Index: node_modules/d3-delaunay/dist/d3-delaunay.js
===================================================================
--- node_modules/d3-delaunay/dist/d3-delaunay.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
+++ node_modules/d3-delaunay/dist/d3-delaunay.js	(revision e4c61dd6cd86e06265bc2bd91adba84a0f04044a)
@@ -0,0 +1,1391 @@
+// https://github.com/d3/d3-delaunay v6.0.4 Copyright 2018-2021 Observable, Inc., 2021 Mapbox
+(function (global, factory) {
+typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
+typeof define === 'function' && define.amd ? define(['exports'], factory) :
+(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.d3 = global.d3 || {}));
+}(this, (function (exports) { 'use strict';
+
+const epsilon$1 = 1.1102230246251565e-16;
+const splitter = 134217729;
+const resulterrbound = (3 + 8 * epsilon$1) * epsilon$1;
+
+// fast_expansion_sum_zeroelim routine from oritinal code
+function sum(elen, e, flen, f, h) {
+    let Q, Qnew, hh, bvirt;
+    let enow = e[0];
+    let fnow = f[0];
+    let eindex = 0;
+    let findex = 0;
+    if ((fnow > enow) === (fnow > -enow)) {
+        Q = enow;
+        enow = e[++eindex];
+    } else {
+        Q = fnow;
+        fnow = f[++findex];
+    }
+    let hindex = 0;
+    if (eindex < elen && findex < flen) {
+        if ((fnow > enow) === (fnow > -enow)) {
+            Qnew = enow + Q;
+            hh = Q - (Qnew - enow);
+            enow = e[++eindex];
+        } else {
+            Qnew = fnow + Q;
+            hh = Q - (Qnew - fnow);
+            fnow = f[++findex];
+        }
+        Q = Qnew;
+        if (hh !== 0) {
+            h[hindex++] = hh;
+        }
+        while (eindex < elen && findex < flen) {
+            if ((fnow > enow) === (fnow > -enow)) {
+                Qnew = Q + enow;
+                bvirt = Qnew - Q;
+                hh = Q - (Qnew - bvirt) + (enow - bvirt);
+                enow = e[++eindex];
+            } else {
+                Qnew = Q + fnow;
+                bvirt = Qnew - Q;
+                hh = Q - (Qnew - bvirt) + (fnow - bvirt);
+                fnow = f[++findex];
+            }
+            Q = Qnew;
+            if (hh !== 0) {
+                h[hindex++] = hh;
+            }
+        }
+    }
+    while (eindex < elen) {
+        Qnew = Q + enow;
+        bvirt = Qnew - Q;
+        hh = Q - (Qnew - bvirt) + (enow - bvirt);
+        enow = e[++eindex];
+        Q = Qnew;
+        if (hh !== 0) {
+            h[hindex++] = hh;
+        }
+    }
+    while (findex < flen) {
+        Qnew = Q + fnow;
+        bvirt = Qnew - Q;
+        hh = Q - (Qnew - bvirt) + (fnow - bvirt);
+        fnow = f[++findex];
+        Q = Qnew;
+        if (hh !== 0) {
+            h[hindex++] = hh;
+        }
+    }
+    if (Q !== 0 || hindex === 0) {
+        h[hindex++] = Q;
+    }
+    return hindex;
+}
+
+function estimate(elen, e) {
+    let Q = e[0];
+    for (let i = 1; i < elen; i++) Q += e[i];
+    return Q;
+}
+
+function vec(n) {
+    return new Float64Array(n);
+}
+
+const ccwerrboundA = (3 + 16 * epsilon$1) * epsilon$1;
+const ccwerrboundB = (2 + 12 * epsilon$1) * epsilon$1;
+const ccwerrboundC = (9 + 64 * epsilon$1) * epsilon$1 * epsilon$1;
+
+const B = vec(4);
+const C1 = vec(8);
+const C2 = vec(12);
+const D = vec(16);
+const u = vec(4);
+
+function orient2dadapt(ax, ay, bx, by, cx, cy, detsum) {
+    let acxtail, acytail, bcxtail, bcytail;
+    let bvirt, c, ahi, alo, bhi, blo, _i, _j, _0, s1, s0, t1, t0, u3;
+
+    const acx = ax - cx;
+    const bcx = bx - cx;
+    const acy = ay - cy;
+    const bcy = by - cy;
+
+    s1 = acx * bcy;
+    c = splitter * acx;
+    ahi = c - (c - acx);
+    alo = acx - ahi;
+    c = splitter * bcy;
+    bhi = c - (c - bcy);
+    blo = bcy - bhi;
+    s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
+    t1 = acy * bcx;
+    c = splitter * acy;
+    ahi = c - (c - acy);
+    alo = acy - ahi;
+    c = splitter * bcx;
+    bhi = c - (c - bcx);
+    blo = bcx - bhi;
+    t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
+    _i = s0 - t0;
+    bvirt = s0 - _i;
+    B[0] = s0 - (_i + bvirt) + (bvirt - t0);
+    _j = s1 + _i;
+    bvirt = _j - s1;
+    _0 = s1 - (_j - bvirt) + (_i - bvirt);
+    _i = _0 - t1;
+    bvirt = _0 - _i;
+    B[1] = _0 - (_i + bvirt) + (bvirt - t1);
+    u3 = _j + _i;
+    bvirt = u3 - _j;
+    B[2] = _j - (u3 - bvirt) + (_i - bvirt);
+    B[3] = u3;
+
+    let det = estimate(4, B);
+    let errbound = ccwerrboundB * detsum;
+    if (det >= errbound || -det >= errbound) {
+        return det;
+    }
+
+    bvirt = ax - acx;
+    acxtail = ax - (acx + bvirt) + (bvirt - cx);
+    bvirt = bx - bcx;
+    bcxtail = bx - (bcx + bvirt) + (bvirt - cx);
+    bvirt = ay - acy;
+    acytail = ay - (acy + bvirt) + (bvirt - cy);
+    bvirt = by - bcy;
+    bcytail = by - (bcy + bvirt) + (bvirt - cy);
+
+    if (acxtail === 0 && acytail === 0 && bcxtail === 0 && bcytail === 0) {
+        return det;
+    }
+
+    errbound = ccwerrboundC * detsum + resulterrbound * Math.abs(det);
+    det += (acx * bcytail + bcy * acxtail) - (acy * bcxtail + bcx * acytail);
+    if (det >= errbound || -det >= errbound) return det;
+
+    s1 = acxtail * bcy;
+    c = splitter * acxtail;
+    ahi = c - (c - acxtail);
+    alo = acxtail - ahi;
+    c = splitter * bcy;
+    bhi = c - (c - bcy);
+    blo = bcy - bhi;
+    s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
+    t1 = acytail * bcx;
+    c = splitter * acytail;
+    ahi = c - (c - acytail);
+    alo = acytail - ahi;
+    c = splitter * bcx;
+    bhi = c - (c - bcx);
+    blo = bcx - bhi;
+    t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
+    _i = s0 - t0;
+    bvirt = s0 - _i;
+    u[0] = s0 - (_i + bvirt) + (bvirt - t0);
+    _j = s1 + _i;
+    bvirt = _j - s1;
+    _0 = s1 - (_j - bvirt) + (_i - bvirt);
+    _i = _0 - t1;
+    bvirt = _0 - _i;
+    u[1] = _0 - (_i + bvirt) + (bvirt - t1);
+    u3 = _j + _i;
+    bvirt = u3 - _j;
+    u[2] = _j - (u3 - bvirt) + (_i - bvirt);
+    u[3] = u3;
+    const C1len = sum(4, B, 4, u, C1);
+
+    s1 = acx * bcytail;
+    c = splitter * acx;
+    ahi = c - (c - acx);
+    alo = acx - ahi;
+    c = splitter * bcytail;
+    bhi = c - (c - bcytail);
+    blo = bcytail - bhi;
+    s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
+    t1 = acy * bcxtail;
+    c = splitter * acy;
+    ahi = c - (c - acy);
+    alo = acy - ahi;
+    c = splitter * bcxtail;
+    bhi = c - (c - bcxtail);
+    blo = bcxtail - bhi;
+    t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
+    _i = s0 - t0;
+    bvirt = s0 - _i;
+    u[0] = s0 - (_i + bvirt) + (bvirt - t0);
+    _j = s1 + _i;
+    bvirt = _j - s1;
+    _0 = s1 - (_j - bvirt) + (_i - bvirt);
+    _i = _0 - t1;
+    bvirt = _0 - _i;
+    u[1] = _0 - (_i + bvirt) + (bvirt - t1);
+    u3 = _j + _i;
+    bvirt = u3 - _j;
+    u[2] = _j - (u3 - bvirt) + (_i - bvirt);
+    u[3] = u3;
+    const C2len = sum(C1len, C1, 4, u, C2);
+
+    s1 = acxtail * bcytail;
+    c = splitter * acxtail;
+    ahi = c - (c - acxtail);
+    alo = acxtail - ahi;
+    c = splitter * bcytail;
+    bhi = c - (c - bcytail);
+    blo = bcytail - bhi;
+    s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
+    t1 = acytail * bcxtail;
+    c = splitter * acytail;
+    ahi = c - (c - acytail);
+    alo = acytail - ahi;
+    c = splitter * bcxtail;
+    bhi = c - (c - bcxtail);
+    blo = bcxtail - bhi;
+    t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
+    _i = s0 - t0;
+    bvirt = s0 - _i;
+    u[0] = s0 - (_i + bvirt) + (bvirt - t0);
+    _j = s1 + _i;
+    bvirt = _j - s1;
+    _0 = s1 - (_j - bvirt) + (_i - bvirt);
+    _i = _0 - t1;
+    bvirt = _0 - _i;
+    u[1] = _0 - (_i + bvirt) + (bvirt - t1);
+    u3 = _j + _i;
+    bvirt = u3 - _j;
+    u[2] = _j - (u3 - bvirt) + (_i - bvirt);
+    u[3] = u3;
+    const Dlen = sum(C2len, C2, 4, u, D);
+
+    return D[Dlen - 1];
+}
+
+function orient2d(ax, ay, bx, by, cx, cy) {
+    const detleft = (ay - cy) * (bx - cx);
+    const detright = (ax - cx) * (by - cy);
+    const det = detleft - detright;
+
+    if (detleft === 0 || detright === 0 || (detleft > 0) !== (detright > 0)) return det;
+
+    const detsum = Math.abs(detleft + detright);
+    if (Math.abs(det) >= ccwerrboundA * detsum) return det;
+
+    return -orient2dadapt(ax, ay, bx, by, cx, cy, detsum);
+}
+
+const EPSILON = Math.pow(2, -52);
+const EDGE_STACK = new Uint32Array(512);
+
+class Delaunator {
+
+    static from(points, getX = defaultGetX, getY = defaultGetY) {
+        const n = points.length;
+        const coords = new Float64Array(n * 2);
+
+        for (let i = 0; i < n; i++) {
+            const p = points[i];
+            coords[2 * i] = getX(p);
+            coords[2 * i + 1] = getY(p);
+        }
+
+        return new Delaunator(coords);
+    }
+
+    constructor(coords) {
+        const n = coords.length >> 1;
+        if (n > 0 && typeof coords[0] !== 'number') throw new Error('Expected coords to contain numbers.');
+
+        this.coords = coords;
+
+        // arrays that will store the triangulation graph
+        const maxTriangles = Math.max(2 * n - 5, 0);
+        this._triangles = new Uint32Array(maxTriangles * 3);
+        this._halfedges = new Int32Array(maxTriangles * 3);
+
+        // temporary arrays for tracking the edges of the advancing convex hull
+        this._hashSize = Math.ceil(Math.sqrt(n));
+        this._hullPrev = new Uint32Array(n); // edge to prev edge
+        this._hullNext = new Uint32Array(n); // edge to next edge
+        this._hullTri = new Uint32Array(n); // edge to adjacent triangle
+        this._hullHash = new Int32Array(this._hashSize).fill(-1); // angular edge hash
+
+        // temporary arrays for sorting points
+        this._ids = new Uint32Array(n);
+        this._dists = new Float64Array(n);
+
+        this.update();
+    }
+
+    update() {
+        const {coords, _hullPrev: hullPrev, _hullNext: hullNext, _hullTri: hullTri, _hullHash: hullHash} =  this;
+        const n = coords.length >> 1;
+
+        // populate an array of point indices; calculate input data bbox
+        let minX = Infinity;
+        let minY = Infinity;
+        let maxX = -Infinity;
+        let maxY = -Infinity;
+
+        for (let i = 0; i < n; i++) {
+            const x = coords[2 * i];
+            const y = coords[2 * i + 1];
+            if (x < minX) minX = x;
+            if (y < minY) minY = y;
+            if (x > maxX) maxX = x;
+            if (y > maxY) maxY = y;
+            this._ids[i] = i;
+        }
+        const cx = (minX + maxX) / 2;
+        const cy = (minY + maxY) / 2;
+
+        let minDist = Infinity;
+        let i0, i1, i2;
+
+        // pick a seed point close to the center
+        for (let i = 0; i < n; i++) {
+            const d = dist(cx, cy, coords[2 * i], coords[2 * i + 1]);
+            if (d < minDist) {
+                i0 = i;
+                minDist = d;
+            }
+        }
+        const i0x = coords[2 * i0];
+        const i0y = coords[2 * i0 + 1];
+
+        minDist = Infinity;
+
+        // find the point closest to the seed
+        for (let i = 0; i < n; i++) {
+            if (i === i0) continue;
+            const d = dist(i0x, i0y, coords[2 * i], coords[2 * i + 1]);
+            if (d < minDist && d > 0) {
+                i1 = i;
+                minDist = d;
+            }
+        }
+        let i1x = coords[2 * i1];
+        let i1y = coords[2 * i1 + 1];
+
+        let minRadius = Infinity;
+
+        // find the third point which forms the smallest circumcircle with the first two
+        for (let i = 0; i < n; i++) {
+            if (i === i0 || i === i1) continue;
+            const r = circumradius(i0x, i0y, i1x, i1y, coords[2 * i], coords[2 * i + 1]);
+            if (r < minRadius) {
+                i2 = i;
+                minRadius = r;
+            }
+        }
+        let i2x = coords[2 * i2];
+        let i2y = coords[2 * i2 + 1];
+
+        if (minRadius === Infinity) {
+            // order collinear points by dx (or dy if all x are identical)
+            // and return the list as a hull
+            for (let i = 0; i < n; i++) {
+                this._dists[i] = (coords[2 * i] - coords[0]) || (coords[2 * i + 1] - coords[1]);
+            }
+            quicksort(this._ids, this._dists, 0, n - 1);
+            const hull = new Uint32Array(n);
+            let j = 0;
+            for (let i = 0, d0 = -Infinity; i < n; i++) {
+                const id = this._ids[i];
+                if (this._dists[id] > d0) {
+                    hull[j++] = id;
+                    d0 = this._dists[id];
+                }
+            }
+            this.hull = hull.subarray(0, j);
+            this.triangles = new Uint32Array(0);
+            this.halfedges = new Uint32Array(0);
+            return;
+        }
+
+        // swap the order of the seed points for counter-clockwise orientation
+        if (orient2d(i0x, i0y, i1x, i1y, i2x, i2y) < 0) {
+            const i = i1;
+            const x = i1x;
+            const y = i1y;
+            i1 = i2;
+            i1x = i2x;
+            i1y = i2y;
+            i2 = i;
+            i2x = x;
+            i2y = y;
+        }
+
+        const center = circumcenter(i0x, i0y, i1x, i1y, i2x, i2y);
+        this._cx = center.x;
+        this._cy = center.y;
+
+        for (let i = 0; i < n; i++) {
+            this._dists[i] = dist(coords[2 * i], coords[2 * i + 1], center.x, center.y);
+        }
+
+        // sort the points by distance from the seed triangle circumcenter
+        quicksort(this._ids, this._dists, 0, n - 1);
+
+        // set up the seed triangle as the starting hull
+        this._hullStart = i0;
+        let hullSize = 3;
+
+        hullNext[i0] = hullPrev[i2] = i1;
+        hullNext[i1] = hullPrev[i0] = i2;
+        hullNext[i2] = hullPrev[i1] = i0;
+
+        hullTri[i0] = 0;
+        hullTri[i1] = 1;
+        hullTri[i2] = 2;
+
+        hullHash.fill(-1);
+        hullHash[this._hashKey(i0x, i0y)] = i0;
+        hullHash[this._hashKey(i1x, i1y)] = i1;
+        hullHash[this._hashKey(i2x, i2y)] = i2;
+
+        this.trianglesLen = 0;
+        this._addTriangle(i0, i1, i2, -1, -1, -1);
+
+        for (let k = 0, xp, yp; k < this._ids.length; k++) {
+            const i = this._ids[k];
+            const x = coords[2 * i];
+            const y = coords[2 * i + 1];
+
+            // skip near-duplicate points
+            if (k > 0 && Math.abs(x - xp) <= EPSILON && Math.abs(y - yp) <= EPSILON) continue;
+            xp = x;
+            yp = y;
+
+            // skip seed triangle points
+            if (i === i0 || i === i1 || i === i2) continue;
+
+            // find a visible edge on the convex hull using edge hash
+            let start = 0;
+            for (let j = 0, key = this._hashKey(x, y); j < this._hashSize; j++) {
+                start = hullHash[(key + j) % this._hashSize];
+                if (start !== -1 && start !== hullNext[start]) break;
+            }
+
+            start = hullPrev[start];
+            let e = start, q;
+            while (q = hullNext[e], orient2d(x, y, coords[2 * e], coords[2 * e + 1], coords[2 * q], coords[2 * q + 1]) >= 0) {
+                e = q;
+                if (e === start) {
+                    e = -1;
+                    break;
+                }
+            }
+            if (e === -1) continue; // likely a near-duplicate point; skip it
+
+            // add the first triangle from the point
+            let t = this._addTriangle(e, i, hullNext[e], -1, -1, hullTri[e]);
+
+            // recursively flip triangles from the point until they satisfy the Delaunay condition
+            hullTri[i] = this._legalize(t + 2);
+            hullTri[e] = t; // keep track of boundary triangles on the hull
+            hullSize++;
+
+            // walk forward through the hull, adding more triangles and flipping recursively
+            let n = hullNext[e];
+            while (q = hullNext[n], orient2d(x, y, coords[2 * n], coords[2 * n + 1], coords[2 * q], coords[2 * q + 1]) < 0) {
+                t = this._addTriangle(n, i, q, hullTri[i], -1, hullTri[n]);
+                hullTri[i] = this._legalize(t + 2);
+                hullNext[n] = n; // mark as removed
+                hullSize--;
+                n = q;
+            }
+
+            // walk backward from the other side, adding more triangles and flipping
+            if (e === start) {
+                while (q = hullPrev[e], orient2d(x, y, coords[2 * q], coords[2 * q + 1], coords[2 * e], coords[2 * e + 1]) < 0) {
+                    t = this._addTriangle(q, i, e, -1, hullTri[e], hullTri[q]);
+                    this._legalize(t + 2);
+                    hullTri[q] = t;
+                    hullNext[e] = e; // mark as removed
+                    hullSize--;
+                    e = q;
+                }
+            }
+
+            // update the hull indices
+            this._hullStart = hullPrev[i] = e;
+            hullNext[e] = hullPrev[n] = i;
+            hullNext[i] = n;
+
+            // save the two new edges in the hash table
+            hullHash[this._hashKey(x, y)] = i;
+            hullHash[this._hashKey(coords[2 * e], coords[2 * e + 1])] = e;
+        }
+
+        this.hull = new Uint32Array(hullSize);
+        for (let i = 0, e = this._hullStart; i < hullSize; i++) {
+            this.hull[i] = e;
+            e = hullNext[e];
+        }
+
+        // trim typed triangle mesh arrays
+        this.triangles = this._triangles.subarray(0, this.trianglesLen);
+        this.halfedges = this._halfedges.subarray(0, this.trianglesLen);
+    }
+
+    _hashKey(x, y) {
+        return Math.floor(pseudoAngle(x - this._cx, y - this._cy) * this._hashSize) % this._hashSize;
+    }
+
+    _legalize(a) {
+        const {_triangles: triangles, _halfedges: halfedges, coords} = this;
+
+        let i = 0;
+        let ar = 0;
+
+        // recursion eliminated with a fixed-size stack
+        while (true) {
+            const b = halfedges[a];
+
+            /* if the pair of triangles doesn't satisfy the Delaunay condition
+             * (p1 is inside the circumcircle of [p0, pl, pr]), flip them,
+             * then do the same check/flip recursively for the new pair of triangles
+             *
+             *           pl                    pl
+             *          /||\                  /  \
+             *       al/ || \bl            al/    \a
+             *        /  ||  \              /      \
+             *       /  a||b  \    flip    /___ar___\
+             *     p0\   ||   /p1   =>   p0\---bl---/p1
+             *        \  ||  /              \      /
+             *       ar\ || /br             b\    /br
+             *          \||/                  \  /
+             *           pr                    pr
+             */
+            const a0 = a - a % 3;
+            ar = a0 + (a + 2) % 3;
+
+            if (b === -1) { // convex hull edge
+                if (i === 0) break;
+                a = EDGE_STACK[--i];
+                continue;
+            }
+
+            const b0 = b - b % 3;
+            const al = a0 + (a + 1) % 3;
+            const bl = b0 + (b + 2) % 3;
+
+            const p0 = triangles[ar];
+            const pr = triangles[a];
+            const pl = triangles[al];
+            const p1 = triangles[bl];
+
+            const illegal = inCircle(
+                coords[2 * p0], coords[2 * p0 + 1],
+                coords[2 * pr], coords[2 * pr + 1],
+                coords[2 * pl], coords[2 * pl + 1],
+                coords[2 * p1], coords[2 * p1 + 1]);
+
+            if (illegal) {
+                triangles[a] = p1;
+                triangles[b] = p0;
+
+                const hbl = halfedges[bl];
+
+                // edge swapped on the other side of the hull (rare); fix the halfedge reference
+                if (hbl === -1) {
+                    let e = this._hullStart;
+                    do {
+                        if (this._hullTri[e] === bl) {
+                            this._hullTri[e] = a;
+                            break;
+                        }
+                        e = this._hullPrev[e];
+                    } while (e !== this._hullStart);
+                }
+                this._link(a, hbl);
+                this._link(b, halfedges[ar]);
+                this._link(ar, bl);
+
+                const br = b0 + (b + 1) % 3;
+
+                // don't worry about hitting the cap: it can only happen on extremely degenerate input
+                if (i < EDGE_STACK.length) {
+                    EDGE_STACK[i++] = br;
+                }
+            } else {
+                if (i === 0) break;
+                a = EDGE_STACK[--i];
+            }
+        }
+
+        return ar;
+    }
+
+    _link(a, b) {
+        this._halfedges[a] = b;
+        if (b !== -1) this._halfedges[b] = a;
+    }
+
+    // add a new triangle given vertex indices and adjacent half-edge ids
+    _addTriangle(i0, i1, i2, a, b, c) {
+        const t = this.trianglesLen;
+
+        this._triangles[t] = i0;
+        this._triangles[t + 1] = i1;
+        this._triangles[t + 2] = i2;
+
+        this._link(t, a);
+        this._link(t + 1, b);
+        this._link(t + 2, c);
+
+        this.trianglesLen += 3;
+
+        return t;
+    }
+}
+
+// monotonically increases with real angle, but doesn't need expensive trigonometry
+function pseudoAngle(dx, dy) {
+    const p = dx / (Math.abs(dx) + Math.abs(dy));
+    return (dy > 0 ? 3 - p : 1 + p) / 4; // [0..1]
+}
+
+function dist(ax, ay, bx, by) {
+    const dx = ax - bx;
+    const dy = ay - by;
+    return dx * dx + dy * dy;
+}
+
+function inCircle(ax, ay, bx, by, cx, cy, px, py) {
+    const dx = ax - px;
+    const dy = ay - py;
+    const ex = bx - px;
+    const ey = by - py;
+    const fx = cx - px;
+    const fy = cy - py;
+
+    const ap = dx * dx + dy * dy;
+    const bp = ex * ex + ey * ey;
+    const cp = fx * fx + fy * fy;
+
+    return dx * (ey * cp - bp * fy) -
+           dy * (ex * cp - bp * fx) +
+           ap * (ex * fy - ey * fx) < 0;
+}
+
+function circumradius(ax, ay, bx, by, cx, cy) {
+    const dx = bx - ax;
+    const dy = by - ay;
+    const ex = cx - ax;
+    const ey = cy - ay;
+
+    const bl = dx * dx + dy * dy;
+    const cl = ex * ex + ey * ey;
+    const d = 0.5 / (dx * ey - dy * ex);
+
+    const x = (ey * bl - dy * cl) * d;
+    const y = (dx * cl - ex * bl) * d;
+
+    return x * x + y * y;
+}
+
+function circumcenter(ax, ay, bx, by, cx, cy) {
+    const dx = bx - ax;
+    const dy = by - ay;
+    const ex = cx - ax;
+    const ey = cy - ay;
+
+    const bl = dx * dx + dy * dy;
+    const cl = ex * ex + ey * ey;
+    const d = 0.5 / (dx * ey - dy * ex);
+
+    const x = ax + (ey * bl - dy * cl) * d;
+    const y = ay + (dx * cl - ex * bl) * d;
+
+    return {x, y};
+}
+
+function quicksort(ids, dists, left, right) {
+    if (right - left <= 20) {
+        for (let i = left + 1; i <= right; i++) {
+            const temp = ids[i];
+            const tempDist = dists[temp];
+            let j = i - 1;
+            while (j >= left && dists[ids[j]] > tempDist) ids[j + 1] = ids[j--];
+            ids[j + 1] = temp;
+        }
+    } else {
+        const median = (left + right) >> 1;
+        let i = left + 1;
+        let j = right;
+        swap(ids, median, i);
+        if (dists[ids[left]] > dists[ids[right]]) swap(ids, left, right);
+        if (dists[ids[i]] > dists[ids[right]]) swap(ids, i, right);
+        if (dists[ids[left]] > dists[ids[i]]) swap(ids, left, i);
+
+        const temp = ids[i];
+        const tempDist = dists[temp];
+        while (true) {
+            do i++; while (dists[ids[i]] < tempDist);
+            do j--; while (dists[ids[j]] > tempDist);
+            if (j < i) break;
+            swap(ids, i, j);
+        }
+        ids[left + 1] = ids[j];
+        ids[j] = temp;
+
+        if (right - i + 1 >= j - left) {
+            quicksort(ids, dists, i, right);
+            quicksort(ids, dists, left, j - 1);
+        } else {
+            quicksort(ids, dists, left, j - 1);
+            quicksort(ids, dists, i, right);
+        }
+    }
+}
+
+function swap(arr, i, j) {
+    const tmp = arr[i];
+    arr[i] = arr[j];
+    arr[j] = tmp;
+}
+
+function defaultGetX(p) {
+    return p[0];
+}
+function defaultGetY(p) {
+    return p[1];
+}
+
+const epsilon = 1e-6;
+
+class Path {
+  constructor() {
+    this._x0 = this._y0 = // start of current subpath
+    this._x1 = this._y1 = null; // end of current subpath
+    this._ = "";
+  }
+  moveTo(x, y) {
+    this._ += `M${this._x0 = this._x1 = +x},${this._y0 = this._y1 = +y}`;
+  }
+  closePath() {
+    if (this._x1 !== null) {
+      this._x1 = this._x0, this._y1 = this._y0;
+      this._ += "Z";
+    }
+  }
+  lineTo(x, y) {
+    this._ += `L${this._x1 = +x},${this._y1 = +y}`;
+  }
+  arc(x, y, r) {
+    x = +x, y = +y, r = +r;
+    const x0 = x + r;
+    const y0 = y;
+    if (r < 0) throw new Error("negative radius");
+    if (this._x1 === null) this._ += `M${x0},${y0}`;
+    else if (Math.abs(this._x1 - x0) > epsilon || Math.abs(this._y1 - y0) > epsilon) this._ += "L" + x0 + "," + y0;
+    if (!r) return;
+    this._ += `A${r},${r},0,1,1,${x - r},${y}A${r},${r},0,1,1,${this._x1 = x0},${this._y1 = y0}`;
+  }
+  rect(x, y, w, h) {
+    this._ += `M${this._x0 = this._x1 = +x},${this._y0 = this._y1 = +y}h${+w}v${+h}h${-w}Z`;
+  }
+  value() {
+    return this._ || null;
+  }
+}
+
+class Polygon {
+  constructor() {
+    this._ = [];
+  }
+  moveTo(x, y) {
+    this._.push([x, y]);
+  }
+  closePath() {
+    this._.push(this._[0].slice());
+  }
+  lineTo(x, y) {
+    this._.push([x, y]);
+  }
+  value() {
+    return this._.length ? this._ : null;
+  }
+}
+
+class Voronoi {
+  constructor(delaunay, [xmin, ymin, xmax, ymax] = [0, 0, 960, 500]) {
+    if (!((xmax = +xmax) >= (xmin = +xmin)) || !((ymax = +ymax) >= (ymin = +ymin))) throw new Error("invalid bounds");
+    this.delaunay = delaunay;
+    this._circumcenters = new Float64Array(delaunay.points.length * 2);
+    this.vectors = new Float64Array(delaunay.points.length * 2);
+    this.xmax = xmax, this.xmin = xmin;
+    this.ymax = ymax, this.ymin = ymin;
+    this._init();
+  }
+  update() {
+    this.delaunay.update();
+    this._init();
+    return this;
+  }
+  _init() {
+    const {delaunay: {points, hull, triangles}, vectors} = this;
+    let bx, by; // lazily computed barycenter of the hull
+
+    // Compute circumcenters.
+    const circumcenters = this.circumcenters = this._circumcenters.subarray(0, triangles.length / 3 * 2);
+    for (let i = 0, j = 0, n = triangles.length, x, y; i < n; i += 3, j += 2) {
+      const t1 = triangles[i] * 2;
+      const t2 = triangles[i + 1] * 2;
+      const t3 = triangles[i + 2] * 2;
+      const x1 = points[t1];
+      const y1 = points[t1 + 1];
+      const x2 = points[t2];
+      const y2 = points[t2 + 1];
+      const x3 = points[t3];
+      const y3 = points[t3 + 1];
+
+      const dx = x2 - x1;
+      const dy = y2 - y1;
+      const ex = x3 - x1;
+      const ey = y3 - y1;
+      const ab = (dx * ey - dy * ex) * 2;
+
+      if (Math.abs(ab) < 1e-9) {
+        // For a degenerate triangle, the circumcenter is at the infinity, in a
+        // direction orthogonal to the halfedge and away from the “center” of
+        // the diagram <bx, by>, defined as the hull’s barycenter.
+        if (bx === undefined) {
+          bx = by = 0;
+          for (const i of hull) bx += points[i * 2], by += points[i * 2 + 1];
+          bx /= hull.length, by /= hull.length;
+        }
+        const a = 1e9 * Math.sign((bx - x1) * ey - (by - y1) * ex);
+        x = (x1 + x3) / 2 - a * ey;
+        y = (y1 + y3) / 2 + a * ex;
+      } else {
+        const d = 1 / ab;
+        const bl = dx * dx + dy * dy;
+        const cl = ex * ex + ey * ey;
+        x = x1 + (ey * bl - dy * cl) * d;
+        y = y1 + (dx * cl - ex * bl) * d;
+      }
+      circumcenters[j] = x;
+      circumcenters[j + 1] = y;
+    }
+
+    // Compute exterior cell rays.
+    let h = hull[hull.length - 1];
+    let p0, p1 = h * 4;
+    let x0, x1 = points[2 * h];
+    let y0, y1 = points[2 * h + 1];
+    vectors.fill(0);
+    for (let i = 0; i < hull.length; ++i) {
+      h = hull[i];
+      p0 = p1, x0 = x1, y0 = y1;
+      p1 = h * 4, x1 = points[2 * h], y1 = points[2 * h + 1];
+      vectors[p0 + 2] = vectors[p1] = y0 - y1;
+      vectors[p0 + 3] = vectors[p1 + 1] = x1 - x0;
+    }
+  }
+  render(context) {
+    const buffer = context == null ? context = new Path : undefined;
+    const {delaunay: {halfedges, inedges, hull}, circumcenters, vectors} = this;
+    if (hull.length <= 1) return null;
+    for (let i = 0, n = halfedges.length; i < n; ++i) {
+      const j = halfedges[i];
+      if (j < i) continue;
+      const ti = Math.floor(i / 3) * 2;
+      const tj = Math.floor(j / 3) * 2;
+      const xi = circumcenters[ti];
+      const yi = circumcenters[ti + 1];
+      const xj = circumcenters[tj];
+      const yj = circumcenters[tj + 1];
+      this._renderSegment(xi, yi, xj, yj, context);
+    }
+    let h0, h1 = hull[hull.length - 1];
+    for (let i = 0; i < hull.length; ++i) {
+      h0 = h1, h1 = hull[i];
+      const t = Math.floor(inedges[h1] / 3) * 2;
+      const x = circumcenters[t];
+      const y = circumcenters[t + 1];
+      const v = h0 * 4;
+      const p = this._project(x, y, vectors[v + 2], vectors[v + 3]);
+      if (p) this._renderSegment(x, y, p[0], p[1], context);
+    }
+    return buffer && buffer.value();
+  }
+  renderBounds(context) {
+    const buffer = context == null ? context = new Path : undefined;
+    context.rect(this.xmin, this.ymin, this.xmax - this.xmin, this.ymax - this.ymin);
+    return buffer && buffer.value();
+  }
+  renderCell(i, context) {
+    const buffer = context == null ? context = new Path : undefined;
+    const points = this._clip(i);
+    if (points === null || !points.length) return;
+    context.moveTo(points[0], points[1]);
+    let n = points.length;
+    while (points[0] === points[n-2] && points[1] === points[n-1] && n > 1) n -= 2;
+    for (let i = 2; i < n; i += 2) {
+      if (points[i] !== points[i-2] || points[i+1] !== points[i-1])
+        context.lineTo(points[i], points[i + 1]);
+    }
+    context.closePath();
+    return buffer && buffer.value();
+  }
+  *cellPolygons() {
+    const {delaunay: {points}} = this;
+    for (let i = 0, n = points.length / 2; i < n; ++i) {
+      const cell = this.cellPolygon(i);
+      if (cell) cell.index = i, yield cell;
+    }
+  }
+  cellPolygon(i) {
+    const polygon = new Polygon;
+    this.renderCell(i, polygon);
+    return polygon.value();
+  }
+  _renderSegment(x0, y0, x1, y1, context) {
+    let S;
+    const c0 = this._regioncode(x0, y0);
+    const c1 = this._regioncode(x1, y1);
+    if (c0 === 0 && c1 === 0) {
+      context.moveTo(x0, y0);
+      context.lineTo(x1, y1);
+    } else if (S = this._clipSegment(x0, y0, x1, y1, c0, c1)) {
+      context.moveTo(S[0], S[1]);
+      context.lineTo(S[2], S[3]);
+    }
+  }
+  contains(i, x, y) {
+    if ((x = +x, x !== x) || (y = +y, y !== y)) return false;
+    return this.delaunay._step(i, x, y) === i;
+  }
+  *neighbors(i) {
+    const ci = this._clip(i);
+    if (ci) for (const j of this.delaunay.neighbors(i)) {
+      const cj = this._clip(j);
+      // find the common edge
+      if (cj) loop: for (let ai = 0, li = ci.length; ai < li; ai += 2) {
+        for (let aj = 0, lj = cj.length; aj < lj; aj += 2) {
+          if (ci[ai] === cj[aj]
+              && ci[ai + 1] === cj[aj + 1]
+              && ci[(ai + 2) % li] === cj[(aj + lj - 2) % lj]
+              && ci[(ai + 3) % li] === cj[(aj + lj - 1) % lj]) {
+            yield j;
+            break loop;
+          }
+        }
+      }
+    }
+  }
+  _cell(i) {
+    const {circumcenters, delaunay: {inedges, halfedges, triangles}} = this;
+    const e0 = inedges[i];
+    if (e0 === -1) return null; // coincident point
+    const points = [];
+    let e = e0;
+    do {
+      const t = Math.floor(e / 3);
+      points.push(circumcenters[t * 2], circumcenters[t * 2 + 1]);
+      e = e % 3 === 2 ? e - 2 : e + 1;
+      if (triangles[e] !== i) break; // bad triangulation
+      e = halfedges[e];
+    } while (e !== e0 && e !== -1);
+    return points;
+  }
+  _clip(i) {
+    // degenerate case (1 valid point: return the box)
+    if (i === 0 && this.delaunay.hull.length === 1) {
+      return [this.xmax, this.ymin, this.xmax, this.ymax, this.xmin, this.ymax, this.xmin, this.ymin];
+    }
+    const points = this._cell(i);
+    if (points === null) return null;
+    const {vectors: V} = this;
+    const v = i * 4;
+    return this._simplify(V[v] || V[v + 1]
+        ? this._clipInfinite(i, points, V[v], V[v + 1], V[v + 2], V[v + 3])
+        : this._clipFinite(i, points));
+  }
+  _clipFinite(i, points) {
+    const n = points.length;
+    let P = null;
+    let x0, y0, x1 = points[n - 2], y1 = points[n - 1];
+    let c0, c1 = this._regioncode(x1, y1);
+    let e0, e1 = 0;
+    for (let j = 0; j < n; j += 2) {
+      x0 = x1, y0 = y1, x1 = points[j], y1 = points[j + 1];
+      c0 = c1, c1 = this._regioncode(x1, y1);
+      if (c0 === 0 && c1 === 0) {
+        e0 = e1, e1 = 0;
+        if (P) P.push(x1, y1);
+        else P = [x1, y1];
+      } else {
+        let S, sx0, sy0, sx1, sy1;
+        if (c0 === 0) {
+          if ((S = this._clipSegment(x0, y0, x1, y1, c0, c1)) === null) continue;
+          [sx0, sy0, sx1, sy1] = S;
+        } else {
+          if ((S = this._clipSegment(x1, y1, x0, y0, c1, c0)) === null) continue;
+          [sx1, sy1, sx0, sy0] = S;
+          e0 = e1, e1 = this._edgecode(sx0, sy0);
+          if (e0 && e1) this._edge(i, e0, e1, P, P.length);
+          if (P) P.push(sx0, sy0);
+          else P = [sx0, sy0];
+        }
+        e0 = e1, e1 = this._edgecode(sx1, sy1);
+        if (e0 && e1) this._edge(i, e0, e1, P, P.length);
+        if (P) P.push(sx1, sy1);
+        else P = [sx1, sy1];
+      }
+    }
+    if (P) {
+      e0 = e1, e1 = this._edgecode(P[0], P[1]);
+      if (e0 && e1) this._edge(i, e0, e1, P, P.length);
+    } else if (this.contains(i, (this.xmin + this.xmax) / 2, (this.ymin + this.ymax) / 2)) {
+      return [this.xmax, this.ymin, this.xmax, this.ymax, this.xmin, this.ymax, this.xmin, this.ymin];
+    }
+    return P;
+  }
+  _clipSegment(x0, y0, x1, y1, c0, c1) {
+    // for more robustness, always consider the segment in the same order
+    const flip = c0 < c1;
+    if (flip) [x0, y0, x1, y1, c0, c1] = [x1, y1, x0, y0, c1, c0];
+    while (true) {
+      if (c0 === 0 && c1 === 0) return flip ? [x1, y1, x0, y0] : [x0, y0, x1, y1];
+      if (c0 & c1) return null;
+      let x, y, c = c0 || c1;
+      if (c & 0b1000) x = x0 + (x1 - x0) * (this.ymax - y0) / (y1 - y0), y = this.ymax;
+      else if (c & 0b0100) x = x0 + (x1 - x0) * (this.ymin - y0) / (y1 - y0), y = this.ymin;
+      else if (c & 0b0010) y = y0 + (y1 - y0) * (this.xmax - x0) / (x1 - x0), x = this.xmax;
+      else y = y0 + (y1 - y0) * (this.xmin - x0) / (x1 - x0), x = this.xmin;
+      if (c0) x0 = x, y0 = y, c0 = this._regioncode(x0, y0);
+      else x1 = x, y1 = y, c1 = this._regioncode(x1, y1);
+    }
+  }
+  _clipInfinite(i, points, vx0, vy0, vxn, vyn) {
+    let P = Array.from(points), p;
+    if (p = this._project(P[0], P[1], vx0, vy0)) P.unshift(p[0], p[1]);
+    if (p = this._project(P[P.length - 2], P[P.length - 1], vxn, vyn)) P.push(p[0], p[1]);
+    if (P = this._clipFinite(i, P)) {
+      for (let j = 0, n = P.length, c0, c1 = this._edgecode(P[n - 2], P[n - 1]); j < n; j += 2) {
+        c0 = c1, c1 = this._edgecode(P[j], P[j + 1]);
+        if (c0 && c1) j = this._edge(i, c0, c1, P, j), n = P.length;
+      }
+    } else if (this.contains(i, (this.xmin + this.xmax) / 2, (this.ymin + this.ymax) / 2)) {
+      P = [this.xmin, this.ymin, this.xmax, this.ymin, this.xmax, this.ymax, this.xmin, this.ymax];
+    }
+    return P;
+  }
+  _edge(i, e0, e1, P, j) {
+    while (e0 !== e1) {
+      let x, y;
+      switch (e0) {
+        case 0b0101: e0 = 0b0100; continue; // top-left
+        case 0b0100: e0 = 0b0110, x = this.xmax, y = this.ymin; break; // top
+        case 0b0110: e0 = 0b0010; continue; // top-right
+        case 0b0010: e0 = 0b1010, x = this.xmax, y = this.ymax; break; // right
+        case 0b1010: e0 = 0b1000; continue; // bottom-right
+        case 0b1000: e0 = 0b1001, x = this.xmin, y = this.ymax; break; // bottom
+        case 0b1001: e0 = 0b0001; continue; // bottom-left
+        case 0b0001: e0 = 0b0101, x = this.xmin, y = this.ymin; break; // left
+      }
+      // Note: this implicitly checks for out of bounds: if P[j] or P[j+1] are
+      // undefined, the conditional statement will be executed.
+      if ((P[j] !== x || P[j + 1] !== y) && this.contains(i, x, y)) {
+        P.splice(j, 0, x, y), j += 2;
+      }
+    }
+    return j;
+  }
+  _project(x0, y0, vx, vy) {
+    let t = Infinity, c, x, y;
+    if (vy < 0) { // top
+      if (y0 <= this.ymin) return null;
+      if ((c = (this.ymin - y0) / vy) < t) y = this.ymin, x = x0 + (t = c) * vx;
+    } else if (vy > 0) { // bottom
+      if (y0 >= this.ymax) return null;
+      if ((c = (this.ymax - y0) / vy) < t) y = this.ymax, x = x0 + (t = c) * vx;
+    }
+    if (vx > 0) { // right
+      if (x0 >= this.xmax) return null;
+      if ((c = (this.xmax - x0) / vx) < t) x = this.xmax, y = y0 + (t = c) * vy;
+    } else if (vx < 0) { // left
+      if (x0 <= this.xmin) return null;
+      if ((c = (this.xmin - x0) / vx) < t) x = this.xmin, y = y0 + (t = c) * vy;
+    }
+    return [x, y];
+  }
+  _edgecode(x, y) {
+    return (x === this.xmin ? 0b0001
+        : x === this.xmax ? 0b0010 : 0b0000)
+        | (y === this.ymin ? 0b0100
+        : y === this.ymax ? 0b1000 : 0b0000);
+  }
+  _regioncode(x, y) {
+    return (x < this.xmin ? 0b0001
+        : x > this.xmax ? 0b0010 : 0b0000)
+        | (y < this.ymin ? 0b0100
+        : y > this.ymax ? 0b1000 : 0b0000);
+  }
+  _simplify(P) {
+    if (P && P.length > 4) {
+      for (let i = 0; i < P.length; i+= 2) {
+        const j = (i + 2) % P.length, k = (i + 4) % P.length;
+        if (P[i] === P[j] && P[j] === P[k] || P[i + 1] === P[j + 1] && P[j + 1] === P[k + 1]) {
+          P.splice(j, 2), i -= 2;
+        }
+      }
+      if (!P.length) P = null;
+    }
+    return P;
+  }
+}
+
+const tau = 2 * Math.PI, pow = Math.pow;
+
+function pointX(p) {
+  return p[0];
+}
+
+function pointY(p) {
+  return p[1];
+}
+
+// A triangulation is collinear if all its triangles have a non-null area
+function collinear(d) {
+  const {triangles, coords} = d;
+  for (let i = 0; i < triangles.length; i += 3) {
+    const a = 2 * triangles[i],
+          b = 2 * triangles[i + 1],
+          c = 2 * triangles[i + 2],
+          cross = (coords[c] - coords[a]) * (coords[b + 1] - coords[a + 1])
+                - (coords[b] - coords[a]) * (coords[c + 1] - coords[a + 1]);
+    if (cross > 1e-10) return false;
+  }
+  return true;
+}
+
+function jitter(x, y, r) {
+  return [x + Math.sin(x + y) * r, y + Math.cos(x - y) * r];
+}
+
+class Delaunay {
+  static from(points, fx = pointX, fy = pointY, that) {
+    return new Delaunay("length" in points
+        ? flatArray(points, fx, fy, that)
+        : Float64Array.from(flatIterable(points, fx, fy, that)));
+  }
+  constructor(points) {
+    this._delaunator = new Delaunator(points);
+    this.inedges = new Int32Array(points.length / 2);
+    this._hullIndex = new Int32Array(points.length / 2);
+    this.points = this._delaunator.coords;
+    this._init();
+  }
+  update() {
+    this._delaunator.update();
+    this._init();
+    return this;
+  }
+  _init() {
+    const d = this._delaunator, points = this.points;
+
+    // check for collinear
+    if (d.hull && d.hull.length > 2 && collinear(d)) {
+      this.collinear = Int32Array.from({length: points.length/2}, (_,i) => i)
+        .sort((i, j) => points[2 * i] - points[2 * j] || points[2 * i + 1] - points[2 * j + 1]); // for exact neighbors
+      const e = this.collinear[0], f = this.collinear[this.collinear.length - 1],
+        bounds = [ points[2 * e], points[2 * e + 1], points[2 * f], points[2 * f + 1] ],
+        r = 1e-8 * Math.hypot(bounds[3] - bounds[1], bounds[2] - bounds[0]);
+      for (let i = 0, n = points.length / 2; i < n; ++i) {
+        const p = jitter(points[2 * i], points[2 * i + 1], r);
+        points[2 * i] = p[0];
+        points[2 * i + 1] = p[1];
+      }
+      this._delaunator = new Delaunator(points);
+    } else {
+      delete this.collinear;
+    }
+
+    const halfedges = this.halfedges = this._delaunator.halfedges;
+    const hull = this.hull = this._delaunator.hull;
+    const triangles = this.triangles = this._delaunator.triangles;
+    const inedges = this.inedges.fill(-1);
+    const hullIndex = this._hullIndex.fill(-1);
+
+    // Compute an index from each point to an (arbitrary) incoming halfedge
+    // Used to give the first neighbor of each point; for this reason,
+    // on the hull we give priority to exterior halfedges
+    for (let e = 0, n = halfedges.length; e < n; ++e) {
+      const p = triangles[e % 3 === 2 ? e - 2 : e + 1];
+      if (halfedges[e] === -1 || inedges[p] === -1) inedges[p] = e;
+    }
+    for (let i = 0, n = hull.length; i < n; ++i) {
+      hullIndex[hull[i]] = i;
+    }
+
+    // degenerate case: 1 or 2 (distinct) points
+    if (hull.length <= 2 && hull.length > 0) {
+      this.triangles = new Int32Array(3).fill(-1);
+      this.halfedges = new Int32Array(3).fill(-1);
+      this.triangles[0] = hull[0];
+      inedges[hull[0]] = 1;
+      if (hull.length === 2) {
+        inedges[hull[1]] = 0;
+        this.triangles[1] = hull[1];
+        this.triangles[2] = hull[1];
+      }
+    }
+  }
+  voronoi(bounds) {
+    return new Voronoi(this, bounds);
+  }
+  *neighbors(i) {
+    const {inedges, hull, _hullIndex, halfedges, triangles, collinear} = this;
+
+    // degenerate case with several collinear points
+    if (collinear) {
+      const l = collinear.indexOf(i);
+      if (l > 0) yield collinear[l - 1];
+      if (l < collinear.length - 1) yield collinear[l + 1];
+      return;
+    }
+
+    const e0 = inedges[i];
+    if (e0 === -1) return; // coincident point
+    let e = e0, p0 = -1;
+    do {
+      yield p0 = triangles[e];
+      e = e % 3 === 2 ? e - 2 : e + 1;
+      if (triangles[e] !== i) return; // bad triangulation
+      e = halfedges[e];
+      if (e === -1) {
+        const p = hull[(_hullIndex[i] + 1) % hull.length];
+        if (p !== p0) yield p;
+        return;
+      }
+    } while (e !== e0);
+  }
+  find(x, y, i = 0) {
+    if ((x = +x, x !== x) || (y = +y, y !== y)) return -1;
+    const i0 = i;
+    let c;
+    while ((c = this._step(i, x, y)) >= 0 && c !== i && c !== i0) i = c;
+    return c;
+  }
+  _step(i, x, y) {
+    const {inedges, hull, _hullIndex, halfedges, triangles, points} = this;
+    if (inedges[i] === -1 || !points.length) return (i + 1) % (points.length >> 1);
+    let c = i;
+    let dc = pow(x - points[i * 2], 2) + pow(y - points[i * 2 + 1], 2);
+    const e0 = inedges[i];
+    let e = e0;
+    do {
+      let t = triangles[e];
+      const dt = pow(x - points[t * 2], 2) + pow(y - points[t * 2 + 1], 2);
+      if (dt < dc) dc = dt, c = t;
+      e = e % 3 === 2 ? e - 2 : e + 1;
+      if (triangles[e] !== i) break; // bad triangulation
+      e = halfedges[e];
+      if (e === -1) {
+        e = hull[(_hullIndex[i] + 1) % hull.length];
+        if (e !== t) {
+          if (pow(x - points[e * 2], 2) + pow(y - points[e * 2 + 1], 2) < dc) return e;
+        }
+        break;
+      }
+    } while (e !== e0);
+    return c;
+  }
+  render(context) {
+    const buffer = context == null ? context = new Path : undefined;
+    const {points, halfedges, triangles} = this;
+    for (let i = 0, n = halfedges.length; i < n; ++i) {
+      const j = halfedges[i];
+      if (j < i) continue;
+      const ti = triangles[i] * 2;
+      const tj = triangles[j] * 2;
+      context.moveTo(points[ti], points[ti + 1]);
+      context.lineTo(points[tj], points[tj + 1]);
+    }
+    this.renderHull(context);
+    return buffer && buffer.value();
+  }
+  renderPoints(context, r) {
+    if (r === undefined && (!context || typeof context.moveTo !== "function")) r = context, context = null;
+    r = r == undefined ? 2 : +r;
+    const buffer = context == null ? context = new Path : undefined;
+    const {points} = this;
+    for (let i = 0, n = points.length; i < n; i += 2) {
+      const x = points[i], y = points[i + 1];
+      context.moveTo(x + r, y);
+      context.arc(x, y, r, 0, tau);
+    }
+    return buffer && buffer.value();
+  }
+  renderHull(context) {
+    const buffer = context == null ? context = new Path : undefined;
+    const {hull, points} = this;
+    const h = hull[0] * 2, n = hull.length;
+    context.moveTo(points[h], points[h + 1]);
+    for (let i = 1; i < n; ++i) {
+      const h = 2 * hull[i];
+      context.lineTo(points[h], points[h + 1]);
+    }
+    context.closePath();
+    return buffer && buffer.value();
+  }
+  hullPolygon() {
+    const polygon = new Polygon;
+    this.renderHull(polygon);
+    return polygon.value();
+  }
+  renderTriangle(i, context) {
+    const buffer = context == null ? context = new Path : undefined;
+    const {points, triangles} = this;
+    const t0 = triangles[i *= 3] * 2;
+    const t1 = triangles[i + 1] * 2;
+    const t2 = triangles[i + 2] * 2;
+    context.moveTo(points[t0], points[t0 + 1]);
+    context.lineTo(points[t1], points[t1 + 1]);
+    context.lineTo(points[t2], points[t2 + 1]);
+    context.closePath();
+    return buffer && buffer.value();
+  }
+  *trianglePolygons() {
+    const {triangles} = this;
+    for (let i = 0, n = triangles.length / 3; i < n; ++i) {
+      yield this.trianglePolygon(i);
+    }
+  }
+  trianglePolygon(i) {
+    const polygon = new Polygon;
+    this.renderTriangle(i, polygon);
+    return polygon.value();
+  }
+}
+
+function flatArray(points, fx, fy, that) {
+  const n = points.length;
+  const array = new Float64Array(n * 2);
+  for (let i = 0; i < n; ++i) {
+    const p = points[i];
+    array[i * 2] = fx.call(that, p, i, points);
+    array[i * 2 + 1] = fy.call(that, p, i, points);
+  }
+  return array;
+}
+
+function* flatIterable(points, fx, fy, that) {
+  let i = 0;
+  for (const p of points) {
+    yield fx.call(that, p, i, points);
+    yield fy.call(that, p, i, points);
+    ++i;
+  }
+}
+
+exports.Delaunay = Delaunay;
+exports.Voronoi = Voronoi;
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+})));