s1.java

小球做圆周运动

import java.applet.Applet;
import java.awt.*;

public class S1 extends Applet implements Runnable{
	 int j = 0;
	 double x;	
	 Image memImg = null;
	 Image memImg1=null;
         Graphics memImgGraphics = null;
         Graphics memImgGraphics1 = null;
	 int speed;//=50;绘图速度
	 Thread t = null;

         /*double f(double x,int h,int w,int s){
      	     return h/6-(Math.sin((x+w-s)*Math.PI/50))*h/10;
         }
	 double f2(double x,int h,int w,int s){
      	     return 5*h/6-(Math.sin((w-x-s)*Math.PI/50))*h/10;
         }
         double f3(double x,int h,int w,int s){
      	     return h/2-(Math.sin((x+w)*Math.PI/50))*(Math.sin(s*Math.PI/50))*h/5;
         }
         double f4(double x,int h,int w){
      	     return h/2-(Math.sin((x+w)*Math.PI/50))*h/5;
         }
         double f5(double x,int h,int w){
      	     return h/2-(Math.sin((x+w)*Math.PI/50))*h/(-5);
         }*/
         double f(double x){
      	     return 100-(Math.cos(x*Math.PI/50))*50;
         }
         double f1(double x){
      	     return 100-(Math.sin(x*Math.PI/50))*50;
         }
	public void init(){
             memImg = createImage(getSize().width, getSize().height);
             memImgGraphics = memImg.getGraphics();//获得memImg的绘图
             memImg1= createImage(getSize().width, getSize().height);
             memImgGraphics1= memImg1.getGraphics();
             speed = Integer.parseInt(getParameter("speed"));//画线速度
        }
        public void start(){
             t = new Thread(this);
             t.start();
        }
        public void run(){
             while(true) {
		 if(j==0){
		      int h= getSize().height;
      	              int w= getSize().width;
		      memImgGraphics1.drawImage(memImg1, 0, 0, null);
		      drawStaticCurve(memImgGraphics1,0,w,h/6,h/2,5*h/6);
		      memImgGraphics.drawImage(memImg1, 0, 0, null);
		     
		 }
                 j++;
                 repaint();
                 try{
                    Thread.sleep(speed);
                 }
                 catch(Exception _ex) { }
             }
        }
        public void paint(Graphics g){
             int h= getSize().height;
      	     int w= getSize().width;
             memImgGraphics.drawImage(memImg1, 0, 0, null);
             memImgGraphics.setColor(Color.red);
             
             //for(x=0;x<w;x++){
             	memImgGraphics.fillOval((int)f(j),(int)f1(j),10,10);
                   //memImgGraphics.drawLine((int)x,(int)f(x,h,w,j),(int)(x+1),(int)f(x+1,h,w,j));
                   //memImgGraphics.drawLine((int)x,(int)f3(x,h,w,j),(int)(x+1),(int)f3(x+1,h,w,j));
                   //memImgGraphics.drawLine((int)x,(int)f3(x,h,w,j)-1,(int)(x+1),(int)f3(x+1,h,w,j)-1);
                   //memImgGraphics.drawLine((int)x,(int)f2(x,h,w,j),(int)(x+1),(int)f2(x+1,h,w,j));
             //}
             g.drawImage(memImg, 0, 0, this);

        }
        public void update(Graphics g){
             paint(g);
        }
        public void drawStaticCurve(Graphics g,int x0,int x,int y1,int y2,int y3){
             g.drawOval(55,55,100,100);
             /*int h= getSize().height;
      	     int w= getSize().width;
      	     Font font=new Font("Times New Roman",Font.ITALIC|Font.BOLD,32);
             g.setColor(Color.black);
             g.setFont(font);
             g.drawLine(x0,y1,x,y1);
             g.drawLine(x0,y2,x,y2);
             g.drawLine(x0,y3,x,y3);
             g.drawString("STATIONARY WAVE",100,35);
             g.setColor(Color.blue);
             for(x=0;x<w;x++){
             g.drawLine((int)x,(int)f4(x,h,w),(int)(x+1),(int)f4(x+1,h,w));
             g.drawLine((int)x,(int)f5(x,h,w),(int)(x+1),(int)f5(x+1,h,w));
             }*/
        }
        public void destroy(){}
}