diff options
Diffstat (limited to 'advtrains/occupation.lua')
| -rw-r--r-- | advtrains/occupation.lua | 186 |
1 files changed, 41 insertions, 145 deletions
diff --git a/advtrains/occupation.lua b/advtrains/occupation.lua index e72d668..3007723 100644 --- a/advtrains/occupation.lua +++ b/advtrains/occupation.lua @@ -1,6 +1,7 @@ -- occupation.lua --[[ Collects and manages positions where trains occupy and/or reserve/require space +THIS SECTION ABOVE IS OUTDATED, look below Zone diagram of a train: |___| |___| --> Direction of travel @@ -41,41 +42,46 @@ occ_chg[n] = { new_val, (0 when entry was deleted) } -*Sequence number: -Sequence number system reserved for possible future use, but unused. -The train will (and has to) memorize it's zone path indexes ("windows"), and do all actions that in any way modify these zone lengths -in the movement phase (after restore, but before reporting occupations) -(( -The sequence number is used to determine out-of-date entries to the occupation list -The current sequence number (seqnum) is increased each step, until it rolls over MAX_SEQNUM, which is when a complete reset is triggered -Inside a step, when a train updates an occupation, the sequence number is set to the currently active sequence number -Whenever checking an entry for other occupations (e.g. in the aware zone), all entries that have a seqnum different from the current seqnum -are considered not existant, and are cleared. -Note that those outdated entries are only cleared on-demand, so there will be a large memory overhead over time. This is why in certain time intervals -complete resets are required (however, this method should be much more performant than resetting the whole occ table each step, to spare continuous memory allocations) -This complex behavior is required because there is no way to reliably determine which positions are _no longer_ occupied... -)) - -Composition of a step: - -1. (only when needed) restore step - write all current occupations into the table -2. trains move -3. trains pass new occupations to here. We keep track of which entries have changed -4. we iterate our change lists and determine what to do +--------------------- +It turned out that, especially for the TSS, some more, even overlapping zones are required. +Packing those into a data structure would just become a huge mess! +Instead, this occupation system will store the path indices of positions in the corresponding. +train's paths. +So, the occupation is a reverse lookup of paths. +Then, a callback system will handle changes in those indices, as follows: + +Whenever the train generates new path items (path_get/path_create), their counterpart indices will be filled in here. +Whenever a path gets invalidated or path items are deleted, their index counterpart is erased from here. + +When a train needs to know whether a position is blocked by another train, it will (and is permitted to) +query the train.index and train.end_index and compare them to the blocked position's index. + +Callback system for 3rd-party path checkers: TODO +advtrains.te_register_on_new_path(func(id, train)) +-- Called when a train's path is re-initalized, either when it was invalidated +-- or the saves were just loaded +-- It can be assumed that everything is in the state of when the last run +-- of on_update was made, but all indices are shifted by an unknown amount. + +advtrains.te_register_on_update(func(id, train)) +-- Called each step and after a train moved, its length changed or some other event occured +-- The path is unmodified, and train.index and train.end_index can be reliably +-- queried for the new position and length of the train. +-- note that this function might be called multiple times per step, and this +-- function being called does not necessarily mean that something has changed. +-- It is ensured that on_new_path callbacks are executed prior to these callbacks whenever +-- an invalidation or a reload occured. + +All callbacks are allowed to save certain values inside the train table, but they must ensure that +those are reinitialized in the on_new_path callback. The on_new_path callback must explicitly +set ALL OF those values to nil or to a new updated value, and must not rely on their existence. ]]-- local o = {} -o.restore_required = true - -local MAX_SEQNUM = 65500 -local seqnum = 0 - local occ = {} local occ_chg = {} -local addchg, handle_chg - local function occget(p) local t = occ[p.y] @@ -112,29 +118,8 @@ local function occgetcreate(p) return t end --- Resets the occupation memory, and sets the o.restore_required flag that instructs trains to report their occupations before moving -function o.reset() - o.restore_required = true - occ = {} - occ_chg = {} - seqnum = 0 -end - --- set occupation inside the restore step -function o.init_occupation(train_id, pos, oid) - local t = occgetcreate(pos) - local i = 1 - while t[i] do - if t[i]==train_id then - break - end - i = i + 2 - end - t[i] = train_id - t[i+1] = oid -end -function o.set_occupation(train_id, pos, oid) +function o.set_item(train_id, pos, idx) local t = occgetcreate(pos) local i = 1 while t[i] do @@ -143,16 +128,12 @@ function o.set_occupation(train_id, pos, oid) end i = i + 2 end - local oldoid = t[i+1] or 0 - if oldoid ~= oid then - addchg(pos, train_id, oldoid, oid) - end t[i] = train_id - t[i+1] = oid + t[i+1] = idx end -function o.clear_occupation(train_id, pos) +function o.clear_item(train_id, pos) local t = occget(pos) if not t then return end local i = 1 @@ -176,94 +157,6 @@ function o.clear_occupation(train_id, pos) end end -function addchg(pos, train_id, old, new) - occ_chg[#occ_chg + 1] = { - pos = pos, - train_id = train_id, - old_val = old, - new_val = new, - } -end - --- Called after all occupations have been fed in --- This function is doing the interesting work... -function o.end_step() - count_chg = false - - for _,chg in ipairs(occ_chg) do - local t = occget(chg.pos) - if not t then - atwarn("o.end_step() change entry but there's no entry in occ table!",chg) - end - handle_chg(t, chg.pos, chg.train_id, chg.old_val, chg.new_val) - end - - seqnum = seqnum + 1 -end - -function handle_chg(t, pos, train_id, old, new) - -- Handling the actual "change" is only necessary on_train_enter (change to 1) and on_train_leave (change from 1) - if new==1 then - o.call_enter_callback(pos, train_id) - elseif old==1 then - o.call_leave_callback(pos, train_id) - end - - --all other cases check the simultaneous presence of 2 or more occupations - if #t<=2 then - return - end - local blocking = {} - local aware = {} - local i = 1 - while t[i] do - if t[i+1] ~= 7 then --anything not aware zone: - blocking[#blocking+1] = i - else - aware[#aware+1] = i - end - i = i + 2 - end - if #blocking > 0 then - -- the aware trains should brake - for _, ix in ipairs(aware) do - advtrains.atc.train_set_command(t[ix], "B2") - end - if #blocking > 1 then - -- not good, 2 trains interfered with their blocking zones - -- make them brake too - local txt = {} - for _, ix in ipairs(blocking) do - advtrains.atc.train_set_command(t[ix], "B2") - txt[#txt+1] = t[ix] - end - atwarn("Trains",table.concat(txt, ","), "interfered with their blocking zones, braking...") - -- TODO: different behavior for automatic trains! they need to be notified of those brake events and handle them! - -- To drive in safety zone is ok when train is controlled by hand - end - end - -end - -function o.call_enter_callback(pos, train_id) - --atprint("instructed to call enter calback") - - local node = advtrains.ndb.get_node(pos) --this spares the check if node is nil, it has a name in any case - local mregnode=minetest.registered_nodes[node.name] - if mregnode and mregnode.advtrains and mregnode.advtrains.on_train_enter then - mregnode.advtrains.on_train_enter(pos, train_id) - end -end -function o.call_leave_callback(pos, train_id) - --atprint("instructed to call leave calback") - - local node = advtrains.ndb.get_node(pos) --this spares the check if node is nil, it has a name in any case - local mregnode=minetest.registered_nodes[node.name] - if mregnode and mregnode.advtrains and mregnode.advtrains.on_train_leave then - mregnode.advtrains.on_train_leave(pos, train_id) - end -end - -- Checks whether some other train (apart from train_id) has it's 0 zone here function o.check_collision(pos, train_id) local npos = advtrains.round_vector_floor_y(pos) @@ -272,7 +165,10 @@ function o.check_collision(pos, train_id) local i = 1 while t[i] do if t[i]~=train_id then - if t[i+1] ~= 7 then + local idx = t[i+1] + local train = advtrains.trains[train_id] + advtrains.train_ensure_clean(train_id, train) + if idx >= train.end_index and idx <= train.index then return true end end |