Gui

Overview

Gui is an engine namespace, not a resident/ module — there’s no .lua source file behind it, no import() call needed, and it’s always globally available to every script. It covers low-level GUI plumbing: toggling which marker types render on screen (faction/pickup/player/vehicle-entrance), a set of underscore-prefixed internal marker primitives that the public Marker namespace appears to wrap, font and texture loading for the HUD, language/localization queries, controller-type detection, reticle screen position, and a handful of shell-lifecycle/dev-only hooks.

A live-probing caveat worth knowing before concluding a function “doesn’t exist”: during a live WebSocket lua-bridge probe (2026-07-22), some Gui functions came back nil/inert when called on the runtime global _G.Gui. Gui functionality apparently does not live entirely on _G.Gui itself — some of it lives only under a separate _GuiInternal table instead (a real, separate table the wiki already documents extensively as the primitive layer beneath MrxGuiBase’s widget methods — see resident/mrxguibase.lua). This is a real, confirmed finding, not a guess: don’t conclude a Gui function “doesn’t exist” just because it’s absent/nil on _G.Gui — it may only be reachable via _GuiInternal.

Provenance

This page’s function list comes from a live pairs(Gui) enumeration in-game (via lua-bridge), not from reading engine source — the engine implementation isn’t available to us. That means the list of 38 function names below is complete and authoritative: every one of them really exists on the namespace. It does not mean every entry is documented with confirmed arguments. Where a function is actually called somewhere in the ~230 decompiled .lua scripts, we can show a real argument pattern. Where it isn’t called anywhere in that corpus, we only know the name — arguments, return values, and behavior for those are unconfirmed.

Functions

Marker Enable Toggles

Function	Signature (best-known)	Notes
`EnablePlayerMarkers`	`Gui.EnablePlayerMarkers(bEnabled)`	Confirmed with a single boolean argument in real scripts, e.g. `Gui.EnablePlayerMarkers(false)` / `Gui.EnablePlayerMarkers(true)` (`mrxbriefing.lua`), used to hide/show player markers during cutscenes/briefings.
`EnableFactionMarkers`	`Gui.EnableFactionMarkers(bEnabled)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed. Signature inferred only by analogy to the confirmed `EnablePlayerMarkers`.
`EnablePickupMarkers`	`Gui.EnablePickupMarkers(bEnabled)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed. Signature inferred only by analogy to the confirmed `EnablePlayerMarkers`.
`EnableVehicleEntranceMarkers`	`Gui.EnableVehicleEntranceMarkers(bEnabled)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed. Signature inferred only by analogy to the confirmed `EnablePlayerMarkers`.
`SetFactionMarkerSize`	`Gui.SetFactionMarkerSize(...)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed.
`SetFactionMarkerVisibleDistance`	`Gui.SetFactionMarkerVisibleDistance(...)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed.
`SetPickupMarkerSize`	`Gui.SetPickupMarkerSize(nSize, bFlag)`	Confirmed in real scripts, e.g. `Gui.SetPickupMarkerSize(18, false)` immediately followed by `Gui.SetPickupMarkerSize(18, true)` (`hero.lua`) — same numeric size passed with the boolean flipped, meaning of the flag unconfirmed (possibly a “near”/”far” or “friendly”/”enemy” marker-set selector).
`SetPickupMarkerVisibleDistance`	`Gui.SetPickupMarkerVisibleDistance(nDistance, bFlag)`	Confirmed in real scripts, e.g. `Gui.SetPickupMarkerVisibleDistance(20, false)` (`hero.lua`), same call site as `SetPickupMarkerSize` above, run inside a 3-second delayed `Event.Create(Event.TimerRelative, ...)` block during survival-mode setup.
`SetVehicleEntranceMarkerSize`	`Gui.SetVehicleEntranceMarkerSize(...)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed.
`SetVehicleEntranceMarkerVisibleDistance`	`Gui.SetVehicleEntranceMarkerVisibleDistance(...)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed.

Internal Marker Primitives

These are almost certainly the internal implementation behind the separate public Marker namespace (documented on its own page). None of them turned up call sites in the decompiled .lua corpus, which is consistent with the underscore-prefix convention elsewhere in this codebase marking “internal, not meant to be called directly from game scripts” — the public Marker.* wrapper is presumably what real scripts call instead.

Function	Notes
`_MarkerAdd`	No call sites found. Name corresponds closely to public `Marker.Add`.
`_MarkerAddOld`	No call sites found. An older/legacy variant of `_MarkerAdd`, judging by the name — the exact relationship to `Marker.AddBlip` (which has no equally-named `_Marker*` counterpart) is unconfirmed; flagged as a naming mismatch rather than assumed.
`_MarkerAdd3D`	No call sites found. Name corresponds closely to public `Marker.Add3D`.
`_MarkerAddDisc`	No call sites found. Name corresponds closely to public `Marker.AddDisc`.
`_MarkerAddTripwire`	No call sites found. Name corresponds closely to public `Marker.AddTripwire`.
`_MarkerHaltPulse`	No call sites found. Name corresponds closely to public `Marker.HaltPulse`.
`_MarkerPulse`	No call sites found. Name corresponds closely to public `Marker.Pulse`.
`_MarkerRemove`	No call sites found. Name corresponds closely to public `Marker.Remove`.
`_MarkerSetBlipLimit`	No call sites found. Name corresponds closely to public `Marker.SetGroupedBlipLimit` (not an exact string match, but the closest by function).
`_MarkerSetColor`	No call sites found. Name corresponds closely to public `Marker.SetColor`.
`_MarkerSetFollowGuid`	No call sites found. Name corresponds closely to public `Marker.SetFollowGuid`.
`_MarkerSetLocation`	No call sites found. Name corresponds closely to public `Marker.SetLocation`.
`_MarkerSetScale`	No call sites found. Name corresponds closely to public `Marker.SetScale`.

On the naming correspondence: the match between these 13 Gui._Marker* names and the 13 public Marker.* function names is a strong naming-pattern observation from the two live pairs() dumps, not a confirmed engine-internals finding — the engine’s native (C++) implementation isn’t available to us, so we cannot show that Marker.Add literally calls Gui._MarkerAdd under the hood. Treat it as a well-supported hypothesis: Marker.Add/Add3D/AddDisc/AddTripwire/HaltPulse/Pulse/Remove/SetColor/ SetFollowGuid/SetLocation/SetScale line up 1:1 by name with _MarkerAdd/_MarkerAdd3D/_MarkerAddDisc/ _MarkerAddTripwire/_MarkerHaltPulse/_MarkerPulse/_MarkerRemove/_MarkerSetColor/_MarkerSetFollowGuid/ _MarkerSetLocation/_MarkerSetScale. Two names don’t line up as cleanly: Marker.SetGroupedBlipLimit vs. _MarkerSetBlipLimit (close but not exact), and Marker.AddBlip has no matching _MarkerAddBlip at all — the closest candidate is _MarkerAddOld, which is a plausible but unconfirmed guess given the “Old” naming.

Localization & Language

Function	Signature (best-known)	Notes
`GetLanguageName`	`s = Gui.GetLanguageName()`	Confirmed with no arguments in real scripts, e.g. `local sLanguage = Gui.GetLanguageName()` (`mrxsoundbanks.lua`), used to pick the correct localized sound bank.
`GetLanguageNum`	`n = Gui.GetLanguageNum()`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed. Presumed numeric-ID counterpart to the confirmed `GetLanguageName`.
`LoadFont`	`Gui.LoadFont(sFontName)`	Confirmed with a single font-name string in real scripts, e.g. `Gui.LoadFont("fanfare_36")` (`mrxguihudmessage.lua`).
`LoadTexture`	`Gui.LoadTexture(sTextureName [, sType])`	Confirmed extensively in real scripts, always at least a texture-name string; commonly called with an explicit `"texture"` type string as the 2nd argument, e.g. `Gui.LoadTexture("icon_hijack_button_A", "texture")` (24 consecutive calls in `mrxguihudactionhijack.lua` preloading HUD icons), and also called with just the name in other places (e.g. `Gui.LoadTexture("global_gui_reticle_stinger_target")` in `mrxguihudreticle.lua`), meaning the 2nd argument is optional.

Input/Controller Detection

Function	Signature (best-known)	Notes
`IsXboxController`	`b = Gui.IsXboxController()`	Confirmed with no arguments in real scripts, always guarded by an existence check first, e.g. `if Gui.IsXboxController and Gui.IsXboxController() then` (`mrxguihudactionhijack.lua`) — the guard pattern suggests this function may not exist on all platform builds.
`ControllerInUse`	`b = Gui.ControllerInUse()`	Confirmed with no arguments in real scripts, also always guard-checked first, e.g. `if Gui.ControllerInUse and Gui.ControllerInUse() then` (`vzacon001.lua`, `wiftutorialboat.lua`, `wiftutorialwheeledvehiclebasic.lua`) — same existence-guard pattern as `IsXboxController`, used to branch tutorial prompts between mouse/keyboard and controller phrasing.
`GetReticlePosition`	`nX, nY = Gui.GetReticlePosition(uOwnerGuid)`	Confirmed in real scripts with an `oWidget:GetOwner()`-style argument, e.g. `local nAimX, nAimY = Gui.GetReticlePosition(oWidget:GetOwner())` (`mrxguihudreticle.lua`, 5 call sites), returning 2D screen-space reticle coordinates. Also always guard-checked at one call site: `if Gui.GetReticlePosition then`. This is a different function from `Player.GetTargetUnderReticle` (see Player) — `Gui.GetReticlePosition` returns 2D screen coordinates of the reticle itself, while `Player.GetTargetUnderReticle` returns the 3D world position and `uGuid` of whatever the reticle is aimed at. The two are complementary, not duplicates.
`FindGuiLocation`	`nX1, nY1, nX2, nY2 = Gui.FindGuiLocation(uOwnerOrPlayerGuid, uTargetGuid)`	Confirmed in real scripts with two arguments and 4 return values, e.g. `local nX1, nY1, nX2, nY2 = Gui.FindGuiLocation(oOverlay:GetOwner(), tEvent.uGuid)` (`mrxguisatellite.lua`) and `local nX, nY, nX2, nY2 = Gui.FindGuiLocation(uPlayerGuid, uGuid)` (`mrxguitutorial.lua`, guarded by `if Gui.FindGuiLocation then`) — likely a screen-space bounding box (two corner points) for a world object, used to anchor UI overlays/tutorial callouts onto it.
`IsPdaOnSelect`	`b = Gui.IsPdaOnSelect()`	Confirmed with no arguments in real scripts, guard-checked first: `if Gui.IsPdaOnSelect and Gui.IsPdaOnSelect() then` (`mrxguipda.lua`).

Misc/Dev

Function	Signature (best-known)	Notes
`AddObjective`	`Gui.AddObjective(...)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed.
`DoSigninCheck`	`Gui.DoSigninCheck()`	Confirmed with no arguments in real scripts, e.g. `Gui.DoSigninCheck()` (`mrxguishell.lua`), part of the shell/platform-signin flow.
`OnGlobalExit`	`Gui.OnGlobalExit()`	Confirmed with no arguments in real scripts, e.g. `Gui.OnGlobalExit()` (`mrxstate.lua`), invoked as part of global game-exit teardown.
`OnShellLoaded`	`Gui.OnShellLoaded()`	Confirmed with no arguments in real scripts, guard-checked first: `if Gui.OnShellLoaded then Gui.OnShellLoaded() end` (`mrxguishell.lua`).
`OutputToPIX`	`Gui.OutputToPIX(...)`	No call sites found in the decompiled corpus — exists (confirmed via live `pairs()` enumeration) but usage/arguments unconfirmed. Name suggests a PIX (graphics-debugger) event/marker output hook for dev builds.
`ShowLoadingHints`	`Gui.ShowLoadingHints(bShow)`	Confirmed with a single boolean argument in real scripts, always guard-checked first, e.g. `if Gui.ShowLoadingHints then Gui.ShowLoadingHints(false) end` / `Gui.ShowLoadingHints(true)` (`mrxgui.lua`), toggling the loading-screen hint text.

Notes for modders

Prefer the public Marker namespace over calling the _Marker* functions on this page directly. The leading underscore is this codebase’s naming convention for “internal, not meant to be called externally” — Marker.* is very likely a thin wrapper around exactly these primitives (see the naming-correspondence discussion above), and using the public API is both safer and more likely to match whatever validation/bookkeeping the wrapper does around the raw primitive.
Several functions here are consistently called behind an existence guard in real scripts (if Gui.ControllerInUse and Gui.ControllerInUse() then, if Gui.ShowLoadingHints then ... end, etc.). That’s a strong signal these functions may not exist on every platform/build target — copy the guard pattern in your own mods rather than calling them unconditionally.
Gui.GetReticlePosition and Player.GetTargetUnderReticle are easy to confuse but answer different questions (2D screen position of the reticle vs. 3D world target under it) — see the comparison note in the Input/Controller Detection table above.
Functions marked “no call sites found” are real (confirmed via the live pairs(Gui) dump) but their argument shape is a guess based on naming convention and analogy only — don’t build mods around them without testing in-game first.