758 lines
23 KiB
JavaScript
758 lines
23 KiB
JavaScript
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(function (global, factory) {
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typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
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typeof define === 'function' && define.amd ? define(factory) :
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(global = typeof globalThis !== 'undefined' ? globalThis : global || self, global.Delaunator = factory());
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}(this, (function () { 'use strict';
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const epsilon = 1.1102230246251565e-16;
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const splitter = 134217729;
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const resulterrbound = (3 + 8 * epsilon) * epsilon;
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// fast_expansion_sum_zeroelim routine from oritinal code
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function sum(elen, e, flen, f, h) {
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let Q, Qnew, hh, bvirt;
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let enow = e[0];
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let fnow = f[0];
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let eindex = 0;
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let findex = 0;
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if ((fnow > enow) === (fnow > -enow)) {
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Q = enow;
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enow = e[++eindex];
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} else {
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Q = fnow;
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fnow = f[++findex];
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}
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let hindex = 0;
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if (eindex < elen && findex < flen) {
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if ((fnow > enow) === (fnow > -enow)) {
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Qnew = enow + Q;
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hh = Q - (Qnew - enow);
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enow = e[++eindex];
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} else {
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Qnew = fnow + Q;
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hh = Q - (Qnew - fnow);
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fnow = f[++findex];
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}
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Q = Qnew;
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if (hh !== 0) {
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h[hindex++] = hh;
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}
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while (eindex < elen && findex < flen) {
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if ((fnow > enow) === (fnow > -enow)) {
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Qnew = Q + enow;
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bvirt = Qnew - Q;
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hh = Q - (Qnew - bvirt) + (enow - bvirt);
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enow = e[++eindex];
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} else {
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Qnew = Q + fnow;
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bvirt = Qnew - Q;
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hh = Q - (Qnew - bvirt) + (fnow - bvirt);
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fnow = f[++findex];
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}
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Q = Qnew;
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if (hh !== 0) {
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h[hindex++] = hh;
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}
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}
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}
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while (eindex < elen) {
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Qnew = Q + enow;
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bvirt = Qnew - Q;
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hh = Q - (Qnew - bvirt) + (enow - bvirt);
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enow = e[++eindex];
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Q = Qnew;
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if (hh !== 0) {
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h[hindex++] = hh;
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}
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}
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while (findex < flen) {
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Qnew = Q + fnow;
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bvirt = Qnew - Q;
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hh = Q - (Qnew - bvirt) + (fnow - bvirt);
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fnow = f[++findex];
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Q = Qnew;
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if (hh !== 0) {
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h[hindex++] = hh;
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}
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}
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if (Q !== 0 || hindex === 0) {
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h[hindex++] = Q;
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}
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return hindex;
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}
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function estimate(elen, e) {
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let Q = e[0];
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for (let i = 1; i < elen; i++) Q += e[i];
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return Q;
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}
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function vec(n) {
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return new Float64Array(n);
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}
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const ccwerrboundA = (3 + 16 * epsilon) * epsilon;
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const ccwerrboundB = (2 + 12 * epsilon) * epsilon;
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const ccwerrboundC = (9 + 64 * epsilon) * epsilon * epsilon;
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const B = vec(4);
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const C1 = vec(8);
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const C2 = vec(12);
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const D = vec(16);
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const u = vec(4);
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function orient2dadapt(ax, ay, bx, by, cx, cy, detsum) {
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let acxtail, acytail, bcxtail, bcytail;
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let bvirt, c, ahi, alo, bhi, blo, _i, _j, _0, s1, s0, t1, t0, u3;
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const acx = ax - cx;
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const bcx = bx - cx;
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const acy = ay - cy;
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const bcy = by - cy;
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s1 = acx * bcy;
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c = splitter * acx;
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ahi = c - (c - acx);
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alo = acx - ahi;
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c = splitter * bcy;
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bhi = c - (c - bcy);
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blo = bcy - bhi;
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s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
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t1 = acy * bcx;
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c = splitter * acy;
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ahi = c - (c - acy);
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alo = acy - ahi;
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c = splitter * bcx;
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bhi = c - (c - bcx);
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blo = bcx - bhi;
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t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
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_i = s0 - t0;
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bvirt = s0 - _i;
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B[0] = s0 - (_i + bvirt) + (bvirt - t0);
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_j = s1 + _i;
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bvirt = _j - s1;
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_0 = s1 - (_j - bvirt) + (_i - bvirt);
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_i = _0 - t1;
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bvirt = _0 - _i;
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B[1] = _0 - (_i + bvirt) + (bvirt - t1);
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u3 = _j + _i;
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bvirt = u3 - _j;
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B[2] = _j - (u3 - bvirt) + (_i - bvirt);
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B[3] = u3;
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let det = estimate(4, B);
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let errbound = ccwerrboundB * detsum;
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if (det >= errbound || -det >= errbound) {
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return det;
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}
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bvirt = ax - acx;
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acxtail = ax - (acx + bvirt) + (bvirt - cx);
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bvirt = bx - bcx;
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bcxtail = bx - (bcx + bvirt) + (bvirt - cx);
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bvirt = ay - acy;
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acytail = ay - (acy + bvirt) + (bvirt - cy);
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bvirt = by - bcy;
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bcytail = by - (bcy + bvirt) + (bvirt - cy);
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if (acxtail === 0 && acytail === 0 && bcxtail === 0 && bcytail === 0) {
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return det;
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}
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errbound = ccwerrboundC * detsum + resulterrbound * Math.abs(det);
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det += (acx * bcytail + bcy * acxtail) - (acy * bcxtail + bcx * acytail);
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if (det >= errbound || -det >= errbound) return det;
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s1 = acxtail * bcy;
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c = splitter * acxtail;
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ahi = c - (c - acxtail);
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alo = acxtail - ahi;
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c = splitter * bcy;
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bhi = c - (c - bcy);
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blo = bcy - bhi;
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s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
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t1 = acytail * bcx;
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c = splitter * acytail;
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ahi = c - (c - acytail);
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alo = acytail - ahi;
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c = splitter * bcx;
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bhi = c - (c - bcx);
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blo = bcx - bhi;
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t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
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_i = s0 - t0;
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bvirt = s0 - _i;
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u[0] = s0 - (_i + bvirt) + (bvirt - t0);
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_j = s1 + _i;
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bvirt = _j - s1;
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_0 = s1 - (_j - bvirt) + (_i - bvirt);
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_i = _0 - t1;
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bvirt = _0 - _i;
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u[1] = _0 - (_i + bvirt) + (bvirt - t1);
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u3 = _j + _i;
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bvirt = u3 - _j;
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u[2] = _j - (u3 - bvirt) + (_i - bvirt);
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u[3] = u3;
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const C1len = sum(4, B, 4, u, C1);
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s1 = acx * bcytail;
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c = splitter * acx;
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ahi = c - (c - acx);
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alo = acx - ahi;
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c = splitter * bcytail;
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bhi = c - (c - bcytail);
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blo = bcytail - bhi;
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s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
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t1 = acy * bcxtail;
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c = splitter * acy;
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ahi = c - (c - acy);
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alo = acy - ahi;
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c = splitter * bcxtail;
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bhi = c - (c - bcxtail);
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blo = bcxtail - bhi;
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t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
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_i = s0 - t0;
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bvirt = s0 - _i;
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u[0] = s0 - (_i + bvirt) + (bvirt - t0);
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_j = s1 + _i;
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bvirt = _j - s1;
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_0 = s1 - (_j - bvirt) + (_i - bvirt);
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_i = _0 - t1;
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bvirt = _0 - _i;
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u[1] = _0 - (_i + bvirt) + (bvirt - t1);
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u3 = _j + _i;
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bvirt = u3 - _j;
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u[2] = _j - (u3 - bvirt) + (_i - bvirt);
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u[3] = u3;
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const C2len = sum(C1len, C1, 4, u, C2);
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s1 = acxtail * bcytail;
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c = splitter * acxtail;
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ahi = c - (c - acxtail);
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alo = acxtail - ahi;
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c = splitter * bcytail;
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bhi = c - (c - bcytail);
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blo = bcytail - bhi;
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s0 = alo * blo - (s1 - ahi * bhi - alo * bhi - ahi * blo);
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t1 = acytail * bcxtail;
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c = splitter * acytail;
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ahi = c - (c - acytail);
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alo = acytail - ahi;
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c = splitter * bcxtail;
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bhi = c - (c - bcxtail);
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blo = bcxtail - bhi;
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t0 = alo * blo - (t1 - ahi * bhi - alo * bhi - ahi * blo);
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_i = s0 - t0;
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bvirt = s0 - _i;
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u[0] = s0 - (_i + bvirt) + (bvirt - t0);
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_j = s1 + _i;
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bvirt = _j - s1;
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_0 = s1 - (_j - bvirt) + (_i - bvirt);
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_i = _0 - t1;
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bvirt = _0 - _i;
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u[1] = _0 - (_i + bvirt) + (bvirt - t1);
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u3 = _j + _i;
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bvirt = u3 - _j;
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u[2] = _j - (u3 - bvirt) + (_i - bvirt);
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u[3] = u3;
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const Dlen = sum(C2len, C2, 4, u, D);
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return D[Dlen - 1];
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}
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function orient2d(ax, ay, bx, by, cx, cy) {
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const detleft = (ay - cy) * (bx - cx);
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const detright = (ax - cx) * (by - cy);
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const det = detleft - detright;
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if (detleft === 0 || detright === 0 || (detleft > 0) !== (detright > 0)) return det;
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const detsum = Math.abs(detleft + detright);
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if (Math.abs(det) >= ccwerrboundA * detsum) return det;
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return -orient2dadapt(ax, ay, bx, by, cx, cy, detsum);
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}
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const EPSILON = Math.pow(2, -52);
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const EDGE_STACK = new Uint32Array(512);
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class Delaunator {
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static from(points, getX = defaultGetX, getY = defaultGetY) {
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const n = points.length;
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const coords = new Float64Array(n * 2);
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for (let i = 0; i < n; i++) {
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const p = points[i];
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coords[2 * i] = getX(p);
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coords[2 * i + 1] = getY(p);
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}
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return new Delaunator(coords);
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}
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constructor(coords) {
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const n = coords.length >> 1;
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if (n > 0 && typeof coords[0] !== 'number') throw new Error('Expected coords to contain numbers.');
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this.coords = coords;
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// arrays that will store the triangulation graph
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const maxTriangles = Math.max(2 * n - 5, 0);
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this._triangles = new Uint32Array(maxTriangles * 3);
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this._halfedges = new Int32Array(maxTriangles * 3);
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// temporary arrays for tracking the edges of the advancing convex hull
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this._hashSize = Math.ceil(Math.sqrt(n));
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this._hullPrev = new Uint32Array(n); // edge to prev edge
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this._hullNext = new Uint32Array(n); // edge to next edge
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this._hullTri = new Uint32Array(n); // edge to adjacent triangle
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this._hullHash = new Int32Array(this._hashSize).fill(-1); // angular edge hash
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// temporary arrays for sorting points
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this._ids = new Uint32Array(n);
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this._dists = new Float64Array(n);
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this.update();
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}
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update() {
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const {coords, _hullPrev: hullPrev, _hullNext: hullNext, _hullTri: hullTri, _hullHash: hullHash} = this;
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const n = coords.length >> 1;
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// populate an array of point indices; calculate input data bbox
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let minX = Infinity;
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let minY = Infinity;
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let maxX = -Infinity;
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let maxY = -Infinity;
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for (let i = 0; i < n; i++) {
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const x = coords[2 * i];
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const y = coords[2 * i + 1];
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if (x < minX) minX = x;
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if (y < minY) minY = y;
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if (x > maxX) maxX = x;
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if (y > maxY) maxY = y;
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this._ids[i] = i;
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}
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const cx = (minX + maxX) / 2;
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const cy = (minY + maxY) / 2;
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let minDist = Infinity;
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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];
|
||
|
|
}
|
||
|
|
|
||
|
|
return Delaunator;
|
||
|
|
|
||
|
|
})));
|