@loaders.gl/geoarrow/dist/mesharrow/get-bounding-box.js

GeoArrow columnar geometry encoding and decoding

// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
import * as arrow from 'apache-arrow';
/** basic helper method to calculate a models upper and lower bounds */
export function getBoundingBoxFromArrowPositions(column) {
    const mins = [Number.MAX_VALUE, Number.MAX_VALUE, Number.MAX_VALUE];
    const maxs = [Number.MIN_VALUE, Number.MIN_VALUE, Number.MIN_VALUE];
    const valueColumn = column.getChildAt(0);
    for (const data of valueColumn.data) {
        const pointSize = 3; // attributes.POSITION.size;
        const pointData = data.buffers[arrow.BufferType.DATA];
        const pointCount = pointData.length / pointSize;
        for (let i = 0; i < pointCount; i += pointSize) {
            const x = pointData[i];
            const y = pointData[i + 1];
            const z = pointData[i + 2];
            if (x < mins[0])
                mins[0] = x;
            else if (x > maxs[0])
                maxs[0] = x;
            if (y < mins[1])
                mins[1] = y;
            else if (y > maxs[1])
                maxs[1] = y;
            if (z < mins[2])
                mins[2] = z;
            else if (z > maxs[2])
                maxs[2] = z;
        }
    }
    return [mins, maxs];
}