dropecho.easings

A small Haxe library of easing functions (linear transformations) and interpolation helpers for games and animation. Compiles to JavaScript and C#.

Install

haxelib install dropecho.easings   # Haxe
npm install @dropecho/easings      # JavaScript

Usage

Easing functions take a normalized time t in [0, 1] and return the eased value, also in [0, 1].

Haxe

import dropecho.Easings;

Easings.easeInQuad(0.25);                  // 0.0625
Easings.easeOutCubic(0.25);                // 0.578125
Easings.smoothStep(0.5);                   // 0.5
Easings.mix(0, 100, 0.25);                 // 25   (lerp is an alias)
Easings.rangeMap(0.25, 0, 1, 0, 255);      // 63.75
Easings.rangeMapClamped(5, 0, 1, 0, 255);  // 255  (input clamped to the in-range)
Easings.clamp(value, 0, 1);

JavaScript

The library is exposed as the easings object (CommonJS export, or a global in the browser).

const { easings } = require("@dropecho/easings");

easings.easeInQuad(0.25); // 0.0625
easings.smoothStep(0.5);  // 0.5

API

| Group | Functions | |---|---| | Range / interpolation | clamp, rangeMap, rangeMapClamped, mix, lerp | | Ease in (accelerate from 0) | easeInQuad, easeInCubic, easeInQuart, easeInQuint, easeInSine | | Ease out (decelerate to 1) | easeOutQuad, easeOutCubic, easeOutQuart, easeOutQuint | | Composite / misc | smoothStep, scale |

• rangeMap extrapolates outside the in-range; rangeMapClamped pins the result to the out-range and handles inverted in-ranges (inMin > inMax).
• scale(t, easing) returns t · easing(t), a cheap way to sharpen an ease.

Development

npm run build   # build JS + C#
npm test        # run the utest suite (via dropecho.testing)
npm run bench   # run the benchmarks

License

MIT