Index: node_modules/d3-zoom/src/zoom.js
===================================================================
--- node_modules/d3-zoom/src/zoom.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-zoom/src/zoom.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,447 @@
+import {dispatch} from "d3-dispatch";
+import {dragDisable, dragEnable} from "d3-drag";
+import {interpolateZoom} from "d3-interpolate";
+import {select, pointer} from "d3-selection";
+import {interrupt} from "d3-transition";
+import constant from "./constant.js";
+import ZoomEvent from "./event.js";
+import {Transform, identity} from "./transform.js";
+import noevent, {nopropagation} from "./noevent.js";
+
+// Ignore right-click, since that should open the context menu.
+// except for pinch-to-zoom, which is sent as a wheel+ctrlKey event
+function defaultFilter(event) {
+  return (!event.ctrlKey || event.type === 'wheel') && !event.button;
+}
+
+function defaultExtent() {
+  var e = this;
+  if (e instanceof SVGElement) {
+    e = e.ownerSVGElement || e;
+    if (e.hasAttribute("viewBox")) {
+      e = e.viewBox.baseVal;
+      return [[e.x, e.y], [e.x + e.width, e.y + e.height]];
+    }
+    return [[0, 0], [e.width.baseVal.value, e.height.baseVal.value]];
+  }
+  return [[0, 0], [e.clientWidth, e.clientHeight]];
+}
+
+function defaultTransform() {
+  return this.__zoom || identity;
+}
+
+function defaultWheelDelta(event) {
+  return -event.deltaY * (event.deltaMode === 1 ? 0.05 : event.deltaMode ? 1 : 0.002) * (event.ctrlKey ? 10 : 1);
+}
+
+function defaultTouchable() {
+  return navigator.maxTouchPoints || ("ontouchstart" in this);
+}
+
+function defaultConstrain(transform, extent, translateExtent) {
+  var dx0 = transform.invertX(extent[0][0]) - translateExtent[0][0],
+      dx1 = transform.invertX(extent[1][0]) - translateExtent[1][0],
+      dy0 = transform.invertY(extent[0][1]) - translateExtent[0][1],
+      dy1 = transform.invertY(extent[1][1]) - translateExtent[1][1];
+  return transform.translate(
+    dx1 > dx0 ? (dx0 + dx1) / 2 : Math.min(0, dx0) || Math.max(0, dx1),
+    dy1 > dy0 ? (dy0 + dy1) / 2 : Math.min(0, dy0) || Math.max(0, dy1)
+  );
+}
+
+export default function() {
+  var filter = defaultFilter,
+      extent = defaultExtent,
+      constrain = defaultConstrain,
+      wheelDelta = defaultWheelDelta,
+      touchable = defaultTouchable,
+      scaleExtent = [0, Infinity],
+      translateExtent = [[-Infinity, -Infinity], [Infinity, Infinity]],
+      duration = 250,
+      interpolate = interpolateZoom,
+      listeners = dispatch("start", "zoom", "end"),
+      touchstarting,
+      touchfirst,
+      touchending,
+      touchDelay = 500,
+      wheelDelay = 150,
+      clickDistance2 = 0,
+      tapDistance = 10;
+
+  function zoom(selection) {
+    selection
+        .property("__zoom", defaultTransform)
+        .on("wheel.zoom", wheeled, {passive: false})
+        .on("mousedown.zoom", mousedowned)
+        .on("dblclick.zoom", dblclicked)
+      .filter(touchable)
+        .on("touchstart.zoom", touchstarted)
+        .on("touchmove.zoom", touchmoved)
+        .on("touchend.zoom touchcancel.zoom", touchended)
+        .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");
+  }
+
+  zoom.transform = function(collection, transform, point, event) {
+    var selection = collection.selection ? collection.selection() : collection;
+    selection.property("__zoom", defaultTransform);
+    if (collection !== selection) {
+      schedule(collection, transform, point, event);
+    } else {
+      selection.interrupt().each(function() {
+        gesture(this, arguments)
+          .event(event)
+          .start()
+          .zoom(null, typeof transform === "function" ? transform.apply(this, arguments) : transform)
+          .end();
+      });
+    }
+  };
+
+  zoom.scaleBy = function(selection, k, p, event) {
+    zoom.scaleTo(selection, function() {
+      var k0 = this.__zoom.k,
+          k1 = typeof k === "function" ? k.apply(this, arguments) : k;
+      return k0 * k1;
+    }, p, event);
+  };
+
+  zoom.scaleTo = function(selection, k, p, event) {
+    zoom.transform(selection, function() {
+      var e = extent.apply(this, arguments),
+          t0 = this.__zoom,
+          p0 = p == null ? centroid(e) : typeof p === "function" ? p.apply(this, arguments) : p,
+          p1 = t0.invert(p0),
+          k1 = typeof k === "function" ? k.apply(this, arguments) : k;
+      return constrain(translate(scale(t0, k1), p0, p1), e, translateExtent);
+    }, p, event);
+  };
+
+  zoom.translateBy = function(selection, x, y, event) {
+    zoom.transform(selection, function() {
+      return constrain(this.__zoom.translate(
+        typeof x === "function" ? x.apply(this, arguments) : x,
+        typeof y === "function" ? y.apply(this, arguments) : y
+      ), extent.apply(this, arguments), translateExtent);
+    }, null, event);
+  };
+
+  zoom.translateTo = function(selection, x, y, p, event) {
+    zoom.transform(selection, function() {
+      var e = extent.apply(this, arguments),
+          t = this.__zoom,
+          p0 = p == null ? centroid(e) : typeof p === "function" ? p.apply(this, arguments) : p;
+      return constrain(identity.translate(p0[0], p0[1]).scale(t.k).translate(
+        typeof x === "function" ? -x.apply(this, arguments) : -x,
+        typeof y === "function" ? -y.apply(this, arguments) : -y
+      ), e, translateExtent);
+    }, p, event);
+  };
+
+  function scale(transform, k) {
+    k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], k));
+    return k === transform.k ? transform : new Transform(k, transform.x, transform.y);
+  }
+
+  function translate(transform, p0, p1) {
+    var x = p0[0] - p1[0] * transform.k, y = p0[1] - p1[1] * transform.k;
+    return x === transform.x && y === transform.y ? transform : new Transform(transform.k, x, y);
+  }
+
+  function centroid(extent) {
+    return [(+extent[0][0] + +extent[1][0]) / 2, (+extent[0][1] + +extent[1][1]) / 2];
+  }
+
+  function schedule(transition, transform, point, event) {
+    transition
+        .on("start.zoom", function() { gesture(this, arguments).event(event).start(); })
+        .on("interrupt.zoom end.zoom", function() { gesture(this, arguments).event(event).end(); })
+        .tween("zoom", function() {
+          var that = this,
+              args = arguments,
+              g = gesture(that, args).event(event),
+              e = extent.apply(that, args),
+              p = point == null ? centroid(e) : typeof point === "function" ? point.apply(that, args) : point,
+              w = Math.max(e[1][0] - e[0][0], e[1][1] - e[0][1]),
+              a = that.__zoom,
+              b = typeof transform === "function" ? transform.apply(that, args) : transform,
+              i = interpolate(a.invert(p).concat(w / a.k), b.invert(p).concat(w / b.k));
+          return function(t) {
+            if (t === 1) t = b; // Avoid rounding error on end.
+            else { var l = i(t), k = w / l[2]; t = new Transform(k, p[0] - l[0] * k, p[1] - l[1] * k); }
+            g.zoom(null, t);
+          };
+        });
+  }
+
+  function gesture(that, args, clean) {
+    return (!clean && that.__zooming) || new Gesture(that, args);
+  }
+
+  function Gesture(that, args) {
+    this.that = that;
+    this.args = args;
+    this.active = 0;
+    this.sourceEvent = null;
+    this.extent = extent.apply(that, args);
+    this.taps = 0;
+  }
+
+  Gesture.prototype = {
+    event: function(event) {
+      if (event) this.sourceEvent = event;
+      return this;
+    },
+    start: function() {
+      if (++this.active === 1) {
+        this.that.__zooming = this;
+        this.emit("start");
+      }
+      return this;
+    },
+    zoom: function(key, transform) {
+      if (this.mouse && key !== "mouse") this.mouse[1] = transform.invert(this.mouse[0]);
+      if (this.touch0 && key !== "touch") this.touch0[1] = transform.invert(this.touch0[0]);
+      if (this.touch1 && key !== "touch") this.touch1[1] = transform.invert(this.touch1[0]);
+      this.that.__zoom = transform;
+      this.emit("zoom");
+      return this;
+    },
+    end: function() {
+      if (--this.active === 0) {
+        delete this.that.__zooming;
+        this.emit("end");
+      }
+      return this;
+    },
+    emit: function(type) {
+      var d = select(this.that).datum();
+      listeners.call(
+        type,
+        this.that,
+        new ZoomEvent(type, {
+          sourceEvent: this.sourceEvent,
+          target: zoom,
+          type,
+          transform: this.that.__zoom,
+          dispatch: listeners
+        }),
+        d
+      );
+    }
+  };
+
+  function wheeled(event, ...args) {
+    if (!filter.apply(this, arguments)) return;
+    var g = gesture(this, args).event(event),
+        t = this.__zoom,
+        k = Math.max(scaleExtent[0], Math.min(scaleExtent[1], t.k * Math.pow(2, wheelDelta.apply(this, arguments)))),
+        p = pointer(event);
+
+    // If the mouse is in the same location as before, reuse it.
+    // If there were recent wheel events, reset the wheel idle timeout.
+    if (g.wheel) {
+      if (g.mouse[0][0] !== p[0] || g.mouse[0][1] !== p[1]) {
+        g.mouse[1] = t.invert(g.mouse[0] = p);
+      }
+      clearTimeout(g.wheel);
+    }
+
+    // If this wheel event won’t trigger a transform change, ignore it.
+    else if (t.k === k) return;
+
+    // Otherwise, capture the mouse point and location at the start.
+    else {
+      g.mouse = [p, t.invert(p)];
+      interrupt(this);
+      g.start();
+    }
+
+    noevent(event);
+    g.wheel = setTimeout(wheelidled, wheelDelay);
+    g.zoom("mouse", constrain(translate(scale(t, k), g.mouse[0], g.mouse[1]), g.extent, translateExtent));
+
+    function wheelidled() {
+      g.wheel = null;
+      g.end();
+    }
+  }
+
+  function mousedowned(event, ...args) {
+    if (touchending || !filter.apply(this, arguments)) return;
+    var currentTarget = event.currentTarget,
+        g = gesture(this, args, true).event(event),
+        v = select(event.view).on("mousemove.zoom", mousemoved, true).on("mouseup.zoom", mouseupped, true),
+        p = pointer(event, currentTarget),
+        x0 = event.clientX,
+        y0 = event.clientY;
+
+    dragDisable(event.view);
+    nopropagation(event);
+    g.mouse = [p, this.__zoom.invert(p)];
+    interrupt(this);
+    g.start();
+
+    function mousemoved(event) {
+      noevent(event);
+      if (!g.moved) {
+        var dx = event.clientX - x0, dy = event.clientY - y0;
+        g.moved = dx * dx + dy * dy > clickDistance2;
+      }
+      g.event(event)
+       .zoom("mouse", constrain(translate(g.that.__zoom, g.mouse[0] = pointer(event, currentTarget), g.mouse[1]), g.extent, translateExtent));
+    }
+
+    function mouseupped(event) {
+      v.on("mousemove.zoom mouseup.zoom", null);
+      dragEnable(event.view, g.moved);
+      noevent(event);
+      g.event(event).end();
+    }
+  }
+
+  function dblclicked(event, ...args) {
+    if (!filter.apply(this, arguments)) return;
+    var t0 = this.__zoom,
+        p0 = pointer(event.changedTouches ? event.changedTouches[0] : event, this),
+        p1 = t0.invert(p0),
+        k1 = t0.k * (event.shiftKey ? 0.5 : 2),
+        t1 = constrain(translate(scale(t0, k1), p0, p1), extent.apply(this, args), translateExtent);
+
+    noevent(event);
+    if (duration > 0) select(this).transition().duration(duration).call(schedule, t1, p0, event);
+    else select(this).call(zoom.transform, t1, p0, event);
+  }
+
+  function touchstarted(event, ...args) {
+    if (!filter.apply(this, arguments)) return;
+    var touches = event.touches,
+        n = touches.length,
+        g = gesture(this, args, event.changedTouches.length === n).event(event),
+        started, i, t, p;
+
+    nopropagation(event);
+    for (i = 0; i < n; ++i) {
+      t = touches[i], p = pointer(t, this);
+      p = [p, this.__zoom.invert(p), t.identifier];
+      if (!g.touch0) g.touch0 = p, started = true, g.taps = 1 + !!touchstarting;
+      else if (!g.touch1 && g.touch0[2] !== p[2]) g.touch1 = p, g.taps = 0;
+    }
+
+    if (touchstarting) touchstarting = clearTimeout(touchstarting);
+
+    if (started) {
+      if (g.taps < 2) touchfirst = p[0], touchstarting = setTimeout(function() { touchstarting = null; }, touchDelay);
+      interrupt(this);
+      g.start();
+    }
+  }
+
+  function touchmoved(event, ...args) {
+    if (!this.__zooming) return;
+    var g = gesture(this, args).event(event),
+        touches = event.changedTouches,
+        n = touches.length, i, t, p, l;
+
+    noevent(event);
+    for (i = 0; i < n; ++i) {
+      t = touches[i], p = pointer(t, this);
+      if (g.touch0 && g.touch0[2] === t.identifier) g.touch0[0] = p;
+      else if (g.touch1 && g.touch1[2] === t.identifier) g.touch1[0] = p;
+    }
+    t = g.that.__zoom;
+    if (g.touch1) {
+      var p0 = g.touch0[0], l0 = g.touch0[1],
+          p1 = g.touch1[0], l1 = g.touch1[1],
+          dp = (dp = p1[0] - p0[0]) * dp + (dp = p1[1] - p0[1]) * dp,
+          dl = (dl = l1[0] - l0[0]) * dl + (dl = l1[1] - l0[1]) * dl;
+      t = scale(t, Math.sqrt(dp / dl));
+      p = [(p0[0] + p1[0]) / 2, (p0[1] + p1[1]) / 2];
+      l = [(l0[0] + l1[0]) / 2, (l0[1] + l1[1]) / 2];
+    }
+    else if (g.touch0) p = g.touch0[0], l = g.touch0[1];
+    else return;
+
+    g.zoom("touch", constrain(translate(t, p, l), g.extent, translateExtent));
+  }
+
+  function touchended(event, ...args) {
+    if (!this.__zooming) return;
+    var g = gesture(this, args).event(event),
+        touches = event.changedTouches,
+        n = touches.length, i, t;
+
+    nopropagation(event);
+    if (touchending) clearTimeout(touchending);
+    touchending = setTimeout(function() { touchending = null; }, touchDelay);
+    for (i = 0; i < n; ++i) {
+      t = touches[i];
+      if (g.touch0 && g.touch0[2] === t.identifier) delete g.touch0;
+      else if (g.touch1 && g.touch1[2] === t.identifier) delete g.touch1;
+    }
+    if (g.touch1 && !g.touch0) g.touch0 = g.touch1, delete g.touch1;
+    if (g.touch0) g.touch0[1] = this.__zoom.invert(g.touch0[0]);
+    else {
+      g.end();
+      // If this was a dbltap, reroute to the (optional) dblclick.zoom handler.
+      if (g.taps === 2) {
+        t = pointer(t, this);
+        if (Math.hypot(touchfirst[0] - t[0], touchfirst[1] - t[1]) < tapDistance) {
+          var p = select(this).on("dblclick.zoom");
+          if (p) p.apply(this, arguments);
+        }
+      }
+    }
+  }
+
+  zoom.wheelDelta = function(_) {
+    return arguments.length ? (wheelDelta = typeof _ === "function" ? _ : constant(+_), zoom) : wheelDelta;
+  };
+
+  zoom.filter = function(_) {
+    return arguments.length ? (filter = typeof _ === "function" ? _ : constant(!!_), zoom) : filter;
+  };
+
+  zoom.touchable = function(_) {
+    return arguments.length ? (touchable = typeof _ === "function" ? _ : constant(!!_), zoom) : touchable;
+  };
+
+  zoom.extent = function(_) {
+    return arguments.length ? (extent = typeof _ === "function" ? _ : constant([[+_[0][0], +_[0][1]], [+_[1][0], +_[1][1]]]), zoom) : extent;
+  };
+
+  zoom.scaleExtent = function(_) {
+    return arguments.length ? (scaleExtent[0] = +_[0], scaleExtent[1] = +_[1], zoom) : [scaleExtent[0], scaleExtent[1]];
+  };
+
+  zoom.translateExtent = function(_) {
+    return arguments.length ? (translateExtent[0][0] = +_[0][0], translateExtent[1][0] = +_[1][0], translateExtent[0][1] = +_[0][1], translateExtent[1][1] = +_[1][1], zoom) : [[translateExtent[0][0], translateExtent[0][1]], [translateExtent[1][0], translateExtent[1][1]]];
+  };
+
+  zoom.constrain = function(_) {
+    return arguments.length ? (constrain = _, zoom) : constrain;
+  };
+
+  zoom.duration = function(_) {
+    return arguments.length ? (duration = +_, zoom) : duration;
+  };
+
+  zoom.interpolate = function(_) {
+    return arguments.length ? (interpolate = _, zoom) : interpolate;
+  };
+
+  zoom.on = function() {
+    var value = listeners.on.apply(listeners, arguments);
+    return value === listeners ? zoom : value;
+  };
+
+  zoom.clickDistance = function(_) {
+    return arguments.length ? (clickDistance2 = (_ = +_) * _, zoom) : Math.sqrt(clickDistance2);
+  };
+
+  zoom.tapDistance = function(_) {
+    return arguments.length ? (tapDistance = +_, zoom) : tapDistance;
+  };
+
+  return zoom;
+}