Program to implement Cohen-Sutherland Line clipping algorithm. -MASTER GUIDE

Program to implement Cohen-Sutherland Line clipping algorithm. 

 #include<stdio.h>

#include<conio.h>

#include<graphics.h>

unsigned int computecode(float x, float y, float xmin, float ymin, float xmax, float ymax);

void clipping(float x1, float y1, float x2, float y2, float xmin,float ymin, float xmax, float ymax);

enum{TOP=0x8, BOTTOM=0x4, RIGHT=0x2, LEFT=0x1};

enum{FALSE,TRUE};

unsigned int computecode(float x, float y, float xmin, float ymin, float xmax, float ymax)

{

unsigned int code=0;

if(y>ymax)

code= code | TOP;

else if(y<ymin)

code= code | BOTTOM;

if(x>xmax)

code= code | RIGHT;

else if (x<xmin)

code =code | LEFT;

return code;

}

void clipping(float x1, float y1, float x2, float y2, float xmin,float ymin, float xmax, float ymax)

{

unsigned int code1, code2, outcode;

float x,y;

int accept=FALSE, done=FALSE;

code1=computecode(x1,y1,xmin,ymin,xmax,ymax);

code2=computecode(x2,y2,xmin,ymin,xmax,ymax);

do

{

if(code1 == 0 & code2== 0)

{

accept=TRUE;

done=TRUE;

}

else if (code1 & code2)

done=TRUE;

else

{

if(code1!=0)

outcode =code1;

else

outcode=code2;

if(outcode & TOP)

{

x=x1+(ymax-y1) * (x2-x1) / (y2-y1);

y=ymax;

}

else if(outcode & BOTTOM)

{

x=x1+ (ymin-y1) * (x2-x1) / (y2-y1);

y=ymin;

}

else if(outcode & RIGHT)

{

y=y1+ (xmax-x1) * (y2-y1) / (x2-x1);

x=xmax;

}

else

{

y=y1+ (xmin-x1) * (y2-y1) / (x2-x1);

x=xmin;

}

if(outcode==code1)

{

x1=x;

y1=y;

code1=computecode(x1,y1,xmin,ymin,xmax,ymax);

}

else

{

x2=x;

y2=y;

code2=computecode(x2,y2,xmin,ymin,xmax,ymax);

}

}

}while(done==FALSE);

clrscr();

cleardevice();

printf("After clipping \n");

if(accept)

{

setcolor(BLUE);

rectangle(xmin,ymin,xmax,ymax);

line(x1,y1,x2,y2);

}

else

{

rectangle(xmin,ymin,xmax,ymax);

printf("Line is invisble");

}

}

void main()

{

int gd=DETECT,gm;

float xmax , ymax , xmin , ymin;

float x1,y1,x2,y2;

initgraph(&gd,&gm,"C:\\TURBOC3\\BGI");

printf("enter the clip window coordinates(xmin,ymin,xmax,ymax):");

scanf("%f%f%f%f",&xmin,&ymin,&xmax,&ymax);

printf("\n enter line endpoints (x1,y1,x2,y2):");

scanf("%f%f%f%f",&x1,&y1,&x2,&y2);

clrscr();

cleardevice();

printf("Before Clipping");

setcolor(RED);

rectangle(xmin,ymin,xmax,ymax);

line(x1,y1,x2,y2);

getch();

clipping(x1,y1,x2,y2,xmin,ymin,xmax,ymax);

getch();

closegraph();

}

OUTPUT: