JavaScript+Canvas实现酷炫的粒子和流星效果
目录
- 一:粒子效果
- 二:流星效果
一:粒子效果
<html> <head> <meta charset="utf-8"> <title>www.husonghe.com</title> <style> html { height: 100%; background-image: -webkit-radial-gradient(ellipse farthest-corner at center center, #1b44e4 0%, #020f3a 100%); background-image: radial-gradient(ellipse farthest-corner at center center, #1b44e4 0%, #020f3a 100%); cursor: move; } body { width: 100%; margin: 0; overflow: hidden; } </style> </head> <body> <canvas id="canv" width="1920" height="572"></canvas> <script> var num = 200; var w = window.innerWidth; var h = window.innerHeight; var max = 100; var _x = 0; var _y = 0; var _z = 150; var dtr = function (d) { return d * Math.PI / 180; }; var rnd = function () { return Math.sin(Math.floor(Math.random() * 360) * Math.PI / 180); }; var dist = function (p1, p2, p3) { return Math.sqrt(Math.pow(p2.x - p1.x, 2) + Math.pow(p2.y - p1.y, 2) + Math.pow(p2.z - p1.z, 2)); }; var cam = { obj: { x: _x, y: _y, z: _z }, dest: { x: 0, y: 0, z: 1 }, dist: { x: 0, y: 0, z: 200 }, ang: { cplane: 0, splane: 0, ctheta: 0, stheta: 0 }, zoom: 1, disp: { x: w / 2, y: h / 2, z: 0 }, upd: function () { cam.dist.x = cam.dest.x - cam.obj.x; cam.dist.y = cam.dest.y - cam.obj.y; cam.dist.z = cam.dest.z - cam.obj.z; cam.ang.cplane = -cam.dist.z / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z); cam.ang.splane = cam.dist.x / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z); cam.ang.ctheta = Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z) / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.y * cam.dist.y + cam.dist.z * cam.dist.z); cam.ang.stheta = -cam.dist.y / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.y * cam.dist.y + cam.dist.z * cam.dist.z); } }; var trans = { parts: { sz: function (p, sz) { return { x: p.x * sz.x, y: p.y * sz.y, z: p.z * sz.z }; }, rot: { x: function (p, rot) { return { x: p.x, y: p.y * Math.cos(dtr(rot.x)) - p.z * Math.sin(dtr(rot.x)), z: p.y * Math.sin(dtr(rot.x)) + p.z * Math.cos(dtr(rot.x)) }; }, y: function (p, rot) { return { x: p.x * Math.cos(dtr(rot.y)) + p.z * Math.sin(dtr(rot.y)), y: p.y, z: -p.x * Math.sin(dtr(rot.y)) + p.z * Math.cos(dtr(rot.y)) }; }, z: function (p, rot) { return { x: p.x * Math.cos(dtr(rot.z)) - p.y * Math.sin(dtr(rot.z)), y: p.x * Math.sin(dtr(rot.z)) + p.y * Math.cos(dtr(rot.z)), z: p.z }; } }, pos: function (p, pos) { return { x: p.x + pos.x, y: p.y + pos.y, z: p.z + pos.z }; } }, pov: { plane: function (p) { return { x: p.x * cam.ang.cplane + p.z * cam.ang.splane, y: p.y, z: p.x * -cam.ang.splane + p.z * cam.ang.cplane }; }, theta: function (p) { return { x: p.x, y: p.y * cam.ang.ctheta - p.z * cam.ang.stheta, z: p.y * cam.ang.stheta + p.z * cam.ang.ctheta }; }, set: function (p) { return { x: p.x - cam.obj.x, y: p.y - cam.obj.y, z: p.z - cam.obj.z }; } }, persp: function (p) { return { x: p.x * cam.dist.z / p.z * cam.zoom, y: p.y * cam.dist.z / p.z * cam.zoom, z: p.z * cam.zoom, p: cam.dist.z / p.z }; }, disp: function (p, disp) { return { x: p.x + disp.x, y: -p.y + disp.y, z: p.z + disp.z, p: p.p }; }, steps: function (_obj_, sz, rot, pos, disp) { var _args = trans.parts.sz(_obj_, sz); _args = trans.parts.rot.x(_args, rot); _args = trans.parts.rot.y(_args, rot); _args = trans.parts.rot.z(_args, rot); _args = trans.parts.pos(_args, pos); _args = trans.pov.plane(_args); _args = trans.pov.theta(_args); _args = trans.pov.set(_args); _args = trans.persp(_args); _args = trans.disp(_args, disp); return _args; } }; (function () { "use strict"; var threeD = function (param) { this.transIn = {}; this.transOut = {}; this.transIn.vtx = (param.vtx); this.transIn.sz = (param.sz); this.transIn.rot = (param.rot); this.transIn.pos = (param.pos); }; threeD.prototype.vupd = function () { this.transOut = trans.steps( this.transIn.vtx, this.transIn.sz, this.transIn.rot, this.transIn.pos, cam.disp ); }; var Build = function () { this.vel = 0.04; this.lim = 360; this.diff = 200; this.initPos = 100; this.toX = _x; this.toY = _y; this.go(); }; Build.prototype.go = function () { this.canvas = document.getElementById("canv"); this.canvas.width = window.innerWidth; this.canvas.height = window.innerHeight; this.$ = canv.getContext("2d"); this.$.globalCompositeOperation = 'source-over'; this.varr = []; this.dist = []; this.calc = []; for (var i = 0, len = num; i < len; i++) { this.add(); } this.rotObj = { x: 0, y: 0, z: 0 }; this.objSz = { x: w / 5, y: h / 5, z: w / 5 }; }; Build.prototype.add = function () { this.varr.push(new threeD({ vtx: { x: rnd(), y: rnd(), z: rnd() }, sz: { x: 0, y: 0, z: 0 }, rot: { x: 20, y: -20, z: 0 }, pos: { x: this.diff * Math.sin(360 * Math.random() * Math.PI / 180), y: this.diff * Math.sin(360 * Math.random() * Math.PI / 180), z: this.diff * Math.sin(360 * Math.random() * Math.PI / 180) } })); this.calc.push({ x: 360 * Math.random(), y: 360 * Math.random(), z: 360 * Math.random() }); }; Build.prototype.upd = function () { cam.obj.x += (this.toX - cam.obj.x) * 0.05; cam.obj.y += (this.toY - cam.obj.y) * 0.05; }; Build.prototype.draw = function () { this.$.clearRect(0, 0, this.canvas.width, this.canvas.height); cam.upd(); this.rotObj.x += 0.1; this.rotObj.y += 0.1; this.rotObj.z += 0.1; for (var i = 0; i < this.varr.length; i++) { for (var val in this.calc[i]) { if (this.calc[i].hasOwnProperty(val)) { this.calc[i][val] += this.vel; if (this.calc[i][val] > this.lim) this.calc[i][val] = 0; } } this.varr[i].transIn.pos = { x: this.diff * Math.cos(this.calc[i].x * Math.PI / 180), y: this.diff * Math.sin(this.calc[i].y * Math.PI / 180), z: this.diff * Math.sin(this.calc[i].z * Math.PI / 180) }; this.varr[i].transIn.rot = this.rotObj; this.varr[i].transIn.sz = this.objSz; this.varr[i].vupd(); if (this.varr[i].transOut.p < 0) continue; var g = this.$.createRadialGradient(this.varr[i].transOut.x, this.varr[i].transOut.y, this.varr[i].transOut.p, this.varr[i].transOut.x, this.varr[i].transOut.y, this.varr[i].transOut.p * 2); this.$.globalCompositeOperation = 'lighter'; g.addColorStop(0, 'hsla(255, 255%, 255%, 1)'); g.addColorStop(.5, 'hsla(' + (i + 2) + ',85%, 40%,1)'); g.addColorStop(1, 'hsla(' + (i) + ',85%, 40%,.5)'); this.$.fillStyle = g; this.$.beginPath(); this.$.arc(this.varr[i].transOut.x, this.varr[i].transOut.y, this.varr[i].transOut.p * 2, 0, Math.PI * 2, false); this.$.fill(); this.$.closePath(); } }; Build.prototype.anim = function () { window.requestAnimationFrame = (function () { return window.requestAnimationFrame || function (callback, element) { window.setTimeout(callback, 1000 / 60); }; })(); var anim = function () { this.upd(); this.draw(); window.requestAnimationFrame(anim); }.bind(this); window.requestAnimationFrame(anim); }; Build.prototype.run = function () { this.anim(); window.addEventListener('mousemove', function (e) { this.toX = (e.clientX - this.canvas.width / 2) * -0.8; this.toY = (e.clientY - this.canvas.height / 2) * 0.8; }.bind(this)); window.addEventListener('touchmove', function (e) { e.preventDefault(); this.toX = (e.touches[0].clientX - this.canvas.width / 2) * -0.8; this.toY = (e.touches[0].clientY - this.canvas.height / 2) * 0.8; }.bind(this)); window.addEventListener('mousedown', function (e) { for (var i = 0; i < 100; i++) { this.add(); } }.bind(this)); window.addEventListener('touchstart', function (e) { e.preventDefault(); for (var i = 0; i < 100; i++) { this.add(); } }.bind(this)); }; var app = new Build(); app.run(); })(); window.addEventListener('resize', function () { canvas.width = w = window.innerWidth; canvas.height = h = window.innerHeight; }, false); </script> </body> </html>
效果图
二:流星效果
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>一起来看流星雨</title> </head> <style type="text/css"> body { background-color: black; } body, html { width: 100%; height: 100%; overflow: hidden; } </style> <body> <canvas id="stars"></canvas> </body> </html> <script> var context; var arr = new Array(); var starCount = 800; var rains = new Array(); var rainCount = 20; //初始化画布及context function init() { //获取canvas var stars = document.getElementById("stars"); windowWidth = window.innerWidth; //当前的窗口的高度 stars.width = windowWidth; stars.height = window.innerHeight; //获取context context = stars.getContext("2d"); } //创建一个星星对象 var Star = function () { this.x = windowWidth * Math.random();//横坐标 this.y = 5000 * Math.random();//纵坐标 this.text = ".";//文本 this.color = "white";//颜色 //产生随机颜色 this.getColor = function () { var _r = Math.random(); if (_r < 0.5) { this.color = "#333"; } else { this.color = "white"; } } //初始化 this.init = function () { this.getColor(); } //绘制 this.draw = function () { context.fillStyle = this.color; context.fillText(this.text, this.x, this.y); } } //画月亮 function drawMoon() { var moon = new Image(); moon.src = "./images/moon.jpg" context.drawImage(moon, -5, -10); } //页面加载的时候 window.onload = function () { init(); //画星星 for (var i = 0; i < starCount; i++) { var star = new Star(); star.init(); star.draw(); arr.push(star); } //画流星 for (var i = 0; i < rainCount; i++) { var rain = new MeteorRain(); rain.init(); rain.draw(); rains.push(rain); } drawMoon();//绘制月亮 playStars();//绘制闪动的星星 playRains();//绘制流星 } //星星闪起来 function playStars() { for (var n = 0; n < starCount; n++) { arr[n].getColor(); arr[n].draw(); } setTimeout("playStars()", 100); } /*流星雨开始*/ var MeteorRain = function () { this.x = -1; this.y = -1; this.length = -1;//长度 this.angle = 30; //倾斜角度 this.width = -1;//宽度 this.height = -1;//高度 this.speed = 1;//速度 this.offset_x = -1;//横轴移动偏移量 this.offset_y = -1;//纵轴移动偏移量 this.alpha = 1; //透明度 this.color1 = "";//流星的色彩 this.color2 = ""; //流星的色彩 /****************初始化函数********************/ this.init = function () //初始化 { this.getPos(); this.alpha = 1;//透明度 this.getRandomColor(); //最小长度,最大长度 var x = Math.random() * 80 + 150; this.length = Math.ceil(x); // x = Math.random()*10+30; this.angle = 30; //流星倾斜角 x = Math.random() + 0.5; this.speed = Math.ceil(x); //流星的速度 var cos = Math.cos(this.angle * 3.14 / 180); var sin = Math.sin(this.angle * 3.14 / 180); this.width = this.length * cos; //流星所占宽度 this.height = this.length * sin;//流星所占高度 this.offset_x = this.speed * cos; this.offset_y = this.speed * sin; } /**************获取随机颜色函数*****************/ this.getRandomColor = function () { var a = Math.ceil(255 - 240 * Math.random()); //中段颜色 this.color1 = "rgba(" + a + "," + a + "," + a + ",1)"; //结束颜色 this.color2 = "black"; } /***************重新计算流星坐标的函数******************/ this.countPos = function ()// { //往左下移动,x减少,y增加 this.x = this.x - this.offset_x; this.y = this.y + this.offset_y; } /*****************获取随机坐标的函数*****************/ this.getPos = function () // { //横坐标200--1200 this.x = Math.random() * window.innerWidth; //窗口高度 //纵坐标小于600 this.y = Math.random() * window.innerHeight; //窗口宽度 } /****绘制流星***************************/ this.draw = function () //绘制一个流星的函数 { context.save(); context.beginPath(); context.lineWidth = 1; //宽度 context.globalAlpha = this.alpha; //设置透明度 //创建横向渐变颜色,起点坐标至终点坐标 var line = context.createLinearGradient(this.x, this.y, this.x + this.width, this.y - this.height); //分段设置颜色 line.addColorStop(0, "white"); line.addColorStop(0.3, this.color1); line.addColorStop(0.6, this.color2); context.strokeStyle = line; //起点 context.moveTo(this.x, this.y); //终点 context.lineTo(this.x + this.width, this.y - this.height); context.closePath(); context.stroke(); context.restore(); } this.move = function () { //清空流星像素 var x = this.x + this.width - this.offset_x; var y = this.y - this.height; context.clearRect(x - 3, y - 3, this.offset_x + 5, this.offset_y + 5); // context.strokeStyle="red"; // context.strokeRect(x,y-1,this.offset_x+1,this.offset_y+1); //重新计算位置,往左下移动 this.countPos(); //透明度增加 this.alpha -= 0.002; //重绘 this.draw(); } } //绘制流星 function playRains() { for (var n = 0; n < rainCount; n++) { var rain = rains[n]; rain.move();//移动 if (rain.y > window.innerHeight) {//超出界限后重来 context.clearRect(rain.x, rain.y - rain.height, rain.width, rain.height); rains[n] = new MeteorRain(); rains[n].init(); } } setTimeout("playRains()", 2); } /*流星雨结束*/ </script>
效果图
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