124 lines
2.6 KiB
JavaScript
124 lines
2.6 KiB
JavaScript
/**
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* 顶部header
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*/
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import Vue from 'vue'
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Vue.component("background-video", {
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template: `
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<canvas id="canvas"></canvas>
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`,
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props: {
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url:{
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type:String
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}
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},
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data() {
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return {
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}
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},
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mounted(){
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var canvas = document.getElementById('canvas'),
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ctx = canvas.getContext('2d'),
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w = canvas.width = window.innerWidth,
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h = canvas.height = window.innerHeight,
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hue = 217,
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stars = [],
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count = 0,
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maxStars = 1200;
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var canvas2 = document.createElement('canvas'),
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ctx2 = canvas2.getContext('2d');
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canvas2.width = 100;
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canvas2.height = 100;
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var half = canvas2.width / 2,
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gradient2 = ctx2.createRadialGradient(half, half, 0, half, half, half);
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gradient2.addColorStop(0.025, '#fff');
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gradient2.addColorStop(0.1, 'hsl(' + hue + ', 61%, 33%)');
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gradient2.addColorStop(0.25, 'hsl(' + hue + ', 64%, 6%)');
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gradient2.addColorStop(1, 'transparent');
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ctx2.fillStyle = gradient2;
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ctx2.beginPath();
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ctx2.arc(half, half, half, 0, Math.PI * 2);
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ctx2.fill();
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// End cache
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function random(min, max) {
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if (arguments.length < 2) {
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max = min;
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min = 0;
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}
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if (min > max) {
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var hold = max;
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max = min;
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min = hold;
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}
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return Math.floor(Math.random() * (max - min + 1)) + min;
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}
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function maxOrbit(x, y) {
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var max = Math.max(x, y),
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diameter = Math.round(Math.sqrt(max * max + max * max));
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return diameter / 2;
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}
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var Star = function() {
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this.orbitRadius = random(maxOrbit(w, h));
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this.radius = random(60, this.orbitRadius) / 5;
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this.orbitX = w / 2;
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this.orbitY = h / 2;
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this.timePassed = random(0, maxStars);
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this.speed = random(this.orbitRadius) / 900000;
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this.alpha = random(2, 10) / 10;
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count++;
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stars[count] = this;
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}
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Star.prototype.draw = function() {
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var x = Math.sin(this.timePassed) * this.orbitRadius + this.orbitX,
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y = Math.cos(this.timePassed) * this.orbitRadius + this.orbitY,
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twinkle = random(10);
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if (twinkle === 1 && this.alpha > 0) {
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this.alpha -= 0.05;
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} else if (twinkle === 2 && this.alpha < 1) {
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this.alpha += 0.05;
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}
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ctx.globalAlpha = this.alpha;
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ctx.drawImage(canvas2, x - this.radius / 2, y - this.radius / 2, this.radius, this.radius);
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this.timePassed += this.speed;
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}
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for (var i = 0; i < maxStars; i++) {
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new Star();
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}
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function animation() {
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ctx.globalCompositeOperation = 'source-over';
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ctx.globalAlpha = 0.8;
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ctx.fillStyle = 'hsla(' + hue + ', 64%, 6%, 1)';
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ctx.fillRect(0, 0, w, h)
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ctx.globalCompositeOperation = 'lighter';
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for (var i = 1, l = stars.length; i < l; i++) {
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stars[i].draw();
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};
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window.requestAnimationFrame(animation);
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}
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animation();
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},
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methods: {
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}
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})
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