xydifferencerenderer.java

提供JFreechart图表功能, 提供JFreechart图表功能,提供JFreechart图表功能

                l_subtrahendNextX = new Double(l_x4);
                l_subtrahendNextY = new Double(l_y4);
            }

            // deassert b_*FastForward (only matters for 1st time through loop)
            b_minuendFastForward    = false;
            b_subtrahendFastForward = false;

            Double l_intersectX = null;
            Double l_intersectY = null;
            boolean b_intersect = false;

            b_minuendAtIntersect    = false;
            b_subtrahendAtIntersect = false;

            // check for intersect
            if ((l_x2 == l_x4) && (l_y2 == l_y4)) {
                // check if line segments are colinear
                if ((l_x1 == l_x3) && (l_y1 == l_y3)) {
                    b_colinear = true;
                }
                else {
                    // the intersect is at the next point for both the minuend 
                    // and subtrahend
                    l_intersectX = new Double(l_x2);
                    l_intersectY = new Double(l_y2);

                    b_intersect             = true;
                    b_minuendAtIntersect    = true;
                    b_subtrahendAtIntersect = true;
                 }
            }
            else {
                // compute common denominator
                double l_denominator = ((l_y4 - l_y3) * (l_x2 - l_x1)) 
                        - ((l_x4 - l_x3) * (l_y2 - l_y1));

                // compute common deltas
                double l_deltaY = l_y1 - l_y3;
                double l_deltaX = l_x1 - l_x3;

                // compute numerators
                double l_numeratorA = ((l_x4 - l_x3) * l_deltaY) 
                        - ((l_y4 - l_y3) * l_deltaX);
                double l_numeratorB = ((l_x2 - l_x1) * l_deltaY) 
                        - ((l_y2 - l_y1) * l_deltaX);

                // check if line segments are colinear
                if ((0 == l_numeratorA) && (0 == l_numeratorB) 
                        && (0 == l_denominator)) {
                    b_colinear = true;
                }
                else {
                    // check if previously colinear
                    if (b_colinear) {
                        // clear colinear points and flag
                        l_minuendXs.clear();
                        l_minuendYs.clear();
                        l_subtrahendXs.clear();
                        l_subtrahendYs.clear();
                        l_polygonXs.clear();
                        l_polygonYs.clear();

                        b_colinear = false;

                        // set new starting point for the polygon
                        boolean b_useMinuend = ((l_x3 <= l_x1) 
                                && (l_x1 <= l_x4));
                        l_polygonXs.add(b_useMinuend ? l_minuendCurX 
                                : l_subtrahendCurX);
                        l_polygonYs.add(b_useMinuend ? l_minuendCurY 
                                : l_subtrahendCurY);
                    }

                    // compute slope components
                    double l_slopeA = l_numeratorA / l_denominator;
                    double l_slopeB = l_numeratorB / l_denominator;

                    // check if the line segments intersect
                    if ((0 < l_slopeA) && (l_slopeA <= 1) && (0 < l_slopeB) 
                            && (l_slopeB <= 1)) {
                        // compute the point of intersection
                        double l_xi = l_x1 + (l_slopeA * (l_x2 - l_x1));
                        double l_yi = l_y1 + (l_slopeA * (l_y2 - l_y1));

                        l_intersectX            = new Double(l_xi);
                        l_intersectY            = new Double(l_yi);
                        b_intersect             = true;
                        b_minuendAtIntersect    = ((l_xi == l_x2) 
                                && (l_yi == l_y2));
                        b_subtrahendAtIntersect = ((l_xi == l_x4) 
                                && (l_yi == l_y4));

                        // advance minuend and subtrahend to intesect
                        l_minuendCurX    = l_intersectX;
                        l_minuendCurY    = l_intersectY;
                        l_subtrahendCurX = l_intersectX;
                        l_subtrahendCurY = l_intersectY;
                    }
                }
            }

            if (b_intersect) {
                // create the polygon
                // add the minuend's points to polygon
                l_polygonXs.addAll(l_minuendXs);
                l_polygonYs.addAll(l_minuendYs);

                // add intersection point to the polygon
                l_polygonXs.add(l_intersectX);
                l_polygonYs.add(l_intersectY);

                // add the subtrahend's points to the polygon in reverse
                Collections.reverse(l_subtrahendXs);
                Collections.reverse(l_subtrahendYs);
                l_polygonXs.addAll(l_subtrahendXs);
                l_polygonYs.addAll(l_subtrahendYs);

                // create an actual polygon
                b_positive = (l_subtrahendMaxY <= l_minuendMaxY) 
                        && (l_subtrahendMinY <= l_minuendMinY);
                createPolygon(x_graphics, x_dataArea, x_plot, x_domainAxis, 
                        x_rangeAxis, b_positive, l_polygonXs, l_polygonYs);

                // clear the point vectors
                l_minuendXs.clear();
                l_minuendYs.clear();
                l_subtrahendXs.clear();
                l_subtrahendYs.clear();
                l_polygonXs.clear();
                l_polygonYs.clear();

                // set the maxY and minY values to intersect y-value
                double l_y       = l_intersectY.doubleValue();
                l_minuendMaxY    = l_y;
                l_subtrahendMaxY = l_y;
                l_minuendMinY    = l_y;
                l_subtrahendMinY = l_y;

                // add interection point to new polygon
                l_polygonXs.add(l_intersectX);
                l_polygonYs.add(l_intersectY);
            }

            // advance the minuend if needed
            if (l_x2 <= l_x4) {
                l_minuendItem++;
                b_minuendAdvanced = true;
            }
            else {
                b_minuendAdvanced = false;
            }

            // advance the subtrahend if needed
            if (l_x4 <= l_x2) {
                l_subtrahendItem++;
                b_subtrahendAdvanced = true;
            }
            else {
                b_subtrahendAdvanced = false;
            }

            b_minuendDone    = (l_minuendItem == (l_minuendItemCount - 1));
            b_subtrahendDone = (l_subtrahendItem == (l_subtrahendItemCount 
                    - 1));
        }

        // check if the final polygon needs to be clipped
        if (b_minuendDone && (l_x3 < l_x2) && (l_x2 < l_x4)) {
            // project onto subtrahend
            double l_slope    = (l_y4 - l_y3) / (l_x4 - l_x3);
            l_subtrahendNextX = l_minuendNextX;
            l_subtrahendNextY = new Double((l_slope * l_x2) 
                    + (l_y3 - (l_slope * l_x3)));
        }

        if (b_subtrahendDone && (l_x1 < l_x4) && (l_x4 < l_x2)) {
            // project onto minuend
            double l_slope = (l_y2 - l_y1) / (l_x2 - l_x1);
            l_minuendNextX = l_subtrahendNextX;
            l_minuendNextY = new Double((l_slope * l_x4) 
                    + (l_y1 - (l_slope * l_x1)));
        }

        // consider last point of minuend and subtrahend for determining 
        // positivity
        l_minuendMaxY    = Math.max(l_minuendMaxY, 
                l_minuendNextY.doubleValue());
        l_subtrahendMaxY = Math.max(l_subtrahendMaxY, 
                l_subtrahendNextY.doubleValue());
        l_minuendMinY    = Math.min(l_minuendMinY, 
                l_minuendNextY.doubleValue());
        l_subtrahendMinY = Math.min(l_subtrahendMinY, 
                l_subtrahendNextY.doubleValue());

        // add the last point of the minuned and subtrahend
        l_minuendXs.add(l_minuendNextX);
        l_minuendYs.add(l_minuendNextY);
        l_subtrahendXs.add(l_subtrahendNextX);
        l_subtrahendYs.add(l_subtrahendNextY);

        // create the polygon
        // add the minuend's points to polygon
        l_polygonXs.addAll(l_minuendXs);
        l_polygonYs.addAll(l_minuendYs);

        // add the subtrahend's points to the polygon in reverse
        Collections.reverse(l_subtrahendXs);
        Collections.reverse(l_subtrahendYs);
        l_polygonXs.addAll(l_subtrahendXs);
        l_polygonYs.addAll(l_subtrahendYs);

        // create an actual polygon
        b_positive = (l_subtrahendMaxY <= l_minuendMaxY) 
                && (l_subtrahendMinY <= l_minuendMinY);
        createPolygon(x_graphics, x_dataArea, x_plot, x_domainAxis, 
                x_rangeAxis, b_positive, l_polygonXs, l_polygonYs);
    }

    /**
     * Draws the visual representation of a single data item, second pass.  In 
     * the second pass, the renderer draws the lines and shapes for the 
     * individual points in the two series.
     *
     * @param x_graphics  the graphics device.
     * @param x_dataArea  the area within which the data is being drawn.
     * @param x_info  collects information about the drawing.
     * @param x_plot  the plot (can be used to obtain standard color 
     *         information etc).
     * @param x_domainAxis  the domain (horizontal) axis.
     * @param x_rangeAxis  the range (vertical) axis.
     * @param x_dataset  the dataset.
     * @param x_series  the series index (zero-based).
     * @param x_item  the item index (zero-based).
     * @param x_crosshairState  crosshair information for the plot 
     *                          (<code>null</code> permitted).
     */
    protected void drawItemPass1(Graphics2D x_graphics,
                                 Rectangle2D x_dataArea,
                                 PlotRenderingInfo x_info,
                                 XYPlot x_plot,
                                 ValueAxis x_domainAxis,
                                 ValueAxis x_rangeAxis,
                                 XYDataset x_dataset,
                                 int x_series,
                                 int x_item,
                                 CrosshairState x_crosshairState) {

        Shape l_entityArea = null;
        EntityCollection l_entities = null;
        if (null != x_info) {
            l_entities = x_info.getOwner().getEntityCollection();
        }

        Paint l_seriesPaint   = getItemPaint(x_series, x_item);
        Stroke l_seriesStroke = getItemStroke(x_series, x_item);
        x_graphics.setPaint(l_seriesPaint);
        x_graphics.setStroke(l_seriesStroke);

        PlotOrientation l_orientation      = x_plot.getOrientation();
        RectangleEdge l_domainAxisLocation = x_plot.getDomainAxisEdge();
        RectangleEdge l_rangeAxisLocation  = x_plot.getRangeAxisEdge();

        double l_x0 = x_dataset.getXValue(x_series, x_item);
        double l_y0 = x_dataset.getYValue(x_series, x_item);
        double l_x1 = x_domainAxis.valueToJava2D(l_x0, x_dataArea, 
                l_domainAxisLocation);
        double l_y1 = x_rangeAxis.valueToJava2D(l_y0, x_dataArea, 
                l_rangeAxisLocation);

        if (getShapesVisible()) {
            Shape l_shape = getItemShape(x_series, x_item);
            if (l_orientation == PlotOrientation.HORIZONTAL) {
                l_shape = ShapeUtilities.createTranslatedShape(l_shape, 
                        l_y1, l_x1);
            }
            else {
                l_shape = ShapeUtilities.createTranslatedShape(l_shape, 
                        l_x1, l_y1);
            }
            if (l_shape.intersects(x_dataArea)) {
                x_graphics.setPaint(getItemPaint(x_series, x_item));
                x_graphics.fill(l_shape);
            }
            l_entityArea = l_shape;
        }

        // add an entity for the item...
        if (null != l_entities) {
            if (null == l_entityArea) {
                l_entityArea = new Rectangle2D.Double((l_x1 - 2), (l_y1 - 2), 
                        4, 4);
            }
            String l_tip = null;
            XYToolTipGenerator l_tipGenerator = getToolTipGenerator(x_series, 
                    x_item);
            if (null != l_tipGenerator) {
                l_tip = l_tipGenerator.generateToolTip(x_dataset, x_series, 
                        x_item);
            }
            String l_url = null;
            XYURLGenerator l_urlGenerator = getURLGenerator();
            if (null != l_urlGenerator) {
                l_url = l_urlGenerator.generateURL(x_dataset, x_series, 
                        x_item);
            }
            XYItemEntity l_entity = new XYItemEntity(l_entityArea, x_dataset, 
                    x_series, x_item, l_tip, l_url);
            l_entities.add(l_entity);
        }