JavaScript+Canvas实现酷炫的粒子和流星效果
布尔科技技术团队 人气:0一：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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