JavaScript+Canvas实现酷炫的粒子和流星效果
作者：布尔科技技术团队
这篇文章主要为大家详细介绍了如何利用JavaScript和Canvas实现酷炫的粒子和流星动画效果，文中的示例代码讲解详细，感兴趣的小伙伴可以跟随小编一起学习一下
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
到此这篇关于JavaScript+Canvas实现酷炫的粒子和流星效果的文章就介绍到这了,更多相关JavaScript粒子流星内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！