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Diffstat (limited to 'advtrains_interlocking/database.lua')
| -rw-r--r-- | advtrains_interlocking/database.lua | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/advtrains_interlocking/database.lua b/advtrains_interlocking/database.lua index 61bf5ad..e318dd2 100644 --- a/advtrains_interlocking/database.lua +++ b/advtrains_interlocking/database.lua @@ -32,6 +32,9 @@ Route setting fails whenever any TC that we want to set ROUTE to is already set Apart from this, we need to set turnouts - Turnouts on the track are set held as ROUTE - Turnouts that purpose as flank protection are set held as FLANK (NOTE: left as an idea for later, because it's not clear how to do this properly without an engineer) +Note: In SimSig, it is possible to set a route into an still occupied section on the victoria line sim. (at the depot exit at seven sisters), although + there are still segments set ahead of the first train passing, remaining from another route. + Because our system will be able to remember "requested routes" and set them automatically once ready, this is not necessary here. == Call-On/Multiple Trains == It will be necessary to join and split trains using call-on routes. A call-on route may be set when: - there are no ROUTE reservations @@ -50,7 +53,196 @@ CALL_ON_ALLOWED - Whether this TC being blocked (TRAIN or ROUTE) does not preven == More notes == - It may not be possible to switch turnouts when their TC has any state entry +== Route releasing (TORR) == +A train passing through a route happens as follows: +Route set from entry to exit signal +Train passes entry signal and enters first TC past the signal +-> Route from signal cleared (TCs remain locked) +-> ROUTE status of first TC past signal cleared +Train continues along the route. +Whenever train leaves a TC +-> Clearing any routes set from this TC outward recursively - see "Reversing problem" +Whenever train enters a TC +-> Clear route status from the just entered TC +== Reversing Problem == +Encountered at the Royston simulation in SimSig. It is solved there by imposing a time limit on the set route. Call-on routes can somehow be set anyway. +Imagine this setup: (T=Train, R=Route, >=in_dir TCB) + O-| Royston P2 |-O +T->---|->RRR-|->RRR-|-- +Train T enters from the left, the route is set to the right signal. But train is supposed to reverse here and stops this way: + O-| Royston P2 |-O +------|-TTTT-|->RRR-|-- +The "Route" on the right is still set. Imposing a timeout here is a thing only professional engineers can determine, not an algorithm. + O-| Royston P2 |-O +<-T---|------|->RRR-|-- +The train has left again, while route on the right is still set. +So, we have to clear the set route when the train has left the left TC. +This does not conflict with call-on routes, because both station tracks are set as "allow call-on" +Because none of the routes extends past any non-call-on sections, call-on route would be allowed here, even though the route +is locked in opposite direction at the time of routesetting. +Another case of this: +--TTT/--|->RRR-- +The / here is a non-interlocked turnout (to a non-frequently used siding). For some reason, there is no exit node there, +so the route is set to the signal at the right end. The train is taking the exit to the siding and frees the TC, without ever +having touched the right TC. ]]-- +local TRAVERSER_LIMIT = 100 + + +local ildb = {} + +local track_circuit_breaks = {} + +function ildb.load(data) + +end + +function ildb.save() + return {} +end + +-- +--[[ +TCB data structure +{ +[1] = { -- Variant: with adjacent TCs. + == Synchronized properties == Apply to the whole TC + adjacent = { <signal specifier>,... } -- Adjacent TCBs, forms a TC with these + conflict = { <signal specifier>,... } -- Conflicting TC's (chosen as a representative TCB member) + -- Used e.g. for crossing rails that do not have nodes in common (like it's currently done) + incomplete = <boolean> -- Set when the recursion counter hit during traverse. Probably needs to add + -- another tcb at some far-away place + route = {origin = <signal>, in_dir = <boolean>} + -- Set whenever a route has been set through this TC. It saves the origin tcb id and side + -- (=the origin signal). in_dir is set when the train will enter the TC from this side + + == Unsynchronized properties == Apply only to this side of the TC + signal = <pos> -- optional: when set, routes can be set from this tcb/direction and signal + -- aspect will be set accordingly. + routetar = <signal> -- Route set from this signal. This is the entry that is cleared once + -- train has passed the signal. (which will set the aspect to "danger" again) + route_committed = <boolean> -- When setting/requesting a route, routetar will be set accordingly, + -- while the signal still displays danger and nothing is written to the TCs + -- As soon as the route can actually be set, all relevant TCs and turnouts are set and this field + -- is set true, clearing the signal +}, +[2] = { -- Variant: end of track-circuited area (initial state of TC) + end_of_interlocking = true, + section_free = <boolean>, --this can be set by an exit node via mesecons or atlatc, + -- or from the tc formspec. +} +} +Signal specifier (a pair of TCB/Side): +{p = <pos>, s = <1/2>} +]] + + +-- +function ildb.create_tcb(pos) + local new_tcb = { + [1] = {end_of_interlocking = true}, + [2] = {end_of_interlocking = true}, + } + local pts = advtrains.roundfloorpts(pos) + track_circuit_breaks[pts] = new_tcb +end + +function ildb.get_tcb(pos) + local pts = advtrains.roundfloorpts(pos) + return track_circuit_breaks[pts] +end + +-- This function will actually handle the node that is in connid direction from the node at pos +-- so, this needs the conns of the node at pos, since these are already calculated +local function traverser(found_tcbs, pos, conns, connid, count) + local adj_pos, adj_connid, conn_idx, nextrail_y, next_conns = advtrains.get_adjacent_rail(pos, conns, connid, advtrains.all_tracktypes) + if not adj_pos then + -- end of track + return + end + -- look whether there is a TCB here + if #next_conns == 2 then --if not, don't even try! + local tcb = ildb.get_tcb(adj_pos) + if tcb then + -- done with this branch + table.insert(found_tcbs, {p=adj_pos, s=adj_connid}) + return + end + end + -- recursion abort condition + if count > TRAVERSER_LIMIT then + atdebug("Traverser hit counter at",adj_pos, adj_connid,"found tcb's:",found_tcbs) + return true + end + -- continue traversing + local counter_hit = false + for nconnid, nconn in ipairs(next_conns) do + if adj_connid ~= nconnid then + counter_hit = counter_hit or traverser(found_tcbs, adj_pos, next_conns, nconnid, count + 1, hit_counter) + end + end + return counter_hit +end + +local function sigd_equal(sigd, cmp) + return vector.equals(sigd.p, cmp.p) and sigd.s==cmp.s +end + + + + + +-- Updates the neighbors of this TCB using the traverser function (see comments above) +-- returns true if the traverser hit the counter, which means that there could be another +-- TCB outside of the traversed range. +function ildb.update_tcb_neighbors(pos, connid) + local found_tcbs = { {p = pos, s = connid} } + local node_ok, conns, rhe = advtrains.get_rail_info_at(pos, advtrains.all_tracktypes) + if not node_ok then + error("update_tcb_neighbors but node is NOK: "..minetest.pos_to_string(pos)) + end + + local counter_hit = traverser(found_tcbs, pos, conns, connid, 0, hit_counter) + + for idx, sigd in pairs(found_tcbs) do + local tcb = ildb.get_tcb(sigd.p) + local tcbs = tcb[sigd.s] + + tcbs.end_of_interlocking = nil + tcbs.incomplete = counter_hit + tcbs.adjacent = {} + + for idx2, other_sigd in pairs(found_tcbs) do + if idx~=idx2 then + ildb.add_adjacent(tcbs, sigd.p, sigd.s, other_sigd) + end + end + end + + return hit_counter +end + +-- Add the adjacency entry into the tcbs, but without duplicating it +-- and without adding a self-reference +function ildb.add_adjacent(tcbs, this_pos, this_connid, sigd) + if sigd_equal(sigd, {p=this_pos, s=this_connid}) then + return + end + tcbs.end_of_interlocking = nil + if not tcbs.adjacent then + tcbs.adjacent = {} + end + for idx, cmp in pairs(tcbs.adjacent) do + if sigd_equal(sigd, cmp) then + return + end + end + table.insert(tcbs.adjacent, sigd) +end + +advtrains.interlocking.db = ildb + + |