diff options
Diffstat (limited to 'advtrains/helpers.lua')
| -rw-r--r-- | advtrains/helpers.lua | 187 |
1 files changed, 173 insertions, 14 deletions
diff --git a/advtrains/helpers.lua b/advtrains/helpers.lua index cf890ca..d7e691d 100644 --- a/advtrains/helpers.lua +++ b/advtrains/helpers.lua @@ -292,18 +292,19 @@ function advtrains.conn_matches_to(conn, other_conns) end -- Going from the rail at pos (does not need to be rounded) along connection with id conn_idx, if there is a matching rail, return it and the matching connid --- returns: <adjacent pos>, <conn index of adjacent>, <my conn index>, <railheight of adjacent> +-- returns: <adjacent pos>, <conn index of adjacent>, <my conn index>, <railheight of adjacent>, (adjacent conns table), (adjacent connmap table) -- parameter this_conns_p is connection table of this rail and is optional, is determined by get_rail_info_at if not provided. -function advtrains.get_adjacent_rail(this_posnr, this_conns_p, conn_idx, drives_on) +function advtrains.get_adjacent_rail(this_posnr, this_conns_p, conn_idx) local this_pos = advtrains.round_vector_floor_y(this_posnr) local this_conns = this_conns_p + local _ if not this_conns then _, this_conns = advtrains.get_rail_info_at(this_pos) end if not conn_idx then for coni, _ in ipairs(this_conns) do - local adj_pos, adj_conn_idx, _, nry, nco = advtrains.get_adjacent_rail(this_pos, this_conns, coni) - if adj_pos then return adj_pos,adj_conn_idx,coni,nry, nco end + local adj_pos, adj_conn_idx, _, nry, nco, ncm = advtrains.get_adjacent_rail(this_pos, this_conns, coni) + if adj_pos then return adj_pos,adj_conn_idx,coni,nry, nco, ncm end end return nil end @@ -317,34 +318,46 @@ function advtrains.get_adjacent_rail(this_posnr, this_conns_p, conn_idx, drives_ adj_pos.y = adj_pos.y + 1 end - local nextnode_ok, nextconns, nextrail_y=advtrains.get_rail_info_at(adj_pos, drives_on) + local nextnode_ok, nextconns, nextrail_y, nextconnmap=advtrains.get_rail_info_at(adj_pos) if not nextnode_ok then adj_pos.y = adj_pos.y - 1 conn_y = conn_y + 1 - nextnode_ok, nextconns, nextrail_y=advtrains.get_rail_info_at(adj_pos, drives_on) + nextnode_ok, nextconns, nextrail_y, nextconnmap=advtrains.get_rail_info_at(adj_pos) if not nextnode_ok then return nil end end local adj_connid = advtrains.conn_matches_to({c=conn.c, y=conn_y}, nextconns) if adj_connid then - return adj_pos, adj_connid, conn_idx, nextrail_y, nextconns + return adj_pos, adj_connid, conn_idx, nextrail_y, nextconns, nextconnmap end return nil end -- when a train enters a rail on connid 'conn', which connid will it go out? --- nconns: number of connections in connection table: --- 2 = straight rail; 3 = turnout, 4 = crossing, 5 = three-way turnout (5th entry is a stub) +-- Since 2.5: This mapping is contained in the conn_map table in the node definition! -- returns: connid_out -local connlku={[2]={2,1}, [3]={2,1,1}, [4]={2,1,4,3}, [5]={2,1,1,1}} -function advtrains.get_matching_conn(conn, nconns) - return connlku[nconns][conn] +function advtrains.get_matching_conn(conn, conn_map) + if tonumber(conn_map) then + error("Legacy call to get_matching_conn! Instead of nconns, conn_map needs to be provided!") + end + if not conn_map then + --OK for two-conn rails, just return the other + if conn==1 then return 2 end + if conn==2 then return 1 end + error("get_matching_conn: For connid >=3, conn_map must not be nil!") + end + local cout = conn_map[conn] + if not cout then + error("get_matching_conn: Connid "..conn.." not found in conn_map which is "..atdump(conn_map)) + end + return cout end -function advtrains.random_id() +function advtrains.random_id(lenp) local idst="" - for i=0,5 do + local len = lenp or 6 + for i=1,len do idst=idst..(math.random(0,9)) end return idst @@ -470,3 +483,149 @@ else end end end + + +-- TrackIterator interface -- + +-- Metatable: +local trackiter_mt = { + -- Internal State: + -- branches: A list of {pos, connid, limit} for where to restart + -- pos: The *next* position that the track iterator will return + -- bconnid: The connid of the connection of the rail at pos that points backward + -- tconns: The connections of the rail at pos + -- limit: the current limit + -- visited: a key-boolean table of already visited rails + + -- get whether there are still unprocessed branches + has_next_branch = function(self) + return #self.branches > 0 + end, + -- go to the next unprocessed branch + -- returns track_pos, track_connid of the switch/crossing node where the track branches off + next_branch = function(self) + local br = table.remove(self.branches, 1) + -- Advance internal state + local adj_pos, adj_connid, _, _, adj_conns, adj_connmap = advtrains.get_adjacent_rail(br.pos, nil, br.connid) + self.pos = adj_pos + self.bconnid = adj_connid + self.tconns = adj_conns + self.tconnmap = adj_connmap + self.limit = br.limit - 1 + self.visited[advtrains.encode_pos(br.pos)] = true + self.last_track_already_visited = false + return br.pos, br.connid + end, + -- get the next track along the current branch, + -- potentially adding branching tracks to the unprocessed branches list + -- returns track_pos, track_connid, track_backwards_connid + -- On error, returns nil, reason; reason is one of "track_end", "limit_hit", "already_visited" + next_track = function(self) + if self.last_track_already_visited then + -- see comment below + return nil, "already_visited" + end + local pos = self.pos + if not pos then + -- last run found track end. Return false + return false, "track_end" + end + -- if limit hit, return nil to signal this + if self.limit <= 0 then + return nil, "limit_hit" + end + -- select next conn (main conn to follow is the associated connection) + local old_bconnid = self.bconnid + local mconnid = advtrains.get_matching_conn(self.bconnid, self.tconnmap) + if self.visited[advtrains.encode_pos(pos)] then + -- node was already seen + -- Due to special requirements for the track section updater, return this first already visited track once + -- but do not process any further rails on this branch + -- The next call will then throw already_visited error + self.last_track_already_visited = true + return pos, mconnid, old_bconnid + end + -- If there are more connections, add these to branches + for nconnid,_ in ipairs(self.tconns) do + if nconnid~=mconnid and nconnid~=self.bconnid then + table.insert(self.branches, {pos = self.pos, connid = nconnid, limit=self.limit}) + end + end + -- Advance internal state + local adj_pos, adj_connid, _, _, adj_conns, adj_connmap = advtrains.get_adjacent_rail(pos, self.tconns, mconnid) + self.pos = adj_pos + self.bconnid = adj_connid + self.tconns = adj_conns + self.tconnmap = adj_connmap + self.limit = self.limit - 1 + self.visited[advtrains.encode_pos(pos)] = true + self.last_track_already_visited = false + return pos, mconnid, old_bconnid + end, + + add_branch = function(self, pos, connid) + table.insert(self.branches, {pos = pos, connid = connid, limit=self.limit}) + end, + + is_visited = function(self, pos) + return self.visited[advtrains.encode_pos(pos)] + end, +} + +-- Returns a new TrackIterator object + +-- Parameters: +-- initial_pos: the initial track position of the track iterator +-- initial_connid: the connection index in which to traverse. If nil, adds a "branch" for every connection of the track (traverse in all directions) +-- limit: maximum distance from the start point after which the traverser stops +-- follow_all: if true, follows all branches at multi-connection tracks, even the ones pointing backwards or the crossing track on crossings. If false, follows only switches in driving direction. + +-- Functions of the returned TrackIterator can be called via the Lua : notation, such as ti:next_track() +-- If only the main track needs to be followed, use only the ti:next_track() function and do not call ti:next_branch(). +function advtrains.get_track_iterator(initial_pos, initial_connid, limit, follow_all) + local ti = { + visited = {} + } + if initial_connid then + ti.branches = { {pos = initial_pos, connid = initial_connid, limit=limit} } + else + -- get track info here + local node_ok, conns, rail_y=advtrains.get_rail_info_at(initial_pos) + assert(node_ok, "get_track_iterator called with non-track node!") + ti.branches = {} + for coni, _ in pairs(conns) do + table.insert(ti.branches, {pos = initial_pos, connid = coni, limit=limit}) + end + end + ti.limit = limit -- safeguard if someone adds a branch before calling anything + setmetatable(ti, {__index=trackiter_mt}) + return ti +end + +--[[ +Example TrackIterator usage structure: + +local ti, pos, connid, ok +ti = advtrains.get_track_iterator(initial_pos, initial_connid, 500, true) +while ti:has_next_branch() do + pos, connid = ti:next_branch() -- in first iteration, this will be the node at initial_pos. In subsequent iterations this will be the switch node from which we are branching off + repeat + <do something with the track> + if <track satisfies an abort condition> then break end --for example, when traversing should stop at TCBs this can check if there is a tcb here + pos, connid = ti:next_track() + until not pos -- this stops the loop when either the track end is reached or the limit is hit + -- while loop continues with the next branch ( diverging branch of one of the switches/crossings) until no more are left +end + +Example for walking only a single track (without branching): + +local ti, pos, connid, ok +ti = advtrains.get_track_iterator(initial_pos, initial_connid, 500, true) + +pos, connid = ti:next_branch() -- this always needs to be done at least one time, and gets the track at initial_pos +repeat + <do something with the track> + if <track satisfies an abort condition> then break end --for example, when traversing should stop at TCBs this can check if there is a tcb here + ok, pos, connid = ti:next_track() +until not ok -- this stops the loop when either the track end is reached or the limit is hit +]] |