Method GetProjParm

ogr/ogrspatialreference.cpp:6150–6195

 */

double OGRSpatialReference::GetProjParm(const char *pszName,
                                        double dfDefaultValue,
                                        OGRErr *pnErr) const

{
    TAKE_OPTIONAL_LOCK();

    d->refreshProjObj();
    GetRoot();  // force update of d->m_bNodesWKT2

    if (pnErr != nullptr)
        *pnErr = OGRERR_NONE;

    /* -------------------------------------------------------------------- */
    /*      Find the desired parameter.                                     */
    /* -------------------------------------------------------------------- */
    const OGR_SRSNode *poPROJCS =
        GetAttrNode(d->m_bNodesWKT2 ? "CONVERSION" : "PROJCS");
    if (poPROJCS == nullptr)
    {
        if (pnErr != nullptr)
            *pnErr = OGRERR_FAILURE;
        return dfDefaultValue;
    }

    const int iChild = FindProjParm(pszName, poPROJCS);
    if (iChild == -1)
    {
        if (IsProjected() && GetAxesCount() == 3)
        {
            OGRSpatialReference *poSRSTmp = Clone();
            poSRSTmp->DemoteTo2D(nullptr);
            const double dfRet =
                poSRSTmp->GetProjParm(pszName, dfDefaultValue, pnErr);
            delete poSRSTmp;
            return dfRet;
        }

        if (pnErr != nullptr)
            *pnErr = OGRERR_FAILURE;
        return dfDefaultValue;
    }

    const OGR_SRSNode *poParameter = poPROJCS->GetChild(iChild);
    return CPLAtof(poParameter->GetChild(1)->GetValue());
}

/************************************************************************/
/*                           OSRGetProjParm()                           */