更新：稍微复杂的动画加上swing计时器会变得一团糟。问题的根源是Java计时器，无论是swing还是utility版本都不可靠，特别是在跨操作系统性能比较时。通过实现一个普通线程，该程序在所有系统上都可以平稳运行。http://zetcode.com/tutorials/javagamestutorial/animation/。此外，在paintComponent()方法中添加Toolkit.getDefaultToolkit().sync()显著有助于改善情况。
I wrote some code that animated smoothly in an awt.Applet (but flickered), then I refactored it to java swing. Now it doesn't flicker but it looks choppy. I've messed with the timer but that doesn't work. Any tips or suggestions for smoothly animating swing components would be greatly appreciated.
import java.util.Random;
import java.util.ArrayList;
import java.awt.event.<em>;
import java.awt.</em>;
import javax.swing.*;
//////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////公共类"Ball"继承自JApplet{
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame();
frame.setTitle("And so the ball rolls");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
initContainer(frame);
frame.pack();
frame.setVisible(true);
}
});
}
public static void initContainer(Container container){
GraphicsPanel graphicsPanel = new GraphicsPanel();
MainPanel mainPanel = new MainPanel(graphicsPanel);
container.add(mainPanel);
graphicsPanel.startTimer();
}
@Override
public void init(){
initContainer(this);
}
/////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////// 主面板类 MainPanel 继承自 JPanel { JLabel label = new JLabel("粒子"); GraphicsPanel gPanel;
public MainPanel(GraphicsPanel gPanel){
this.gPanel = gPanel;
add(gPanel);
add(label);
}
///////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
类GraphicsPanel继承自JPanel，实现了MouseListener接口。
private ArrayList<Particle> ballArr = new ArrayList<Particle>();
private String state="s"; //"s"=spiral, "p"=particle
private int speed=10; //~20 Hz
private Timer timer;
public GraphicsPanel(){
System.out.println("echo from gpanel");
setPreferredSize(new Dimension(500,500));
timer = new Timer(speed, new TimerListener());
addMouseListener(this);
}
public void startTimer(){
timer.start();
}
@Override
public void paintComponent(Graphics g){
super.paintComponent(g);
for (Particle b: ballArr){
g.setColor(b.getColor());
g.fillOval(b.getXCoor(),b.getYCoor(),
b.getTheSize(),b.getTheSize());
}
}
public void mousePressed(MouseEvent e) {
ballArr.add(new Particle(e.getX(), e.getY(), state));
}
public void mouseReleased(MouseEvent e) {}
public void mouseEntered(MouseEvent e){}
public void mouseExited(MouseEvent e){}
public void mouseClicked(MouseEvent e) {}
class TimerListener implements ActionListener {
public void actionPerformed(ActionEvent e){
for (Particle b: ballArr)
b.move();
setBackground(Color.WHITE);
repaint();
}
}
////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////// 类 粒子 { private static int instanceCount; {{instanceCount++;}} private int z = 11, t=1, u=1; private int[] RGB = new int[3]; private int[] randomizeColor = new int[3]; private double radius, theta; private int x, y, centerX, centerY, size, spiralDirection=1, ballSizeLowerBound, ballSizeUpperBound, radiusLowerBound, radiusUpperBound, mouseInputX, mouseInputY, radiusXMultiplier, radiusYMultiplier; private Color color; private String state; private Random random = new Random(); /////////////////////////////////////////////////////////////////////////// public Particle(int x, int y, int centerX, int centerY, int radius, int theta, int size, Color color){ this.x=x;this.y=y;this.centerX=centerX;this.centerY=centerY; this.radius=radius;this.theta=theta;this.size=size;this.color=color; }
public Particle(int mouseInputX, int mouseInputY, String state){
this.mouseInputX=mouseInputX;
this.mouseInputY=mouseInputY;
this.state=state;
//随机颜色
RGB[0] = random.nextInt(252);
RGB[1] = random.nextInt(252);
RGB[2] = random.nextInt(252);
randomizeColor[0] = 1+random.nextInt(3);
randomizeColor[0] = 1+random.nextInt(3);
randomizeColor[0] = 1+random.nextInt(3);
centerX=mouseInputX;
centerY=mouseInputY;
if (state.equals("s")){ //设置螺旋状态
ballSizeLowerBound=5;
ballSizeUpperBound=18;
radiusLowerBound=0;
radiusUpperBound=50;
radiusXMultiplier=1;
radiusYMultiplier=1;
}
if (state.equals("p")){ //设置粒子状态
ballSizeLowerBound = 15;
ballSizeUpperBound =20 + random.nextInt(15);
radiusLowerBound = 5;
radiusUpperBound = 15+ random.nextInt(34);
radiusXMultiplier=1 + random.nextInt(3);
radiusYMultiplier=1 + random.nextInt(3);
}
size = ballSizeUpperBound-1; //球的大小
radius = radiusUpperBound-1;
if (instanceCount %2 == 0) // 螺旋方向交替
spiralDirection=-spiralDirection;
}
///////////////////////////////////////////////////////////////////////////
public int getXCoor(){return centerX+x*spiralDirection;}
public int getYCoor(){return centerY+y;}
public int getTheSize(){return size;}
public Color getColor(){return color;}
//////////////////////////////////////////////////////////////////////////
void move(){
//螺旋: 在边界处，dr/dt的变化
if (radius > radiusUpperBound || radius < radiusLowerBound)
u = -u;
//螺旋形状公式: 极坐标方程为半径=角度
x = (int) (radius * radiusXMultiplier * Math.cos(theta));
y = (int) (radius * radiusYMultiplier * Math.sin(theta));
radius += .1*u;
theta += .1;
//球的大小公式
if (size == ballSizeUpperBound || size == ballSizeLowerBound)
t = -t;
size += t;
//球的颜色变化
for (int i = 0; i < RGB.length; i++)
if (RGB[i] >= 250 || RGB[i] <= 4)
randomizeColor[i] = -randomizeColor[i];
RGB[0]+= randomizeColor[0];
RGB[1]+= randomizeColor[1];
RGB[2]+= randomizeColor[2];
color = new Color(RGB[0],RGB[1],RGB[2]);
}
}