Index: node_modules/d3-shape/src/curve/basis.js
===================================================================
--- node_modules/d3-shape/src/curve/basis.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/basis.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,51 @@
+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); // falls through
+      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); // falls through
+      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);
+}
Index: node_modules/d3-shape/src/curve/basisClosed.js
===================================================================
--- node_modules/d3-shape/src/curve/basisClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/basisClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,52 @@
+import noop from "../noop.js";
+import {point} from "./basis.js";
+
+function BasisClosed(context) {
+  this._context = context;
+}
+
+BasisClosed.prototype = {
+  areaStart: noop,
+  areaEnd: noop,
+  lineStart: function() {
+    this._x0 = this._x1 = this._x2 = this._x3 = this._x4 =
+    this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = NaN;
+    this._point = 0;
+  },
+  lineEnd: function() {
+    switch (this._point) {
+      case 1: {
+        this._context.moveTo(this._x2, this._y2);
+        this._context.closePath();
+        break;
+      }
+      case 2: {
+        this._context.moveTo((this._x2 + 2 * this._x3) / 3, (this._y2 + 2 * this._y3) / 3);
+        this._context.lineTo((this._x3 + 2 * this._x2) / 3, (this._y3 + 2 * this._y2) / 3);
+        this._context.closePath();
+        break;
+      }
+      case 3: {
+        this.point(this._x2, this._y2);
+        this.point(this._x3, this._y3);
+        this.point(this._x4, this._y4);
+        break;
+      }
+    }
+  },
+  point: function(x, y) {
+    x = +x, y = +y;
+    switch (this._point) {
+      case 0: this._point = 1; this._x2 = x, this._y2 = y; break;
+      case 1: this._point = 2; this._x3 = x, this._y3 = y; break;
+      case 2: this._point = 3; this._x4 = x, this._y4 = y; this._context.moveTo((this._x0 + 4 * this._x1 + x) / 6, (this._y0 + 4 * this._y1 + y) / 6); break;
+      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 BasisClosed(context);
+}
Index: node_modules/d3-shape/src/curve/basisOpen.js
===================================================================
--- node_modules/d3-shape/src/curve/basisOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/basisOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,39 @@
+import {point} from "./basis.js";
+
+function BasisOpen(context) {
+  this._context = context;
+}
+
+BasisOpen.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() {
+    if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
+    this._line = 1 - this._line;
+  },
+  point: function(x, y) {
+    x = +x, y = +y;
+    switch (this._point) {
+      case 0: this._point = 1; break;
+      case 1: this._point = 2; break;
+      case 2: this._point = 3; var x0 = (this._x0 + 4 * this._x1 + x) / 6, y0 = (this._y0 + 4 * this._y1 + y) / 6; this._line ? this._context.lineTo(x0, y0) : this._context.moveTo(x0, y0); break;
+      case 3: this._point = 4; // falls through
+      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 BasisOpen(context);
+}
Index: node_modules/d3-shape/src/curve/bump.js
===================================================================
--- node_modules/d3-shape/src/curve/bump.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/bump.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,75 @@
+import pointRadial from "../pointRadial.js";
+
+class Bump {
+  constructor(context, x) {
+    this._context = context;
+    this._x = x;
+  }
+  areaStart() {
+    this._line = 0;
+  }
+  areaEnd() {
+    this._line = NaN;
+  }
+  lineStart() {
+    this._point = 0;
+  }
+  lineEnd() {
+    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
+    this._line = 1 - this._line;
+  }
+  point(x, y) {
+    x = +x, y = +y;
+    switch (this._point) {
+      case 0: {
+        this._point = 1;
+        if (this._line) this._context.lineTo(x, y);
+        else this._context.moveTo(x, y);
+        break;
+      }
+      case 1: this._point = 2; // falls through
+      default: {
+        if (this._x) this._context.bezierCurveTo(this._x0 = (this._x0 + x) / 2, this._y0, this._x0, y, x, y);
+        else this._context.bezierCurveTo(this._x0, this._y0 = (this._y0 + y) / 2, x, this._y0, x, y);
+        break;
+      }
+    }
+    this._x0 = x, this._y0 = y;
+  }
+}
+
+class BumpRadial {
+  constructor(context) {
+    this._context = context;
+  }
+  lineStart() {
+    this._point = 0;
+  }
+  lineEnd() {}
+  point(x, y) {
+    x = +x, y = +y;
+    if (this._point === 0) {
+      this._point = 1;
+    } else {
+      const p0 = pointRadial(this._x0, this._y0);
+      const p1 = pointRadial(this._x0, this._y0 = (this._y0 + y) / 2);
+      const p2 = pointRadial(x, this._y0);
+      const p3 = pointRadial(x, y);
+      this._context.moveTo(...p0);
+      this._context.bezierCurveTo(...p1, ...p2, ...p3);
+    }
+    this._x0 = x, this._y0 = y;
+  }
+}
+
+export function bumpX(context) {
+  return new Bump(context, true);
+}
+
+export function bumpY(context) {
+  return new Bump(context, false);
+}
+
+export function bumpRadial(context) {
+  return new BumpRadial(context);
+}
Index: node_modules/d3-shape/src/curve/bundle.js
===================================================================
--- node_modules/d3-shape/src/curve/bundle.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/bundle.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,56 @@
+import {Basis} from "./basis.js";
+
+function Bundle(context, beta) {
+  this._basis = new Basis(context);
+  this._beta = beta;
+}
+
+Bundle.prototype = {
+  lineStart: function() {
+    this._x = [];
+    this._y = [];
+    this._basis.lineStart();
+  },
+  lineEnd: function() {
+    var x = this._x,
+        y = this._y,
+        j = x.length - 1;
+
+    if (j > 0) {
+      var x0 = x[0],
+          y0 = y[0],
+          dx = x[j] - x0,
+          dy = y[j] - y0,
+          i = -1,
+          t;
+
+      while (++i <= j) {
+        t = i / j;
+        this._basis.point(
+          this._beta * x[i] + (1 - this._beta) * (x0 + t * dx),
+          this._beta * y[i] + (1 - this._beta) * (y0 + t * dy)
+        );
+      }
+    }
+
+    this._x = this._y = null;
+    this._basis.lineEnd();
+  },
+  point: function(x, y) {
+    this._x.push(+x);
+    this._y.push(+y);
+  }
+};
+
+export default (function custom(beta) {
+
+  function bundle(context) {
+    return beta === 1 ? new Basis(context) : new Bundle(context, beta);
+  }
+
+  bundle.beta = function(beta) {
+    return custom(+beta);
+  };
+
+  return bundle;
+})(0.85);
Index: node_modules/d3-shape/src/curve/cardinal.js
===================================================================
--- node_modules/d3-shape/src/curve/cardinal.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/cardinal.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,61 @@
+export function point(that, x, y) {
+  that._context.bezierCurveTo(
+    that._x1 + that._k * (that._x2 - that._x0),
+    that._y1 + that._k * (that._y2 - that._y0),
+    that._x2 + that._k * (that._x1 - x),
+    that._y2 + that._k * (that._y1 - y),
+    that._x2,
+    that._y2
+  );
+}
+
+export function Cardinal(context, tension) {
+  this._context = context;
+  this._k = (1 - tension) / 6;
+}
+
+Cardinal.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x0 = this._x1 = this._x2 =
+    this._y0 = this._y1 = this._y2 = NaN;
+    this._point = 0;
+  },
+  lineEnd: function() {
+    switch (this._point) {
+      case 2: this._context.lineTo(this._x2, this._y2); break;
+      case 3: point(this, 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; this._x1 = x, this._y1 = y; break;
+      case 2: this._point = 3; // falls through
+      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 Cardinal(context, tension);
+  }
+
+  cardinal.tension = function(tension) {
+    return custom(+tension);
+  };
+
+  return cardinal;
+})(0);
Index: node_modules/d3-shape/src/curve/cardinalClosed.js
===================================================================
--- node_modules/d3-shape/src/curve/cardinalClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/cardinalClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,61 @@
+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);
Index: node_modules/d3-shape/src/curve/cardinalOpen.js
===================================================================
--- node_modules/d3-shape/src/curve/cardinalOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/cardinalOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,49 @@
+import {point} from "./cardinal.js";
+
+export function CardinalOpen(context, tension) {
+  this._context = context;
+  this._k = (1 - tension) / 6;
+}
+
+CardinalOpen.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x0 = this._x1 = this._x2 =
+    this._y0 = this._y1 = this._y2 = NaN;
+    this._point = 0;
+  },
+  lineEnd: function() {
+    if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
+    this._line = 1 - this._line;
+  },
+  point: function(x, y) {
+    x = +x, y = +y;
+    switch (this._point) {
+      case 0: this._point = 1; break;
+      case 1: this._point = 2; break;
+      case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
+      case 3: this._point = 4; // falls through
+      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 CardinalOpen(context, tension);
+  }
+
+  cardinal.tension = function(tension) {
+    return custom(+tension);
+  };
+
+  return cardinal;
+})(0);
Index: node_modules/d3-shape/src/curve/catmullRom.js
===================================================================
--- node_modules/d3-shape/src/curve/catmullRom.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/catmullRom.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,88 @@
+import {epsilon} from "../math.js";
+import {Cardinal} from "./cardinal.js";
+
+export function point(that, x, y) {
+  var x1 = that._x1,
+      y1 = that._y1,
+      x2 = that._x2,
+      y2 = that._y2;
+
+  if (that._l01_a > epsilon) {
+    var a = 2 * that._l01_2a + 3 * that._l01_a * that._l12_a + that._l12_2a,
+        n = 3 * that._l01_a * (that._l01_a + that._l12_a);
+    x1 = (x1 * a - that._x0 * that._l12_2a + that._x2 * that._l01_2a) / n;
+    y1 = (y1 * a - that._y0 * that._l12_2a + that._y2 * that._l01_2a) / n;
+  }
+
+  if (that._l23_a > epsilon) {
+    var b = 2 * that._l23_2a + 3 * that._l23_a * that._l12_a + that._l12_2a,
+        m = 3 * that._l23_a * (that._l23_a + that._l12_a);
+    x2 = (x2 * b + that._x1 * that._l23_2a - x * that._l12_2a) / m;
+    y2 = (y2 * b + that._y1 * that._l23_2a - y * that._l12_2a) / m;
+  }
+
+  that._context.bezierCurveTo(x1, y1, x2, y2, that._x2, that._y2);
+}
+
+function CatmullRom(context, alpha) {
+  this._context = context;
+  this._alpha = alpha;
+}
+
+CatmullRom.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x0 = this._x1 = this._x2 =
+    this._y0 = this._y1 = this._y2 = NaN;
+    this._l01_a = this._l12_a = this._l23_a =
+    this._l01_2a = this._l12_2a = this._l23_2a =
+    this._point = 0;
+  },
+  lineEnd: function() {
+    switch (this._point) {
+      case 2: this._context.lineTo(this._x2, this._y2); break;
+      case 3: this.point(this._x2, this._y2); 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;
+
+    if (this._point) {
+      var x23 = this._x2 - x,
+          y23 = this._y2 - y;
+      this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
+    }
+
+    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; // falls through
+      default: point(this, x, y); break;
+    }
+
+    this._l01_a = this._l12_a, this._l12_a = this._l23_a;
+    this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
+    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(alpha) {
+
+  function catmullRom(context) {
+    return alpha ? new CatmullRom(context, alpha) : new Cardinal(context, 0);
+  }
+
+  catmullRom.alpha = function(alpha) {
+    return custom(+alpha);
+  };
+
+  return catmullRom;
+})(0.5);
Index: node_modules/d3-shape/src/curve/catmullRomClosed.js
===================================================================
--- node_modules/d3-shape/src/curve/catmullRomClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/catmullRomClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,74 @@
+import {CardinalClosed} from "./cardinalClosed.js";
+import noop from "../noop.js";
+import {point} from "./catmullRom.js";
+
+function CatmullRomClosed(context, alpha) {
+  this._context = context;
+  this._alpha = alpha;
+}
+
+CatmullRomClosed.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._l01_a = this._l12_a = this._l23_a =
+    this._l01_2a = this._l12_2a = this._l23_2a =
+    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;
+
+    if (this._point) {
+      var x23 = this._x2 - x,
+          y23 = this._y2 - y;
+      this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
+    }
+
+    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._l01_a = this._l12_a, this._l12_a = this._l23_a;
+    this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
+    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(alpha) {
+
+  function catmullRom(context) {
+    return alpha ? new CatmullRomClosed(context, alpha) : new CardinalClosed(context, 0);
+  }
+
+  catmullRom.alpha = function(alpha) {
+    return custom(+alpha);
+  };
+
+  return catmullRom;
+})(0.5);
Index: node_modules/d3-shape/src/curve/catmullRomOpen.js
===================================================================
--- node_modules/d3-shape/src/curve/catmullRomOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/catmullRomOpen.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,62 @@
+import {CardinalOpen} from "./cardinalOpen.js";
+import {point} from "./catmullRom.js";
+
+function CatmullRomOpen(context, alpha) {
+  this._context = context;
+  this._alpha = alpha;
+}
+
+CatmullRomOpen.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x0 = this._x1 = this._x2 =
+    this._y0 = this._y1 = this._y2 = NaN;
+    this._l01_a = this._l12_a = this._l23_a =
+    this._l01_2a = this._l12_2a = this._l23_2a =
+    this._point = 0;
+  },
+  lineEnd: function() {
+    if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
+    this._line = 1 - this._line;
+  },
+  point: function(x, y) {
+    x = +x, y = +y;
+
+    if (this._point) {
+      var x23 = this._x2 - x,
+          y23 = this._y2 - y;
+      this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
+    }
+
+    switch (this._point) {
+      case 0: this._point = 1; break;
+      case 1: this._point = 2; break;
+      case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
+      case 3: this._point = 4; // falls through
+      default: point(this, x, y); break;
+    }
+
+    this._l01_a = this._l12_a, this._l12_a = this._l23_a;
+    this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
+    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(alpha) {
+
+  function catmullRom(context) {
+    return alpha ? new CatmullRomOpen(context, alpha) : new CardinalOpen(context, 0);
+  }
+
+  catmullRom.alpha = function(alpha) {
+    return custom(+alpha);
+  };
+
+  return catmullRom;
+})(0.5);
Index: node_modules/d3-shape/src/curve/linear.js
===================================================================
--- node_modules/d3-shape/src/curve/linear.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/linear.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,31 @@
+function Linear(context) {
+  this._context = context;
+}
+
+Linear.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._point = 0;
+  },
+  lineEnd: function() {
+    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; // falls through
+      default: this._context.lineTo(x, y); break;
+    }
+  }
+};
+
+export default function(context) {
+  return new Linear(context);
+}
Index: node_modules/d3-shape/src/curve/linearClosed.js
===================================================================
--- node_modules/d3-shape/src/curve/linearClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/linearClosed.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,25 @@
+import noop from "../noop.js";
+
+function LinearClosed(context) {
+  this._context = context;
+}
+
+LinearClosed.prototype = {
+  areaStart: noop,
+  areaEnd: noop,
+  lineStart: function() {
+    this._point = 0;
+  },
+  lineEnd: function() {
+    if (this._point) this._context.closePath();
+  },
+  point: function(x, y) {
+    x = +x, y = +y;
+    if (this._point) this._context.lineTo(x, y);
+    else this._point = 1, this._context.moveTo(x, y);
+  }
+};
+
+export default function(context) {
+  return new LinearClosed(context);
+}
Index: node_modules/d3-shape/src/curve/monotone.js
===================================================================
--- node_modules/d3-shape/src/curve/monotone.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/monotone.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,104 @@
+function sign(x) {
+  return x < 0 ? -1 : 1;
+}
+
+// Calculate the slopes of the tangents (Hermite-type interpolation) based on
+// the following paper: Steffen, M. 1990. A Simple Method for Monotonic
+// Interpolation in One Dimension. Astronomy and Astrophysics, Vol. 239, NO.
+// NOV(II), P. 443, 1990.
+function slope3(that, x2, y2) {
+  var h0 = that._x1 - that._x0,
+      h1 = x2 - that._x1,
+      s0 = (that._y1 - that._y0) / (h0 || h1 < 0 && -0),
+      s1 = (y2 - that._y1) / (h1 || h0 < 0 && -0),
+      p = (s0 * h1 + s1 * h0) / (h0 + h1);
+  return (sign(s0) + sign(s1)) * Math.min(Math.abs(s0), Math.abs(s1), 0.5 * Math.abs(p)) || 0;
+}
+
+// Calculate a one-sided slope.
+function slope2(that, t) {
+  var h = that._x1 - that._x0;
+  return h ? (3 * (that._y1 - that._y0) / h - t) / 2 : t;
+}
+
+// According to https://en.wikipedia.org/wiki/Cubic_Hermite_spline#Representations
+// "you can express cubic Hermite interpolation in terms of cubic Bézier curves
+// with respect to the four values p0, p0 + m0 / 3, p1 - m1 / 3, p1".
+function point(that, t0, t1) {
+  var x0 = that._x0,
+      y0 = that._y0,
+      x1 = that._x1,
+      y1 = that._y1,
+      dx = (x1 - x0) / 3;
+  that._context.bezierCurveTo(x0 + dx, y0 + dx * t0, x1 - dx, y1 - dx * t1, x1, y1);
+}
+
+function MonotoneX(context) {
+  this._context = context;
+}
+
+MonotoneX.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x0 = this._x1 =
+    this._y0 = this._y1 =
+    this._t0 = NaN;
+    this._point = 0;
+  },
+  lineEnd: function() {
+    switch (this._point) {
+      case 2: this._context.lineTo(this._x1, this._y1); break;
+      case 3: point(this, this._t0, slope2(this, this._t0)); break;
+    }
+    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
+    this._line = 1 - this._line;
+  },
+  point: function(x, y) {
+    var t1 = NaN;
+
+    x = +x, y = +y;
+    if (x === this._x1 && y === this._y1) return; // Ignore coincident points.
+    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; point(this, slope2(this, t1 = slope3(this, x, y)), t1); break;
+      default: point(this, this._t0, t1 = slope3(this, x, y)); break;
+    }
+
+    this._x0 = this._x1, this._x1 = x;
+    this._y0 = this._y1, this._y1 = y;
+    this._t0 = t1;
+  }
+}
+
+function MonotoneY(context) {
+  this._context = new ReflectContext(context);
+}
+
+(MonotoneY.prototype = Object.create(MonotoneX.prototype)).point = function(x, y) {
+  MonotoneX.prototype.point.call(this, y, x);
+};
+
+function ReflectContext(context) {
+  this._context = context;
+}
+
+ReflectContext.prototype = {
+  moveTo: function(x, y) { this._context.moveTo(y, x); },
+  closePath: function() { this._context.closePath(); },
+  lineTo: function(x, y) { this._context.lineTo(y, x); },
+  bezierCurveTo: function(x1, y1, x2, y2, x, y) { this._context.bezierCurveTo(y1, x1, y2, x2, y, x); }
+};
+
+export function monotoneX(context) {
+  return new MonotoneX(context);
+}
+
+export function monotoneY(context) {
+  return new MonotoneY(context);
+}
Index: node_modules/d3-shape/src/curve/natural.js
===================================================================
--- node_modules/d3-shape/src/curve/natural.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/natural.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,65 @@
+function Natural(context) {
+  this._context = context;
+}
+
+Natural.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x = [];
+    this._y = [];
+  },
+  lineEnd: function() {
+    var x = this._x,
+        y = this._y,
+        n = x.length;
+
+    if (n) {
+      this._line ? this._context.lineTo(x[0], y[0]) : this._context.moveTo(x[0], y[0]);
+      if (n === 2) {
+        this._context.lineTo(x[1], y[1]);
+      } else {
+        var px = controlPoints(x),
+            py = controlPoints(y);
+        for (var i0 = 0, i1 = 1; i1 < n; ++i0, ++i1) {
+          this._context.bezierCurveTo(px[0][i0], py[0][i0], px[1][i0], py[1][i0], x[i1], y[i1]);
+        }
+      }
+    }
+
+    if (this._line || (this._line !== 0 && n === 1)) this._context.closePath();
+    this._line = 1 - this._line;
+    this._x = this._y = null;
+  },
+  point: function(x, y) {
+    this._x.push(+x);
+    this._y.push(+y);
+  }
+};
+
+// See https://www.particleincell.com/2012/bezier-splines/ for derivation.
+function controlPoints(x) {
+  var i,
+      n = x.length - 1,
+      m,
+      a = new Array(n),
+      b = new Array(n),
+      r = new Array(n);
+  a[0] = 0, b[0] = 2, r[0] = x[0] + 2 * x[1];
+  for (i = 1; i < n - 1; ++i) a[i] = 1, b[i] = 4, r[i] = 4 * x[i] + 2 * x[i + 1];
+  a[n - 1] = 2, b[n - 1] = 7, r[n - 1] = 8 * x[n - 1] + x[n];
+  for (i = 1; i < n; ++i) m = a[i] / b[i - 1], b[i] -= m, r[i] -= m * r[i - 1];
+  a[n - 1] = r[n - 1] / b[n - 1];
+  for (i = n - 2; i >= 0; --i) a[i] = (r[i] - a[i + 1]) / b[i];
+  b[n - 1] = (x[n] + a[n - 1]) / 2;
+  for (i = 0; i < n - 1; ++i) b[i] = 2 * x[i + 1] - a[i + 1];
+  return [a, b];
+}
+
+export default function(context) {
+  return new Natural(context);
+}
Index: node_modules/d3-shape/src/curve/radial.js
===================================================================
--- node_modules/d3-shape/src/curve/radial.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/radial.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,36 @@
+import curveLinear from "./linear.js";
+
+export var curveRadialLinear = curveRadial(curveLinear);
+
+function Radial(curve) {
+  this._curve = curve;
+}
+
+Radial.prototype = {
+  areaStart: function() {
+    this._curve.areaStart();
+  },
+  areaEnd: function() {
+    this._curve.areaEnd();
+  },
+  lineStart: function() {
+    this._curve.lineStart();
+  },
+  lineEnd: function() {
+    this._curve.lineEnd();
+  },
+  point: function(a, r) {
+    this._curve.point(r * Math.sin(a), r * -Math.cos(a));
+  }
+};
+
+export default function curveRadial(curve) {
+
+  function radial(context) {
+    return new Radial(curve(context));
+  }
+
+  radial._curve = curve;
+
+  return radial;
+}
Index: node_modules/d3-shape/src/curve/step.js
===================================================================
--- node_modules/d3-shape/src/curve/step.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-shape/src/curve/step.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,53 @@
+function Step(context, t) {
+  this._context = context;
+  this._t = t;
+}
+
+Step.prototype = {
+  areaStart: function() {
+    this._line = 0;
+  },
+  areaEnd: function() {
+    this._line = NaN;
+  },
+  lineStart: function() {
+    this._x = this._y = NaN;
+    this._point = 0;
+  },
+  lineEnd: function() {
+    if (0 < this._t && this._t < 1 && this._point === 2) this._context.lineTo(this._x, this._y);
+    if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath();
+    if (this._line >= 0) this._t = 1 - this._t, 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; // falls through
+      default: {
+        if (this._t <= 0) {
+          this._context.lineTo(this._x, y);
+          this._context.lineTo(x, y);
+        } else {
+          var x1 = this._x * (1 - this._t) + x * this._t;
+          this._context.lineTo(x1, this._y);
+          this._context.lineTo(x1, y);
+        }
+        break;
+      }
+    }
+    this._x = x, this._y = y;
+  }
+};
+
+export default function(context) {
+  return new Step(context, 0.5);
+}
+
+export function stepBefore(context) {
+  return new Step(context, 0);
+}
+
+export function stepAfter(context) {
+  return new Step(context, 1);
+}