Waterplantbrain

Based on game build 714014 | Last updated: 2026-02-27

Overview

The WaterplantBrain component defines the behavior tree logic for water plant entities (e.g., bosses like the Ancient Water Plant). It orchestrates decision-making via a priority-based behavior tree (BT), selecting actions such as emergency cloud spraying, stage-specific attacks, and face-targeting behaviors. This component is attached to entities that have a _stage property and burnable, health, and sleeper components, and it relies heavily on state checks from these dependencies to guide behavior transitions.

Usage example

local inst = CreateEntity()
inst:AddComponent("waterplantbrain")
inst._stage = 3 -- Example: Fully open stage
inst._can_cloud = true

-- The brain automatically begins executing its behavior tree on `OnStart`
inst:DoTaskInTime(0, function() inst.components.waterplantbrain:OnStart() end)

Dependencies & tags

Components used:

• burnable: Calls IsBurning(), IsSmoldering() for emergency cloud logic.
• health: Calls IsDead() to prevent cloud spraying while dead.
• sleeper: Calls IsAsleep() to suppress cloud spraying while asleep.

Tags: This component does not directly add or remove tags. It checks the "notarget" tag on potential targets via target:HasTag("notarget"), but does not manage it.

Properties

Property	Type	Default Value	Description
inst._stage	number	N/A	Current stage of the water plant. Controls whether combat/face behavior is active (stage 3 is fully open).
inst._can_cloud	boolean	N/A	Flag indicating whether the entity is allowed to spawn pollen clouds.

Main functions

WaterPlantBrain:OnStart()

• Description: Initializes and assigns the behavior tree root node. This function must be called after the entity is fully constructed and all required state variables (e.g., _stage, _can_cloud) are set. It builds a prioritized behavior tree to manage in-game decisions.
• Parameters: None.
• Returns: nil.
• Error states: Fails silently if required dependencies (burnable, health, sleeper) are missing — conditional checks inside helper functions (should_emergency_pollen, should_spray_cloud) will return false, effectively disabling cloud spraying. No explicit error handling is present.

GetFaceTargetFn(inst)

• Description: Internal helper function used by FaceEntity behavior to locate the nearest valid target for face alignment.
• Parameters: inst (Entity) — the water plant instance.
• Returns: Entity or nil — the closest player within START_FACE_DIST that does not have the "notarget" tag, or nil if none exist.
• Error states: Returns nil if no players are in range or if all nearby players have the "notarget" tag.

KeepFaceTargetFn(inst, target)

• Description: Internal helper used by FaceEntity to determine if the entity should continue facing a given target.
• Parameters:
  • inst (Entity) — the water plant instance.
  • target (Entity) — the current face target.
• Returns: boolean — true if the target is within KEEP_FACE_DIST and does not have the "notarget" tag; otherwise false.
• Error states: Returns false if target is nil (handled implicitly by target:HasTag(...) returning false on nil in Lua, but in practice target is guaranteed non-nil from GetFaceTargetFn).

should_emergency_pollen(inst)

• Description: Evaluates whether the entity should perform an emergency pollen cloud spray (triggered when burning or smoldering).
• Parameters: inst (Entity) — the water plant instance.
• Returns: boolean — true if _can_cloud is true and either burnable:IsBurning() or burnable:IsSmoldering() returns true; otherwise false.
• Error states: Returns false if burnable component is missing.

should_spray_cloud(inst)

• Description: Evaluates whether a routine pollen cloud spray is allowed (based on sleep/death state and _can_cloud flag).
• Parameters: inst (Entity) — the water plant instance.
• Returns: boolean — true only if _can_cloud is true and neither sleeper:IsAsleep() nor health:IsDead() is true; otherwise false.
• Error states: Returns false if sleeper or health components are missing.

spray_cloud(inst)

• Description: Simple wrapper that fires the "spray_cloud" event on the entity.
• Parameters: inst (Entity) — the water plant instance.
• Returns: nil.
• Error states: None — safe even if no listeners are registered for "spray_cloud".

Events & listeners

• Listens to: None. This component does not register any event listeners via inst:ListenForEvent.
• Pushes: "spray_cloud" — fired via inst:PushEvent("spray_cloud") in both emergency and routine cloud spray logic paths.