Function process

source/MRIOExtras/MRLas.cpp:266–391

}

Expected<PointCloud> process( lazperf::reader::basic_file& reader, const PointsLoadSettings& settings )
{
    const auto pointCount = reader.pointCount();

    const auto& header = reader.header();
    const auto pointFormat = header.pointFormat();
    if ( pointFormat < 0 || pointFormat > 10 )
        return unexpected( fmt::format( "Unsupported LAS point format: {}", pointFormat ) );

    if ( LasPointSize[pointFormat] > header.point_record_length )
        return unexpected( fmt::format( "Too short LAS point record length {} for point format {}, expected length {}",
            header.point_record_length, pointFormat, LasPointSize[pointFormat] ) );

    const auto extraBytesVlr = reader.vlrData( "LASF_Spec", 4 );
    bool hasNormals = false;
    if ( extraBytesVlr.size() == 3 * sizeof( ExtraBytes ) )
    {
        ExtraBytes extraBytes[3];
        for ( int i = 0; i < 3; ++i )
            std::memcpy( extraBytes + i, extraBytesVlr.data() + i * sizeof( ExtraBytes ), sizeof( ExtraBytes ) );
        if ( extraBytes[0].data_type == 10 && extraBytes[1].data_type == 10 && extraBytes[2].data_type == 10 ) // all extra types are doubles
        {
            // https://github.com/ASPRSorg/LAS/issues/37#issuecomment-1695757865
            // enough to check first field only
            hasNormals = strcmp( extraBytes[0].name, "NormalX" ) == 0 ||
                 strcmp( extraBytes[0].name, "nx" ) == 0 ||
                 strcmp( extraBytes[0].name, "normal_x" ) == 0 ||
                 strcmp( extraBytes[0].name, "normalx" ) == 0 ||
                 strcmp( extraBytes[0].name, "normal x" ) == 0;
        }
    }
    if ( hasNormals && LasPointSize[pointFormat] + 3 * sizeof( double ) > header.point_record_length )
        return unexpected( fmt::format( "Too short LAS point+normal record length {} for point format {}, expected length {}",
            header.point_record_length, pointFormat, LasPointSize[pointFormat] + 3 * sizeof( double ) ) );

    PointCloud result;
    result.points.reserve( pointCount );
    if ( settings.colors )
        settings.colors->reserve( pointCount );
    if ( hasNormals )
        result.normals.reserve( pointCount );

    Vector3d offset {
        header.offset.x,
        header.offset.y,
        header.offset.z,
    };
    if ( settings.outXf )
    {
        const Box3d box {
            { header.minx, header.miny, header.minz },
            { header.maxx, header.maxy, header.maxz },
        };
        const auto center = box.center();
        *settings.outXf = AffineXf3f::translation( Vector3f( center ) );
        offset -= center;
    }