canvas-multiple-object.kt

val itemsToAnimate = remember {
    mutableStateOf<List<ItemState>>(mutableListOf())
}

val itemsChannel = remember {
    Channel<List<ItemState>>(Channel.UNLIMITED)
}
var job: Job? = remember {
    null
}

LaunchedEffect(true) {
    for (_items in itemsChannel) {
        job?.cancel()
        job = launch {
            withContext(Dispatchers.IO) {
                val items = _items.toMutableList()
                while (true) {
                    delay(10)
                    val iterator = items.iterator()
                    var i = 0
                    while (iterator.hasNext()) {
                        val element = iterator.next() //element is ItemState
                        val elapsedTime = System.nanoTime() - element.startTime
                        items.safeSet(i) { 
                            it.copy(
                                y = element.yAnimation.getValueFromNanos(counter),
                                x = element.xAnimation.getValueFromNanos(counter),
                            )
                        }
                        i++
                    }
                    itemsToAnimate.value = items.toMutableList()
                }
            }
        }
    }
}

/////

data class ItemState(
    val x: Float,
    val y: Float,
    val xAnimation: Animation<Float, AnimationVector1D>,
    val yAnimation: Animation<Float, AnimationVector1D>,
    val startTime: Long,
)