text: export function point(that, x, y) {
    that._context.bezierCurveTo((2 * that._x0 + that._x1) / 3, (2 * that._y0 + that._y1) / 3, (that._x0 + 2 * that._x1) / 3, (that._y0 + 2 * that._y1) / 3, (that._x0 + 4 * that._x1 + x) / 6, (that._y0 + 4 * that._y1 + y) / 6);
  }
  export function Basis(context) {
    this._context = context;
  }
  Basis.prototype = {
    areaStart: function () {
      this._line = 0;
    },
    areaEnd: function () {
      this._line = NaN;
    },
    lineStart: function () {
      this._x0 = this._x1 = this._y0 = this._y1 = NaN;
      this._point = 0;
    },
    lineEnd: function () {
      switch (this._point) {
        case 3:
          point(this, this._x1, this._y1);
        // proceed
  
        case 2:
          this._context.lineTo(this._x1, this._y1);
  
          break;
      }
  
      if (this._line || this._line !== 0 && this._point === 1) this._context.closePath();
      this._line = 1 - this._line;
    },
    point: function (x, y) {
      x = +x, y = +y;
  
      switch (this._point) {
        case 0:
          this._point = 1;
          this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y);
          break;
  
        case 1:
          this._point = 2;
          break;
  
        case 2:
          this._point = 3;
  
          this._context.lineTo((5 * this._x0 + this._x1) / 6, (5 * this._y0 + this._y1) / 6);
  
        // proceed
  
        default:
          point(this, x, y);
          break;
      }
  
      this._x0 = this._x1, this._x1 = x;
      this._y0 = this._y1, this._y1 = y;
    }
  };
  export default function (context) {
    return new Basis(context);
  }