Sglunarthrall Plant Vine

Based on game build 714014 | Last updated: 2026-03-08

Overview

SGlunarthrall_plant_vine defines the state graph for vine segments of the Lunarthrall boss encounter. These segments act as independent entities that can spawn, move forward (extend), move backward (retract), attack, and be damaged. The vine chain maintains a parent–child relationship: each segment (nub) is attached to a parent (headplant or parentplant) and can spawn a new child vine. The state machine handles transitions between idle, emerging, attacking, retracting, and dying states, and supports freezing/thawing behavior across the vine chain via state tags and event propagation.

Usage example

-- A vine segment is automatically created by the Lunarthrall boss logic.
-- To manually spawn and configure one (for testing or modding):
local vine = SpawnPrefab("lunarthrall_plant_vine")
vine.headplant = parent_vine_or_plant
vine.parentplant = parent_vine_or_plant
vine:AddTag("lunarthrall_plant_end")
vine:AddTag("weakvine")
vine:DoTaskInTime(0.5, function() vine.sg:GoToState("nub_spawn") end)

Dependencies & tags

Components used: burnable, colouradder, combat, freezable, health, inventoryitem, mine, timer, transform, soundemitter, animstate, fueled (indirect), propagator (indirect via burnable) Tags added/removed/checked:

• Common tags: idle, busy, emerged, retracting, nub, dead, frozen, thawing, noattack, noelectrocute, caninterrupt
• Custom tags: weakvine, lunarthrall_plant_end, lunarthrall_plant_segment, INLIMBO, DECOR, invisible, notarget, noattack, wall, lunarthrall_plant

Properties

Property	Type	Default Value	Description
headplant	Entity?	nil	Reference to the immediate parent vine or plant segment (typically the base). Used for coldness redirection.
parentplant	Entity?	nil	Logical parent vine (often the same as headplant), used for lifecycle management and chain propagation.
tintcolor	{r,g,b}	nil	Optional RGB color used to tint the vine's animation.
indirectdamage	boolean	nil	Flag affecting death animation; set externally during damage.
tails	table	{}	Array of child vine segments spawned ahead of this one. Controls extension length.

Main functions

This stategraph does not define standalone components or function modules; it is a StateGraph. The following are internal helper functions and event handlers used within the state definitions.

nub_addcoldness(nub, coldness, freezetime, nofreeze)

• Description: Redirects coldness application from a child vine segment (nub) to its parent vine or plant (headplant). Enables freezing effects to propagate upward in the vine chain.
• Parameters:
  • nub (Entity) — child vine segment being frozen.
  • coldness, freezetime, nofreeze — standard Freezable component arguments.
• Returns: true if redirection succeeded (parent found and valid), false otherwise.
• Error states: Returns false if headplant is nil or invalid.

movetail(inst, anim)

• Description: Staggered animation trigger for tail segments in a vine chain. Causes each tail to transition to the given animation (anim) over increasing time delays (e.g., 0.1s per segment).
• Parameters:
  • inst (Entity) — vine segment triggering the movement.
  • anim (string) — animation name to play in each tail (e.g., "nub_forward", "nub_reverse").
• Returns: Nothing.

teleportback(inst)

• Description: Recedes the vine chain by one segment: removes the last tail, teleports the current vine to the tail's position and rotation, sets weak state, and transitions to "nub_idle". If no tails remain, removes the vine entirely.
• Parameters: inst (Entity) — current vine segment.
• Returns: Nothing.

teleportahead(inst, pos)

• Description: Extends the vine chain forward by spawning a new child vine at the current location, adjusting the parent's position and rotation based on pos, and linking them visually and functionally.
• Parameters:
  • inst (Entity) — current vine segment.
  • pos (Vector3) — target position for the new vine head.
• Returns: Nothing.

DoToss(inst)

• Description: Clears nearby interactable items (e.g., mines) and launches lightweight inventory items away from the vine upon emerging or spawning.
• Parameters: inst (Entity) — vine segment performing the toss.
• Returns: Nothing.

cancelmovetail(tail)

• Description: Cancels any pending tail movement task previously scheduled for a tail segment.
• Parameters: tail (Entity) — tail segment whose task to cancel.
• Returns: Nothing.

onmovetailtask(inst, tail, anim)

• Description: Callback used by movetail to transition a tail segment into the specified animation once its delay expires.
• Parameters:
  • inst (Entity) — main vine (unused here).
  • tail (Entity) — tail segment to animate.
  • anim (string) — animation name to apply.
• Returns: Nothing.

Events & listeners

• Listens to:

  • "animover" — triggered when animations complete; drives transitions to next states (e.g., idle, spawn, attack).
  • "attacked" — initiates "hit" state if interruptible and not dead; also handles electrocution via CommonHandlers.TryElectrocuteOnAttacked.
  • "doattack" — triggers "attack" (if emerged), "nub_retract" (if nub), or "emerge" states depending on current state.
  • "death" — immediately transitions to "death" state.
  • "moveback" — retracts vine via "retract", "nub_retract", or teleportback.
  • "moveforward" — extends vine via "retract", teleportahead, or "nub_spawn".
  • "emerge" — forces "emerge" state if interruptible and not already emerged.
  • "electrocute" — handled via CommonStates.AddElectrocuteStates, which adds "sync_frozen" and "sync_thaw" states and propagates effects to vine children and parent.

• Pushes:

  • "onextinguish" — via burnable component during "retract" (via Extinguish).
  • "death" — via health component → "death" state transition.
  • "animover" — fired internally by animstate when animations finish.