Java tutorial
/* =========================================================== * JFreeChart : a free chart library for the Java(tm) platform * =========================================================== * * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors. * * Project Info: http://www.jfree.org/jfreechart/index.html * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2.1 of the License, or * (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public * License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. * * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. * Other names may be trademarks of their respective owners.] * * --------------------------------- * XYSmoothLineAndShapeRenderer.java * --------------------------------- * (C) Copyright 2007, by Object Refinery Limited and Contributors. * * Original Author: -; * Contributor(s): -; * * Changes * ------- * 14-Jun-2007 : Version 1; * */ package ChartUsingJava; import java.awt.Graphics2D; import java.awt.geom.Point2D; import java.awt.geom.Rectangle2D; import org.jfree.chart.axis.ValueAxis; import org.jfree.chart.entity.EntityCollection; import org.jfree.chart.plot.CrosshairState; import org.jfree.chart.plot.PlotOrientation; import org.jfree.chart.plot.XYPlot; import org.jfree.chart.renderer.xy.XYItemRendererState; import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer; import org.jfree.data.xy.XYDataset; import org.jfree.ui.RectangleEdge; /** * A line and shape renderer that performs line smoothing. See * http://www.jfree.org/phpBB2/viewtopic.php?t=20671 * * WARNING: THIS CLASS IS NOT PART OF THE STANDARD JFREECHART API AND IS * SUBJECT TO ALTERATION OR REMOVAL. DO NOT RELY ON THIS CLASS FOR * PRODUCTION USE. Please experiment with this code and provide feedback. */ public class XYSmoothLineAndShapeRenderer extends XYLineAndShapeRenderer { /** * Draws the item (first pass). This method draws the lines * connecting the items. * * @param g2 the graphics device. * @param state the renderer state. * @param dataArea the area within which the data is being drawn. * @param plot the plot (can be used to obtain standard color * information etc). * @param domainAxis the domain axis. * @param rangeAxis the range axis. * @param dataset the dataset. * @param pass the pass. * @param series the series index (zero-based). * @param item the item index (zero-based). */ protected void drawPrimaryLine(XYItemRendererState state, Graphics2D g2, XYPlot plot, XYDataset dataset, int pass, int series, int item, ValueAxis domainAxis, ValueAxis rangeAxis, Rectangle2D dataArea) { if (item == 0) { return; } // get the data point... double x1 = dataset.getXValue(series, item); double y1 = dataset.getYValue(series, item); if (Double.isNaN(y1) || Double.isNaN(x1)) { return; } double x0 = dataset.getXValue(series, item - 1); double y0 = dataset.getYValue(series, item - 1); if (Double.isNaN(y0) || Double.isNaN(x0)) { return; } RectangleEdge xAxisLocation = plot.getDomainAxisEdge(); RectangleEdge yAxisLocation = plot.getRangeAxisEdge(); double transX0 = domainAxis.valueToJava2D(x0, dataArea, xAxisLocation); double transY0 = rangeAxis.valueToJava2D(y0, dataArea, yAxisLocation); double transX1 = domainAxis.valueToJava2D(x1, dataArea, xAxisLocation); double transY1 = rangeAxis.valueToJava2D(y1, dataArea, yAxisLocation); // only draw if we have good values if (Double.isNaN(transX0) || Double.isNaN(transY0) || Double.isNaN(transX1) || Double.isNaN(transY1)) { return; } Point2D.Double point0 = new Point2D.Double(); Point2D.Double point1 = new Point2D.Double(); Point2D.Double point2 = new Point2D.Double(); Point2D.Double point3 = new Point2D.Double(); if (item == 1) { point0 = null; } else { point0.x = domainAxis.valueToJava2D(dataset.getXValue(series, item - 2), dataArea, xAxisLocation); point0.y = rangeAxis.valueToJava2D(dataset.getYValue(series, item - 2), dataArea, yAxisLocation); } point1.x = transX0; point1.y = transY0; point2.x = transX1; point2.y = transY1; if ((item + 1) == dataset.getItemCount(series)) { point3 = null; } else { point3.x = domainAxis.valueToJava2D(dataset.getXValue(series, item + 1), dataArea, xAxisLocation); point3.y = rangeAxis.valueToJava2D(dataset.getYValue(series, item + 1), dataArea, yAxisLocation); } int steps = ((int) ((point2.x - point1.x) / 0.2) < 30) ? (int) ((point2.x - point1.x) / 0.2) : 30; Point2D.Double[] points = getBezierCurve(point0, point1, point2, point3, 1, steps); for (int i = 1; i < points.length; i++) { transX0 = points[i - 1].x; transY0 = points[i - 1].y; transX1 = points[i].x; transY1 = points[i].y; PlotOrientation orientation = plot.getOrientation(); if (orientation == PlotOrientation.HORIZONTAL) { state.workingLine.setLine(transY0, transX0, transY1, transX1); } else if (orientation == PlotOrientation.VERTICAL) { state.workingLine.setLine(transX0, transY0, transX1, transY1); } if (state.workingLine.intersects(dataArea)) { drawFirstPassShape(g2, pass, series, item, state.workingLine); } } } /** * Draws the item shapes and adds chart entities (second pass). This method * draws the shapes which mark the item positions. If <code>entities</code> * is not <code>null</code> it will be populated with entity information * for points that fall within the data area. * * @param g2 the graphics device. * @param plot the plot (can be used to obtain standard color * information etc). * @param domainAxis the domain axis. * @param dataArea the area within which the data is being drawn. * @param rangeAxis the range axis. * @param dataset the dataset. * @param pass the pass. * @param series the series index (zero-based). * @param item the item index (zero-based). * @param crosshairState the crosshair state. * @param entities the entity collection. */ protected void drawSecondaryPass(Graphics2D g2, XYPlot plot, XYDataset dataset, int pass, int series, int item, ValueAxis domainAxis, Rectangle2D dataArea, ValueAxis rangeAxis, CrosshairState crosshairState, EntityCollection entities) { // super.drawSecondaryPass(g2, plot, dataset, pass, series, item, // domainAxis, dataArea, rangeAxis, crosshairState, entities); } /** * Updates the control points. * * @param point0 * @param point1 * @param point2 * @param point3 * @param control1 * @param control2 * @param smooth */ public static void getControlPoints(Point2D.Double point0, Point2D.Double point1, Point2D.Double point2, Point2D.Double point3, Point2D.Double control1, Point2D.Double control2, double smooth) { // Reference: http://www.antigrain.com/research/bezier_interpolation/ if (point0 == null) point0 = point1; //new Point2D.Double(0, 0); if (point3 == null) point3 = point2; //new Point2D.Double(0, 0); Point2D.Double c1 = new Point2D.Double((point0.x + point1.x) / 2.0, (point0.y + point1.y) / 2.0); Point2D.Double c2 = new Point2D.Double((point1.x + point2.x) / 2.0, (point1.y + point2.y) / 2.0); Point2D.Double c3 = new Point2D.Double((point2.x + point3.x) / 2.0, (point2.y + point3.y) / 2.0); double len1 = point1.distance(point0); double len2 = point2.distance(point1); double len3 = point3.distance(point2); double k1 = len1 / (len1 + len2); double k2 = len2 / (len2 + len3); Point2D.Double m1 = new Point2D.Double(c1.x + (c2.x - c1.x) * k1, c1.y + (c2.y - c1.y) * k1); Point2D.Double m2 = new Point2D.Double(c2.x + (c3.x - c2.x) * k2, c2.y + (c3.y - c2.y) * k2); control1.setLocation(new Point2D.Double(m1.x + (c2.x - m1.x) * smooth + point1.x - m1.x, m1.y + (c2.y - m1.y) * smooth + point1.y - m1.y)); control2.setLocation(new Point2D.Double(m2.x + (c2.x - m2.x) * smooth + point2.x - m2.x, m2.y + (c2.y - m2.y) * smooth + point2.y - m2.y)); } /** * Returns the points for a bezier curve. * * @param point0 * @param point1 * @param point2 * @param point3 * @param smooth * @param steps * * @return The curve points. */ public static Point2D.Double[] getBezierCurve(Point2D.Double point0, Point2D.Double point1, Point2D.Double point2, Point2D.Double point3, double smooth, int steps) { Point2D.Double control1 = new Point2D.Double(); Point2D.Double control2 = new Point2D.Double(); getControlPoints(point0, point1, point2, point3, control1, control2, smooth); Point2D.Double C = new Point2D.Double(3 * (control1.x - point1.x), 3 * (control1.y - point1.y)); Point2D.Double B = new Point2D.Double(3 * (control2.x - control1.x) - C.x, 3 * (control2.y - control1.y) - C.y); Point2D.Double A = new Point2D.Double(point2.x - point1.x - C.x - B.x, point2.y - point1.y - C.y - B.y); Point2D.Double[] res = new Point2D.Double[steps + 1]; double stepSize = 1.0 / steps; double step = stepSize; res[0] = point1; for (int i = 1; i < steps; i++) { res[i] = new Point2D.Double(A.x * Math.pow(step, 3) + B.x * Math.pow(step, 2) + C.x * step + point1.x, A.y * Math.pow(step, 3) + B.y * Math.pow(step, 2) + C.y * step + point1.y); //System.out.println(step + " : " + res[i]); step += stepSize; } res[steps] = point2; return res; } }