
+
+
+-- mapper-specific
+
+function ndb.mapper_find_starting_point()
+	for y, ty in pairs(ndb_nodes) do
+		for x, tx in pairs(ty) do
+			for z, v in pairs(tx) do
+				local pos = {x=x, y=y, z=z}
+				local node_ok, conns, _ = advtrains.get_rail_info_at(pos)
+				if node_ok then
+					return pos, conns
+				else
+					-- this is a signal or something similar, ignore.
+					tx[z]=nil
+				end
+			end
+		end
+	end
+end
+
+
+advtrains.ndb = ndb
-- 
cgit v1.2.3