Animation Events

Sprites emit gfx.ChangeTag when their animation tag changes. Events are emitted to the entity's address in the world's event system.

Available Events

Event	When It Fires
gfx.ChangeTag	When the animation tag changes via setTag()

ChangeTag Event

ChangeTag fires when setTag() is called, including the initial tag set during spawn.

Event Properties

Property	Type	Description
entity	integer	The entity ID
oldTag	string	Previous animation tag (empty on first load)
newTag	string	New animation tag
anim	Sprite	Reference to the Sprite component

Examples

world:observe(entityId, gfx.ChangeTag, function(event)
    print("Entity", event.entity, "changed from", event.oldTag, "to", event.newTag)
end)

world:observe(entityId, gfx.ChangeTag, function(event)
    if event.newTag == "death" then
        world:remove(entityId, PlayerController)
    end
end)

local sounds = {
    walk = love.audio.newSource("sounds/footsteps.ogg", "static"),
    attack = love.audio.newSource("sounds/sword.ogg", "static"),
}

world:observe(entityId, gfx.ChangeTag, function(event)
    local sound = sounds[event.newTag]
    if sound then
        sound:stop()
        sound:play()
    end
end)

Event Lifetimes

Direct constructors such as gfx.ChangeTag(...) allocate a fresh event instance. Internal sprite code uses world:emit(entityId, gfx.ChangeTag, ...), which reuses world-local storage and should be treated as callback-local. Do not store references to event objects received from observers.

local lastTag = ""

world:observe(entityId, gfx.ChangeTag, function(event)
    lastTag = event.newTag
end)