网页点击烟火特效(JS实现)

发布于 2018-10-19  556 次阅读


<script type="text/javascript" src="https://cdn.bootcss.com/animejs/2.2.0/anime.min.js"></script>
<canvas class="fireworks" style="position:fixed;left:0;top:0;z-index:99999999;pointer-events:none;"></canvas>
<script type="text/javascript" src="/fireworks.js"></script> 

fireworks.js

function updateCoords(e) {
    pointerX = (e.clientX || e.touches[0].clientX) - canvasEl.getBoundingClientRect

().left,
    pointerY = e.clientY || e.touches[0].clientY - canvasEl.getBoundingClientRect().top
}
function setParticuleDirection(e) {
    var t = anime.random(0, 360) * Math.PI / 180
      , a = anime.random(50, 180)
      , n = [-1, 1][anime.random(0, 1)] * a;
    return {
        x: e.x + n * Math.cos(t),
        y: e.y + n * Math.sin(t)
    }
}
function createParticule(e, t) {
    var a = {};
    return a.x = e,
    a.y = t,
    a.color = colors[anime.random(0, colors.length - 1)],
    a.radius = anime.random(16, 32),
    a.endPos = setParticuleDirection(a),
    a.draw = function() {
        ctx.beginPath(),
        ctx.arc(a.x, a.y, a.radius, 0, 2 * Math.PI, !0),
        ctx.fillStyle = a.color,
        ctx.fill()
    }
    ,
    a
}
function createCircle(e, t) {
    var a = {};
    return a.x = e,
    a.y = t,
    a.color = "#F00",
    a.radius = .1,
    a.alpha = .5,
    a.lineWidth = 6,
    a.draw = function() {
        ctx.globalAlpha = a.alpha,
        ctx.beginPath(),
        ctx.arc(a.x, a.y, a.radius, 0, 2 * Math.PI, !0),
        ctx.lineWidth = a.lineWidth,
        ctx.strokeStyle = a.color,
        ctx.stroke(),
        ctx.globalAlpha = 1
    }
    ,
    a
}
function renderParticule(e) {
    for (var t = 0; t < e.animatables.length; t++)
        e.animatables[t].target.draw()
}
function animateParticules(e, t) {
    for (var a = createCircle(e, t), n = [], i = 0; i < numberOfParticules; i++)
        n.push(createParticule(e, t));
    anime.timeline().add({
        targets: n,
        x: function(e) {
            return e.endPos.x
        },
        y: function(e) {
            return e.endPos.y
        },
        radius: .1,
        duration: anime.random(1200, 1800),
        easing: "easeOutExpo",
        update: renderParticule
    }).add({
        targets: a,
        radius: anime.random(80, 160),
        lineWidth: 0,
        alpha: {
            value: 0,
            easing: "linear",
            duration: anime.random(600, 800)
        },
        duration: anime.random(1200, 1800),
        easing: "easeOutExpo",
        update: renderParticule,
        offset: 0
    })
}
function debounce(fn, delay) {
  var timer
  return function () {
    var context = this
    var args = arguments
    clearTimeout(timer)
    timer = setTimeout(function () {
      fn.apply(context, args)
    }, delay)
  }
}

var canvasEl = document.querySelector(".fireworks");
if (canvasEl) {
    var ctx = canvasEl.getContext("2d")
      , numberOfParticules = 30
      , pointerX = 0
      , pointerY = 0
      , tap = "mousedown"
      , colors = ["#FF1461", "#18FF92", "#5A87FF", "#FBF38C"]
      , setCanvasSize = debounce(function() {
        canvasEl.width = 2 * window.innerWidth,
        canvasEl.height = 2 * window.innerHeight,
        canvasEl.style.width = window.innerWidth + "px",
        canvasEl.style.height = window.innerHeight + "px",
        canvasEl.getContext("2d").scale(2, 2)
    },500)
      , render = anime({
        duration: 1 / 0,
        update: function() {
            ctx.clearRect(0, 0, canvasEl.width, canvasEl.height)
        }
    });
    document.addEventListener(tap, function(e) {
        "sidebar" !== e.target.id && "toggle-sidebar" !== e.target.id && "A" !== 

e.target.nodeName && "IMG" !== e.target.nodeName && (render.play(),
        updateCoords(e),
        animateParticules(pointerX, pointerY))
    }, !1),
    setCanvasSize(),
    window.addEventListener("resize", setCanvasSize, !1)
}

 


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