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canvas粒子效果

canvas粒子效果

作者: adtk | 来源:发表于2017-06-09 17:32 被阅读0次
    image.png image.png
    <!DOCTYPE html>
    <html lang="en">
    
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>Document</title>
        <style>
            *{margin:0;padding: 0;border:0;}
            canvas{
                position: fixed;
                top: 0;
                left: 0;
            }
        </style>
    </head>
    
    <body>
        <canvas id="canvas" width="500" height="500"></canvas>
    
        <script type="text/javascript">
    (function(win, doc) {
        function particleFn(el) {
            var _this = this;
    
            var vendors = ['ms', 'moz', 'webkit', 'o'];
            for (var x = 0; x < vendors.length && !win.requestAnimationFrame; ++x) {
                win.requestAnimationFrame = win[vendors[x] + 'RequestAnimationFrame'];
                win.cancelAnimationFrame = win[vendors[x] + 'CancelAnimationFrame'] || win[vendors[x] + 'CancelRequestAnimationFrame'];
            }
    
            function arcData() { //生成每个粒子的参数
                this.x = parseInt(Math.random() * (_this.width));
                this.y = parseInt(Math.random() * (_this.height));
            
                //半径由初始先变最大,再变最小
                this.r = parseInt(Math.random() * 5); //半径,初始半径
                this.minR = Math.random() * 5; //半径,最小半径
                this.maxR = Math.random() * (this.r) + 5; //最大半径
                this.flagR = false;
    
                this.directionx = parseInt(Math.random() * 2); //0,1表示运动方向
                this.directiony = parseInt(Math.random() * 2);
    
                this.speedx = Math.random() * 0.3 * (_this.speed || 1) + 0.05; //运动速度,0.05是防止速度=0
                this.speedy = Math.random() * 0.3 * (_this.speed || 1) + 0.05;
    
                // 定义color为rgb;
                this.color = _this.color[parseInt(Math.random() * _this.color.length)] || '#8a7b7b';
    
                this.rgb = {
                    r: parseInt(Math.random() * 255),
                    g: parseInt(Math.random() * 255),
                    b: parseInt(Math.random() * 255),
                    a: 0.5,
                    minA: Math.random(), //最小透明度
                    flag: true, //true表示该减了
                }
                this.lineColor = _this.lineColor[parseInt(Math.random() * _this.lineColor.length)] || '#9a8686';
            }
            this.drawArc = function(arc, index) { //画圆
                _this.cxt.beginPath();
                _this.cxt.arc(arc.x, arc.y, arc.r, 0, 2 * Math.PI);
                // 颜色
                if (_this.color.length > 0) {
                    _this.cxt.fillStyle = arc.color;
                } else {
                    _this.cxt.fillStyle = 'rgba(' + arc.rgb.r + ',' + arc.rgb.g + ',' + arc.rgb.b + ',' + arc.rgb.a + ')';
                    if (arc.rgb.flag) {
                        arc.rgb.a -= 0.005;
                        if (arc.rgb.a <= arc.rgb.minA) {
                            arc.rgb.flag = false;
                        }
                    } else {
                        arc.rgb.a += 0.01;
                        if (arc.rgb.a >= 1) {
                            arc.rgb.flag = true;
                        }
                    }
                }
    
                if (arc.flagR) { //圆的半径变化
                    arc.r -= 0.01;
                    if (arc.r <= arc.minR) {
                        arc.flagR = false;
                    }
                } else {
                    arc.r += 0.05;
                    if (arc.r >= arc.maxR) {
                        arc.flagR = true;
                    }
                }
    
                _this.cxt.fill(); //画空心圆
                _this.cxt.closePath();
    
                //超出canvas就删除
                if (arc.x > _this.width + arc.r || arc.y > _this.height + arc.r || arc.x < 0 - arc.r || arc.y < 0 - arc.r) {
                    this.arcArr.splice(index, 1) //[i];
                }
            }
            this.drawLine = function(arc, nextArc) { //连线
                //直角三角形中,x的平方+y的平方=z的平方,求平方根:Math.sqrt(9)==3
                // arc.x - nextArc.x求得是x坐标的差,arc.y - nextArc.y求的是y坐标的差,两个值是直角的两边,第三边就是距离。。。
                var distance = Math.sqrt((arc.x - nextArc.x) * (arc.x - nextArc.x) + (arc.y - nextArc.y) * (arc.y - nextArc.y));
                if (distance < _this.maxLine) { //小于_this.maxLine距离的连线
                    _this.cxt.beginPath();
                    _this.cxt.moveTo(arc.x, arc.y);
                    _this.cxt.lineTo(nextArc.x, nextArc.y);
                    _this.cxt.lineWidth = 1;
                    _this.cxt.strokeStyle = arc.lineColor;
                    _this.cxt.stroke();
                }
            }
            this.mouseX = 0;
            this.mouseY = 0;
            this.mouseLine = function(nextArc) { //鼠标连线
                if (this.mouseX && this.mouseY) {
                    this.drawLine({
                        x: this.mouseX,
                        y: this.mouseY,
                        lineColor: _this.mouseLineColor[parseInt(Math.random() * _this.mouseLineColor.length)] || '#8a7b7b'
                    }, nextArc)
                }
            }
            this.shove = function(nextArc) { //推移
                if ((nextArc.x < _this.mouseX + _this.Maxshove && nextArc.x > _this.mouseX - _this.Maxshove) && (nextArc.y < _this.mouseY + _this.Maxshove && nextArc.y > _this.mouseY - _this.Maxshove)) {
    
                    if (nextArc.x < _this.mouseX + _this.Maxshove && nextArc.x > _this.mouseX - _this.Maxshove) {
                        nextArc.directionx = nextArc.directionx ? 0 : 1;
                        if (nextArc.x < _this.mouseX) {
                            nextArc.x -= 1;
                        } else {
                            nextArc.x += 1;
                        }
                    }
                    if (nextArc.y < _this.mouseY + _this.Maxshove && nextArc.y > _this.mouseY - _this.Maxshove) {
                        nextArc.directiony = nextArc.directiony ? 0 : 1;
                        if (nextArc.y < _this.mouseY) {
                            nextArc.y -= 1;
                        } else {
                            nextArc.y += 1;
                        }
                    }
                }
            }
            this.move = function(arc) { //移动
                if (!arc) {
                    return
                }
                if (arc.directionx) {
                    arc.x += arc.speedx;
                } else {
                    arc.x -= arc.speedx;
                }
                if (arc.directiony) {
                    arc.y += arc.speedy;
                } else {
                    arc.y -= arc.speedy;
                }
            }
            this.draw = function() {
                _this.cxt.clearRect(0, 0, _this.width, _this.height);
    
                for (var i = 0; i < _this.arcArr.length; i++) {
                    if (_this.showLine) {
                        for (var k = i + 1; k < _this.arcArr.length; k++) {
                            _this.drawLine(_this.arcArr[i], _this.arcArr[k]);
                        }
                    }
                    if (_this.showMouseLine) {
                        _this.mouseLine(_this.arcArr[i]);
                    }
                    if (_this.isShove) {
                        _this.shove(_this.arcArr[i]);
                    }
                    _this.move(_this.arcArr[i]);
                    _this.drawArc(_this.arcArr[i], i); //传递下标i是为了删除
                }
            }
            this.stop = function() {
                cancelAnimationFrame(_this.requestId);
                return true
            }
            this.start = function() { //生成粒子
    
                cancelAnimationFrame(_this.requestId);
                if (_this.arcArr) {
                    for (var i = _this.arcArr.length; i < _this.num; i++) {
                        _this.arcArr.push(new arcData());
                    }
                    _this.draw();
                }
                _this.requestId = requestAnimationFrame(_this.start);
            }
            var timeout = null;
            this.init = function(initData) {
                clearTimeout(timeout);
                timeout = setTimeout(function() { //避免多次init初始化
                    cancelAnimationFrame(_this.requestId);
                    if (!initData || !initData.el) {
                        _this.el = document.getElementById(el);
                        _this.cxt = _this.el.getContext("2d");
                        _this.width = _this.el.width; //canvas宽高
                        _this.height = _this.el.height;
                    }
                    _this.num = 30; //粒子数量,默认30
                    _this.color = []; //粒子颜色,默认随机
                    _this.showLine = true;
                    _this.maxLine = 50; //连线距离
                    _this.lineColor = ['#8a7b7b']; // 默认
    
                    _this.showMouseLine = true; //显示鼠标连线
                    _this.mouseLineColor = ['red']; //鼠标连线颜色
    
                    _this.isShove = true;
                    _this.Maxshove = 50;
    
                    for (var i in initData) {
                        if (initData.hasOwnProperty(i)) {
                            _this[i] = initData[i];
                            if (i == 'el') {
                                _this.el = document.getElementById(initData[i]);
                                _this.cxt = _this.el.getContext("2d");
                                _this.width = _this.el.width; //canvas宽高
                                _this.height = _this.el.height;
                            }
                        }
                    }
                    _this.el.onmousemove = function(e) {
                        // 这个得改,需要获取鼠标在canvas上的位置
                        _this.mouseX = e.layerX;
                        _this.mouseY = e.layerY;
                        console.log(e.layerX, e.layerY);
                    }
                    _this.el.onmouseout = function(e) {
                        _this.mouseX = 0;
                        _this.mouseY = 0;
                        console.log(e.layerX, e.layerY);
                    }
    
                    _this.arcArr = []; //所有粒子存放的数组
                    _this.start();
                    console.log(_this);
                }, 200)
            }
        }
        win.particle = particleFn;
    })(window, document)
    
    
            document.getElementById('canvas').width=document.documentElement.clientWidth;
            document.getElementById('canvas').height=document.documentElement.clientHeight;
            var c = new particle("canvas");//接受一个canvas的id:必填
                c.init();
                c.init({//初始化,接受一个对象,所有属性可选
                    el:"canvas",//可以替换new方法中的id,可选
                    num:200,//粒子数量,默认30
                    color:[],//粒子颜色,默认随机
                    lineColor:[],//若不传递值,连线颜色默认['#8a7b7b']
                    
                    speed:2,//1为正常移动速度
                    showLine:true,//显示连线,默认true
                    
                    showMouseLine:true,//showLine必须为true
                    mouseLineColor:[],
                    
                    isShove:true,//是否推动
                    Maxshove:50,//推动距离
    
                    maxLine:60,//链接线的最大长度,默认50
                })
                c.stop();//停止动画
                c.start();//停止动画
        </script>
    </body>
    
    </html>
    

    可以实现鼠标推移粒子,连线粒子,鼠标连线粒子,自定义颜色

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          本文标题:canvas粒子效果

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