imgfireworks.js

/**
 * 基于 Canvas 的鼠标点击效果
 * 出处不明
 * https://cdn.jsdelivr.net/npm/animejs@2.2.0/anime.min.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)
}