code: function pathRotate(contour, angle, centerX, centerY) {
              angle = angle === undefined ? 0 : angle;
              var x = centerX || 0;
              var y = centerY || 0;
              var cos = Math.cos(angle);
              var sin = Math.sin(angle);
              var px;
              var py;
              var p;
  
              // x1=cos(angle)*x-sin(angle)*y;
              // y1=cos(angle)*y+sin(angle)*x;
              for (var i = 0, l = contour.length; i < l; i++) {
                  p = contour[i];
                  px = cos * (p.x - x) - sin * (p.y - y);
                  py = cos * (p.y - y) + sin * (p.x - x);
                  p.x = px + x;
                  p.y = py + y;
              }
  
              return contour;
          }
docs: 对path坐标进行调整
  
  @param {Object} contour 坐标点
  @param {number} angle 角度
  @param {number} centerX x偏移
  @param {number} centerY y偏移
  
  @return {Object} contour 坐标点