渐变的圆

画光盘：

源代码：

package MoveComponent;

import java.awt.*;

import javax.swing.*;

import java.lang.*;

public class   MoveComponent  extends JApplet implements Runnable{

private Thread t;

boolean dstatus=true;

public static final double PI=Math.PI/180;

Image offScreenImage=null;

Graphics offScreenBuffer=null;

int width=600;

int height=600;

double R=35;

public void init(){

t=new Thread(this);

t.start();

//创建缓冲区内的图形

offScreenImage=this.createImage(width,height);

//得到g

offScreenBuffer=offScreenImage.getGraphics();

}

public void run(){

while(true){

repaint();    //重画

}

}

public void paint(Graphics g){

//绘制的起点坐标

int cx=240,    cy=170;

//实现图形的放大与缩小

if(dstatus){

R+=1.0;

if(R>=150.0){

dstatus=false;

}

}

else{

R-=1.0;

if(R<=35.0){

dstatus=true;

}

}

offScreenBuffer.clearRect(0,0,600,600);

for(int i=0;i<=360;i++){

drawCircle(g,cx,cy,R,i);

}

}

public void drawCircle(Graphics g,double x,double y,double R,double a){

double x1,y1,x2,y2;

x1=x+R*Math.cos(a*PI);

y1=y+R*Math.sin(a*PI);

x2=x+R*Math.cos((a+1)*PI);

y2=y+R*Math.sin((a+1)*PI);

g.setColor(Color.blue);

g.drawLine((int)x1, (int)y1, (int)x2, (int)y2);

}

}

运行的结果：

不断变大缩小的圆环：

源代码：

package MoveComponent;

import java.awt.*;

import javax.swing.*;

import java.lang.*;

public class   MoveComponent  extends JApplet implements Runnable{

private Thread t;

boolean dstatus=true;

public static final double PI=Math.PI/180;

Image offScreenImage=null;

Graphics offScreenBuffer=null;

int width=600;

int height=600;

double R=35;

public void init(){

t=new Thread(this);

t.start();

offScreenImage=this.createImage(width,height);

offScreenBuffer=offScreenImage.getGraphics();

}

public void run(){

while(true){

repaint();

}

}

public void paint(Graphics g){

int cx=220,    cy=170;

if(dstatus){

R+=1.0;

if(R>=130.0){

dstatus=false;

}

g.drawImage(offScreenImage,0,0,this);

}

else{

R-=1.0;

if(R<=1.0){

dstatus=true;

}

g.drawImage(offScreenImage,0,0,this);

}

offScreenBuffer.clearRect(0,0,600,600);

for(int i=0;i<=360;i++){

drawCircle(g,cx,cy,R,i);

}

}

public void drawCircle(Graphics g,double x,double y,double R,double a){

double x1,y1,x2,y2;

x1=x+R*Math.cos(a*PI);

y1=y+R*Math.sin(a*PI);

x2=x+R*Math.cos((a+1)*PI);

y2=y+R*Math.sin((a+1)*PI);

g.setColor(Color.blue);

g.drawLine((int)x1, (int)y1, (int)x2, (int)y2);

}

}

运行的结果：

 

圆的平移：

源代码：

package MoveComponent;

import java.awt.*;

import javax.swing.*;

import java.lang.*;

public class   MoveComponent  extends JApplet implements Runnable{

private Thread t;

boolean dstatus=true;

public static final double PI=Math.PI/180;

Image offScreenImage=null;

Graphics offScreenBuffer=null;

int width=600;

int height=600;

double R=35;

int cx=30,    cy=70;

public void init(){

t=new Thread(this);

t.start();

offScreenImage=this.createImage(width,height);

offScreenBuffer=offScreenImage.getGraphics();

}

public void run(){

while(true){

repaint();

}

}

public void paint(Graphics g){

if(dstatus){

cx+=1;

if(cx>=250){

dstatus=false;

}

g.drawImage(offScreenImage,0,0,this);

}

else{

cx-=1;

if(cx<=30){

dstatus=true;

}

g.drawImage(offScreenImage,0,0,this);

}

offScreenBuffer.clearRect(0,0,600,600);

drawCircle(g,cx,cy);

}

public void drawCircle(Graphics g,double x,double y){

g.setColor(Color.blue);

g.drawOval((int)x, (int)y, (int)50, (int)50);

}

}

运行的结果：

 

正弦移动：

源代码：

package MoveComponent;

import java.awt.*;

import javax.swing.*;

import java.lang.*;

public class   MoveComponent  extends JApplet implements Runnable{

private Thread t;

boolean dstatus=true;

public static final double PI=Math.PI/180;

Image offScreenImage=null;

Graphics offScreenBuffer=null;

int width=600;

int height=600;

double h=50;

double cx=30,    cy;

public void init(){

t=new Thread(this);

t.start();

offScreenImage=this.createImage(width,height);

offScreenBuffer=offScreenImage.getGraphics();

}

public void run(){

while(true){

repaint();

}

}

public void paint(Graphics g){

if(dstatus){

cx+=0.1;

cy=90-h*Math.sin((cx-30)*PI);

if(cx>=390){

dstatus=false;

}

g.drawImage(offScreenImage,0,0,this);

}

else{

cx-=0.1;

cy=90-h*Math.sin((cx-30)*PI);

if(cx<=30){

dstatus=true;

}

g.drawImage(offScreenImage,0,0,this);

}

drawCircle(g,cx,cy);

}

public void drawCircle(Graphics g,double x,double y){

g.setColor(Color.blue);

g.fillOval((int)x, (int)y, (int)20, (int)20);

}

}

运行的结果：