molstar
Version:
A comprehensive macromolecular library.
84 lines • 2.4 kB
JavaScript
/**
* Copyright (c) 2017-2021 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author David Sehnal <david.sehnal@gmail.com>
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
// from http://burtleburtle.net/bob/hash/integer.html
export function hash1(i) {
var a = i ^ (i >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
export function hash2(i, j) {
var a = 23;
a = (31 * a + i) | 0;
a = (31 * a + j) | 0;
a = a ^ (a >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
export function hash3(i, j, k) {
var a = 23;
a = (31 * a + i) | 0;
a = (31 * a + j) | 0;
a = (31 * a + k) | 0;
a = a ^ (a >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
export function hash4(i, j, k, l) {
var a = 23;
a = (31 * a + i) | 0;
a = (31 * a + j) | 0;
a = (31 * a + k) | 0;
a = (31 * a + l) | 0;
a = a ^ (a >> 4);
a = (a ^ 0xdeadbeef) + (a << 5);
a = a ^ (a >> 11);
return a;
}
export function hashString(s) {
var h = 0;
for (var i = 0, l = s.length; i < l; i++) {
h = (h << 5) - h + s.charCodeAt(i++) | 0;
}
return h;
}
/**
* A unique number for each pair of integers
* Biggest representable pair is (67108863, 67108863) (limit imposed by Number.MAX_SAFE_INTEGER)
*/
export function cantorPairing(a, b) {
return (a + b) * (a + b + 1) / 2 + b;
}
/**
* A unique number for each sorted pair of integers
* Biggest representable pair is (67108863, 67108863) (limit imposed by Number.MAX_SAFE_INTEGER)
*/
export function sortedCantorPairing(a, b) {
return a < b ? cantorPairing(a, b) : cantorPairing(b, a);
}
export function invertCantorPairing(out, z) {
var w = Math.floor((Math.sqrt(8 * z + 1) - 1) / 2);
var t = (w * w + w) / 2;
var y = z - t;
out[0] = w - y;
out[1] = y;
return out;
}
/**
* 32 bit FNV-1a hash, see http://isthe.com/chongo/tech/comp/fnv/
*/
export function hashFnv32a(array) {
var hval = 0x811c9dc5;
for (var i = 0, il = array.length; i < il; ++i) {
hval ^= array[i];
hval += (hval << 1) + (hval << 4) + (hval << 7) + (hval << 8) + (hval << 24);
}
return hval >>> 0;
}
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