Visual Effects
Visual effects are composed from GFFEffectCommon plus a GFFTarget and a GFFTweener.
Registered shortcuts: flash, color, alpha.
Flash
GFFFlashTweener drives a short blink toward flash_color.
CanvasItem bleach (2D / UI)
On CanvasItem trees (including a parent Node2D with a child Sprite2D), flash uses a temporary canvas shader that mixes texture RGB toward flash_color. That means a white flash can turn a sprite fully white — including assets that are already mostly white — which plain modulate multiplication cannot do.
Or build it explicitly:
var flash = GFFEffectCommon.new()
flash.target = GFFColorTarget.new()
flash.tweener = GFFFlashTweener.new()
flash.tweener.flash_color = Color.WHITE
flash.duration = 0.15
GameFeelFlow.play(flash, $Subject)
Non-canvas fallback
For targets that are not CanvasItem, flash falls back to multiplying modulate / color toward flash_color (legacy path). Prefer a tinted flash color there if the mesh/material is already bright.
Color
Tweens modulate (CanvasItem) toward target_color.
var effect = GFFEffectCommon.new()
effect.target = GFFColorTarget.new()
effect.target.target_color = Color(0.35, 0.85, 1.0)
effect.tweener = GFFColorTweener.new()
effect.duration = 0.35
effect.restore_after_play = true
effect.restore_mode = GFFEffect.RestoreMode.GRADUAL
effect.restore_duration = 0.35
GameFeelFlow.play(effect, $Sprite2D)
Alpha
Tweens opacity via GFFAlphaTarget.target_alpha (default registered effect fades toward 0.0 and restores).
Or:
var effect = GFFEffectCommon.new()
effect.target = GFFAlphaTarget.new()
effect.target.target_alpha = 0.0
effect.tweener = GFFLinearTweener.new()
effect.duration = 0.35
effect.restore_after_play = true
effect.restore_mode = GFFEffect.RestoreMode.GRADUAL
GameFeelFlow.play(effect, $Sprite2D)
Parent vs child
Playing on a parent Node2D cascades modulate / alpha to children. Bleach flash installs materials on drawable descendants (Sprite2D, AnimatedSprite2D, TextureRect, …).