SPIRAL JAVA APPLET PROGRAM

                

Program :

/*<applet code = spiral height = 800 width = 800>

</applet>*/

import java.awt.*;

import java.applet.*;

import java.awt.event.*;

public class spiral extends Applet implements ActionListener {

Dimension d;

Label l = new Label("radius = ");

TextField t = new TextField(3);

Button b = new Button("DRAW");

int xc,yc,rad;

public void init(){

add(l);

add(t);

add(b);

b.addActionListener(this);

}

public void  paint(Graphics g)

{

d=getSize();

xc = d.width/2;

yc=d.width/4;

rad=Integer.parseInt(t.getText());

int check=1;

int increment =1;

while(rad>0 && increment<rad)

{

int x=0;

int y=increment;

float p=5/4-y;

while(x<y)

{

if(p<0)

{

x++;

p=p+2*x+2+1;

}

else

{

x++;

y--;

p=p+2*x+2+1-2*y+2;

}

switch(check)

{

case 1:g.drawString(".",xc+x,yc+y);

g.setColor(Color.red);

break;

case 2:g.drawString(".",xc+y,yc+x);

g.setColor(Color.blue);

break;

case 3:g.drawString(".",xc-x,yc+y);

g.setColor(Color.green);

break;

case 4:g.drawString(".",xc-y,yc+x);

g.setColor(Color.black);

break;

case 5:g.drawString(".",xc-x,yc-y);

g.setColor(Color.yellow);

break;

case 6:g.drawString(".",xc-y,yc-x);

g.setColor(Color.orange);

break;

case 7:g.drawString(".",xc+x,yc-y);

g.setColor(Color.pink);

break;

case 8:g.drawString(".",xc+y,yc-x);

g.setColor(Color.magenta);

break;

}

}

check++;

if(check>8)

check=1;

increment+=1;

}

}

public void actionPerformed(ActionEvent aw)

{ 

repaint();

}

}

ELLIPSE - MID POINT

                                    

Program : 

/*<applet code = ellipse height = 400 width = 400>

</applet>*/

import java.awt.*;

import java.applet.*;

import java.awt.event.*;

public class ellipse extends Applet implements ActionListener {

float x,y,xc,yc,rx,ry,p1,p2;

Label l1 = new Label("semi major axis = ");

Label l2 = new Label("semi minor axis = ");

Label l3 = new Label("x = ");

Label l4 = new Label("y = ");

TextField t1 = new TextField(3);

TextField t2 = new TextField(3);

TextField t3 = new TextField(3);

TextField t4 = new TextField(3);

Button bw = new Button("DRAW");

public void init(){

add(l1);

add(t1);

add(l2);

add(t2);

add(l3);

add(t3);

add(l4);

add(t4);

add(bw);

bw.addActionListener(this);

}

public void  paint(Graphics g)

{

rx=Integer.parseInt(t1.getText());

ry=Integer.parseInt(t2.getText());

xc=Integer.parseInt(t3.getText());

yc=Integer.parseInt(t4.getText());

x=0;

y=ry;

p1=(ry*ry)-(rx*rx*y)+(rx*rx/4);

do{

g.drawString(".",Math.round(xc-x),Math.round(yc+y));

g.drawString(".",Math.round(xc-x),Math.round(yc-y));

g.drawString(".",Math.round(xc+x),Math.round(yc+y));

g.drawString(".",Math.round(xc+x),Math.round(yc-y));

x++;

if(p1<0)

p1=p1+(2*ry*ry*x)+(ry*ry);

else

{

y-=1;

p1=p1+(2*ry*ry*x)-(2*rx*rx*y)+(ry*ry);

}

}

while((2*ry*ry*x)<(2*rx*rx*y));

p2= (ry*ry*(x+1/2)*(x+1/2))+(rx*rx*(y-1)*(y-1))-(ry*ry*rx*rx);

while(y>0)

{

g.drawString(".",Math.round(xc-x),Math.round(yc+y));

g.drawString(".",Math.round(xc-x),Math.round(yc-y));

g.drawString(".",Math.round(xc+x),Math.round(yc+y));

g.drawString(".",Math.round(xc+x),Math.round(yc-y));

y--;

if(p2>0)

p2 = p2-(2*rx*rx*y)+(ry*ry);

else{

x+=1;

p2 = p2=(2*ry*ry*x)+(2*rx*rx*y)+(ry*ry);

}

}

public void actionPerformed(ActionEvent aw)

{ 

repaint();

}

}

MID POINT CIRCLE

                                    

Program : 

/*<applet code = circle height=400 width= 400>

</applet>*/

import java.awt.*;

import java.applet.*;

import java.awt.event.*;

public class circle extends Applet implements ActionListener {

Label l1 = new Label("x0 = ");

Label l2 = new Label("y0 = ");

Label l3 = new Label("radius = ");

TextField t1 = new TextField(3);

TextField t2 = new TextField(3);

TextField t3 = new TextField(3);

Button bw = new Button("DRAW");

public void init(){

add(l1);

add(t1);

add(l2);

add(t2);

add(l3);

add(t3);

add(bw);

bw.addActionListener(this);

}

public void  paint(Graphics g)

{

int xc=Integer.parseInt(t1.getText());

int yc=Integer.parseInt(t2.getText());

int rad=Integer.parseInt(t3.getText());

int X=0;

int Y=rad;

int p = 5/4-rad;

while(X<Y)

{

if(p<0)

{

X++;

p=p+2*X+2+1;

}

else

{

X++;

Y--;

p = p+2*X+2+1-2*Y+2;

}

g.drawString(".",xc+X,yc+Y);

g.drawString(".",xc+Y,yc-X);

g.drawString(".",xc-Y,yc+X);

g.drawString(".",xc-X,yc+Y);

g.drawString(".",xc+X,yc-Y);

g.drawString(".",xc+Y,yc+X);

g.drawString(".",xc-Y,yc-X);

g.drawString(".",xc-X,yc-Y);

}

}

public void actionPerformed(ActionEvent aw)

{ 

repaint();

}

}

3) Bresenham's line drawing algorithm

        

PROGRAM:

/*<applet code = bresen height=400 width= 400>
</applet>*/

import java.awt.*;
import java.applet.*;
import java.awt.event.*;

public class bresen extends Applet implements ActionListener {

Label l1 = new Label("x1 = ");
Label l2 = new Label("x2 = ");
Label l3 = new Label("y1 = ");
Label l4 = new Label("y2 = ");

TextField t1 = new TextField(3);
TextField t2 = new TextField(3);
TextField t3 = new TextField(3);
TextField t4 = new TextField(3);
Button bw = new Button("DRAW");

public void init(){
add(l1);
add(t1);
add(l2);
add(t2);
add(l3);
add(t3);
add(l4);
add(t4);
add(bw);
bw.addActionListener(this);
}
public void  paint(Graphics g)
{
int x1=Integer.parseInt(t1.getText());
int x2=Integer.parseInt(t2.getText());
int y1=Integer.parseInt(t3.getText());
int y2=Integer.parseInt(t4.getText());

int dx=x2-x1;
int dy=y2-y1;
int count=dx;
int p=2*dy-dx;
int xend,X,Y;
if(x1>x2){
X=x2;
Y=y2;
xend=x1;
}
else
{
X=x1;
Y=y1;
xend=x2;
}
g.drawString(".",X,Y);
while(count>0)
{
X+=1;
if(p<0)
{
p=p+2*dy;
}
else
{
Y+=1;
p=p+2*(dy-dx);
}
g.drawString(".",X,Y);
count--;
}
}
public void actionPerformed(ActionEvent aw)
{ 
repaint();
}
}

2) DDA - LINE DRAWING ALGORITHM

       

/*<applet code = DDA height = 400 width = 400>

</applet>*/

import java.awt.*;

import java.applet.*;

import java.awt.event.*;

public class DDA extends Applet implements ActionListener {

int x1,x2,y1,y2,step,dx,dy;

float xinc,yinc,X,Y;

Label l1 = new Label("x1 = ");

Label l2 = new Label("x2 = ");

Label l3 = new Label("y1 = ");

Label l4 = new Label("y2 = ");

TextField t1 = new TextField(3);

TextField t2 = new TextField(3);

TextField t3 = new TextField(3);

TextField t4 = new TextField(3);

Button b = new Button("DRAW");

public void init(){

add(l1);

add(t1);

add(l2);

add(t2);

add(l3);

add(t3);

add(l4);

add(t4);

add(b);

b.addActionListener(this);

}

public void paint (Graphics g){

x1=Integer.parseInt(t1.getText());

x2=Integer.parseInt(t2.getText());

y1=Integer.parseInt(t3.getText());

y2=Integer.parseInt(t4.getText());

dx=x2-x1;

dy=y2-y1;

if(Math.abs(dx)>Math.abs(dy))

step=Math.abs(dx);

else

step=Math.abs(dy);

xinc=(float)dx/step;

yinc=(float)dy/step;

X=x1;

Y=y1;

//g.setColor(Color.Red);

g.drawString(".",(int)X,(int)Y);

for(int i=1;i<step;i++)

{

X=X+xinc;

Y=Y+yinc;

//g.setColor(Color.RED);

g.drawString(".",(int)X,(int)Y);

}

}

public void actionPerformed(ActionEvent a)

{

repaint();

}

}