Export glTF / GLB

import type { TopoDS_Shape } from '@taucad/opencascade.js';
import { getOc } from './ocjs-init';

export const shapeToGlb = async (shape: TopoDS_Shape): Promise<Uint8Array> => {
  const oc = await getOc();

  using docName = new oc.TCollection_ExtendedString('doc', true);
  const doc = new oc.TDocStd_Document(docName);
  const shapeTool = oc.XCAFDoc_DocumentTool.ShapeTool(doc.Main()).get();
  shapeTool.AddShape(shape, false, false);

  using _mesh = new oc.BRepMesh_IncrementalMesh(shape, 0.1, false, 0.5, false);

  const path = `/out_${Date.now()}.glb`;
  using asciiPath = new oc.TCollection_AsciiString(path);
  using writer = new oc.RWGltf_CafWriter(asciiPath, true); // true = binary GLB
  using metadata = new oc.TColStd_IndexedDataMapOfStringString();
  using progress = new oc.Message_ProgressRange();
  writer.Perform(doc, metadata, progress);

  const raw = oc.FS.readFile(path) as Uint8Array;
  oc.FS.unlink(path);
  return new Uint8Array(raw);
};

const shapeLabel = shapeTool.AddShape(shape, false, false);

using matName = new oc.TCollection_AsciiString('Brass');
const vmTool = oc.XCAFDoc_DocumentTool.VisMaterialTool(doc.Main()).get();
using visMat = new oc.XCAFDoc_VisMaterial();
using pbr = new oc.XCAFDoc_VisMaterialPBR();
pbr.BaseColor = new oc.Quantity_ColorRGBA(0.85, 0.65, 0.13, 1);
pbr.Metallic = 0.9;
pbr.Roughness = 0.25;
visMat.SetPbrMaterial(pbr);
const matLabel = vmTool.AddMaterial(visMat, matName);
vmTool.SetShapeMaterial(shapeLabel, matLabel);