HTML5超炫酷粒子效果的进度条的实现示例

这是一款基于HTML5和JavaScript的进度条应用，这款进度条插件非常有特点，它在进度展示的时候呈现粒子的动画效果，也就是说，进度条在滑动的同时，会产生一些小粒子掉落下来，效果非常酷。另外还有一个特点是随着进度的变化，进度条的颜色也会变化。

JavaScript代码

/*========================================================*/  /* Light Loader/*========================================================*/VAR lightLoader = function(c, cw, ch){
        var _this = this;
        this.c = c;
        this.ctx = c.getContext('2d');
        this.cw = cw;
        this.ch = ch;
                   this.loaded = 0;
        this.loaderSPEed = .6;
        this.loaderHeight = 10;
        this.loaderWidth = 310;
                 this.loader = {
        x: (this.cw/2) - (this.loaderWidth/2),        y: (this.ch/2) - (this.loaderHeight/2)    }
    ;
        this.particles = [];
        this.particleLift = 180;
        this.hueStart = 0    this.hueEnd = 120;
        this.hue = 0;
        this.gravITy = .15;
        this.particleRate = 4;
      /*========================================================*/        /* Initialize    /*========================================================*/    this.init = function(){
            this.loop();
    }
    ;
    /*========================================================*/        /* Utility Functions    /*========================================================*/                    this.rand = function(rMi, rMa){
    return ~~((Math.random()*(rMa-rMi+1))+rMi);
}
    ;
    this.hittest = function(x1, y1, w1, h1, x2, y2, w2, h2){
    return !(x1 + w1  x2 || x2 + w2  x1 || y1 + h1  y2 || y2 + h2  y1);
}
    ;
    /*========================================================*/        /* Update Loader    /*========================================================*/    this.updateLoader = function(){
        if(this.loaded  100){
                this.loaded += this.loaderSpeed;
        }
 else {
                this.loaded = 0;
        }
    }
    ;
    /*========================================================*/        /* Render Loader    /*========================================================*/    this.renderLoader = function(){
            this.ctx.fillStyle = '#000';
            this.ctx.fillRect(this.loader.x, this.loader.y, this.loaderWidth, this.loaderHeight);
            this.hue = this.hueStart + (this.loaded/100)*(this.hueEnd - this.hueStart);
            var newWidth = (this.loaded/100)*this.loaderWidth;
            this.ctx.fillStyle = 'hsla('+this.hue+', 100%, 40%, 1)';
            this.ctx.fillRect(this.loader.x, this.loader.y, newWidth, this.loaderHeight);
            this.ctx.fillStyle = '#222';
            this.ctx.fillRect(this.loader.x, this.loader.y, newWidth, this.loaderHeight/2);
    }
    ;
      /*========================================================*/        /* Particles    /*========================================================*/    this.Particle = function(){
                             this.x = _this.loader.x + ((_this.loaded/100)*_this.loaderWidth) - _this.rand(0, 1);
            this.y = _this.ch/2 + _this.rand(0,_this.loaderHeight)-_this.loaderHeight/2;
            this.vx = (_this.rand(0,4)-2)/100;
            this.vy = (_this.rand(0,_this.particleLift)-_this.particleLift*2)/100;
            this.width = _this.rand(1,4)/2;
            this.height = _this.rand(1,4)/2;
            this.hue = _this.hue;
    }
    ;
    this.Particle.PRototype.update = function(i){
            this.vx += (_this.rand(0,6)-3)/100;
             this.vy += _this.gravity;
            this.x += this.vx;
            this.y += this.vy;
            if(this.y >
 _this.ch){
                _this.particles.splice(i, 1);
        }
                       }
    ;
    this.Particle.prototype.render = function(){
            _this.ctx.fillStyle = 'hsla('+this.hue+', 100%, '+_this.rand(50,70)+'%, '+_this.rand(20,100)/100+')';
            _this.ctx.fillRect(this.x, this.y, this.width, this.height);
    }
    ;
    this.createParticles = function(){
            var i = this.particleRate;
        while(i--){
                this.particles.push(new this.Particle());
        }
    ;
    }
    ;
    this.updateParticles = function(){
                              var i = this.particles.length;
                              while(i--){
                var p = this.particles[i];
                p.update(i);
                                                    }
    ;
                          }
    ;
    this.renderParticles = function(){
            var i = this.particles.length;
                              while(i--){
                var p = this.particles[i];
                p.render();
                                                 }
    ;
                      }
    ;
    /*========================================================*/        /* Clear Canvas    /*========================================================*/    this.clearCanvas = function(){
            this.ctx.globalCompositeoperation = 'source-over';
            this.ctx.clearRect(0,0,this.cw,this.ch);
                                this.ctx.globalCompositeOperation = 'lighter';
    }
    ;
    /*========================================================*/        /* Animation Loop    /*========================================================*/    this.loop = function(){
        var loopIt = function(){
                requestAnimationFrame(loopIt, _this.c);
                _this.clearCanvas();
                _this.createParticles();
                _this.updateLoader();
                _this.updateParticles();
                _this.renderLoader();
                _this.renderParticles();
        }
    ;
            loopIt();
                       }
    ;
}
    ;
/*========================================================*/    /* Check Canvas Support/*========================================================*/var isCanvasSupported = function(){
        var elem = document.createElement('canvas');
        return !!(elem.getContext &
    &
     elem.getContext('2d'));
}
    ;
/*========================================================*/    /* SETUP requestAnimationFrame/*========================================================*/var setupRAF = function(){
        var lastTime = 0;
        var vendors = ['ms', 'moz', 'webkit', 'o'];
        for(var x = 0;
     x  vendors.length &
    &
     !window.requestAnimationFrame;
 ++x){
            window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
            window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] || window[vendors[x]+'CancelRequestAnimationFrame'];
    }
    ;
    if(!window.requestAnimationFrame){
        window.requestAnimationFrame = function(callback, element){
                var currTime = new Date().getTime();
                var timeToCall = Math.max(0, 16 - (currTime - lastTime));
            var id = window.setTimeout(function() {
     callback(currTime + timeToCall);
 }
    , timeToCall);
                lastTime = currTime + timeToCall;
                return id;
        }
    ;
    }
    ;
    if (!window.cancelAnimationFrame){
        window.cancelAnimationFrame = function(id){
                clearTimeout(id);
        }
    ;
    }
    ;
}
    ;
          /*========================================================*/    /* define Canvas and Initialize/*========================================================*/if(isCanvasSupported){
      var c = document.createElement('canvas');
      c.width = 400;
      c.height = 100;
                 var cw = c.width;
      var ch = c.height;
          document.body.appendChild(c);
       var cl = new lightLoader(c, cw, ch);
                    setupRAF();
      cl.init();
}
    

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。

声明：本文内容由网友自发贡献，本站不承担相应法律责任。对本内容有异议或投诉，请联系2913721942#qq.com核实处理，我们将尽快回复您，谢谢合作！