keyframe-resample-wasm

Resamples and optimizes keyframe data using WebAssembly. Minzipped size is about 6-7 kb.

Installation

npm install --save keyframe-resample

Compatibility

The keyframe-resample module will load a WebAssembly binary as a static resource, as described in Web.Dev: Bundling non-JavaScript resources . This method in compatible with Node.js, most browsers, and applications compiled with a modern bundler. For older bundlers, a keyframe-resample/compat module is also available, loading the WebAssembly binary from an inline Data URI. The compatibility build is a couple kilobytes larger, and requires more time to process the WebAssembly binary.

API

import { ready, resample } from 'keyframe-resample'; // Node.js, browsers, and modern bundlers
import { ready, resample } from 'keyframe-resample/compat'; // Legacy bundlers

// wait for WASM to compile
await ready;

// keyframe times, in seconds
const srcTimes = new Float32Array([0, 0.1, 0.2, 0.3, 0.4]);

// keyframe values, N-dimensional vectors
const srcValues = new Float32Array([
    0, 0, 1,
    0, 0, 2,
    0, 0, 3,
    0, 0, 4,
    0, 0, 5,
]);

// resample keyframes, remove those unnecessary with interpolation.
const count = resample(srcTimes, srcValues, 'lerp');

// results are written to start of source array.
const dstTimes = srcTimes.slice(0, count); // → [0, 0.4]
const dstValues = srcValues.slice(0, count * 3); // → [0, 0, 1, 0, 0, 5]

In addition to the resample(...) function implemented in WebAssembly, a resampleDebug(...) function implemented in plain JavaScript is also exported. The WebAssembly implementation runs considerably faster.

Exports

| export | description | |--------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------| | | | | ready: Promise<void> | Promise resolving when WASM is initialized and module is ready for use. | | | | | resample( times: Float32Array, values: Float32Array, interp: 'step' | 'lerp' | 'slerp', tolerance = 1e4) | WebAssembly implementation of keyframe interpolation. | | | | | resampleDebug( times: Float32Array, values: Float32Array, interp: 'step' | 'lerp' | 'slerp', tolerance = 1e4) | JavaScript implementation of keyframe interpolation. |

Interpolation modes

| mode | description | |-----------|-------------------------------------------------------------| | 'step' | Step (also called discrete or constant) interpolation. | | 'lerp' | Linear, per-component interpolation. | | 'slerp' | Spherical linear interpolation, valid only for quaternions. |

Contributing

To build the project locally, run:

npm install
npm run dist

To test changes:

npm run test
npm run benchmark

Optimizations and bug fixes are welcome. Please consider filing an issue to discuss possible feature additions.

License

Licensed under Blue Oak Model License 1.0.0.