Sizetweener

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

Overview

Sizetweener is a component that performs linear interpolation (lerp) between an entity's current scale and a target scale over a specified duration. It integrates with the entity's update loop to gradually adjust the Transform:SetScale() values, enabling smooth size animations. The component notifies listeners via events (sizetweener_start, sizetweener_end) and optionally invokes a user-provided callback upon completion. It is typically added to visual prefabs requiring size-changing effects (e.g., growth, shrinkage, pulsing).

Usage example

local inst = CreateEntity()
inst:AddComponent("sizetweener")

-- Grow the entity over 2 seconds and trigger a callback
inst.components.sizetweener:StartTween(2.0, 2, function(target)
    print("Size tween finished! New scale:", target.Transform:GetScale())
end)

-- Shrink instantly (time = 0)
inst.components.sizetweener:StartTween(0.5, 0)

Dependencies & tags

Components used: None identified
Tags: None identified

Properties

Property	Type	Default Value	Description
i_size	number or nil	nil	Initial scale (x, y, z) at tween start; nil if no active tween.
t_size	number or nil	nil	Target scale (applied uniformly to x, y, z); nil if no active tween.
callback	function or nil	nil	Optional function called when the tween completes.
time	number or nil	nil	Total duration of the tween in seconds; nil if no active tween.
timepassed	number	0	Elapsed time since the tween started.
tweening	boolean	false	Whether a tween is currently in progress.

Main functions

StartTween(size, time, callback)

• Description: Begins a size tween. Sets the i_size to the current scale, stores the target size and time, and starts the update loop if time > 0. Immediately fires the sizetweener_start event.
• Parameters:
  • size (number) — Uniform scale factor applied to x, y, z axes.
  • time (number) — Duration in seconds. If <= 0, the tween completes immediately.
  • callback (function or nil) — Optional function called with self.inst as the sole argument upon completion.
• Returns: Nothing.
• Error states: If time == 0, the tween completes instantly, skips the update loop, and directly calls EndTween().

EndTween()

• Description: Finalizes the tween: stops the update loop, sets the final scale, clears internal state, fires sizetweener_end, and invokes the callback (if any).
• Parameters: None.
• Returns: Nothing.
• Error states: No-op if tweening is false. Does nothing if t_size is nil.

OnUpdate(dt)

• Description: Called automatically by the engine during StartUpdatingComponent (when time > 0). Advances the tween by dt, updates the scale via linear interpolation, and ends the tween if complete.
• Parameters:
  • dt (number) — Delta time since last frame.
• Returns: Nothing.
• Error states: If i_size or t_size is nil, no interpolation occurs (defensive programming; should not happen in normal flow).

Events & listeners

• Listens to: None identified
• Pushes:
  • sizetweener_start — fired when a tween begins (StartTween).
  • sizetweener_end — fired when a tween completes (EndTween).