Healthtrigger

Overview

The HealthTrigger component monitors changes in an entity's health percentage and executes registered callback functions when the health crosses predefined threshold values. It is typically attached to entities (e.g., players, creatures) that have a health component and enables event-driven logic based on health milestones (e.g., when health drops below 25%).

Dependencies & Tags

• Component Dependency: Requires the health component to be present on the same entity (inst.components.health), as it relies on the healthdelta event emitted by the health component.
• Tags: None identified.

Properties

Property	Type	Default Value	Description
inst	Entity	nil	Reference to the entity the component is attached to.
triggers	table	{}	A dictionary mapping health percentages (thresholds, as floats between 0.0 and 1.0) to callback functions.

Main Functions

AddTrigger(amount, fn)

• Description: Registers a callback function (fn) to be invoked when the entity's health percentage crosses the specified amount threshold (e.g., 0.25 for 25% health). Thresholds are interpreted as fractions of max health (0.0 = dead, 1.0 = full health).
• Parameters:
  • amount (number): A float in the range [0.0, 1.0] representing the health percentage threshold.
  • fn (function): A callback function that accepts the entity instance (inst) as its only argument.

OnHealthDelta(data)

• Description: Internal handler called when the entity's health changes. Evaluates registered thresholds against the old and new health percentages and triggers callbacks in the correct order (descending for health loss, ascending for health gain).
• Parameters:
  • data (table): Event payload from the healthdelta event, expected to contain oldpercent and newpercent fields (floats between 0.0 and 1.0).

OnRemoveFromEntity()

• Description: Cleans up event listeners when the component is removed from the entity.
• Parameters: None.

Events & Listeners

• Listens to "healthdelta" events on self.inst, triggering OnHealthDelta.
• Removes the "healthdelta" callback during OnRemoveFromEntity().