class VerticalMetricsTable extends TTFTable
{
    /**
     * A tag that identifies this table type.
     */
    public static final String TAG = "vmtx";
    
    private int[] advanceHeight;
    private short[] topSideBearing;
    private short[] additionalTopSideBearing;
    private int numVMetrics;

    VerticalMetricsTable()
    {
        super();
    }

    /**
     * This will read the required data from the stream.
     * 
     * @param ttf The font that is being read.
     * @param data The stream to read the data from.
     * @throws IOException If there is an error reading the data.
     */
    @Override
    void read(TrueTypeFont ttf, TTFDataStream data) throws IOException
    {
        VerticalHeaderTable vHeader = ttf.getVerticalHeader();
        if (vHeader == null)
        {
            throw new IOException("Could not get vhea table");
        }
        numVMetrics = vHeader.getNumberOfVMetrics();
        int numGlyphs = ttf.getNumberOfGlyphs();

        int bytesRead = 0;
        advanceHeight = new int[ numVMetrics ];
        topSideBearing = new short[ numVMetrics ];
        for( int i=0; i<numVMetrics; i++ )
        {
            advanceHeight[i] = data.readUnsignedShort();
            topSideBearing[i] = data.readSignedShort();
            bytesRead += 4;
        }

        if (bytesRead < getLength())
        {
            int numberNonVertical = numGlyphs - numVMetrics;

            // handle bad fonts with too many vmetrics
            if (numberNonVertical < 0)
            {
                numberNonVertical = numGlyphs;
            }

            additionalTopSideBearing = new short[numberNonVertical];
            for( int i=0; i<numberNonVertical; i++ )
            {
                if (bytesRead < getLength())
                {
                    additionalTopSideBearing[i] = data.readSignedShort();
                    bytesRead += 2;
                }
            }
        }

        initialized = true;
    }

    /**
     * Returns the top sidebearing for the given GID
     *
     * @param gid GID
     * @return top sidebearing for the given GID
     * 
     */
    public int getTopSideBearing(int gid)
    {
        if (gid < numVMetrics)
        {
            return topSideBearing[gid];
        }
        else
        {
            return additionalTopSideBearing[gid - numVMetrics];
        }
    }

    /**
     * Returns the advance height for the given GID.
     *
     * @param gid GID
     * @return advance height for the given GID
     */
    public int getAdvanceHeight(int gid)
    {<FILL_FUNCTION_BODY>}
}

        if (gid < numVMetrics)
        {
            return advanceHeight[gid];
        }
        else
        {
            // monospaced fonts may not have a height for every glyph
            // the last one is for subsequent glyphs
            return advanceHeight[advanceHeight.length -1];
        }
    
<methods>public long getCheckSum() ,public boolean getInitialized() ,public long getLength() ,public long getOffset() ,public java.lang.String getTag() <variables>private long checkSum,protected boolean initialized,private long length,private long offset,private java.lang.String tag