/*生成迁徙线*/
renderLine(startA,endA,index){
let that=this;
let oG=this.oG;
//获取贝塞尔曲线控制点
function computeControlPoint(ps, pe, arc = 0.5) {
const deltaX = pe[0] - ps[0];
const deltaY = pe[1] - ps[1];
const theta = Math.atan(deltaY / deltaX);