Variable Font Emoji in Compose

Varimoji.kt

// Download the varimoji font from https://crt-mate.github.io/varimoji/varimojiVF.woff2
// Convert it to TTF and put that under res/font/

@OptIn(ExperimentalTextApi::class)
@Composable
fun VariableFontEmoji() {
    var actv by remember { mutableFloatStateOf(50f) }
    var vlnc by remember { mutableFloatStateOf(50f) }
    Column(
        modifier = Modifier.padding(32.dp),
        horizontalAlignment = Alignment.CenterHorizontally
    ) {
        Text(
            text = "A",
            fontFamily = FontFamily(
                Font(
                    resId = R.font.varimoji,
                    variationSettings = FontVariation.Settings(
                        FontVariation.Setting("ACTV", actv),
                        FontVariation.Setting("VLNC", vlnc),
                    )
                )
            ),
            fontSize = 140.sp
        )
        Spacer(modifier = Modifier.height(32.dp))
        Box(modifier = Modifier
            .fillMaxSize()
            .pointerInput(Unit) {
                awaitEachGesture {
                    do {
                        val event = awaitPointerEvent()
                        event.changes.filter { it.pressed }.forEach {
                            val coercedPosition = Offset(
                                it.position.x.coerceIn(0f, size.width.toFloat()),
                                it.position.y.coerceIn(0f, size.height.toFloat()),
                            )
                            actv = coercedPosition.x / size.width * 100f
                            vlnc = coercedPosition.y / size.height * 100f
                            it.consume()
                        }
                    } while (event.changes.all { it.pressed })
                }
            }
            .drawBehind {
                drawRect(
                    Brush.linearGradient(
                        listOf(Color(0xFFE5E5E5), Color.White),
                        start = Offset(size.width / 2f, size.height / 2f),
                        end = Offset(size.width, 0f)
                    ),
                    topLeft = Offset(size.width / 2f, 0f),
                    size = size / 2f
                )

                drawRect(
                    Brush.linearGradient(
                        listOf(Color(0xFFE5E5E5), Color.White),
                        start = Offset(size.width / 2f, size.height / 2f),
                        end = Offset(0f, size.height)
                    ),
                    topLeft = Offset(0f, size.height / 2f),
                    size = size / 2f
                )

                val point = Offset(actv / 100f * size.width, vlnc / 100f * size.height)
                drawCircle(
                    Brush.radialGradient(
                        listOf(Color.Red.copy(alpha = 0.5f), Color.Transparent),
                        radius = 36.dp.toPx(),
                        center = point
                    ),
                    radius = 36.dp.toPx(),
                    center = point
                )
            }) {
        }
    }
}