confetti.js

// Confetti.js - downloaded from https://www.cssscript.com/confetti-falling-animation/

var confetti = {
  maxCount: 100, //set max confetti count
  speed: 5, //set the particle animation speed
  frameInterval: 15, //the confetti animation frame interval in milliseconds
  alpha: 1.0, //the alpha opacity of the confetti (between 0 and 1, where 1 is opaque and 0 is invisible)
  gradient: false, //whether to use gradients for the confetti particles
  start: null, //call to start confetti animation (with optional timeout in milliseconds, and optional min and max random confetti count)
  stop: null, //call to stop adding confetti
  toggle: null, //call to start or stop the confetti animation depending on whether it's already running
  pause: null, //call to freeze confetti animation
  resume: null, //call to unfreeze confetti animation
  togglePause: null, //call to toggle whether the confetti animation is paused
  remove: null, //call to stop the confetti animation and remove all confetti immediately
  isPaused: null, //call and returns true or false depending on whether the confetti animation is paused
  isRunning: null, //call and returns true or false depending on whether the animation is running
};

confetti.start = startConfetti;
confetti.stop = stopConfetti;
confetti.toggle = toggleConfetti;
confetti.pause = pauseConfetti;
confetti.resume = resumeConfetti;
confetti.togglePause = toggleConfettiPause;
confetti.isPaused = isConfettiPaused;
confetti.remove = removeConfetti;
confetti.isRunning = isConfettiRunning;
var supportsAnimationFrame =
  window.requestAnimationFrame ||
  window.webkitRequestAnimationFrame ||
  window.mozRequestAnimationFrame ||
  window.oRequestAnimationFrame ||
  window.msRequestAnimationFrame;
var colors = [
  "rgba(30,144,255,",
  "rgba(107,142,35,",
  "rgba(255,215,0,",
  "rgba(255,192,203,",
  "rgba(106,90,205,",
  "rgba(173,216,230,",
  "rgba(238,130,238,",
  "rgba(152,251,152,",
  "rgba(70,130,180,",
  "rgba(244,164,96,",
  "rgba(210,105,30,",
  "rgba(220,20,60,",
];
var streamingConfetti = false;
var animationTimer = null;
var pause = false;
var lastFrameTime = Date.now();
var particles = [];
var waveAngle = 0;
var context = null;

function resetParticle(particle, width, height) {
  particle.color =
    colors[(Math.random() * colors.length) | 0] + (confetti.alpha + ")");
  particle.color2 =
    colors[(Math.random() * colors.length) | 0] + (confetti.alpha + ")");
  particle.x = Math.random() * width;
  particle.y = Math.random() * height - height;
  particle.diameter = Math.random() * 10 + 5;
  particle.tilt = Math.random() * 10 - 10;
  particle.tiltAngleIncrement = Math.random() * 0.07 + 0.05;
  particle.tiltAngle = Math.random() * Math.PI;
  return particle;
}

function toggleConfettiPause() {
  if (pause) resumeConfetti();
  else pauseConfetti();
}

function isConfettiPaused() {
  return pause;
}

function pauseConfetti() {
  pause = true;
}

function resumeConfetti() {
  pause = false;
  runAnimation();
}

function runAnimation() {
  if (pause) return;
  else if (particles.length === 0) {
    context.clearRect(0, 0, window.innerWidth, window.innerHeight);
    animationTimer = null;
  } else {
    var now = Date.now();
    var delta = now - lastFrameTime;
    if (!supportsAnimationFrame || delta > confetti.frameInterval) {
      context.clearRect(0, 0, window.innerWidth, window.innerHeight);
      updateParticles();
      drawParticles(context);
      lastFrameTime = now - (delta % confetti.frameInterval);
    }
    animationTimer = requestAnimationFrame(runAnimation);
  }
}

function startConfetti(timeout, min, max) {
  var width = window.innerWidth;
  var height = window.innerHeight;
  window.requestAnimationFrame = (function () {
    return (
      window.requestAnimationFrame ||
      window.webkitRequestAnimationFrame ||
      window.mozRequestAnimationFrame ||
      window.oRequestAnimationFrame ||
      window.msRequestAnimationFrame ||
      function (callback) {
        return window.setTimeout(callback, confetti.frameInterval);
      }
    );
  })();
  var canvas = document.getElementById("confetti-canvas");
  if (canvas === null) {
    canvas = document.createElement("canvas");
    canvas.setAttribute("id", "confetti-canvas");
    canvas.setAttribute(
      "style",
      "display:block;z-index:999999;pointer-events:none;position:fixed;top:0"
    );
    document.body.prepend(canvas);
    canvas.width = width;
    canvas.height = height;
    window.addEventListener(
      "resize",
      function () {
        canvas.width = window.innerWidth;
        canvas.height = window.innerHeight;
      },
      true
    );
    context = canvas.getContext("2d");
  } else if (context === null) context = canvas.getContext("2d");
  var count = confetti.maxCount;
  if (min) {
    if (max) {
      if (min == max) count = particles.length + max;
      else {
        if (min > max) {
          var temp = min;
          min = max;
          max = temp;
        }
        count = particles.length + ((Math.random() * (max - min) + min) | 0);
      }
    } else count = particles.length + min;
  } else if (max) count = particles.length + max;
  while (particles.length < count)
    particles.push(resetParticle({}, width, height));
  streamingConfetti = true;
  pause = false;
  runAnimation();
  if (timeout) {
    window.setTimeout(stopConfetti, timeout);
  }
}

function stopConfetti() {
  streamingConfetti = false;
}

function removeConfetti() {
  stop();
  pause = false;
  particles = [];
}

function toggleConfetti() {
  if (streamingConfetti) stopConfetti();
  else startConfetti();
}

function isConfettiRunning() {
  return streamingConfetti;
}

function drawParticles(context) {
  var particle;
  var x, y, x2, y2;
  for (var i = 0; i < particles.length; i++) {
    particle = particles[i];
    context.beginPath();
    context.lineWidth = particle.diameter;
    x2 = particle.x + particle.tilt;
    x = x2 + particle.diameter / 2;
    y2 = particle.y + particle.tilt + particle.diameter / 2;
    if (confetti.gradient) {
      var gradient = context.createLinearGradient(x, particle.y, x2, y2);
      gradient.addColorStop("0", particle.color);
      gradient.addColorStop("1.0", particle.color2);
      context.strokeStyle = gradient;
    } else context.strokeStyle = particle.color;
    context.moveTo(x, particle.y);
    context.lineTo(x2, y2);
    context.stroke();
  }
}

function updateParticles() {
  var width = window.innerWidth;
  var height = window.innerHeight;
  var particle;
  waveAngle += 0.01;
  for (var i = 0; i < particles.length; i++) {
    particle = particles[i];
    if (!streamingConfetti && particle.y < -15) particle.y = height + 100;
    else {
      particle.tiltAngle += particle.tiltAngleIncrement;
      particle.x += Math.sin(waveAngle) - 0.5;
      particle.y +=
        (Math.cos(waveAngle) + particle.diameter + confetti.speed) * 0.5;
      particle.tilt = Math.sin(particle.tiltAngle) * 15;
    }
    if (particle.x > width + 20 || particle.x < -20 || particle.y > height) {
      if (streamingConfetti && particles.length <= confetti.maxCount)
        resetParticle(particle, width, height);
      else {
        particles.splice(i, 1);
        i--;
      }
    }
  }
}

export { startConfetti, stopConfetti, removeConfetti };