81.游戏项目-物体任意角度飞行和停止

package test;
import java.awt.Color;
import java.awt.Font;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
/**
 * 测试物体沿着任意角度飞行 和停止
 * @author Nicholas
 * 
 */
public class GameFrame3 extends Frame {
    Image img = GameUtil.getImage("picture/test3.jpg");

    public void launchFrame(){
        setSize(500,500);
        setLocation(300,150);
        setVisible(true);
        
        new PaintThread().start();
        
        addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
    }
    
    private double x = 100, y = 100;
    private double degree = 3.14/3;// 弧度：[0,2*pi];
    private double speed = 10;//控制速率
    
    public void paint(Graphics g) {
        g.drawImage(img, (int)x, (int)y, null);
        x +=speed * Math.cos(degree);
        y +=speed * Math.sin(degree);
        if(speed > 0){
            speed -= 0.05;
        }else {
            speed = 0;
        }
        if(y > 500-50 || y < 30){
            degree=-degree;
        }
        if(x < 0 || x >= 500-50){
            degree=Math.PI-degree;
        }
    }
    
    class PaintThread extends Thread{
        public void run(){
            while(true){
                repaint();
                try {
                    Thread.sleep(40);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }
    public static void main(String[] args) {
        GameFrame3 gf=new GameFrame3();
        gf.launchFrame();
    }    
}