Re-write of Shopify's -> Arrive's Confetti in Reanimated v2

confetti.js

import React, { useEffect } from "react";
import Animated, { FadeOut, withDelay, withTiming, useSharedValue, useAnimatedStyle, cancelAnimation } from "react-native-reanimated";
import PropTypes from "prop-types";
import { Dimensions, StyleSheet } from "react-native";
import FastImage from "react-native-fast-image";
import ConfettiImage from "../../../assets/img/confetti.png";

const NUM_CONFETTI = 100;
const COLORS = ["#31ECBC", "#E0DAFE", "#6345F9"];
const CONFETTI_SIZE = 16;

const { width: screenWidth, height: screenHeight } = Dimensions.get("window");

const styles = StyleSheet.create({
  confettiContainer: {
    position: "absolute",
    top: 0,
    left: 0,
  },
  confetti: {
    width: CONFETTI_SIZE,
    height: CONFETTI_SIZE,
  },
});

const ConfettiPiece = ({ x, y, xVel, angle, delay, yVel, angleVel, color, elasticity }) => {
  const clock = useSharedValue(0);
  const duration = useSharedValue(getDuration());
  const localX = useSharedValue(x);
  const localY = useSharedValue(y);
  const localXVel = useSharedValue(xVel);
  const localAngle = useSharedValue(angle);
  const timeDiff = useSharedValue(0);
  const dt = useSharedValue(0);
  const dy = useSharedValue(0);
  const dx = useSharedValue(0);
  const dAngle = useSharedValue(0);

  function getDuration() {
    // Adding an extra 100 to the screen's height to ensure it goes off the screen.
    // Then using time = distance / speed for the time calc.
    let a = screenHeight + 100;
    return (a / yVel) * 1000;
  }

  useEffect(() => {
    // delay is multiplied by 1000 to convert into milliseconds
    clock.value = withDelay(delay * 1000, withTiming(1, { duration: duration.value }));
    return () => {
      cancelAnimation(clock);
    };
  });

  const uas = useAnimatedStyle(() => {
    // Because our clock.value is going from 0 to 1, it's value will let us
    // get the actual number of milliseconds by taking it multiplied by the
    // total duration of the animation.
    timeDiff.value = clock.value * duration.value;
    dt.value = timeDiff.value / 1000;

    dy.value = dt.value * yVel;
    dx.value = dt.value * localXVel.value;
    dAngle.value = dt.value * angleVel;
    localY.value = y + dy.value;
    localX.value = x + dx.value;
    localAngle.value += dAngle.value;

    if (localX.value > screenWidth - CONFETTI_SIZE) {
      localX.value = screenWidth - CONFETTI_SIZE;
      localXVel.value = localXVel.value * -1 * elasticity;
    }

    if (localX.value < 0) {
      localX.value = 0;
      localXVel.value = xVel.value * -1 * elasticity;
    }

    return {
      transform: [{ translateX: localX.value }, { translateY: localY.value }, { rotate: localAngle.value + "deg" }, { rotateX: localAngle.value + "deg" }, { rotateY: localAngle.value + "deg" }],
    };
  });

  return (
    <Animated.View style={[styles.confettiContainer, uas]}>
      <FastImage source={ConfettiImage} tintColor={color} style={styles.confetti} />
    </Animated.View>
  );
};

const Confetti = ({ run }) => {
  const confetti = [...new Array(NUM_CONFETTI)].map((_, index) => {
    // For 'x', spawn confetti from two different sources, a quarter
    // from the left and a quarter from the right edge of the screen.
    return {
      key: index,
      x: screenWidth * (index % 2 ? 0.25 : 0.75) - CONFETTI_SIZE / 2,
      y: -60,
      angle: 0,
      xVel: Math.random() * 400 - 200,
      yVel: Math.random() * 165 + 165,
      angleVel: (Math.random() * 3 - 1.5) * Math.PI,
      delay: Math.floor(index / 10) * 0.5,
      elasticity: Math.random() * 0.3 + 0.1,
      color: COLORS[index % COLORS.length],
    };
  });
  return run ? (
    <Animated.View pointerEvents="none" style={StyleSheet.absoluteFill} exiting={FadeOut.duration(500)}>
      {confetti.map((e) => {
        return <ConfettiPiece key={e.key} {...e} />;
      })}
    </Animated.View>
  ) : null;
};

Confetti.propTypes = {
  run: PropTypes.bool,
};

export default Confetti;

confetti.png

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[email protected]

awesomenesss. Thanks man @imcrainjames

Hi, how can i detect when confetti finish? THanks