Bug 212291 SWT Chart render engine always uses 96 DPI(Display) resolution
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/AxesRenderHelper.java
* 
		 * @param i
		 *            tick index
		 * @throws ChartException
		 */
		void handlePreEachTick( int i ) throws ChartException;
		/**
		 * Handles computation after rendering each axes tick
		 * 
		 * @param i
		 *            tick index
		 * @throws ChartException
		 */
		void handlePostEachTick( int i ) throws ChartException;
	}
	private final class TextAxisTypeComputation implements IAxisTypeComputation
	{
		ComputationContext context;
		ITextMetrics itmText;
		int iDateTimeUnit;
		TextAxisTypeComputation( ComputationContext context )
		{
			this.context = context;
		}
		public void initialize( ) throws ChartException
		{
			iDateTimeUnit = ( sc.getType( ) == IConstants.DATE_TIME ) ? CDateTime.computeUnit( sc.getData( ) )
					: IConstants.UNDEFINED;
			itmText = xs.getTextMetrics( la );
			sc.getData( ).reset( );