Practical File of Computer Graphics

(1)

P

RACTICAL

F

ILE OF

C

OMPUTER

G

RAPHICS

(2)

I

NDEX

Aim

Page

Remarks

1. Write a program to draw a stick man

2

2. Write a program to draw a rectangle using

line function

4

3. Write a program to draw a line using DDA’s line

drawing algorithm

6

4. Write a program to draw a line using

Bresenham’s line drawing algorithm

9

5. Write a program to draw a circle using

equation of circle

12

6 Write a program to draw a circle using

Bresenham’s circle drawing algorithm

14

7. Write a program to draw a circle using midpoint

circle drawing algorithm

17

8. Write a program to draw a circle using polar co-

ordinates

20

9. Write a program to fill a circle using Boundary

Fill Algorithm

23

10. Write a program to fill a circle using Flood Fill

Algorithm

27

11. Write a program for line clipping using cohen-

Sutherland algorithm

30

12. Write a program to translate a triangle

about the origin

36

13. Write a program to scale a triangle about a

fixed point taken as one of the vertex of

the triangle

39

14. Write a program to rotate a triangle about

a fixed point taken as one of the vertex of

the triangle

(3)

P

RACTICAL

N

O

.1

Write a program to draw a stick man

#include<math.h> #include<conio.h> #include<graphics.h> void main() { intgd=DETECT,gm; int x,y,r,c1; initgraph(&gd,&gm,""); circle(150,70,70); circle(120,50,10); circle(190,50,10); line(155,60,155,80); arc(155,100,180,360,20); line(130,140,130,170); line(170,140,170,170); rectangle(80,170,230,260); line(110,260,110,360); line(205,260,205,360); line(80,190,55,240); line(230,190,255,240); getch(); }

(4)

(5)

P

RACTICAL

N

O

.

2 Write a program to draw a rectangle using line function

#include<graphics.h> void main() { intgd=DETECT,gm; initgraph(&gd,&gm," "); line(100,100,100,300); line(100,100,300,100); line(100,300,300,300); line(300,100,300,300); getch(); }

(6)

(7)

P

RACTICAL

N

O

.

3 Write a program to draw a line using DDA’s line drawing

algorithm

#include<stdio.h> #include<conio.h> #include<graphics.h> #include<dos.h> voidlineDDA(int,int,int,int); void main() { int x1,y1,xn,yn; intgd=DETECT,gm; initgraph(&gd,&gm,"");

printf("enter the starting coordinates of the line:"); scanf("%d%d",&x1,&y1);

printf("enter the ending coordinates of the line:"); scanf("%d%d",&xn,&yn);

lineDDA(x1,y1,xn,yn); getch();

}

voidlineDDA(int x1,int y1,int xn,intyn) {

intdx,dy,m,i;

(8)

{ if(m<=1) { dx=1; dy=(m*dx); } else { dy=1; dx=(dy/m); } x1=x1+dx; y1=y1+dy; { putpixel(x1,y1,RED); delay(20); } } }

(9)

(10)

P

ROGRAM

N

O

.4

Write a program to draw a line using Bresenham’s line

drawing algorithm

#include<conio.h> #include<stdio.h> #include<graphics.h> #include<dos.h> voidlineBres(int,int,int,int); void main() { int x1,y1,xn,yn; intgd=DETECT,gm; initgraph(&gd,&gm,"");

printf("Enter the starting coordinate at line:"); scanf("%d%d", &x1, &y1);

printf("Enter the ending coordinate at line:"); scanf("%d%d", &xn, &yn);

lineBres(x1,y1,xn,yn); getch();

}

voidlineBres(int x1,int y1,int xn,intyn) {

int dx = xn-x1,dy=yn-y1; int di = 2*dy-dx;

(11)

putpixel(x1,y1,RED); while(x1<xn) { x1++; if(di<0) { di=di+ds; } else { y1++; di=di+dt; } putpixel(x1,y1,RED); delay(20); } }

(12)

(13)

P

RACTICAL

N

O

.

5 Write a program to draw a circle using equation of circle

#include<conio.h> #include<graphics.h> void main() { intgd=DETECT,gm; int x,y,r,c1; initgraph(&gd,&gm,""); circle(200,200,50); getch(); closegraph(); }

(14)

(15)

P

RACTICAL

N

O

.

6 Write a program to draw a circle using Bresenham’s

circle drawing algorithm

#include<stdio.h> #include<conio.h> #include<dos.h> #include<graphics.h> voidcircleBres(int,int,int); voiddrawcircle(int,int,int,int); void main() { intxc,yc,r; intgd=DETECT,gm; initgraph(&gd,&gm,"");

printf("Enter the centre coordinates of the circle"); scanf("%d%d",&xc,&yc);

printf("Enter radius of circle:"); scanf("%d",&r); circleBres(xc,yc,r); getch(); } voidcircleBres(intxc,intyc,int r) { int x=0,y=r;

(16)

while(x<y) { drawcircle(xc,yc,x,y); x++; if(d<0) d=d+4*(x)+6; else { y--; d=d+4*(x-y)+10; drawcircle(xc,yc,x,y); delay(50); } } } voiddrawcircle(intxc,intyc,intx,int y) { putpixel(xc+x,yc+y,RED); putpixel(xc+y,yc+x,YELLOW); putpixel(xc-x,yc+y,BLUE); putpixel(xc-y,yc+x,GREEN); putpixel(xc-x,yc-y,GREEN); putpixel(xc-y,yc-x,YELLOW); putpixel(xc+y,yc-x,RED); putpixel(xc+x,yc-y,YELLOW); }

(17)

(18)

P

RACTICAL

N

O

.

7 Write a program to draw a circle using midpoint circle

drawing algorithm

#include<stdio.h> #include<conio.h> #include<graphics.h> #include<dos.h> voidcirclemidpoint(int,int,int); voiddrawcircle(int,int,int,int); void main() { intxc,yc,r; intgd=DETECT,gm; initgraph(&gd,&gm,"");

printf("Enter center coordinates of the circle: "); scanf("%d%d",&xc,&yc);

printf("Enter radius of the circle: "); scanf("%d",&r); circlemidpoint(xc,yc,r); getch(); } voidcirclemidpoint(intxc,intyc,int r) { int x=0,y=r; int p=1-r; while(x<y) { drawcircle(xc,yc,x,y); x++; if(p<0) {

(19)

p=p+2*x+1; } else { y--; p=p+2*(x-y)+1; } drawcircle(xc,yc,x,y); delay(50); } } voiddrawcircle(intxc,intyc,intx,int y) { putpixel(xc+x,yc+y,RED); putpixel(xc-x,yc+y,BLUE); putpixel(xc+x,yc-y,GREEN); putpixel(xc-x,yc-y,RED); putpixel(xc+y,yc+xGREEN); putpixel(xc-y,yc+x,YELLOW); putpixel(xc+y,yc-x, YELLOW); putpixel(xc-y,yc-x, YELLOW); }

(20)

(21)

P

RACTICAL

N

O

.

8 Write a program to draw a circle using polar

co-ordinates

#include<graphics.h> #include<math.h> #include<conio.h> voidacircle(inth,intk,int r); voiddpixel(intx,inty,inth,int k); void main() { intgd=DETECT,gm; initgraph(&gd,&gm,""); setbkcolor(YELLOW); acircle(100,100,100); getch(); closegraph(); } voidacircle(inth,intk,int r) { inty,x; int theta; for(theta=0;theta<=360;theta+=1) { x=r*cos(theta); y=r*sin(theta);

(22)

} } voiddpixel(intx,inty,inth,int k) { putpixel(x+h,y+k,RED); putpixel(y+h,x+k,RED); putpixel(-y+h,x+k,RED); putpixel(-x+h,y+k,RED); putpixel(-x+h,-y+k,RED); putpixel(-y+h,-x+k,RED); putpixel(y+h,-x+k,RED); putpixel(x+h,-y+k,RED); }

(23)

(24)

P

RACTICAL

N

O

.

9 Write a program to fill a circle using Boundary Fill

Algorithm

#include<graphics.h> #include<math.h> #include<conio.h> voiddcircle(inth,intk,int r); voiddpixel(intx,inty,inth,int k);

voidcfill(intx,int y, intfcolor, intbcolor); void main() { intgd=DETECT,gm; initgraph(&gd,&gm,""); setbkcolor(YELLOW); dcircle(30,30,27); cfill(30,30,BLUE,RED); getch(); closegraph(); } voiddcircle(inth,intk,int r) { inty,i;

(25)

for(i=0;i<=r;i++) { y=sqrt((r*r-(i)*(i))); dpixel(i,y,h,k); } } voiddpixel(intx,inty,inth,int k) { putpixel(x+h,y+k,RED); putpixel(y+h,x+k,RED); putpixel(-y+h,x+k,RED); putpixel(-x+h,y+k,RED); putpixel(-x+h,-y+k,RED); putpixel(-y+h,-x+k,RED); putpixel(y+h,-x+k,RED); putpixel(x+h,-y+k,RED); }

voidcfill(intx,int y, intfcolor, intbcolor) {

int current;

(26)

{ putpixel(x,y,fcolor); cfill(x+1,y,BLUE,RED); cfill(x-1,y,BLUE,RED); cfill(x,y+1,BLUE,RED); cfill(x,y-1,BLUE,RED); } }

(27)

(28)

P

RACTICAL

N

O

.

10 Write a program to fill a circle using Flood Fill Algorithm

#include<graphics.h> #include<math.h> #include<conio.h>

voiddcircle(inth,intk,int r); voiddpixel(intx,inty,inth,int k);

voidffill(intx,int y, intfcolor, intbcolor); void main() { intgd=DETECT,gm; initgraph(&gd,&gm,""); setbkcolor(YELLOW); dcircle(30,30,27); ffill(30,30,YELLOW,BLACK); getch(); closegraph(); } voiddcircle(inth,intk,int r) { inty,i; for(i=0;i<=r;i++) { y=sqrt((r*r-(i)*(i))); dpixel(i,y,h,k); } }

(29)

voiddpixel(intx,inty,inth,int k) { putpixel(x+h,y+k,RED); putpixel(y+h,x+k,RED); putpixel(-y+h,x+k,RED); putpixel(-x+h,y+k,RED); putpixel(-x+h,-y+k,RED); putpixel(-y+h,-x+k,RED); putpixel(y+h,-x+k,RED); putpixel(x+h,-y+k,RED); }

voidffill(intx,int y, intfcolor, intbcolor) { if(getpixel(x,y)==bcolor) { putpixel(x,y,fcolor); ffill(x+1,y,YELLOW,BLACK); ffill(x-1,y,YELLOW,BLACK); ffill(x,y+1,YELLOW,BLACK); ffill(x,y-1,YELLOW,BLACK); } }

(30)

(31)

P

ROGRAM

N

O

.

11 Write a program for line clipping using cohen Sutherland

algorithm

#include<stdio.h> #include<graphics.h> #include<conio.h>

typedef unsigned intoutcode;

enum { TOP=0x1, BOTTOM=0x2, RIGHT=0x4, LEFT=0x8 }; voidlineclip(x0,y0,x1,y1,xwmin,ywmin,xwmax,ywmax ) float x0,y0,x1,y1,xwmin,ywmin,xwmax,ywmax;

{

intgd,gm;

outcode code0,code1,codeout; int accept = 0, done=0;

code0 = calcode(x0,y0,xwmin,ywmin,xwmax,ywmax); code1 = calcode(x1,y1,xwmin,ywmin,xwmax,ywmax); do{ if(!(code0 | code1)) { accept =1 ; done =1; } else

if(code0 & code1) done = 1;

(32)

{

floatx,y;

codeout = code0 ? code0 : code1; if(codeout& TOP) { x = x0 + (x1-x0)*(ywmax-y0)/(y1-y0); y = ywmax; } else if(codeout& BOTTOM) { x = x0 + (x1-x0)*(ywmin-y0)/(y1-y0); y = ywmin; } else if ( codeout& RIGHT) { y = y0+(y1-y0)*(xwmax-x0)/(x1-x0); x = xwmax; } else { y = y0 + (y1-y0)*(xwmin-x0)/(x1-x0); x = xwmin; } if(codeout == code0)

(33)

{ x0 = x; y0 = y; code0=calcode(x0,y0,xwmin,ywmin,xwmax,ywma x); } else { x1 = x; y1 = y; code1 = calcode(x1,y1,xwmin,ywmin,xwmax,ywmax); } } } while( done == 0); if(accept) line(x0,y0,x1,y1); rectangle(xwmin,ywmin,xwmax,ywmax); getch(); } intcalcode (x,y,xwmin,ywmin,xwmax,ywmax) floatx,y,xwmin,ywmin,xwmax,ywmax; { int code =0; if(y>ywmax) code |=TOP;

(34)

else if(x >xwmax) code |= RIGHT; else if ( x<xwmin) code |= LEFT; return(code); } main() { float x2,y2,x1,y1,xwmin,ywmin,xwmax,ywmax; intgd=DETECT,gm; clrscr(); initgraph(&gd,&gm,"e:\\tc\\bgi");

printf("\n\n\tEnter the co-ordinates of Line :"); printf("\n\n\tX1 Y1 : ");

scanf("%f %f",&x1,&y1); printf("\n\n\tX2 Y2 : "); scanf("%f %f",&x2,&y2);

printf("\n\tEnter the co_ordinates of window :\n "); printf("\n\txwmin , ywmin : "); scanf("%f %f",&xwmin,&ywmin); printf("\n\txwmax , ywmax : "); scanf("%f %f",&xwmax,&ywmax); clrscr(); line(x1,y1,x2,y2); rectangle(xwmin,ywmin,xwmax,ywmax); getch();

(35)

clrscr();

lineclip(x1,y1,x2,y2,xwmin,ywmin,xwmax,ywmax ); getch();

closegraph(); }

(36)

(37)

P

RACTICAL

N

O

.

12 Write a program to translate a triangle about the origin

#include<stdio.h> #include<conio.h> #include<graphics.h> #include<process.h> #include<math.h> voidRectAngle(intx,inty,intHeight,int Width); void Translate(intx,inty,intHeight,int Width); void main()

{

intgd=DETECT,gm; intx,y,Height,Width; initgraph(&gd,&gm," ");

printf("Enter the First point for the Rectangle:"); scanf("%d%d",&x,&y);

printf("Enter the Height&Width for the Rectangle:"); scanf("%d%d",&Height,&Width);

RectAngle(x,y,Height,Width); getch();

cleardevice();

(38)

} voidRectAngle(intx,inty,intHeight,int Width) { line(x,y,x+Width,y); line(x,y,x,y+Height); line(x+Width,y,x+Width,y+Height); line(x,y+Height,x+Width,y+Height); }

void Translate(intx,inty,intHeight,int Width) {

intNewx,Newy,a,b;

printf("Enter the Transaction coordinates"); scanf("%d%d",&Newx,&Newy); cleardevice(); a=x+Newx; b=y+Newy; RectAngle(a,b,Height,Width); }

(39)

(40)

P

RACTICAL

N

O

.

13 Write a program to scale a triangle about a fixed point

taken as one of the vertex of the triangle

#include<stdio.h> #include<conio.h> #include<graphics.h> void main() { int x1,y1,x2,y2,x3,y3,x4,y4; intsx,sy; int poly[8]; intgd=DETECT,gm; initgraph(&gd,&gm,""); cleardevice();

printf("Enter the first coordinates of triangle: "); scanf("%d%d",&x1,&y1);

printf("Enter the second coordinates of triangle: "); scanf("%d%d",&x2,&y2);

printf("Enter the third coordinates of triangle: "); scanf("%d%d",&x3,&y3); poly[0]=x1; poly[1]=y1; poly[2]=x2; poly[3]=y2; poly[4]=x3; poly[5]=y3; poly[6]=x1; poly[7]=y1; cleardevice(); drawpoly(4,poly); getch();

(41)

scanf("%d%d",&sx,&sy); x4=sx*x1-x1; y4=sy*y1-y1; x1=sx*x1-x4; y1=sy*y1-y4; x2=sx*x2-x4; y2=sy*y2-y4; x3=sx*x3-x4; y3=sy*y3-y4; poly[0]=x1; poly[1]=y1; poly[2]=x2; poly[3]=y2; poly[4]=x3; poly[5]=y3; poly[6]=x1; poly[7]=y1; getch(); cleardevice(); drawpoly(4,poly);2 getch(); closegraph(); }

(42)

O

UTPUT

(43)

Program No. 14

Write a program to rotate a triangle about a fixed point

taken as one of the vertex of the triangle

#include<stdio.h> #include<conio.h> #include<graphics.h> #include<process.h> #include<math.h>

void TriAngle(int x1,int y1,int x2,int y2,int x3,int y3); void Rotate(int x1,int y1,int x2,int y2,int x3,int y3); void main()

{

intgd=DETECT,gm;

int x1,y1,x2,y2,x3,y3; initgraph(&gd,&gm," ");

printf("Enter the 1st point for the triangle: "); scanf("%d%d",&x1,&y1);

printf("Enter the 2nd point for the triangle: "); scanf("%d%d",&x2,&y2);

printf("Enter the 3rd point for the triangle: "); scanf("%d%d",&x3,&y3); TriAngle(x1,y1,x2,y2,x3,y3); getch(); cleardevice(); Rotate(x1,y1,x2,y2,x3,y3); setcolor(5); TriAngle(x1,y1,x2,y2,x3,y3); getch(); }

(44)

line(x1,y1,x2,y2); line(x2,y2,x3,y3); line(x3,y3,x1,y1); }

void Rotate(int x1,int y1,int x2,int y2,int x3,int y3) {

int x,y,a1,b1,a2,b2,a3,b3; float Angle;

printf("Enter the angle for rotation: "); scanf("%f",&Angle); cleardevice(); Angle=(Angle*3.14)/180; a1=x2+(x1-x2)*cos(Angle)-(y1-y2)*sin(Angle); b1=y2+(x1-x2)*sin(Angle)+(y1-y2)*cos(Angle); a2=x2+(x2-x2)*cos(Angle)-(y2-y2)*sin(Angle); b2=y2+(x2-x2)*sin(Angle)+(y2-y2)*cos(Angle); a3=x2+(x3-x2)*cos(Angle)-(y3-y2)*sin(Angle); b3=y2+(x3-x2)*sin(Angle)+(y3-y2)*cos(Angle); printf("Rotated: "); TriAngle(a1,b1,a2,b2,a3,b3); }

(45)

(46)