t.body.clientWidth;
    canvas.height = window.innerHeight || document.documentElement.clientHeight || document.body.clientHeight;
  }

  var RAF = (function() {
    return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(callback) {
          window.setTimeout(callback, 1000 / 60);
        };
  })();

  // 鼠标活动时，获取鼠标坐标
  var warea = {x: null, y: null, m