H3Error lineHexEstimate()

in h3_bbox.c [158:177]

• 18 lines of code
• 4 McCabe index (conditional complexity)

H3Error lineHexEstimate(const LatLng *origin, const LatLng *destination,
                        int res, int64_t *out) {
    // Get the area of the pentagon as the maximally-distorted area possible
    H3Index pentagons[12] = {0};
    H3Error pentagonsErr = H3_EXPORT(getPentagons)(res, pentagons);
    if (pentagonsErr) {
        return pentagonsErr;
    }
    double pentagonRadiusKm = _hexRadiusKm(pentagons[0]);

    double dist = H3_EXPORT(greatCircleDistanceKm)(origin, destination);
    double distCeil = ceil(dist / (2 * pentagonRadiusKm));
    if (!isfinite(distCeil)) {
        return E_FAILED;
    }
    int64_t estimate = (int64_t)distCeil;
    if (estimate == 0) estimate = 1;
    *out = estimate;
    return E_SUCCESS;
}