fixed

42.13/media/lua/client/TowBar/Config.lua

@@ -3,7 +3,7 @@ if not TowBarMod.Config then TowBarMod.Config = {} end
 
 TowBarMod.Config.lowLevelAnimation = "RemoveGrass"
 TowBarMod.Config.rigidTowbarDistance = 1.0
-TowBarMod.Config.devMode = true
+TowBarMod.Config.devMode = false
 TowBarMod.Config.vanillaTowbarModelScaleMin = 1.5
 TowBarMod.Config.vanillaTowbarModelScaleMax = 2.0
 TowBarMod.Config.smallScaleTowbarIndexOffset = 2

42.13/media/lua/client/TowBar/TowSyncClient.lua

@@ -0,0 +1,125 @@
+if isServer() then return end
+
+if not TowBarMod then TowBarMod = {} end
+TowBarMod.Sync = TowBarMod.Sync or {}
+if TowBarMod.Sync._towSyncClientLoaded then return end
+TowBarMod.Sync._towSyncClientLoaded = true
+
+local function resolveVehicle(id)
+    if not id then return nil end
+    return getVehicleById(id)
+end
+
+local function ensureAttachment(vehicle, attachmentId)
+    if not vehicle or not attachmentId then return false end
+
+    local script = vehicle:getScript()
+    if not script then return false end
+    if script:getAttachmentById(attachmentId) ~= nil then return true end
+
+    local wheelCount = script:getWheelCount()
+    local yOffset = -0.5
+    if wheelCount > 0 then
+        local wheel = script:getWheel(0)
+        if wheel and wheel:getOffset() then
+            yOffset = wheel:getOffset():y() + 0.1
+        end
+    end
+
+    local chassis = script:getPhysicsChassisShape()
+    if not chassis then return false end
+
+    local attach = ModelAttachment.new(attachmentId)
+    if attachmentId == "trailer" then
+        attach:getOffset():set(0, yOffset, -chassis:z() / 2 - 0.1)
+        attach:setZOffset(-1)
+    else
+        attach:getOffset():set(0, yOffset, chassis:z() / 2 + 0.1)
+        attach:setZOffset(1)
+    end
+    script:addAttachment(attach)
+    return true
+end
+
+local function isLinked(vehicleA, vehicleB)
+    if not vehicleA or not vehicleB then return false end
+    return vehicleA:getVehicleTowing() == vehicleB and vehicleB:getVehicleTowedBy() == vehicleA
+end
+
+local function reconcilePairState(vehicleA, vehicleB, attachmentA, attachmentB)
+    if TowBarMod.Utils and TowBarMod.Utils.updateAttachmentsForRigidTow then
+        TowBarMod.Utils.updateAttachmentsForRigidTow(vehicleA, vehicleB, attachmentA, attachmentB)
+    end
+
+    local towingMd = vehicleA:getModData()
+    local towedMd = vehicleB:getModData()
+    local currentScript = vehicleB:getScriptName()
+
+    if towingMd then
+        towingMd["isTowingByTowBar"] = true
+        vehicleA:transmitModData()
+    end
+    if towedMd then
+        if towedMd.towBarOriginalScriptName == nil and currentScript ~= "notTowingA_Trailer" then
+            towedMd.towBarOriginalScriptName = currentScript
+        end
+        if towedMd.towBarOriginalMass == nil then
+            towedMd.towBarOriginalMass = vehicleB:getMass()
+        end
+        if towedMd.towBarOriginalBrakingForce == nil then
+            towedMd.towBarOriginalBrakingForce = vehicleB:getBrakingForce()
+        end
+        towedMd["isTowingByTowBar"] = true
+        towedMd["towed"] = true
+        vehicleB:transmitModData()
+    end
+
+    vehicleB:setScriptName("notTowingA_Trailer")
+    if TowBarMod.Hook and TowBarMod.Hook.setVehiclePostAttach then
+        pcall(TowBarMod.Hook.setVehiclePostAttach, nil, vehicleB)
+    end
+end
+
+local function applyAttachSync(args)
+    if not args then return end
+
+    local vehicleA = resolveVehicle(args.vehicleA)
+    local vehicleB = resolveVehicle(args.vehicleB)
+    if not vehicleA or not vehicleB then return end
+
+    local attachmentA = args.attachmentA or "trailer"
+    local attachmentB = args.attachmentB or "trailerfront"
+    if not ensureAttachment(vehicleA, attachmentA) or not ensureAttachment(vehicleB, attachmentB) then
+        return
+    end
+
+    if not isLinked(vehicleA, vehicleB) then
+        vehicleA:addPointConstraint(nil, vehicleB, attachmentA, attachmentB)
+    end
+
+    reconcilePairState(vehicleA, vehicleB, attachmentA, attachmentB)
+end
+
+local function safeBreak(vehicle)
+    if not vehicle then return end
+    if vehicle:getVehicleTowing() == nil and vehicle:getVehicleTowedBy() == nil then return end
+    vehicle:breakConstraint(true, true)
+end
+
+local function applyDetachSync(args)
+    if not args then return end
+    safeBreak(resolveVehicle(args.vehicleA))
+    safeBreak(resolveVehicle(args.vehicleB))
+end
+
+local function onServerCommand(module, command, args)
+    if module ~= "towbar" then return end
+
+    if command == "forceAttachSync" then
+        applyAttachSync(args)
+    elseif command == "forceDetachSync" then
+        applyDetachSync(args)
+    end
+end
+
+Events.OnServerCommand.Add(onServerCommand)

42.13/media/lua/client/TowBar/TowingHooking.lua

@@ -33,6 +33,19 @@ local function getTowBarItem(playerObj)
     return inventory:getItemFromTypeRecurse("TowBar.TowBar")
 end
 
+local function sendTowAttachCommand(playerObj, args)
+    if not playerObj or not args then return end
+
+    -- MP-safe/server-authoritative attach path (Landtrain style).
+    if isClient() and isMultiplayer() then
+        sendClientCommand(playerObj, "towbar", "attachTowBar", args)
+        return
+    end
+
+    -- Keep vanilla attach path for SP/local behavior.
+    sendClientCommand(playerObj, "vehicle", "attachTrailer", args)
+end
+
 local TowbarVariantSize = 24
 local TowbarNormalStart = 0
 local TowbarLargeStart = 24
@@ -278,11 +291,38 @@ local function reattachTowBarPair(playerObj, towingVehicle, towedVehicle, requir
         attachmentA = attachmentA,
         attachmentB = attachmentB
     }
-    sendClientCommand(playerObj, "vehicle", "attachTrailer", args)
+    sendTowAttachCommand(playerObj, args)
     ISTimedActionQueue.add(TowBarScheduleAction:new(playerObj, 10, TowBarMod.Hook.setVehiclePostAttach, towedVehicle))
     return true
 end
 
+local function reattachTowBarPairAfterCleanDetach(playerObj, towingVehicle, towedVehicle, requireDriver)
+    if not playerObj or not towingVehicle or not towedVehicle then
+        return false
+    end
+    if requireDriver and not towingVehicle:isDriver(playerObj) then
+        return false
+    end
+
+    local detachArgs = {
+        towingVehicle = towingVehicle:getId(),
+        vehicle = towedVehicle:getId()
+    }
+    sendClientCommand(playerObj, "towbar", "detachTowBar", detachArgs)
+
+    -- World load/spawn can restore constraints in a bad state. Reattach one
+    -- short tick later so the detach is fully applied first.
+    ISTimedActionQueue.add(TowBarScheduleAction:new(
+        playerObj,
+        1,
+        reattachTowBarPair,
+        towingVehicle,
+        towedVehicle,
+        requireDriver
+    ))
+    return true
+end
+
 local function recoverTowBarVehicleAfterLoad(playerObj, vehicle, retriesLeft)
     if not vehicle then return end
 
@@ -295,8 +335,14 @@ local function recoverTowBarVehicleAfterLoad(playerObj, vehicle, retriesLeft)
     local localPlayer = playerObj or getPlayer()
     local towingVehicle = vehicle:getVehicleTowedBy()
 
+    if towingVehicle then
+        -- Apply rigid spacing as soon as the tow link exists to avoid a visible
+        -- bumper-to-bumper snap while waiting for reattach recovery.
+        TowBarMod.Hook.setVehiclePostAttach(nil, vehicle)
+    end
+
     if localPlayer and towingVehicle then
-        if reattachTowBarPair(localPlayer, towingVehicle, vehicle, false) then
+        if reattachTowBarPairAfterCleanDetach(localPlayer, towingVehicle, vehicle, false) then
             return
         end
     end
@@ -376,7 +422,7 @@ function TowBarMod.Hook.performAttachTowBar(playerObj, towingVehicle, towedVehic
         attachmentA = attachmentA,
         attachmentB = attachmentB
     }
-    sendClientCommand(playerObj, "vehicle", "attachTrailer", args)
+    sendTowAttachCommand(playerObj, args)
     ISTimedActionQueue.add(TowBarScheduleAction:new(playerObj, 10, TowBarMod.Hook.setVehiclePostAttach, towedVehicle))
 end
 

42.13/media/lua/server/TowingCommands.lua

@@ -3,6 +3,10 @@ if isClient() then return end
 local TowingCommands = {}
 local Commands = {}
 local TowBarItemType = "TowBar.TowBar"
+local SyncDelayTicks = 2
+local SnapshotIntervalTicks = 120
+local pendingSync = {}
+local snapshotTickCounter = 0
 
 TowingCommands.wantNoise = getDebug() or false
 
@@ -12,6 +16,133 @@ local noise = function(msg)
     end
 end
 
+local function queueSync(kind, player, args)
+    if not args then return end
+    table.insert(pendingSync, {
+        kind = kind,
+        ticks = SyncDelayTicks,
+        player = player,
+        args = args
+    })
+end
+
+local function resolveAttachmentA(args, vehicleA)
+    if args and args.attachmentA then return args.attachmentA end
+    if vehicleA and vehicleA:getTowAttachmentSelf() then return vehicleA:getTowAttachmentSelf() end
+    return "trailer"
+end
+
+local function resolveAttachmentB(args, vehicleB)
+    if args and args.attachmentB then return args.attachmentB end
+    if vehicleB and vehicleB:getTowAttachmentSelf() then return vehicleB:getTowAttachmentSelf() end
+    return "trailerfront"
+end
+
+local function isLinked(vehicleA, vehicleB)
+    if not vehicleA or not vehicleB then return false end
+    return vehicleA:getVehicleTowing() == vehicleB and vehicleB:getVehicleTowedBy() == vehicleA
+end
+
+local function hasTowBarState(vehicle)
+    if not vehicle then return false end
+    local md = vehicle:getModData()
+    if not md then return false end
+    return md["isTowingByTowBar"] == true
+end
+
+local function broadcastAttach(vehicleA, vehicleB, attachmentA, attachmentB)
+    if not vehicleA or not vehicleB then return end
+    sendServerCommand("towbar", "forceAttachSync", {
+        vehicleA = vehicleA:getId(),
+        vehicleB = vehicleB:getId(),
+        attachmentA = attachmentA,
+        attachmentB = attachmentB
+    })
+end
+
+local function broadcastDetach(vehicleAId, vehicleBId)
+    sendServerCommand("towbar", "forceDetachSync", {
+        vehicleA = vehicleAId,
+        vehicleB = vehicleBId
+    })
+end
+
+local function processAttachSync(item)
+    local args = item.args or {}
+    local vehicleA = args.vehicleA and getVehicleById(args.vehicleA) or nil
+    local vehicleB = args.vehicleB and getVehicleById(args.vehicleB) or nil
+    if not vehicleA or not vehicleB then
+        noise("attach sync skipped missing vehicles A=" .. tostring(args.vehicleA) .. " B=" .. tostring(args.vehicleB))
+        return
+    end
+
+    local attachmentA = resolveAttachmentA(args, vehicleA)
+    local attachmentB = resolveAttachmentB(args, vehicleB)
+    if not isLinked(vehicleA, vehicleB) then
+        vehicleA:addPointConstraint(item.player, vehicleB, attachmentA, attachmentB)
+    end
+    if isLinked(vehicleA, vehicleB) then
+        broadcastAttach(vehicleA, vehicleB, attachmentA, attachmentB)
+    end
+end
+
+local function processDetachSync(item)
+    local args = item.args or {}
+    local vehicleAId = args.towingVehicle or args.vehicleA or args.vehicle
+    local vehicleBId = args.vehicleB
+    broadcastDetach(vehicleAId, vehicleBId)
+end
+
+local function snapshotActiveTowbarLinksServer()
+    local cell = getCell()
+    if not cell then return end
+    local list = cell:getVehicles()
+    if not list then return end
+
+    for i = 0, list:size() - 1 do
+        local towingVehicle = list:get(i)
+        local towedVehicle = towingVehicle and towingVehicle:getVehicleTowing() or nil
+        if towingVehicle and towedVehicle and towedVehicle:getVehicleTowedBy() == towingVehicle then
+            if hasTowBarState(towingVehicle) or hasTowBarState(towedVehicle) then
+                local attachmentA = resolveAttachmentA(nil, towingVehicle)
+                local towedMd = towedVehicle:getModData()
+                local attachmentB = (towedMd and towedMd["towBarChangedAttachmentId"]) or resolveAttachmentB(nil, towedVehicle)
+                if attachmentA == attachmentB then
+                    attachmentA = "trailer"
+                    attachmentB = "trailerfront"
+                end
+                broadcastAttach(towingVehicle, towedVehicle, attachmentA, attachmentB)
+            end
+        end
+    end
+end
+
+local function processPendingSync()
+    snapshotTickCounter = snapshotTickCounter + 1
+    if snapshotTickCounter >= SnapshotIntervalTicks then
+        snapshotTickCounter = 0
+        snapshotActiveTowbarLinksServer()
+    end
+
+    if #pendingSync == 0 then return end
+
+    local remaining = {}
+    for i = 1, #pendingSync do
+        local item = pendingSync[i]
+        item.ticks = item.ticks - 1
+        if item.ticks <= 0 then
+            if item.kind == "attach" then
+                processAttachSync(item)
+            elseif item.kind == "detach" then
+                processDetachSync(item)
+            end
+        else
+            table.insert(remaining, item)
+        end
+    end
+    pendingSync = remaining
+end
+
 function Commands.attachTowBar(player, args)
     local vehicleA = getVehicleById(args.vehicleA)
     local vehicleB = getVehicleById(args.vehicleB)
@@ -92,6 +223,16 @@ Commands.attachConstraint = Commands.attachTowBar
 Commands.detachConstraint = Commands.detachTowBar
 
 TowingCommands.OnClientCommand = function(module, command, player, args)
+    if module == "vehicle" and command == "attachTrailer" then
+        queueSync("attach", player, args)
+    elseif module == "vehicle" and command == "detachTrailer" then
+        queueSync("detach", player, args)
+    elseif module == "towbar" and command == "attachTowBar" then
+        queueSync("attach", player, args)
+    elseif module == "towbar" and command == "detachTowBar" then
+        queueSync("detach", player, args)
+    end
+
     if module == "towbar" and Commands[command] then
         local argStr = ""
         args = args or {}
@@ -104,3 +245,4 @@ TowingCommands.OnClientCommand = function(module, command, player, args)
 end
 
 Events.OnClientCommand.Add(TowingCommands.OnClientCommand)
+Events.OnTick.Add(processPendingSync)