1. Program
converting a line using Digital Differential Algorithm.
#include<iostream.h>
#include<conio.h>
#include<math.h>
#include<graphics.h>
#include<dos.h>
void linedda(int xa,int
ya,int xb,int yb);
void main()
{
int gd=DETECT,gm;
initgraph(&gd,&gm,"\\tc\\bgi\\");
int xa,ya,xb,yb;
cout<<"enter the
coordinates"<<endl;
cin>>xa>>ya>>xb>>yb;
linedda(xa,ya,xb,yb);
getch();
closegraph();
restorecrtmode();
}
void linedda(int xa,int
ya,int xb,int yb)
{
int step,x,y,k;
float dx,dy,xinc,yinc;
dx=abs(xb-xa);
dy=abs(yb-ya);
if(dx>dy)
step=dx;
else
step=dy;
xinc=dx/step;
yinc=dy/step;
x=xa,y=ya;
putpixel(x,y,5);
for(k=0;k<step;k++)
{
if(xa>xb &&
ya>yb)
{
x=x-xinc;
y=y-yinc;
putpixel(x,y,5);
delay(50);
}
else if(xa>xb &&
ya<yb)
{
x=x-xinc;
y=y+yinc;
putpixel(x,y,5);
delay(50);
}
else if (xa<xb &&
ya>yb)
{
x=x+xinc;
y=y-yinc;
putpixel(x,y,5);
delay(50);
}
else
{
x=x+xinc;
y=y+yinc;
putpixel(x,y,5);
delay(50);
}
}
}
2. Program to
draw a circle using the Mid-point algorithm.
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
float x0,y0;
void circlepoints(float
x,float y)
{
putpixel(x0+x,y0+y,1);
putpixel(x0+y,y0+x,2);
putpixel(x0+y,y0-x,3);
putpixel(x0+x,y0-y,4);
putpixel(x0-x,y0-y,5);
putpixel(x0-y,y0-x,6);
putpixel(x0-y,y0+x,7);
putpixel(x0-x,y0+y,8);
}
void main()
{
int a=DETECT,b;
initgraph(&a,&b,"\\tc\\bgi\\");
float x,y,radius,d;
cout<<"\n Enter
the radius of the circle:-";
cin>>radius;
cout<<"\n Enter
the centre of the circle (x,y):-";
cin>>x0>>y0;
x=0;
y=radius;
d=(5.0/4.0)-radius;
setcolor(YELLOW);
settextstyle(3,0,5);
outtextxy(180,70,"The
Circle");
putpixel(x0,y0,13);
circlepoints(x,y);
while(x<y)
{
if (d<0) //select the lower point i.e. E
{
d=d=(2.0*x)+3.0;
}
else //select the upper point i.e. SE
{
d=d+2.0*(x-y)+5.0;
y--;
}
x++;
circlepoints(x,y);
}
getch();
closegraph();
}//end o main
3. Program to
draw an ellipse using the Mid-point algorithm.
#include <stdio.h>
#include <conio.h>
#include <graphics.h>
#include <math.h>
void ELLIPSE(int x,int y,int
a,int b);
void plot(int x,int y,int
x1,int y1);
void main()
{
int driver = DETECT,mode;
int x,y;
int a,b;
clrscr();
printf("\nEnter x co. for center of Ellipse : ¯
");
scanf("%d",&x);
printf("\nEnter y co. for center of Ellipse : ¯
");
scanf("%d",&y);
printf("\nEnter length of Horizontal axis `2a' : ¯
");
scanf("%d",&a);
a=a/2;
printf("\nEnter length of Vertical axis `2b' : ¯
");
scanf("%d",&b);
b=b/2;
printf("\n\n\nPress any key to see the
Ellipse......");
getch();
initgraph(&driver,&mode,"c:\\tc\\bgi");
clearviewport();
ELLIPSE(x,y,a,b);
getch();
closegraph();
}
void ELLIPSE(int x1,int
y1,int a,int b)
{
int x=0,y=b;
double d1,d2;
d1=pow(b,2)-(pow(a,2)*b)+(0.25*pow(a,2));
while(pow(a,2)*(y-0.5)>=pow(b,2)*(x+1))
{
plot(x,y,x1,y1);
if(d1<0)
d1+=pow(b,2)*(2*x+3);
else
{
d1+=pow(b,2)*(2*x+3)+pow(a,2)*(-2*y+2);
y--;
}
x++;
}
d2=pow(b,2)*pow(x+0.5,2)+pow(a,2)*pow(y-1,2)-(pow(a,2)*pow(b,2));
while(y>=0)
{
plot(x,y,x1,y1);
if(d2<0)
{
d2+=pow(b,2)*(2*x+2)+pow(a,2)*(-2*y+3);
x++;
}
else
d2+=pow(a,2)*(-2*y+3);
y--;
}
}
void plot(int x, int y,int
x1,int y1)
{
putpixel((x+x1),(y+y1),YELLOW);
putpixel((x+x1),(-y+y1),YELLOW);
putpixel((-x+x1),(y+y1),YELLOW);
putpixel((-x+x1),(-y+y1),YELLOW);
}
4. Program to
rotate a coin on table.
#include<graphics.h>
#include<conio.h>
#include<iostream.h>
#include<dos.h>
#include<stdio.h>
#include <stdlib.h>
int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
int midx, midy;
int stangle = 0, endangle = 360;
int yradius = 30;
/* initialize graphics, local variables */
initgraph(&gdriver, &gmode,
"\\tc\\bgi\\");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk)
/* an error occurred */
{
printf("Graphics error: %s\n",
grapherrormsg(errorcode));
printf("Press any key to
halt:");
getch();
exit(1);
/* terminate with an error code */
}
midx = getmaxx() / 2;
midy = getmaxy() / 2;
setcolor(BROWN);
/* draw ellipse */
settextstyle(8,0,4);
outtextxy(100,100,"PRESS SPACEBAR TO
EXIT ");
line(midx-80,midy-40,midx+120,midy-40);
line(midx-100,midy+60,midx-80,midy-40);
line(midx+100,midy+60,midx+120,midy-40);
line(midx-100,midy+60,midx+100,midy+60);
rectangle(midx-100,midy+60,midx-80,midy+160);
rectangle(midx+100,midy+60,midx+80,midy+160);
rectangle(midx-80,midy-40,midx-60,midy+40);
rectangle(midx+120,midy-40,midx+100,midy+40);
l:
for(int i=30;i>=0;i--)
{
delay(30);
ellipse(midx, midy, stangle, endangle,i,
yradius);
setfillstyle(1,LIGHTGRAY);
fillellipse(midx,midy,i,yradius);
setcolor(BLACK);
ellipse(midx, midy, stangle, endangle,i,
yradius);
}
for( i=0;i<=30;i++)
{
delay(30);
ellipse(midx, midy, stangle, endangle,i,
yradius);
setfillstyle(1,LIGHTBLUE);
fillellipse(midx,midy,i,yradius);
setcolor(BLACK);
ellipse(midx, midy, stangle, endangle,i,
yradius);
}
char
ch= getch();
while(ch!=32)
{
goto l;
}
/* clean up */
closegraph();
return 0;
}
5. Program to
design output of a ball hitting the Four Corners
of a window.
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include<dos.h>
int main(void)
{
/* request auto detection */
int gdriver = DETECT, gmode, errorcode;
/* initialize graphics and local variables
*/
initgraph(&gdriver, &gmode,
"c:\\tc\\bgi");
/* read result of initialization */
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n",
grapherrormsg(errorcode));
printf("Press any key to
halt:");
getch();
exit(1); /* terminate with an error code
*/
}
setcolor(YELLOW);
/* draw the circle */
rectangle(85,90,313,313);
setcolor(RED);
while(!kbhit()){
for ( int
i=100,j=100;i<=300,j<=300;i=i+6,j=j+6)
{
setcolor(WHITE);
circle(i, j, 8);
delay(100);
setcolor(BLACK);
circle(i,j,8);
}
for (
j=300;j>=100;j=j-6)
{
setcolor(WHITE);
circle(i, j, 8);
delay(100);
setcolor(BLACK);
circle(i,j,8);
}
for (
i=300,j=100;i>=100,j<=300;i=i-6,j=j+6)
{
setcolor(WHITE);
circle(i, j, 8);
delay(100);
setcolor(BLACK);
circle(i,j,8);
}
for (
j=300;j>=100;j=j-6)
{
setcolor(WHITE);
circle(i, j, 8);
delay(100);
setcolor(BLACK);
circle(i,j,8);
/* clean up */
}
}
getch();
closegraph();
return 0;
}
6. Program to
draw a rectangle using line drawing algorithm.
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
void main()
{
int driver = DETECT,mode;
int x1,x2,y1,y2,t,x[5],y[5];
float m,i,j,s;
printf("\nEnter LEFT : ¯ ");
scanf("%d",&x1);
printf("\nEnter TOP : ¯ ");
scanf("%d",&y1);
printf("\nEnter RIGHT : ¯ ");
scanf("%d",&x2);
printf("\nEnter BOTTOM : ¯ ");
scanf("%d",&y2);
printf("\n\n\nPress any key to see the
line...........");
getch();
clrscr();
initgraph(&driver,&mode,"c:\\tc\\bgi");
clearviewport();
x[0]=x1;
y[0]=y1;
x[1]=x2;
y[1]=y1;
x[2]=x2;
y[2]=y2;
x[3]=x1;
y[3]=y2;
int l,flag=1;
int k;
for(k=0;k<=3;k++){
l=k+1;
if(l==4)
{
k=2;
l=0;
flag=0;
}
m=((1.0*(y[l]-y[k]))/(x[l]-x[k]));
if((m<=1)&&(x[k]!=x[l]))
{
if(x[k]>x[l])
{
t=x[k];
x[k]=x[l];
x[l]=t;
t=y[k];
y[k]=y[l];
y[l]=t;
}
j=y[k];
for(i=x[k];i<=x[l];i++)
{
putpixel(i,j,YELLOW);
j=j+m;
}
}
else
{
if(y[k]>y[l])
{
t=x[k];
x[k]=x[l];
x[l]=t;
t=y[k];
y[k]=y[l];
y[l]=t;
}
i=x[k];
if((x[l]-x[k])!=0)
s=1/m;
else
s=0;
for(j=y[k];j<=y[l];j++)
{
putpixel(i,j,YELLOW);
i=i+s;
}
}
if(flag==0)
k=4;
}
getch();
closegraph();
}
7.
Program to rotate a circle alternately inside and
outside around the circumference of another circle.
#include<iostream.h>
#include<conio.h>
#include<dos.h>
#include<graphics.h>
#include<stdlib.h>
void erase1(int,int);
void erase2(int,int);
int r=15;
void main()
{
int gdriver = DETECT,gmode,errcode;
initgraph(&gdriver,&gmode,"C:\\TC");
errcode=graphresult();
if(errcode != 0)
{
cout<<grapherrormsg(errcode);
exit(0);
}
delay(400);
circle(319,239,100);
erase1(319,159);
erase2(369,119);
erase1(369,189);
erase2(439,189);
erase1(399,239);
erase2(439,289);
erase1(369,289);
erase2(369,359);
erase1(319,319);
erase2(259,359);
erase1(269,289);
erase2(199,289);
erase1(239,239);
erase2(199,189);
erase1(259,189);
erase2(259,119);
erase1(319,159);
circle(319,159,r);
getch();
closegraph();
}
void erase1(int a,int b)
{
for(int i=r;i>=0;i--)
{
setcolor(WHITE);
ellipse(a,b,0,360,i,r);
delay(30);
setcolor(BLACK);
ellipse(a,b,0,360,i,r);
setcolor(WHITE);
}
}
void erase2(int a,int b)
{
for(int i=5;i<=r;i++)
{
setcolor(WHITE);
ellipse(a,b,0,360,i,r);
delay(30);
setcolor(BLACK);
ellipse(a,b,0,360,i,r);
setcolor(WHITE);
}
}
8. Program to
design flying colored balloons.
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<dos.h>
void main()
{
int gd=DETECT,gm;
initgraph(&gd,&gm,"\\tc\\bgi\\");
for(int i=250;i>=0;i--)
{
circle(200+i,150+i,50);
setfillstyle(SOLID_FILL,RED);
floodfill(200+i,150+i,getmaxcolor());
outtextxy(170+i,130+i,"Happy");
outtextxy(170+i,150+i,"DIWALI");
arc(200+i,225+i,75,200,25);
arc(170+i,259+i,300,75,25);
circle(300+i,250+i,50);
setfillstyle(SOLID_FILL,13);
floodfill(300+i,250+i,getmaxcolor());
outtextxy(270+i,230+i,"Happy");
outtextxy(270+i,250+i,"Birthday");
arc(300+i,325+i,75,230,25);
arc(270+i,364+i,300,70,25);
delay(35);
cleardevice();
}
closegraph();
restorecrtmode();
}
9. Program to
perform shearing transformation on a rectangle.
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<process.h>
#include<sdlib.h>
#include<math.h>
#include<dos.h>
void main()
{
clrscr();
int gdriver=DETECT,gmode, errcode, left, top, right,
bottom;
initgraph(&gdrive, &gmode, “ \\tc\\bgi”);
errcode=grphresult();
if(errcode!=0)
{
cout<<”Graphics error:- “;
cout<<grapherrormsg(errcode);
exit(0);
}
cout<<”\n Enter left value for rectangle :- “;
cin>> left;
cout<<”\n Enter top value for rectangle:- “;
cin>>top;
cout<<”\n Enter right value for rectangle:- “;
cin>>right;
cout<<”\n Enter bottom value for rectangle:- “;
cin>>bottom;
cout<<”\n Press any key to see rectangle:- ……….“;
getch();
clrscr();
clearviewport();
char ch;
int s, lx, ly, i;
rectangle(left, top, right,
bottom);
lx=right-left;
ly=bottom-top;
while(1)
{
cout<<” You want to shear along x axis or about y
axis(x or y)?: “;
cin>>ch:
if(ch!=’x’&&
ch!=’X’&& ch!’y’ &&
ch!=’Y’)
{
cout<<”\n Wrong Choice,
Press any key”;
getch();
}
else
break;
}
clearviewport();
cout<<”\n\n
Enter the value by which it is to be
sheared: “;
fflush(stdin);
cin>>s;
cout<<”\n
Press any key to see original and transformed rectangle”;
getch();
clrscr();
clearviewport();
rectangle(left,
top, right, bottom);
delay(500);
if(ch==’x’ || ch==’X’)
for(i=0-;i<=s;i++)
{
delay(100);
clearviewport();
move(left+i,top,left+lx+i,top);
move(left+lx+i,top, left+lx,
top+ly);
move(left+lx, top+ly, left,
top+ly);
move(left,top+ly,left+i,top);
}
if(ch==’y’||ch++’Y’)
for(i=0;i<=s;i++)
{
delay(100);clearviewport();
move(left,top,left+lx,top+i);
move(left+lx,top+i,left+lx,top+ly+i);
move(left+lx,top+ly,left,top);
}
getch();
clearviewport();
}
void
move(int x1,int y1,int x2, int y2)
{
float
x,y,xx,yy,xinc,yinc,dx,dy,step;
dx=x2-x1;
dy=y2-y1;
if(abs(dx)>abs(dy))
step=abs(dx);
else
step=abs(dy);
xinc=dx/step;
xx=x1+0.5;
yy=y1+0.5;
for(x=x1,y=y1;(xx!=x2) ||
(yy!=y2);x+=yinc)
{
putpixel(x,y,WHITE);
xx=(int)(x+0.5);
yy=(int)(y+0.5);
}
}
10. Program to
make bar chart for a student’s result of 5 years.
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<process.h>
void axis();
void main()
{
int c,d,e,f,g;
int a=DETECT,b;
initgraph(&a,&b,"\\tc\\bgi\\");
cout<<"\n Enter
the Marks of the First Year (In %):-";
cin>>c;
cout<<"\n Enter
the Marks of the Second Year (In %):-";
cin>>d;
cout<<"\n Enter
the Marks of the Third Year (In %):-";
cin>>e;
cout<<"\n Enter
the Marks of the Fourth Year (In %):-";
cin>>f;
cout<<"\n Enter
the Marks of the Fifth Year (In %):-";
cin>>g;
if ((c>100)||(d>100)||(e>100)||(f>100)||(g>100))
{
cout<<"\n\n\n\n\t\t
Result can't be more than 100%";
getch();
exit(0);
}
axis();
bar3d(163,400,150,((100-c)*3+110),5,10);
//1st year bar
bar3d(223,400,210,((100-d)*3+110),5,10);
//2nd year bar
bar3d(283,400,270,((100-e)*3+110),5,10);
//3rd year bar
bar3d(343,400,330,((100-f)*3+110),5,10); //4th year bar
bar3d(403,400,390,((100-g)*3+110),5,10);
//5th year bar
getch();
closegraph();
}
void axis()
{
cleardevice();
//y-axis
line(100,400,100,50);
//x-axis
line(100,400,500,400);
outtextxy(10,250,"Marks(%)");
outtextxy(170,430,"Students
Result (In Year)");
//numbers on x-axis
line(160,405,160,395);
outtextxy(150,408,"1st");
line(220,405,220,395);
outtextxy(210,408,"2nd");
line(280,405,280,395);
outtextxy(270,408,"3rd");
line(340,405,340,395);
outtextxy(330,408,"4th");
line(400,405,400,395);
outtextxy(390,408,"5th");
//numbers on y-axis
line(95,370,105,370);
outtextxy(76,367,"10");
line(95,340,105,340);
outtextxy(76,337,"20");
line(95,310,105,310);
outtextxy(76,307,"30");
line(95,280,105,280);
outtextxy(76,277,"40");
line(95,250,105,250);
outtextxy(76,247,"50");
line(95,220,105,220);
outtextxy(76,217,"60");
line(95,190,105,190);
outtextxy(76,187,"70");
line(95,160,105,160);
outtextxy(76,157,"80");
line(95,130,105,130);
outtextxy(76,127,"90");
line(95,100,105,100);
outtextxy(70,97,"100");
}
11. Program to
rotate a teddy bear in 3D.
#include<iostream.h>
#include<graphics.h>
#include<stdlib.h>
#include<conio.h>
#include<dos.h>
void teddy1(void);
void teddy2(void);
void teddy3(void);
void teddy4(void);
void teddy5(void);
void teddy6(void);
int main(void)
{
int gdriver=DETECT,gmode,errorcode;
initgraph(&gdriver,&gmode,”\\tc\\bgi”);
errorcode = graphresult();
if(errorcode != grOk)
// an error occurred
{
cout<<”Graphics
error”<grapherrormsg(errrorcode)<<”\n”;
getch(); exit(1);
}
while(!kbhit())
{
if(!kbhit())
{
teddy1();
delay(700); clearviewport();
}
if(!kbhit())
{
teddy3();
delay(700);
clearviewport();
}
if(!kbhit())
{
teddy4();
delay(700);
clearviewport();
}
if(!kbhit())
{
teddy2();
delay(700);
clearviewport();
}
if(!kbhit())
{
teddy5();
delay(700);clearviewport();
}
}
getch();
closegraph();
return 0;
}
void teddy1()
{
ellipse(300,100,0,360,70,70);
ellipse(300,280,,0,360,100,110);
circle(270,65,10);
circle(330,65,10);
circle(300,120,40);
circle( 300,105,10);
ellipse(300,110,230,310,30,30);
line(380,210,450,170);
line(400,250,460,220);
line(220,210,150,170);
line(200,250,140,220);
ellipse(455,195,280,100,25,25);
ellipse(145,195,80,260,25,25);
line(390,325,470,325);
line(365,370,460,370);
line(210,325,130,325);
line(235,370,140,370);
ellipse(465,348,260,70,23,23);
ellipse(136,348,110,280,23,23);
}
void teddy2()
{
ellipse(300,100,0,360,70,70);
ellipse(300,280,0,360,100,110);
line(380,210,450,170);
line(400,250,460,220);
line(220,210,150,170);
line(200,250,140,220);
ellipse(455,195,280,100,25,25);
ellipse(145,195,80,260,25,25);
line(390,325,470,325);
line(365,370,460,370);
line(210,325,130,325);
line(225,370,140,370);
ellipse(465,348,260,70,23,23);
ellipse(136,348,110,280,23,23);
}
void teddy3()
{
ellipse(300,100,0,360,60,70);
ellipse(300,280,0,360,90,110);
circle(280,65,10);
ellipse(260,120,270,130,20,30);
ellipse(260,105,0,360,5,10);
ellipse(260,210,250,290,30,30);
line(320,210,370,230);
line(320,250,270,90,20,20);
ellipse(370,250,270,90,20,20);
line(320,320,370,340);
line(320,360,370,380);
ellipse(370,360,270,90,20,20);
}
void teddy4()
{
ellipse(300,100,0,360,60,70);
ellipse(300,280,0,360,90,110);
line(280,210,230,230);
line(280,250,230,270);
ellipse(230,250,90,270,20,20);
line(280,320,230,340);
line(280,360,230,380);
ellipse(230,360,90,270,20,20);
}
void teddy5()
{
ellipse(300,100,0,360,60,70);
ellipse(300,280,0,360,90,110);
line(320,210,370,230);
line(320,250,370,270);
ellipse(370,250,270,90,20,20);
line(320,320,370,340);
line(320,360,370,380);
ellipse(370,360,270,90,20,20);
}
void teddy6()
{
ellipse(300,100,0,360,60,70);
ellipse(300,280,0,360,90,110);
circle(320,65,10);
ellipse(340,120,40,270,20,30);
ellipse(340,105,0,360,5,10);
ellipse(340,110,250,290,30,30);
line(280,210,230,230);
line(280,250,230,270);
ellipse(230,250,90,270,20,20);
line(280,320,230,340);
line(280,360,230,380);
ellipse(230,390,90,270,20,20);
}
12. Program to
rotate a doll in 2D plane.
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<dos.h>
#include<stdlib.h>
void top();
void bottom();
void left();
void right();
void main()
{
clrscr();
int gdriver=DETECT,gmode,errcode;
initgraph (&gdriver,gmode,”\\tc\\bgi”);
if(errorcode != grOk)
// an error occurred
{
cout<<”Graphics
error”<grapherrormsg(errrorcode)<<”\n”;
getch(); exit(0);
}
int n,time=200;
cout<<”Enter the number of time
Your want rotate doll \n”;
cin>> n;
for(int i=0; i<n;i++)
{
top();
delay(time); clearviewport();
right();
delay(time); clearviewport();
bottom();
delay(time); clearviewport();
left();
delay(time); clearviewport();
}
top();
getch();
closegraph();
}
void
top()
{
setfillstyle(1,WHITE); setcolor(WHITE);
fillellipse(320,240,20,30);
line(320,260,320,400);
line(320,290,280,310);
line(320,290,360,310);
line(320,400,360,430);
line(320,400,280,430);
setfillstyle(1,BLACK);
fillellipse(310,225,3,5);
fillellipse(330,225,3,5);
setcolor(BLACK);
line(315,255,325,255);
line(320,235,320,245);
}
void
right()
{
setfillstyle(1,WHITE);
setcolor(WHITE);
fillellipse(320,240,30,20);
line(340,240,480,240);
line(370,240,400,200;
line(370,240,400,280);
line(480,240,510,200);
line(480,240,510,270);
setfillstyle(1,BLACK);
fillellipse(305,230,53);
fillellipse(305,250,5,3);
setfillstyle(BLACK);
line(315,240,325,240);
line(335,235,335,245);
}
void
bottom()
{
setfillstyle(1,WHITE);
setcolor(WHITE);
fillellipse(320,240,20,30);
line(320,220,320,80);
line(30,190,350,170);
line(320,190,290,170);
line(30,80,290,40);
line(320,80,350,40);
setfillstyle(1,BLACK);
fillellipse(310,225,3,5);
fillellipse(330,255,3,5);
setcolor(BLACK);
line(315,225,325,225);
line(320,235,320,245);
}
void
left()
{
setfillstyle(1,WHITE);
setcolor(WHITE);
fillellipse(320,240,30,20);
line(290,240,150,240,);
line(260,240,230,280);
line(260,240,230,200);
line(150,240,110,280);
line(150,240,110,200);
setfillstyle(1,BLACK);
fillellipse(335,230,5,3);
fillellipse(335,250,5,3);
setcolor(BLACK);
line(315,240,325,240);
line(305,235,305,245);
}
13. Program to
implement Cohen-Sutherland line clipping algorithm.
#include<iostream.h>
#include<conio.h>
#include<graphics.h>
float xmin,xmax,ymin,ymax;
class outcode
{
public:
int top,bottom,right,left;
void compcode(int x,int y)//computes the outcode for a
particular point
{
if (y>ymax)
top=1;
else
top=0;
if (y<ymin)
bottom=1;
else
bottom=0;
if (x>xmax)
right=1;
else
right=0;
if (x<xmin)
left=1;
else
left=0;
}
void show();
};
void outcode::show()
{
cout<<top<<bottom<<right<<left;
}
int check1(outcode A,outcode
B) //checks for trivial acceptance
{
if ((!A.right && !B.right) &&
(!A.left && !B.left) && (!A.top && !B.top) &&
(!A.bottom && !B.bottom)==1)
return 1;
else
return 0;
}
int check2(outcode A,outcode
B) //checks for trivial acceptance
{
if ((A.right && B.right) &&
(A.left && B.left) && (A.top && B.top) &&
(A.bottom && B.bottom)==1)
return 1;
else
return 0;
}
outcode choose(outcode
A,outcode B) //to choose the outer point
{
if
((A.left==0)&&(A.right==0)&&(A.top==0)&&(A.bottom==0))
return B;
else
return A;
}
int see(outcode A,outcode B)
{
if
((A.left==B.left)&&(A.right==B.right)&&(A.top==B.top)&&(A.bottom==B.bottom))
return 1;
else
return 0;
}
void main()
{
clrscr();
float x0,y0,x1,y1,accept=0,done=0;
float x,y,m;
int driver,a;
driver=DETECT;
initgraph(&driver,&a,"\\tc\\bgi\\");
cout<<"\n Enter the diagonal coordinates of the
rectangle:-";
cout<<"\n Enter the left top coordinate, xmin ,
ymin:-";
cin>>xmin>>ymin;
cout<<"\n Enter the right bottom coordinate ,
xmax ,ymax:-";
cin>>xmax>>ymax;
cout<<"\n Enter the end coordinate of
line:-";
cin>>x0>>y0>>x1>>y1;
m=(x1-x0)/(y1-y0);
outcode outcode0,outcode1,outcodeout;
outcode0.compcode(x0,y0);
// computing the outcode for the 1st end coordinate
outcode1.compcode(x1,y1); // -- do-- for 2nd coordinate
while(done==0)
{
if
(check1(outcode0,outcode1)) //check for trivial acceptance
{
done=1;
accept=1;
}
if
((check2(outcode0,outcode1))) // check for trivial rejection
{
done=1;
accept=0;
cout<<"\n\n The line has been trivially
rejected";
}
if (done!=1)
{
//failed
both the tests , so calculate the line segment to clip
//atleast
one end point is outside the clip rectangle so find it
outcodeout=choose(outcode0,outcode1);
//finding
intersection points
if
(outcodeout.top==1) //divide line at top of clip rectangle
{
x=x0+(ymax-y0)*m;
y=ymax;
}
if
(outcodeout.bottom==1) //divide line at bottom edge of clip rectangle
{
x=x0+(ymin-y0)*m;
y=ymin;
}
if
(outcodeout.right==1) //divide line at right edge of clip rectangle
{
y=y0+(xmax-x0)*m;
x=xmax;
}
if
(outcodeout.top==1) //divide line at top of clip rectangle
{
y=y0+(xmin-x0)*m;
x=xmin;
}
// move
from outside point to the intersection point
if (see(outcodeout,outcode0))
{
x0=x;
y0=y;
outcode0.compcode(x0,y0);
}
else
{
x1=x;
y1=y;
outcode1.compcode(x1,y1);
}
}
}//end of while loop
if (accept==1)
{
cout<<"\n\n The intersection points of the line
with the rectangle"<<"are:
"<<x0<<","<<y0<<" and
"<<x1<<","<<y1;
setlinestyle(0,0,6);
setcolor(BLUE);
rectangle(xmin,ymin,xmax,ymax);
setcolor(12);
line(x0,y0,x1,y1);
}
getch();
closegraph();
}//end of main
