@fr0/core

The resolution layer — pure TypeScript, zero dependencies, no DOM.

Status

✅ Complete

Purpose

@fr0/core is the heart of the fr0 engine. Given a Timeline IR and a frame number, resolve(timeline, frame) returns a fully-resolved state for every layer — transforms applied, animations interpolated, text expressions evaluated — ready for any renderer to consume.

Key modules

| Module | Purpose | |---|---| | types/ | Timeline, Layer, Animation, Easing, Resolved, Validation, Input, Font, Capability | | easings/ | 31 built-in curves + cubic-bezier solver + spring LUT + memoized parser | | presets/ | 33 animation presets (entrance / exit / emphasis / text) | | core/ | resolve, interpolate, resolveKeyframes, resolveAnimation, resolveLayer, applyLayout, sequence, series, loop, shape builders, path utils, noise, springs, random | | validation/ | validate(unknown) + JSON Schema (draft-2020-12) + Damerau-Levenshtein suggestions | | template/ | processTemplate (input resolution) + TemplateProcessor | | capabilities/ | getCapabilities (dynamic preset introspection) | | fonts/ | Bundled Inter + JetBrains Mono variable fonts |

Quick start

import { resolve, validate, type Timeline } from '@fr0/core';

const timeline: Timeline = { /* ... */ };
validate(timeline);                     // throws on invalid
const state = resolve(timeline, 0);     // frame 0

Testing

pnpm --filter @fr0/core test

What this package is NOT

• Not a renderer (see @fr0/renderer-canvas, @fr0/renderer-browser)
• Not a player or UI component
• Not an encoder or exporter