Bug 128586 Change parameter in drill through link doesn't work in pdf.
Description: Change parameter in drill through link doesn't work in pdf. Steps to reproduce: 1. New a report source and a report target. 2. Insert a report parameter p1 in target.rptdesign, drag it to Layout. 3. Insert a label in source.rptdesign, define a drill through link to target.rptdesign and set p1 to "first". 4. Preview source.rptdesign in pdf and click the link. 5. Revise drill through link to set p1 to "second", then preview in pdf, click the link. Expected result: Target show "second" as value. Actual result: Target still showed "first"
engine/org.eclipse.birt.report.engine.emitter.pdf/src/org/eclipse/birt/report/engine/emitter/pdf/PDFEmitter.java
float alpha = (float) Math.tan(0f * Math.PI / 180);
		float beta = (float) Math.tan(15f * Math.PI / 180);
		cb.setTextMatrix(1, alpha, beta, 1, x, y);
	}
	
	
	
	/**
	 * convert the layout measure to PDF, the measure of layout is 1000 times
	 * larger than that of PDF
	 * 
	 * @param layoutMeasure
	 *            the measure computed in layout manager
	 * @return the measure in PDF
	 */
	private float pdfMeasure( int layoutMeasure )
	{
		return layoutMeasure/(float)LAYOUT_TO_PDF_RATIO;
	}
	/**
	 * convert the X coordinate of a point from layout to X coordinate in PDF
	 * @param layoutX 		the X coordinate specified from layout
	 * @return				the PDF X coordinate
	 */
	private float layoutPointX2PDF(int layoutX)
	{
		return pdfMeasure(layoutX);
	}
	
	/**