@loaders.gl/3d-tiles/dist/lib/encoders/helpers/encode-3d-tile-header.js

3D Tiles, an open standard for streaming massive heterogeneous 3D geospatial datasets.

// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright vis.gl contributors
// HELPER ENCODERS
import { assert } from '@loaders.gl/loader-utils';
export function encode3DTileHeader(tile, dataView, byteOffset) {
    const HEADER_SIZE = 12;
    if (!dataView) {
        return byteOffset + HEADER_SIZE;
    }
    const { magic, version = 1, byteLength = 12 } = tile;
    assert(Array.isArray(magic) && Number.isFinite(version) && Number.isFinite(byteLength));
    dataView.setUint8(byteOffset + 0, magic[0]);
    dataView.setUint8(byteOffset + 1, magic[1]);
    dataView.setUint8(byteOffset + 2, magic[2]);
    dataView.setUint8(byteOffset + 3, magic[3]);
    dataView.setUint32(byteOffset + 4, version, true); // version
    dataView.setUint32(byteOffset + 8, byteLength, true); // byteLength
    byteOffset += HEADER_SIZE;
    return byteOffset;
}
// Bytelength is sometimes only known at the end of writing a tile
export function encode3DTileByteLength(dataView, byteOffsetTileStart, byteLength) {
    if (!dataView) {
        return;
    }
    dataView.setUint32(byteOffsetTileStart + 8, byteLength, true); // byteLength
}