diff --git a/src/mol-math/interpolate.ts b/src/mol-math/interpolate.ts new file mode 100644 index 0000000000000000000000000000000000000000..83d8f7cd27d24db488aaf11984448a0469001c8c --- /dev/null +++ b/src/mol-math/interpolate.ts @@ -0,0 +1,61 @@ +/** + * Copyright (c) 2018 mol* contributors, licensed under MIT, See LICENSE file for more info. + * + * @author Alexander Rose <alexander.rose@weirdbyte.de> + */ + +export function normalize (value: number, min: number, max: number) { + return (value - min) / (max - min) +} + +export function clamp (value: number, min: number, max: number) { + return Math.max(min, Math.min(max, value)) +} + +export function pclamp (value: number) { + return clamp(value, 0, 100) +} + +export function saturate (value: number) { + return clamp(value, 0, 1) +} + +export function damp (value: number, dampingFactor: number) { + const dampedValue = value * dampingFactor + return Math.abs(dampedValue) < 0.1 ? 0 : dampedValue +} + +export function lerp (start: number, stop: number, alpha: number) { + return start + (stop - start) * alpha +} + +export function spline (p0: number, p1: number, p2: number, p3: number, t: number, tension: number) { + 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 +} + +export function smoothstep (min: number, max: number, x: number) { + x = saturate(normalize(x, min, max)) + return x * x * (3 - 2 * x) +} + +export function smootherstep (min: number, max: number, x: number) { + x = saturate(normalize(x, min, max)) + return x * x * x * (x * (x * 6 - 15) + 10) +} + +export function smootheststep (min: number, max: number, x: number) { + 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) +} + +export function almostIdentity (value: number, start: number, stop: number) { + 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 +} \ No newline at end of file