@ifc-lite/wasm

Pre-built WebAssembly bindings for the IFClite Rust core. ~650 KB binary (~260 KB gzipped) covering STEP parsing, geometry tessellation, georeferencing, and zero-copy GPU upload.

You probably don't need to use this package directly. It's the WASM binary plus generated JS/TypeScript bindings that @ifc-lite/parser, @ifc-lite/geometry, and @ifc-lite/renderer consume internally. Reach for it when you want raw access to the Rust core without the higher-level wrappers.

Installation

npm install @ifc-lite/wasm

Direct WASM use

IfcAPI methods take the raw IFC text (a string), not a Uint8Array. Decode the buffer first.

import init, { IfcAPI } from '@ifc-lite/wasm';

await init();                         // load and instantiate the WASM module

const api = new IfcAPI();
const buffer = await fetch('model.ifc').then(r => r.arrayBuffer());
const content = new TextDecoder().decode(buffer);

// Lightweight parse — returns { entityCount, ... }
const result = await api.parse(content);
console.log(`Entities: ${result.entityCount}`);

// Tessellated meshes — each entry has expressId, positions, indices, normals, color
const meshes = api.parseMeshes(content);
console.log(`${meshes.length} meshes`);
for (let i = 0; i < meshes.length; i++) {
  const mesh = meshes.get(i);
  console.log(mesh.ifcType, mesh.expressId, mesh.vertexCount, 'vertices');
}

meshes.free();                        // free the Rust-side mesh buffer
api.free();                           // free the API instance

Streaming mesh batches

For progressive rendering, stream meshes in batches and yield to the browser between them:

import init, { IfcAPI } from '@ifc-lite/wasm';

await init();
const api = new IfcAPI();

await api.parseMeshesAsync(content, {
  batchSize: 100,
  onRtcOffset: ({ x, y, z, hasRtc }) => {
    if (hasRtc) viewer.setWorldOffset(x, y, z);
  },
  onBatch: (meshes, progress) => {
    for (const mesh of meshes) scene.add(toThreeMesh(mesh));
    console.log(`${progress.percent}%`);
  },
  onComplete: ({ totalMeshes }) => console.log(`Done — ${totalMeshes} meshes`),
});

Zero-copy GPU upload

parseToGpuGeometry returns interleaved (position + normal) vertex data with pointers into WASM linear memory, ready for direct GPUBuffer upload:

import init, { IfcAPI } from '@ifc-lite/wasm';

await init();
const api = new IfcAPI();
const gpuGeom = api.parseToGpuGeometry(content);
const memory = api.getMemory();

// Direct views into WASM memory — no intermediate copy
const vertexView = new Float32Array(memory.buffer, gpuGeom.vertexDataPtr, gpuGeom.vertexDataLen);
const indexView = new Uint32Array(memory.buffer, gpuGeom.indicesPtr, gpuGeom.indicesLen);

device.queue.writeBuffer(gpuVertexBuffer, 0, vertexView);
device.queue.writeBuffer(gpuIndexBuffer, 0, indexView);

// IMPORTANT: views are only valid until the next WASM allocation. Free immediately after upload.
gpuGeom.free();

For deduplicated geometry (one mesh per shape, per-instance transforms), use parseToGpuInstancedGeometry(content) and iterate GpuInstancedGeometryCollection.

Georeferencing

import init, { IfcAPI } from '@ifc-lite/wasm';

await init();
const api = new IfcAPI();
const georef = api.getGeoReference(content);

if (georef) {
  console.log(`CRS: ${georef.crsName}`);
  const [e, n, h] = georef.localToMap(10, 20, 5);
  console.log(`Local (10,20,5) → Map (${e}, ${n}, ${h})`);
  georef.free();
}

Exports

| Class | Purpose | |---|---| | IfcAPI | Top-level parser entry point — parse, parseMeshes, parseMeshesAsync, parseToGpuGeometry, parseZeroCopy, getGeoReference, extractProfiles, parseSymbolicRepresentations, … | | MeshCollection, MeshDataJs | Tessellated geometry output | | MeshCollectionWithRtc, RtcOffsetJs | Mesh collection with relative-to-centre offset for large-coordinate models | | InstancedMeshCollection, InstancedGeometry, InstanceData | Instanced geometry path (deduplicated meshes + per-instance transforms) | | ZeroCopyMesh, GpuGeometry, GpuMeshMetadata | Zero-copy GPU upload handles | | GpuInstancedGeometry, GpuInstancedGeometryCollection, GpuInstancedGeometryRef | Zero-copy instanced path | | GeoReferenceJs | Georeferencing transform | | ProfileCollection, ProfileEntryJs | Cross-section profile data (extruded-area solids) | | SymbolicRepresentationCollection, SymbolicCircle, SymbolicPolyline | 2D symbolic representations (for plan / annotation views) |

All classes implement free() and [Symbol.dispose]() — call free() (or use using) to release Rust-side memory.

When to use a higher-level package instead

| You want… | Use | |---|---| | A typed, idiomatic TS API for parsing | @ifc-lite/parser | | Streaming geometry with worker support | @ifc-lite/geometry | | WebGPU rendering | @ifc-lite/renderer | | To avoid managing WASM lifecycles by hand | Any of the above |

Rust source

This package ships the bindings only. The Rust source lives in rust/wasm-bindings/ and the core in rust/core/. Available on crates.io as ifc-lite-core.

API

See the WASM API Reference.

License

MPL-2.0