H3Error H3_EXPORT()

in h3_algos.c [775:805]

• 23 lines of code
• 5 McCabe index (conditional complexity)

H3Error H3_EXPORT(maxPolygonToCellsSize)(const GeoPolygon *geoPolygon, int res,
                                         uint32_t flags, int64_t *out) {
    H3Error flagErr = validatePolygonFlags(flags);
    if (flagErr) {
        return flagErr;
    }
    // Get the bounding box for the GeoJSON-like struct
    BBox bbox;
    const GeoLoop geoloop = geoPolygon->geoloop;
    bboxFromGeoLoop(&geoloop, &bbox);
    int64_t numHexagons;
    H3Error estimateErr = bboxHexEstimate(&bbox, res, &numHexagons);
    if (estimateErr) {
        return estimateErr;
    }
    // This algorithm assumes that the number of vertices is usually less than
    // the number of hexagons, but when it's wrong, this will keep it from
    // failing
    int totalVerts = geoloop.numVerts;
    for (int i = 0; i < geoPolygon->numHoles; i++) {
        totalVerts += geoPolygon->holes[i].numVerts;
    }
    if (numHexagons < totalVerts) numHexagons = totalVerts;
    // When the polygon is very small, near an icosahedron edge and is an odd
    // resolution, the line tracing needs an extra buffer than the estimator
    // function provides (but beefing that up to cover causes most situations to
    // overallocate memory)
    numHexagons += POLYGON_TO_CELLS_BUFFER;
    *out = numHexagons;
    return E_SUCCESS;
}