Map Boundaries And Offmap Enforcement

Map Boundaries and Off-Map Enforcement

Source-refreshed 2026-06-21 against current origin/master@0139a346 after the cf2a6d6a4..0139a346 drift check. Paths relative to Missions/[55-2hc]warfarev2_073v48co.chernarus/ unless noted. Arma 2 OA 1.64.

The boundaries system enforces a playable zone by shape-testing each client's position every 5 seconds, displaying a countdown hint when the player leaves the zone, and killing the vehicle/player when the countdown expires. It also clamps paradrop aircraft spawn points to map edges and drives the random-town distribution algorithm. The feature is parameter-controlled and silently self-disables on unregistered terrain.

Current-head note: the post-cf2a6d6a4 changes shifted constants, parameters, support-paradrop and stringtable anchors, but did not replace the boundary geometry or countdown handler shape checked below.

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Init and Terrain Lookup

Common/Init/Init_Boundaries.sqf runs on every machine (client and server) from Common/Init/Init_Common.sqf:326. It sets the single missionNamespace variable that all consumers read.

// Common/Init/Init_Boundaries.sqf:1-37 (abridged)
Private ['_boundariesXY'];
_boundariesXY = -1;

switch (toLower(worldName)) do {
    case 'chernarus':     {_boundariesXY = 15360};
    case 'eden':          {_boundariesXY = 12800};
    case 'isladuala':     {_boundariesXY = 10240};
    case 'takistan':      {_boundariesXY = 12800};
    case 'utes':          {_boundariesXY = 5120};
    case 'tasmania2010':  {_boundariesXY = 25360};
    case 'napf':          {_boundariesXY = 20500};
    case 'lingor':        {_boundariesXY = 10300};
    case 'smd_sahrani_a2':{_boundariesXY = 20480};
    case 'tavi':          {_boundariesXY = 25600};
    case 'dingor':        {_boundariesXY = 10300};
};

Common/Init/Init_Boundaries.sqf:4-16

Terrain XY Table

worldName (toLower)	WFBE_BOUNDARIESXY
chernarus	15360
eden	12800
isladuala	10240
takistan	12800
utes	5120
tasmania2010	25360
napf	20500
lingor	10300
smd_sahrani_a2	20480
tavi	25600
dingor	10300
(any other worldName)	-1 (feature disabled)

Common/Init/Init_Boundaries.sqf:4-16

Enabled-Parameter Branch

After the switch, the script branches on WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED (Common/Init/Init_Boundaries.sqf:19):

Condition	Result
Enabled AND terrain known	missionNamespace setVariable ['WFBE_BOUNDARIESXY', _boundariesXY]
Enabled AND terrain unknown (_boundariesXY == -1)	Forces WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED to 0; nils BoundariesIsOnMap and BoundariesHandleOnMap on local player; logs warning
Disabled AND terrain known	Sets WFBE_BOUNDARIESXY anyway (support callers need it); logs {Boundaries parameter is disabled}
Disabled AND terrain unknown	Logs warning only

The nil-out of BoundariesIsOnMap/BoundariesHandleOnMap only executes on the machine where local player is true, i.e. each client independently. Common/Init/Init_Boundaries.sqf:23-24

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Parameter Definition

Parameter class	Default	Values	File
WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED	1 (Enabled)	{0, 1}	Rsc/Parameters.hpp:269

The hardcoded fallback (if the mission starts without a lobby parameter value) is set at Common/Init/Init_CommonConstants.sqf:792:

if (isNil "WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED") then {WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED = 1};

The timeout constant lives in the same file:

WFBE_C_PLAYERS_OFFMAP_TIMEOUT = 50; //--- Player may remain x second outside of the map before being killed.

Common/Init/Init_CommonConstants.sqf:427

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Globals Written

Variable	Scope	Written by	Read by
WFBE_BOUNDARIESXY	missionNamespace	Init_Boundaries.sqf	Client_IsOnMap.sqf, three Support_Para*.sqf, Server/Init/Init_Towns.sqf
WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED	missionNamespace	Parameters / Init_CommonConstants.sqf	Init_Boundaries.sqf, updateavailableactions.fsm
WFBE_C_PLAYERS_OFFMAP_TIMEOUT	missionNamespace	Init_CommonConstants.sqf	Client_HandleOnMap.sqf
BoundariesIsOnMap	missionNamespace (global code var)	Init_Client.sqf:69 (compiled)	updateavailableactions.fsm:134, Client_HandleOnMap.sqf:8
BoundariesHandleOnMap	missionNamespace (global code var)	Init_Client.sqf:70 (compiled)	updateavailableactions.fsm:136
paramBoundariesRunning	missionNamespace (global bool)	Client_HandleOnMap.sqf:4 (set on spawn)	updateavailableactions.fsm:136,139

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Square-Zone Geometry (Client_IsOnMap.sqf)

The playable zone is a square of side WFBE_BOUNDARIESXY, with its origin at [0, 0]. The script uses polar math to find the distance from the player to the nearest edge of the square, then compares it to the player's distance from the square's centre point.

// Client/Functions/Client_IsOnMap.sqf:1-17
Private ['_adis','_bdis','_borderdis','_boundary','_difx','_dify','_dir',
         '_position','_positiondis','_sqrradH','_sqrradHR'];

_boundary   = missionNamespace getVariable 'WFBE_BOUNDARIESXY';
_sqrradH    = _boundary / 2;
_sqrradHR   = [_sqrradH, _sqrradH];                       // centre of the square
_position   = [getPos player select 0, getPos player select 1];

_difx = (_position select 0) - _sqrradH;
_dify = (_position select 1) - _sqrradH;
_dir  = atan (_difx / _dify);
if (_dify < 0) then {_dir = _dir + 180};
_adis       = abs (_sqrradH / cos (90 - _dir));
_bdis       = abs (_sqrradH / cos _dir);
_borderdis  = _adis min _bdis;                             // nearest edge distance
_positiondis = _position distance _sqrradHR;               // player distance from centre

if (_positiondis < _borderdis) then {true} else {false}

Client/Functions/Client_IsOnMap.sqf:1-17

Geometry Notes

• _sqrradH is half the terrain XY value. For Chernarus this is 7680 — both the X and Y centre coordinates in world space.
• The polar decomposition (atan, then a cosine correction on each axis) computes the radius of the inscribed square at the player's bearing rather than a circle. A player directly on a diagonal can be further from the centre than one at a cardinal heading while both are at the same _positiondis.
• The check is not a circle radius test. On Chernarus a player at bearing 45° can be roughly 41% further from centre before triggering than a player at bearing 0° or 90° (a factor of sqrt(2), since the effective boundary at 45° is 7680/cos(45°) ≈ 10 860 m versus 7 680 m at cardinal headings).
• The function is called with no arguments: Call BoundariesIsOnMap. Returns true (inside) or false (outside).

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Off-Map Kill Countdown (Client_HandleOnMap.sqf)

When the FSM detects the player is off-map and no countdown is already running, it spawns BoundariesHandleOnMap:

// Client/Functions/Client_HandleOnMap.sqf:1-16
Private ['_isOnMap','_timeToKill'];

_timeToKill = missionNamespace getVariable "WFBE_C_PLAYERS_OFFMAP_TIMEOUT";
paramBoundariesRunning = true;

while {true} do {
    sleep 1;
    _isOnMap = Call BoundariesIsOnMap;
    if !(_isOnMap) then {
        hint parseText(Format[localize 'STR_WF_INFO_OffmapWarning', _timeToKill]);
        _timeToKill = _timeToKill - 1;
    };
    if (_timeToKill < 0 || _isOnMap || !(alive player)) exitWith {
        if !(_isOnMap && alive player) then {(vehicle player) setDamage 1};
        paramBoundariesRunning = false;
    };
};

Client/Functions/Client_HandleOnMap.sqf:1-16

Countdown Behaviour

Event	What happens
Player off-map	Hint fires each second: STR_WF_INFO_OffmapWarning formatted with remaining seconds
Player returns to map before timeout	exitWith fires; setDamage 1 is not called; paramBoundariesRunning = false
Countdown reaches -1	exitWith fires; (vehicle player) setDamage 1 kills the player (and the vehicle if mounted)
Player dies while off-map	!(alive player) guard exits the loop; setDamage 1 is not double-applied

Default timeout: 50 seconds (Common/Init/Init_CommonConstants.sqf:427).

The hint text (stringtable.xml:1118) is red and localised: English reads Warning! You are leaving the battlefield! <N> Seconds left.

Design note: setDamage 1 is applied to vehicle player, not player directly. If the player is on foot, vehicle player returns the player unit and the effect is identical. If mounted, the vehicle is destroyed along with the player.

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FSM Caller — updateavailableactions.fsm

The FSM runs on each client and ticks roughly every 5 seconds (condition: time - _lastUpdate > 5). It is the only caller that decides whether to spawn a new countdown coroutine.

// Client/FSM/updateavailableactions.fsm:46 (init section)
"_boundaries_enabled = if ((missionNamespace getVariable ""WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED"") > 0) then {true} else {false};"

// Client/FSM/updateavailableactions.fsm:132-141 (Update_Client_Ac state)
"//--- Boundaries are limited ?"
"if (_boundaries_enabled) then {"
"    _isOnMap = Call BoundariesIsOnMap;"
"    if (!_isOnMap && alive player && !WFBE_Client_IsRespawning) then {"
"        if !(paramBoundariesRunning) then {_handle = [] Spawn BoundariesHandleOnMap};"
"    } else {"
"        if !(isNil '_handle') then {terminate _handle; _handle = nil};"
"        paramBoundariesRunning = false;"
"    };"
"};"

Client/FSM/updateavailableactions.fsm:46,133-141

Gating Logic

FSM check	Effect
!_isOnMap && alive player && !WFBE_Client_IsRespawning	Spawns BoundariesHandleOnMap if not already running
Player is on-map OR dead	Terminates any running _handle; clears paramBoundariesRunning
WFBE_Client_IsRespawning true	Suppresses spawn — prevents a false off-map kill during respawn fade

The FSM's 5-second tick means there is a latency window: a player can step off-map and return before the next FSM update without seeing a hint or countdown, as long as BoundariesHandleOnMap has not already been spawned.

---

Paradrop Edge-Spawn Clamping

All three paradrop support scripts use WFBE_BOUNDARIESXY to build a four-corner array of map-edge spawn positions at altitude ~400–600 m. If the variable is nil (terrain unregistered or script ran before init), they fall back to a two-point hardcoded array.

File	Line	Usage
Server/Support/Support_ParaAmmo.sqf	12	_bd = missionNamespace getVariable 'WFBE_BOUNDARIESXY'
Server/Support/Support_Paratroopers.sqf	14	same
Server/Support/Support_ParaVehicles.sqf	12	same

// Shared pattern — e.g. Support_Paratroopers.sqf:14-27
_bd = missionNamespace getVariable 'WFBE_BOUNDARIESXY';
if !(isNil '_bd') then {
    _ranPos = [
        [0+random(200),       0+random(200),       400+random(200)],
        [0+random(200),       _bd-random(200),      400+random(200)],
        [_bd-random(200),     _bd-random(200),      400+random(200)],
        [_bd-random(200),     0+random(200),        400+random(200)]
    ];
    _ranDir = [45, 145, 225, 315];
} else {
    _ranPos = [[0+random(200),0+random(200),400+random(200)],
               [15000+random(200),0+random(200),400+random(200)]];
    _ranDir = [45, 315];
};

Server/Support/Support_Paratroopers.sqf:14-27

The fallback 15000 value is a bare constant and does not reflect any registered terrain's XY — a paradrop on an unregistered map wider than 15 km will spawn aircraft off one side only.

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Town Distribution Usage (Server Init_Towns.sqf)

When the random-towns parameter is active (case 3), Server/Init/Init_Towns.sqf:71 reads WFBE_BOUNDARIESXY to compute a geometric centre and ellipse for allocating Resistance towns:

// Server/Init/Init_Towns.sqf:71
_boundaries = missionNamespace getVariable 'WFBE_BOUNDARIESXY';
// ...
if !(isNil '_boundaries') then {
    _searchArea = [(_boundaries / 2)-0.1, (_boundaries / 2)+0.1, 0];
    // ellipse math to assign ~50% towns to Resistance
};

Server/Init/Init_Towns.sqf:71

If WFBE_BOUNDARIESXY is nil (unregistered terrain with boundaries disabled), the ellipse block is skipped entirely and town assignment falls through to a random-fill loop.

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Adding a New Map

1. Add a case entry to the switch block in Common/Init/Init_Boundaries.sqf:4-16 with the correct full-map XY extent in world units.
2. Confirm the correct worldName string by checking call BIS_fnc_worldName or the terrain's config.cpp. The switch uses toLower(worldName), so capitalisation in config does not matter.
3. Verify WFBE_BOUNDARIESXY covers the playable area — setting it too small kills players near valid terrain edges; too large allows unintended off-map vehicle use.
4. Without a registered entry, the system silently forces WFBE_C_GAMEPLAY_BOUNDARIES_ENABLED to 0 and paradrop aircraft use the hardcoded two-point fallback.

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Behaviour Matrix

Scenario	BoundariesIsOnMap nil?	WFBE_BOUNDARIESXY set?	Countdown fires?	Paradrop corners?
Known terrain, Enabled=1	No	Yes	Yes	4-corner
Known terrain, Enabled=0	No	Yes	No	4-corner
Unknown terrain, Enabled=1	Yes (nilled)	No	No (FSM call skipped — nil guard)	2-point fallback
Unknown terrain, Enabled=0	No	No	No	2-point fallback

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Continue Reading

• Variable-And-Naming-Conventions — naming rules for WFBE_C_*, WFBE_UP_*, and global code variables like BoundariesIsOnMap
• Networking-And-Public-Variables — how missionNamespace variables flow between server and clients; WFBE_Client_IsRespawning respawn gate
• Server-Gameplay-Runtime-Atlas — runtime overview including support call dispatch; paradrop scripts in context
• Function-And-Module-Index — full index of compiled functions and FSM entry points
• SQF-Code-Atlas — cross-reference of all SQF files including Init_Common.sqf and Init_Client.sqf init ordering