Deployable Bipod Weapon Resting

Deployable Bipod / Weapon Resting

Source-verified 2026-06-21 against master 0139a346. Paths relative to Missions/[55-2hc]warfarev2_073v48co.chernarus/ unless noted. Arma 2 OA 1.64.

A client-side, player-facing "deploy bipod" / weapon-resting mechanic. While carrying one of a fixed whitelist of machine guns and sniper rifles, a player who presses TAB in a valid stance (prone, or crouched directly behind a short solid object) has their weapon recoil zeroed and gets an audible/visual confirmation. The entire feature lives in a single function, Common\Functions\Common_Bipod.sqf (header credits // -WASP- and // 3JIbIDEHb aka Smirnoff_ICE, Common_Bipod.sqf:1-2), is execVM'd once at client init, and is invisible to the server — it only adjusts the local player's recoil coefficient.

Auto-Bipod Feature (Merged)

Trello #210 / PR #90 merged into master (commit 5af02b843 via a78634e55). Bipod_AddAutoDeploy is live in Common_Bipod.sqf:74-82. It is one commit on current stable origin/master@f8a76de34, changes four maintained-root files / +46 / -2, and git diff --check origin/master..origin/claude/trello-auto-bipod is clean. The touched files are source Chernarus plus maintained Vanilla Common/Functions/Common_Bipod.sqf and Client/Functions/Client_OnKilled.sqf.

The branch does not add a new server path, public variable, weapon list, sound, localization key or recoil model. Instead, it adds Bipod_AddAutoDeploy after the existing Bipod_ON handler in both maintained Common_Bipod.sqf copies (:74-82). The helper stores the local AnimChanged event-handler id in Bipod_AutoEH, removes any older local handler, attaches a fresh AnimChanged handler to player, and calls the existing 15 call Bipod_ON path when the new animation is exactly amovppnemstpsraswrfldnon. That means auto-deploy still reuses the existing TAB case, whitelist, prone gate, HintSilent, Bipod_ON sound and recoil reset behavior.

The branch also reattaches the local animation handler in the killed/respawn lifecycle. In both maintained Client_OnKilled.sqf copies, line :90 guards if (!isNil "Bipod_AddAutoDeploy") then {[] call Bipod_AddAutoDeploy}; after the existing player killed handler is restored (:77-84) and before PreRespawnHandler runs (:95). Current stable lacks Bipod_AddAutoDeploy, Bipod_AutoEH, AnimChanged and 15 call Bipod_ON hits in the maintained roots, so this is branch-only behavior.

Promotion gates: smoke a whitelisted MG/sniper going prone without TAB, a non-whitelisted weapon going prone, the manual TAB fallback, crouched/object resting, death/respawn reattachment, repeated stance changes without sound spam, and source Chernarus plus maintained Vanilla parity. Keep the existing str_bipod localization debt and unconditional key-down recoil reset documented unless the owner intentionally fixes them in the same target branch.

Wiring and lifecycle

The function is launched once per client during client init, after the local HandleDamage rearmor handler is attached:

Step	Where	Detail
Launch	Client\Init\Init_Client.sqf:91	[] execVM "Common\Functions\Common_Bipod.sqf"; — fire-and-forget, no return value used, no global handle stored.
Wait for UI	Common_Bipod.sqf:5	waituntil {!isnull (finddisplay 46)}; — blocks until the main mission display (IDD 46) exists, so the KeyDown handler attaches to a live display.
Attach key hook	Common_Bipod.sqf:5	(findDisplay 46) displayAddEventHandler ["KeyDown","_this select 1 call Bipod_ON; false"]; — the handler passes the DIK key code (_this select 1) into Bipod_ON and returns false, so the keypress is not consumed (TAB still performs its normal in-game function).
Define handler	Common_Bipod.sqf:7-65	Bipod_ON = { switch (_this) do { ... } }; — a global code value invoked on every key-down event.

Because Bipod_ON is a global and the KeyDown handler is bound to display 46, the function runs on each player's machine only. There is no server call, no publicVariable, and no setVehicleInit — nothing about bipod state propagates off the local client.

The TAB case and stance gate

Bipod_ON is called for every key-down on display 46 but only acts on one key:

Element	Path:line	Behavior
Switch on key code	Common_Bipod.sqf:8	switch (_this) do where _this is the raw DIK code from the KeyDown event.
TAB case	Common_Bipod.sqf:11	case 15: — DIK code 15 is TAB (the inline comment at Common_Bipod.sqf:10 reads "For using bipod hit TAB"). All other keys fall through with no effect.
Current weapon	Common_Bipod.sqf:12	_weapon = currentWeapon player; — captured for the whitelist test below.
Target object	Common_Bipod.sqf:48	_behind = cursorTarget; — the object the player is currently looking at, used as the "rest" surface.
Object size	Common_Bipod.sqf:49	_size = sizeOf (typeOf _behind); — the configured bounding size of that object's class.
Proximity/size test	Common_Bipod.sqf:50	Stands_behind = ((player distance _behind < _size/2.2) && (_size < 16.2)); — true when the player is close to a small object (the _size < 16.2 cap rejects large structures).
Prone path	Common_Bipod.sqf:51	Lying_stand = ((animationState player == "amovppnemstpsraswrfldnon") && (_weapon in _affected)); — prone rifle-down idle animation and a whitelisted weapon.
Crouch path	Common_Bipod.sqf:52	Crouch_stand = ((Stands_behind) && (_weapon in _affected) && (!(typeof _behind isKindOf "Man")) && (!(typeof _behind isKindOf "Air"))); — close to a small object, whitelisted weapon, and the rested object is neither a man nor an aircraft.
Apply	Common_Bipod.sqf:53-55	if (Lying_stand or Crouch_stand) then { ... }; — only one of the two gates needs to pass.

So there are exactly two ways to "deploy": be prone with a supported weapon (no object required), or be near a small solid prop (vehicle/structure under the size cap, not a person or aircraft) with a supported weapon.

Effect when the gate passes

Action	Path:line	Effect
On-screen text	Common_Bipod.sqf:54	SetBipodOn = HintSilent (localize "str_bipod"); — a silent hint. Note: the str_bipod key is commented out in stringtable.xml:44-52 (the <!--<Key ID="str_bipod"> block, original text "Bipod deployed"), so localize "str_bipod" returns the literal string "str_bipod" at runtime rather than the intended "Bipod deployed". The hint result is stored in the global SetBipodOn, which is never read anywhere else.
Zero recoil	Common_Bipod.sqf:54	player setUnitRecoilCoefficient 0; — the actual rest effect: removes weapon recoil for the local player.
Confirm sound	Common_Bipod.sqf:54	player say "Bipod_ON"; — plays the mission sound Bipod_ON, defined at Sounds/description.ext:66-69 (name = "Bipod_ON"; sound[] = {"\Sounds\Bipod_ON-10.ogg", 10, 1};).
Reset recoil	Common_Bipod.sqf:64	player setUnitRecoilCoefficient 1; — sits outside all case labels in the switch body (after the closing }; of case 15 at line 62, before the switch's own }; at line 65) and runs unconditionally on every key-down event — not just TAB presses. Because every key-down both potentially sets recoil to 0 (inside the TAB case if gate) and then unconditionally restores it to 1 here, the zeroed-recoil state is momentary unless re-asserted; a player effectively pulses recoil off by holding/tapping TAB.

The private declaration at Common_Bipod.sqf:3 (private ["_unit","_weapon","_affected","_behind","_size"]) lists _unit, which is never assigned or used inside the function. The globals Stands_behind, Lying_stand, Crouch_stand, and SetBipodOn are created without private and leak into mission namespace, but none are read outside this file (verified by grep across *.sqf).

Supported-weapon whitelist

_affected (Common_Bipod.sqf:13-47) is a hard-coded array of weapon class names; only currentWeapon player matching one of these enables the rest. The list mixes BAF/PMC DLC weapons, OA base sniper rifles, and squad automatic weapons:

Category	Classes (verbatim from Common_Bipod.sqf:13-47)
Heavy/anti-materiel sniper	ksvk, m107, m107_TWS_EP1, BAF_AS50_scoped, BAF_AS50_TWS, BAF_LRR_scoped, BAF_LRR_scoped_W, PMC_AS50_scoped, PMC_AS50_TWS
Marksman / sniper rifles	BAF_L86A2_ACOG, M110_NVG_EP1, M110_TWS_EP1, M24, M24_des_EP1, M40A3, m8_sharpshooter, SCAR_H_LNG_Sniper, SCAR_H_LNG_Sniper_SD
GPMG / MMG	BAF_L7A2_GPMG, M240, m240_scoped_EP1, M60A4_EP1, Mk_48, Mk_48_DES_EP1, Pecheneg, PK
SAW / LMG	BAF_L110A1_Aim, M249, M249_EP1, M249_m145_EP1, M249_TWS_EP1, m8_SAW, MG36, MG36_camo, RPK_74

Any weapon not on this exact list (including newer/modded MGs and snipers) gets no rest effect even in a valid stance. The list is a literal, so adding support means editing Common_Bipod.sqf directly.

Dead/debug code in the same case

Below the TAB block, a case 57: ("Hit SPACE", Common_Bipod.sqf:57) and a closing debug hint line (Common_Bipod.sqf:61) are fully commented out, along with a trailing HintSilent ""; (Common_Bipod.sqf:63). They were a development bounding-box probe and are inert. The only live key is TAB.

Continue Reading

• Engine Stealth & Fuel Toggle Reference — a sibling client-side key/action toggle of similar shape.
• Earplugs Audio Toggle Reference — another local, player-only quality-of-life toggle.
• Client UI HUD And Menus — where display 46 KeyDown hooks and client HUD wiring are catalogued.
• Mission Entrypoints And Lifecycle — the Init_Client.sqf client-init chain that execVMs this function.
• Faction Unit And Vehicle Roster Catalog — context for the weapon classes in the whitelist.