add hw2

node_modules/robust-predicates/esm/orient2d.js

@@ -0,0 +1,184 @@
+import {epsilon, splitter, resulterrbound, estimate, vec, sum} from './util.js';
+
+const ccwerrboundA = (3 + 16 * epsilon) * epsilon;
+const ccwerrboundB = (2 + 12 * epsilon) * epsilon;
+const ccwerrboundC = (9 + 64 * epsilon) * epsilon * epsilon;
+
+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];
+}
+
+export function orient2d(ax, ay, bx, by, cx, cy) {
+    const detleft = (ay - cy) * (bx - cx);
+    const detright = (ax - cx) * (by - cy);
+    const det = detleft - detright;
+
+    const detsum = Math.abs(detleft + detright);
+    if (Math.abs(det) >= ccwerrboundA * detsum) return det;
+
+    return -orient2dadapt(ax, ay, bx, by, cx, cy, detsum);
+}
+
+export function orient2dfast(ax, ay, bx, by, cx, cy) {
+    return (ay - cy) * (bx - cx) - (ax - cx) * (by - cy);
+}