js实现点击页面出现心形动效

Date: 2017-04-20

原生js实现点击页面出现心形动效的效果

(function(window,document,undefined){
  var hearts = [];
  window.requestAnimationFrame = (function(){
    return window.requestAnimationFrame ||
    window.webkitRequestAnimationFrame ||
    window.mozRequestAnimationFrame ||
    window.oRequestAnimationFrame ||
    window.msRequestAnimationFrame ||
    function (callback){
      setTimeout(callback,1000/60);
    }
  })();
  init();
  function init(){
    css(".heart{width: 10px;height: 10px;position: fixed;background: #f00;transform: rotate(45deg);-webkit-transform: rotate(45deg);-moz-transform: rotate(45deg);}.heart:after,.heart:before{content: '';width: inherit;height: inherit;background: inherit;border-radius: 50%;-webkit-border-radius: 50%;-moz-border-radius: 50%;position: fixed;}.heart:after{top: -5px;}.heart:before{left: -5px;}");
    attachEvent();
    gameloop();
  }
  function gameloop(){
    for(var i=0;i<hearts.length;i++){
      if(hearts[i].alpha <=0){
        document.body.removeChild(hearts[i].el);
        hearts.splice(i,1);
        continue;
      }
      hearts[i].y--;
      hearts[i].scale += 0.004;
      hearts[i].alpha -= 0.013;
      hearts[i].el.style.cssText = "left:"+hearts[i].x+"px;top:"+hearts[i].y+"px;opacity:"+hearts[i].alpha+";transform:scale("+hearts[i].scale+","+hearts[i].scale+") rotate(45deg);background:"+hearts[i].color+";z-index:99999";
    }
    requestAnimationFrame(gameloop);
  }
  function attachEvent(){
    var old = typeof window.onclick==="function" && window.onclick;
    window.onclick = function(event){
      old && old();
      createHeart(event);
    }
  }
  function createHeart(event){
    var d = document.createElement("div");
    d.className = "heart";
    hearts.push({
      el : d,
      x : event.clientX - 5,
      y : event.clientY - 5,
      scale : 1,
      alpha : 1,
      color : randomColor()
    });
    document.body.appendChild(d);
  }
  function css(css){
    var style = document.createElement("style");
    style.type="text/css";
    try{
      style.appendChild(document.createTextNode(css));
    }catch(ex){
      style.styleSheet.cssText = css;
    }
    document.getElementsByTagName('head')[0].appendChild(style);
  }
  function randomColor(){
    return "rgb("+(~~(Math.random()*255))+","+(~~(Math.random()*255))+","+(~~(Math.random()*255))+")";
  }
})(window,document);

来源：A-Ten's Blog源码研究