ui/node_modules/d3-shape/src/curve/cardinalClosed.js

import noop from "../noop.js";
import {point} from "./cardinal.js";

export function CardinalClosed(context, tension) {
  this._context = context;
  this._k = (1 - tension) / 6;
}

CardinalClosed.prototype = {
  areaStart: noop,
  areaEnd: noop,
  lineStart: function() {
    this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
    this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
    this._point = 0;
  },
  lineEnd: function() {
    switch (this._point) {
      case 1: {
        this._context.moveTo(this._x3, this._y3);
        this._context.closePath();
        break;
      }
      case 2: {
        this._context.lineTo(this._x3, this._y3);
        this._context.closePath();
        break;
      }
      case 3: {
        this.point(this._x3, this._y3);
        this.point(this._x4, this._y4);
        this.point(this._x5, this._y5);
        break;
      }
    }
  },
  point: function(x, y) {
    x = +x, y = +y;
    switch (this._point) {
      case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
      case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
      case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
      default: point(this, x, y); break;
    }
    this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
    this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
  }
};

export default (function custom(tension) {

  function cardinal(context) {
    return new CardinalClosed(context, tension);
  }

  cardinal.tension = function(tension) {
    return custom(+tension);
  };

  return cardinal;
})(0);