molstar
Version:
A comprehensive macromolecular library.
71 lines (70 loc) • 2.18 kB
JavaScript
;
/**
* Copyright (c) 2018 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.normalize = normalize;
exports.clamp = clamp;
exports.pclamp = pclamp;
exports.saturate = saturate;
exports.damp = damp;
exports.lerp = lerp;
exports.spline = spline;
exports.quadraticBezier = quadraticBezier;
exports.smoothstep = smoothstep;
exports.smootherstep = smootherstep;
exports.smootheststep = smootheststep;
exports.almostIdentity = almostIdentity;
function normalize(value, min, max) {
return (value - min) / (max - min);
}
function clamp(value, min, max) {
return Math.max(min, Math.min(max, value));
}
function pclamp(value) {
return clamp(value, 0, 100);
}
function saturate(value) {
return clamp(value, 0, 1);
}
function damp(value, dampingFactor) {
const dampedValue = value * dampingFactor;
return Math.abs(dampedValue) < 0.1 ? 0 : dampedValue;
}
function lerp(start, stop, alpha) {
return start + (stop - start) * alpha;
}
/** Catmul-Rom spline */
function spline(p0, p1, p2, p3, t, tension) {
const v0 = (p2 - p0) * tension;
const v1 = (p3 - p1) * tension;
const t2 = t * t;
const t3 = t * t2;
return (2 * p1 - 2 * p2 + v0 + v1) * t3 + (-3 * p1 + 3 * p2 - 2 * v0 - v1) * t2 + v0 * t + p1;
}
function quadraticBezier(p0, p1, p2, t) {
const k = 1 - t;
return (k * k * p0) + (2 * k * t * p1) + (t * t * p2);
}
function smoothstep(min, max, x) {
x = saturate(normalize(x, min, max));
return x * x * (3 - 2 * x);
}
function smootherstep(min, max, x) {
x = saturate(normalize(x, min, max));
return x * x * x * (x * (x * 6 - 15) + 10);
}
function smootheststep(min, max, x) {
x = saturate(normalize(x, min, max));
return -20 * Math.pow(x, 7) + 70 * Math.pow(x, 6) - 84 * Math.pow(x, 5) + 35 * Math.pow(x, 4);
}
function almostIdentity(value, start, stop) {
if (value > start)
return value;
const a = 2 * stop - start;
const b = 2 * start - 3 * stop;
const t = value / start;
return (a * t + b) * t * t + stop;
}