Graphics programs

1. 1 Clipping/fill algorithms
//Graphics Point Clipping C Program
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
int tlx,tly,brx,bry,px,py;
void point_clip()
{ int wxmin,wymin,wxmax,wymax;
wxmin=tlx;
wxmax=brx;
wymin=tly;
wymax=bry;
if(px>=wxmin&&px<=wxmax)
if(py>=wymin&&py<=wymax)
putpixel(px,py,RED);
getch();
closegraph();
}
void main(void)
{ int gd=DETECT,gm,xc,yc,r;
clrscr();
printf("Enter the top left coordinate");
scanf("%d%d",&tlx,&tly);
printf("Enter the bottom right coordinate");
scanf("%d%d",&brx,&bry);
printf("n Enter the point");
scanf("%d%d",&px,&py);
initgraph(&gd,&gm,"c:tcbgi"); /*Sometimes it may be
"C:TCBGI" , It depends machine to mac..*/
setbkcolor(YELLOW);
setcolor(RED);
rectangle(tlx,tly,brx,bry);
point_clip();
}

2. 2 Clipping/fill algorithms
//Sutherland-Hodgeman Polygon clipping Algorithm
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
void clip(float,float,float);
int i,j=0,n;
int rx1,rx2,ry1,ry2;
float x1[8],y1[8];
void main()
{
int gd=DETECT,gm;
int i,n;
float x[8],y[8],m;
clrscr();
initgraph(&gd,&gm,"");
printf("coordinates for rectangle : ");
scanf("%d%d%d%d",&rx1,&ry1,&rx2,&ry2);
printf("no. of sides for polygon : ");
scanf("%d",&n);
printf("coordinates : ");
for(i=0;i<n;i++)
{
scanf("%f%f",&x[i],&y[i]);
}
cleardevice();
outtextxy(10,10,"Before clipping");
outtextxy(10,470,"Press any key....");
rectangle(rx1,ry1,rx2,ry2);
for(i=0;i<n-1;i++)
line(x[i],y[i],x[i+1],y[i+1]);
line(x[i],y[i],x[0],y[0]);
getch();
cleardevice();

3. 3 Clipping/fill algorithms
for(i=0;i<n-1;i++)
{
m=(y[i+1]-y[i])/(x[i+1]-x[i]);
clip(x[i],y[i],m);
}
clip(x[0],y[0],m);
outtextxy(10,10,"After clipping");
outtextxy(10,470,"Press any key....");
rectangle(rx1,ry1,rx2,ry2);
for(i=0;i<j-1;i++)
line(x1[i],y1[i],x1[i+1],y1[i+1]);
getch();
}
void clip(float e,float f,float m)
{
while(e<rx1 e>rx2 f<ry1 f>ry2)
{
if(e<rx1)
{
f+=m*(rx1-e);
e=rx1;
}
else if(e>rx2)
{
f+=m*(rx2-e);
e=rx1;
}
if(f<ry1)
{
e+=(ry1-f)/m;
f=ry1;
}
else if(f>ry2)

4. 4 Clipping/fill algorithms
{
e+=(ry2-f)/m;
f=ry2;
}
x1[j]=e;
y1[j]=f;
j++;
}
}
OUTPUT
Enter the x1 & y1 coordinates:
X1 : 70
Y1 : 80
Enter the x2 & y2 coordinates:
X2 : 250
Y2 : 280

5. 5 Clipping/fill algorithms
//polygon clipping
#include<graphics.h>
#include<dos.h>
#include<conio.h>
#include<stdlib.h>
void main()
{
int gd, gm ;
int x1 , y1 , x2 , y2 ;
int wxmin,wymin,wxmax, wymax ;
float u1 = 0.0,u2 = 1.0 ;
int p1 , q1 , p2 , q2 , p3 , q3 , p4 ,q4 ;
float r1 , r2 , r3 , r4 ;
int x11 , y11 , x22 , y22 ;
clrscr();
printf("Enter the windows left xmin , top boundry yminn");
scanf("%d%d",&wxmin,&wymin);
printf("Enter the windows right xmax ,bottom boundry
ymaxn");
scanf("%d%d",&wxmax,&wymax);
printf("Enter line x1 , y1 co-ordinaten");
scanf("%d%d",&x1,&y1);
printf("Enter line x2 , y2 co-ordinaten");
scanf("%d%d",&x2,&y2);
printf("liang barsky express these 4 inequalities using
lpk<=qpkn");
p1 = -(x2 - x1 ); q1 = x1 - wxmin ;
p2 = ( x2 - x1 ) ; q2 = wxmax - x1 ;
p3 = - ( y2 - y1 ) ; q3 = y1 - wymin ;

6. 6 Clipping/fill algorithms
p4 = ( y2 - y1 ) ; q4 = wymax - y1 ;
printf("p1=0 line is parallel to left clippingn");
printf("p2=0 line is parallel to right clippingn");
printf("p3=0 line is parallel to bottom clippingn");
printf("p4=0 line is parallel to top clippingn");
if( ( ( p1 == 0.0 ) && ( q1 < 0.0 ) ) ||
( ( p2 == 0.0 ) && ( q2 < 0.0 ) ) ||
( ( p3 == 0.0 ) && ( q3 < 0.0 ) ) ||
( ( p4 == 0.0 ) && ( q4 < 0.0 ) ) )
{
printf("Line is rejectedn");
getch();
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"c:tcbgi");
setcolor(RED);
rectangle(wxmin,wymax,wxmax,wymin);
setcolor(BLUE);
line(x1,y1,x2,y2);
getch();
setcolor(WHITE);
line(x1,y1,x2,y2);
getch();
}
else
{
if( p1 != 0.0 )
{
r1 =(float) q1 /p1 ;
if( p1 < 0 )
u1 = max(r1 , u1 );

7. 7 Clipping/fill algorithms
else
u2 = min(r1 , u2 );
}
if( p2 != 0.0 )
{
r2 = (float ) q2 /p2 ;
if( p2 < 0 )
u1 = max(r2 , u1 );
else
u2 = min(r2 , u2 );
}
if( p3 != 0.0 )
{
r3 = (float )q3 /p3 ;
if( p3 < 0 )
u1 = max(r3 , u1 );
else
u2 = min(r3 , u2 );
}
if( p4 != 0.0 )
{
r4 = (float )q4 /p4 ;
if( p4 < 0 )
u1 = max(r4 , u1 );
else
u2 = min(r4 , u2 );
}
if( u1 > u2 )
printf("line rejectedn");
else

8. 8 Clipping/fill algorithms
{
x11 = x1 + u1 * ( x2 - x1 ) ;
y11 = y1 + u1 * ( y2 - y1 ) ;
x22 = x1 + u2 * ( x2 - x1 );
y22 = y1 + u2 * ( y2 - y1 );
printf("Original line cordinatesn");
printf("x1 = %d , y1 = %d, x2 = %d, y2 = %dn",x1,y1,x2,y2);
printf("Windows coordinate are n");
printf("wxmin = %d, wymin = %d,wxmax = %d , wymax = %d
",wxmin,wymin,wxmax,wymax);
printf("New coordinates are n");
printf("x1 = %d, y1 = %d,x2 = %d , y2 =
%dn",x11,y11,x22,y22);
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"C:TCBGI");
setcolor(2);
rectangle(wxmin,wymax,wxmax,wymin);
setcolor(1);
line(x1,y1,x2,y2);
getch();
setcolor(0);
line(x1,y1,x2,y2);
setcolor(3);
line(x11,y11,x22,y22);
getch();
}
}
}

9. 9 Clipping/fill algorithms
//C Program For Oblique projection of a 3D object
#include<stdio.h>
#include<math.h>
#include<graphics.h>
main()
{
int x1,y1,x2,y2,gd,gm;
int ymax,a[4][8];
float par[4][4],b[4][8];
int i,j,k,m,n,p;
double L1,phi;
a[0][0] = 100; a[1][0] = 100; a[2][0] = 100;
a[0][1] = 200; a[1][1] = 100; a[2][1] = 100;
a[0][2] = 200; a[1][2] = 200; a[2][2] = 100;
a[0][3] = 100; a[1][3] = 200; a[2][3] = 100;
a[0][4] = 100; a[1][4] = 100; a[2][4] = 200;
a[0][5] = 200; a[1][5] = 100; a[2][5] = 200;
a[0][6] = 200; a[1][6] = 200; a[2][6] = 200;
a[0][7] = 100; a[1][7] = 200; a[2][7] = 200;
phi = (double) (3.14*45.0)/180 ;
L1 = 0.5;
par[0][0] = 1; par[0][1] = 0;
par[0][2] = L1*cos(phi); par[0][3] = 0;

10. 10 Clipping/fill algorithms
par[1][0] = 0; par[1][1] = 1;
par[1][2] = L1*sin(phi); par[1][3] = 0;
par[2][0] = 0; par[2][1] = 0;
par[2][2] = 0; par[2][3] = 0;
par[3][0] = 0; par[3][1] = 0;
par[3][2] = 0; par[3][3] = 1;
m=4; n=4; p=8;
for(i=0; i<m; i++)
for(k=0; k<p; k++)
b[i][k] = 0;
for(i=0; i<m; i++)
for(k=0; k<p; k++)
for(j=0; j<n; j++)
b[i][k] += (float)par[i][j] * a[j][k];
detectgraph(&gd,&gm);
initgraph(&gd,&gm, "c:tcbgi");
ymax = getmaxy();
/*- front plane display -*/
for(j=0;j<3;j++)
{
x1=(int) b[0][j]; y1=(int) b[1][j];
x2=(int) b[0][j+1]; y2=(int) b[1][j+1];
line( x1,ymax-y1,x2,ymax-y2);

11. 11 Clipping/fill algorithms
}
x1=(int) b[0][3]; y1=(int) b[1][3];
x2=(int) b[0][0]; y2=(int) b[1][0];
line( x1,ymax-y1,x2,ymax-y2);
/*- back plane display -*/
setcolor(11);
for(j=4;j<7;j++)
{
x1=(int) b[0][j]; y1=(int) b[1][j];
x2=(int) b[0][j+1]; y2=(int) b[1][j+1];
line( x1,ymax-y1,x2,ymax-y2);
}
x1=(int) b[0][7]; y1=(int) b[1][7];
x2=(int) b[0][4]; y2=(int) b[1][4];
line( x1,ymax-y1,x2,ymax-y2);
setcolor(13);
for(i=0;i<4;i++)
{
x1=(int) b[0][i]; y1=(int) b[1][i];
x2=(int) b[0][4+i]; y2=(int) b[1][4+i];
line( x1,ymax-y1,x2,ymax-y2);
}
getch(); getch();
}

12. 12 Clipping/fill algorithms
C Program to implement Boundary Fill Algorithm
#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<dos.h>
void fill_right(x,y)
int x , y ;
{
if((getpixel(x,y) != WHITE)&&(getpixel(x,y) != RED))
{
putpixel(x,y,RED);
fill_right(++x,y);
x = x - 1 ;
fill_right(x,y-1);
fill_right(x,y+1);
}
delay(1);
}
void fill_left(x,y)
int x , y ;
{
if((getpixel(x,y) != WHITE)&&(getpixel(x,y) != RED))
{
putpixel(x,y,RED);
fill_left(--x,y);
x = x + 1 ;
fill_left(x,y-1);

13. 13 Clipping/fill algorithms
fill_left(x,y+1);
}
delay(1);
}
void main()
{
int x,y,n,i;
int gd=DETECT,gm;
clrscr();
initgraph(&gd,&gm,"c:tcbgi");
/*- draw object -*/
line (50,50,200,50);
line (200,50,200,300);
line (200,300,50,300);
line (50,300,50,50);
/*- set seed point -*/
x = 100; y = 100;
fill_right(x,y);
fill_left(x-1,y);
getch();
}

14. 14 Clipping/fill algorithms
//C Program to Implement Flood Fill Algorithm
#include<conio.h>
#include<stdio.h>
#include<graphics.h>
#include<dos.h>
void fill_right(x,y)
int x , y ;
{
if(getpixel(x,y) == 0)
{
putpixel(x,y,RED);
fill_right(++x,y);
x = x - 1 ;
fill_right(x,y-1);
fill_right(x,y+1);
}
}
void fill_left(x,y)
int x , y ;
{
if(getpixel(x,y) == 0)
{
putpixel(x,y,RED);
fill_left(--x,y);
x = x + 1 ;
fill_left(x,y-1);
fill_left(x,y+1);

15. 15 Clipping/fill algorithms
}
}
void main()
{
int x , y ,a[10][10];
int gd, gm ,n,i;
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"c:tcbgi");
printf("nntEnter the no. of edges of polygon : ");
scanf("%d",&n);
printf("nntEnter the cordinates of polygon :nnn ");
for(i=0;i<n;i++)
{
printf("tX%d Y%d : ",i,i);
scanf("%d %d",&a[i][0],&a[i][1]);
}
a[n][0]=a[0][0];
a[n][1]=a[0][1];
printf("nntEnter the seed pt. : ");
scanf("%d%d",&x,&y);
cleardevice();
setcolor(WHITE);
for(i=0;i<n;i++) /*- draw poly -*/
{

16. 16 Clipping/fill algorithms
line(a[i][0],a[i][1],a[i+1][0],a[i+1][1]);
}
fill_right(x,y);
fill_left(x-1,y);
getch();
}
/*SAMPLE INPUT*/
/*Enter the number of edges of polygon 4
X0 Y0 = 50 50
X1 Y1 = 200 50
X2 Y2 = 200 300
X3 Y3 = 50 300
Enter the seed point 100 100*/