web-app-v1/components/flytocart/fly-to-cart.js

export default function bezier(pots, amount) {
	var pot;
    var lines;
    var ret = [];
    var points;
    for (var i = 0; i <= amount; i++) {
      points = pots.slice(0);
      lines = [];
      while (pot = points.shift()) {
        if (points.length) {
          lines.push(pointLine([pot, points[0]], i / amount));
        } else if (lines.length > 1) {
          points = lines;
          lines = [];
        } else {
          break;
        }
      }
      ret.push(lines[0]);
    }
    function pointLine(points, rate) {
      var pointA, pointB, pointDistance, xDistance, yDistance, tan, radian, tmpPointDistance;
      var ret = [];
      pointA = points[0];//点击
      pointB = points[1];//中间
      xDistance = pointB.x - pointA.x;
      yDistance = pointB.y - pointA.y;
      pointDistance = Math.pow(Math.pow(xDistance, 2) + Math.pow(yDistance, 2), 1 / 2);
      tan = yDistance / xDistance;
      radian = Math.atan(tan);
      tmpPointDistance = pointDistance * rate;
      ret = {
        x: pointA.x + tmpPointDistance * Math.cos(radian),
        y: pointA.y + tmpPointDistance * Math.sin(radian)
      };
      return ret;
    }
    return ret
}