我复制了一个在 Java 中绘制样条曲线的程序，但它并不像我想要的那样平滑。这是程序（它实际上将我刚才提到的程序与我从其他地方复制的另一个程序合并）。
import java.applet.Applet;
import java.awt.BorderLayout; // Using AWT containers and components
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.awt.geom.CubicCurve2D;
import java.awt.geom.Point2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.xy.XYSplineRenderer;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.math3.analysis.interpolation.SplineInterpolator;
import edu.umd.cs.piccolo.nodes.PPath;
// Using AWT events and listener interfaces
// Using Swing components and containers
/**
*
* @author User
*/
public class SplinePanel extends Applet{
public JPanel createContentPane(){
// This is where we'll put all our widgets
// in the next tutorials!
JPanel panel = new JPanel();
/*
SplineFactory s = new SplineFactory();
double[] c = new double[12];
c[0] = 0.0; // x0
c[1] = 0.0; // y0
c[2] = 0.0; // z0
c[3] = 1.0; // x1
c[4] = 1.0; // y1
c[5] = 0.0; // z1
c[6] = 2.0; // x2
c[7] = -1.0; // y2
c[8] = 0.0; // z2
c[9] = 10.0; // x3
c[10] = 0.0; // y3
c[11] = 0.0; // z3
double[] spline1 = SplineFactory.createBezier (c, 20);
double[] spline2 = SplineFactory.createCubic (c, 20);
double[] spline3 = SplineFactory.createCatmullRom (c, 20);
/*
System.out.println ("-- Bezier");
for (int i = 0; i < spline1.length; i+=3)
System.out.println (spline1[i] + "," + spline1[i+1] + "," + spline1[i+2]);
System.out.println ("-- Cubic");
for (int i = 0; i < spline2.length; i+=3)
System.out.println (spline2[i] + "," + spline2[i+1] + "," + spline2[i+2]);
System.out.println ("-- Catmull-Rom");
for (int i = 0; i < spline3.length; i+=3)
System.out.println (spline3[i] + "," + spline3[i+1] + "," + spline3[i+2]);
*/
panel.setLayout(new BorderLayout());
XYSeries series = new XYSeries("MyGraph");
/*
System.out.println ("-- Bezier");
for (int i = 0; i < spline1.length; i+=3)
System.out.println (spline1[i] + "," + spline1[i+1] + "," + spline1[i+2]);
// series.add(spline1[i])
System.out.println ("-- Cubic");
for (int i = 0; i < spline2.length; i+=3)
System.out.println (spline2[i] + "," + spline2[i+1] + "," + spline2[i+2]);
System.out.println ("-- Catmull-Rom");
for (int i = 0; i < spline3.length; i+=3)
System.out.println (spline3[i] + "," + spline3[i+1] + "," + spline3[i+2]);
*/
/*
series.add(0, 1);
series.add(1, 2);
series.add(2, 5);
series.add(7, 8);
series.add(9, 10);
*/
/*
double[] x = new double[5];
double[] y = new double[5];
x[0] = 0;
x[1] = 2;
x[2] = 2;
x[3] = 7;
x[4] = 9;
y[0] = 1;
y[1] = 2;
y[2] = 5;
y[3] = 8;
y[4] = 10;
SplineInterpolator s = new SplineInterpolator();
CubicCurve2D c = new CubicCurve2D.Double();
// draw CubicCurve2D.Double with set coordinates
*
*/
/*
c.setCurve(x1, y1, ctrlx1,
ctrly1, ctrlx2, ctrly2, x2, y2);
*/
/*
c.setCurve(x[0], x[0], x[2],
y[2], x[3], y[3], x[4], y[4]);
Graphics2D g2 = (Graphics2D)g;
g2.draw(c);
*/
/*
List<Point2D> points = new ArrayList<Point2D>();
// Collect points
Shape shape = new CurveCreator().getShape(points);
PPath p = new PPath();
p.setPathTo(shape);
*/
series.add(0, 1);
series.add(1, 2);
series.add(2, 5);
series.add(7, 8);
series.add(9, 10);
XYSeriesCollection dataset = new XYSeriesCollection();
dataset.addSeries(series);
JFreeChart chart = ChartFactory.createXYLineChart(
"XY Chart",
"x-axis",
"y-axis",
dataset,
PlotOrientation.VERTICAL,
true,
true,
false
);
ChartPanel chartPanel = new ChartPanel(chart);
chart.getXYPlot().setRenderer(new XYSplineRenderer());
panel.add(chartPanel);
//panel.setSize(800, 500);
//content panes must be opaque
panel.setOpaque(true);
return panel;
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D)(g);
CubicCurve2D c = new CubicCurve2D.Double();
// draw CubicCurve2D.Double with set coordinates
/*
c.setCurve(x1, y1, ctrlx1,
ctrly1, ctrlx2, ctrly2, x2, y2);
*/
double[] x = new double[5];
double[] y = new double[5];
x[0] = 0;
x[1] = 2;
x[2] = 2;
x[3] = 7;
x[4] = 9;
y[0] = 1;
y[1] = 2;
y[2] = 5;
y[3] = 8;
y[4] = 10;
c.setCurve(x[0], x[0], x[2],
y[2], x[3], y[3], x[4], y[4]);
g2.scale(5.0, 5.0);
g2.draw(c);
}
private static void createAndShowGUI() {
JFrame.setDefaultLookAndFeelDecorated(true);
JFrame frame = new JFrame("[=] There's a JPanel in here! [=]");
//Create and set up the content pane.
SplinePanel demo = new SplinePanel();
frame.setContentPane(demo.createContentPane());
// The other bits and pieces that make our program a bit more stable.
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(1300, 650);
frame.setVisible(true);
/*
Graphics g = demo.getGraphics();
demo.paint(g);
*/
JFrame jp1 = new JFrame();
jp1.getContentPane().add(demo, BorderLayout.CENTER);
jp1.setSize(new Dimension(500,500));
jp1.setVisible(true);
jp1.getContentPane().add(demo, BorderLayout.CENTER);
jp1.setSize(new Dimension(500,500));
jp1.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}