molstar
Version:
A comprehensive macromolecular library.
69 lines (68 loc) • 1.99 kB
JavaScript
;
/**
* Copyright (c) 2018-2021 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author Alexander Rose <alexander.rose@weirdbyte.de>
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.PiDiv180 = exports.halfPI = void 0;
exports.degToRad = degToRad;
exports.radToDeg = radToDeg;
exports.isPowerOfTwo = isPowerOfTwo;
exports.absMax = absMax;
exports.arcLength = arcLength;
exports.spiral2d = spiral2d;
exports.halfPI = Math.PI / 2;
exports.PiDiv180 = Math.PI / 180;
function degToRad(deg) {
return deg * exports.PiDiv180; // deg * Math.PI / 180
}
function radToDeg(rad) {
return rad / exports.PiDiv180; // rad * 180 / Math.PI
}
function isPowerOfTwo(x) {
return (x !== 0) && (x & (x - 1)) === 0;
}
/** return the value that has the largest absolute value */
function absMax(...values) {
let max = 0;
let absMax = 0;
for (let i = 0, il = values.length; i < il; ++i) {
const value = values[i];
const abs = Math.abs(value);
if (abs > absMax) {
max = value;
absMax = abs;
}
}
return max;
}
/** Length of an arc with angle in radians */
function arcLength(angle, radius) {
return angle * radius;
}
/** Create an outward spiral of given `radius` on a 2d grid */
function spiral2d(radius) {
let x = 0;
let y = 0;
let deltaX = 0;
let deltaY = -1;
const size = radius * 2 + 1;
const halfSize = size / 2;
const out = [];
for (let i = Math.pow(size, 2); i > 0; --i) {
if ((-halfSize < x && x <= halfSize) && (-halfSize < y && y <= halfSize)) {
out.push([x, y]);
}
if (x === y || (x < 0 && x === -y) || (x > 0 && x === 1 - y)) {
// change direction
const prevDeltaX = deltaX;
const prevDeltaY = deltaY;
deltaX = -prevDeltaY;
deltaY = prevDeltaX;
}
x += deltaX;
y += deltaY;
}
return out;
}