double x2 = dataset.getXValue(series, Math.min(item + 1, 
                itemCount - 1));
        double y2 = dataset.getYValue(series, Math.min(item + 1, 
                itemCount - 1));
        if (Double.isNaN(y2)) {
            y2 = 0.0;
        }
        double transX2 = domainAxis.valueToJava2D(x2, dataArea, 
                plot.getDomainAxisEdge());
        double transY2 = rangeAxis.valueToJava2D(y2, dataArea, 
                plot.getRangeAxisEdge());
        
        double transZero = rangeAxis.valueToJava2D(0.0, dataArea, 
                plot.getRangeAxisEdge());
        Polygon hotspot = null;
        if (plot.getOrientation() == PlotOrientation.HORIZONTAL) {
            hotspot = new Polygon();
            hotspot.addPoint((int) transZero, 
                    (int) ((transX0 + transX1) / 2.0));
            hotspot.addPoint((int) ((transY0 + transY1) / 2.0), 
                    (int) ((transX0 + transX1) / 2.0));
            hotspot.addPoint((int) transY1, (int) transX1);
            hotspot.addPoint((int) ((transY1 + transY2) / 2.0), 
                    (int) ((transX1 + transX2) / 2.0));
            hotspot.addPoint((int) transZero, 
                    (int) ((transX1 + transX2) / 2.0));
        }
        else {  // vertical orientation
            hotspot = new Polygon();
            hotspot.addPoint((int) ((transX0 + transX1) / 2.0), 
                    (int) transZero);
            hotspot.addPoint((int) ((transX0 + transX1) / 2.0), 
                    (int) ((transY0 + transY1) / 2.0));
            hotspot.addPoint((int) transX1, (int) transY1);
            hotspot.addPoint((int) ((transX1 + transX2) / 2.0), 
                    (int) ((transY1 + transY2) / 2.0));
            hotspot.addPoint((int) ((transX1 + transX2) / 2.0), 
                    (int) transZero);