@refrain-lyre/core

Dependency-free TypeScript evaluation core: parameters → composed values → bindings → deformed geometry, plus the normative draw-order sort. Runs headless in Node (usable for testing without a GPU) and in the browser.

Implements the normative evaluation model of the specification: value-source composition (§6.1), binding interpolation (§7), the per-frame pipeline and deformer math (§8.1–8.2), mask union (§8.4), and — under the physics capability — the double-precision pendulum simulation (§9).

Does not rasterize; a renderer (see @refrain-lyre/render-webgl) consumes this package's output surface description.

Tested with hand-computed expectations from the normative math (see test/); the conformance corpus exercises the full pipeline end to end.

loadModel() accepts already parsed model documents. Parse source text with the exported parseLyreJson() helper rather than plain JSON.parse() so duplicate object members remain a load error as required by §2. Container readers remain responsible for inventory, byte-size, decompression, symlink, and texture-decoding limits before handing documents to the core.

Object ownership

loadModel() returns a normalized object graph that downstream Lyre objects borrow by reference. Treat that model, including its nested arrays, maps, sets, and typed buffers, as read-only for as long as a runtime or validator may use it. Likewise, an EvalFrame and its geometry buffers are borrowed read-only views; copy them before making application-specific changes or retaining mutable working data. Mutating either object behind the runtime can invalidate its validated limits and cached mesh state and is unsupported.

See the specification.