LINE CLIPPING USING COHEN SUTHERLAND ALGORITHM

LINE CLIPPING USING COHEN SUTHERLAND ALGORITHM

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#define FALSE 0

#define TRUE 1

#define LEFTEDGE 0x1

#define RIGHTEDGE 0x2

#define TOPEDGE 0x8

#define BOTTOMEDGE 0x4

#define INSIDE(a) (!a)

#define REJECT(a,b) (a&b)

#define ACCEPT(a,b) (!(a|b))

unsigned char encode(int x,int y,int minx,int maxx,int miny,int maxy)

{

            unsigned char code=0X00;

            if(x<minx)

                        code=code|LEFTEDGE;

            if(x>maxx)

                        code=code|RIGHTEDGE;

            if(y<miny)

                        code=code|BOTTOMEDGE;

            if(y>maxy)

                        code=code|TOPEDGE;

            return(code);

}

void swappts(int *x1,int *y1,int *x2,int *y2)

{

            int tx,ty;

            tx=*x1;

            ty=*y1;

            *x1=*x2;

            *y1=*y2;

            *x2=tx;

            *y2=ty;

}

void swapcode(unsigned char *c1,unsigned char *c2)

{

            unsigned char temp;

            temp=*c1;

*c1=*c2;

*c2=temp;

}

void clipline(int minx,int maxx,int miny,int maxy,int x1,int y1,int x2,int y2)

{

            unsigned char code1,code2;

            int done=FALSE;

            int draw=FALSE;

            float m;

            while(!done)

            {

                        code1=encode(x1,y1,minx,maxx,miny,maxy);

                        code2=encode(x2,y2,minx,maxx,miny,maxy);

                        if(ACCEPT(code1,code2))

                        {

                                    done=TRUE;

                                    draw=TRUE;

                        }

                        else if(REJECT(code1,code2))

                                    done=TRUE;

                        else

                        {

                                    if(INSIDE(code1))

                                    {

                                                swappts(&x1,&y1,&x2,&y2);

                                                swapcode(&code1,&code2);

                                    }

                                    if(x2!=x1)

                                                m=(y2-y1)/(x2-x1);

                                    if(code1&LEFTEDGE)

                                    {

                                                y1+=(minx-x1)*m;

                                                x1=minx;

                                    }

                                    else if(code1&RIGHTEDGE)

                                    {

                                                y1+=(maxx-x1)*m;

                                                x1=maxx;

                                    }

                                    else if(code1&BOTTOMEDGE)

                                    {

                                                if(x2!=x1)

                                                            x1+=(miny-y1)/m;

                                                y1=miny;

                                    }

                                    else if(code1&TOPEDGE)

                                    {

                                                if(x2!=x1)

                                                x1+=(maxy-y1)/m;

                                                y1=maxy;

                                    }

                        }

            }

            if(draw)

                        line(x1,y1,x2,y2);

}

void main()

{

            int x1,x2,y1,y2,minx,miny,maxx,maxy;

            int gd=DETECT,gm;

            initgraph(&gd,&gm,"");

            printf("Enter the minimum and maximum values of x:");

            scanf("%d%d",&minx,&maxx);

            printf("Enter the minimum and maximum values of y: ");

            scanf("%d%d",&miny,&maxy);

            printf("Enter the first enpoint of line: ");

            scanf("%d%d",&x1,&y1);

            printf("Enter the second endpoint of line: ");

            scanf("%d%d",&x2,&y2);

            printf("BEFORE CLIPPING");

            rectangle(minx,maxy,maxx,miny);

            line(x1,y1,x2,y2);

            getch();

            clrscr();

            printf("AFTER CLIPPING");

            rectangle(minx,maxy,maxx,miny);

            clipline(minx,maxx,miny,maxy,x1,y1,x2,y2);

            getch();

            closegraph();

}

OUTPUT:-

           

            Enter the minimum and maximum values of x: 300  400

            Enter the minimum and maximum values of y: 300  400

            Enter the first endpoint  of line: 275  300

            Enter the second endpoint of line: 350  420

            BEFORE CLIPPING

           

                                                                               

 AFTER CLIPPING                            

                                                                                                                                     

                                                                       

                                                      

         

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LINE CLIPPING USING LIANG BARSKY ALGORITHM

LINE CLIPPING USING LIANG BARSKY ALGORITHM

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<dos.h>

#define ROUND(a)((int)(a+0.5))

int cliptest(float p,float q,float *u1,float *u2)

{

            float r;

            int retval=1;

            if(p<0.0)

            {

                        r=q/p;

                        if(r>*u2)

                                    retval=0;

                        if(r>*u1)

                                    *u1=r;

            }

            else if(p>0.0)

            {

                        r=q/p;

                        if(r<*u1)

                                    retval=0;

                        if(r<*u2)

                                    *u2=r;

            }

            else if(q<0.0)

                        retval=0;

            return(retval);

}

void clipline(int minx,int miny,int maxx,int maxy,int x1,int y1,int x2,int y2)

{

            float u1=0.0,u2=1.0,dx=x2-x1,dy;

            if(cliptest(-dx,x1-minx,&u1,&u2))

                        if(cliptest(dx,maxx-x1,&u1,&u2))

                        {

                                    dy=y2-y1;

                                    if(cliptest(-dy,y1-miny,&u1,&u2))

                                                if(cliptest(dy,maxy-y1,&u1,&u2))

                                                {

                                                            if(u2<1.0)

                                                            {

                                                                        x2=x1+u2*dx;

                                                                        y2=y1+u2*dy;

                                                            }

                                                            if(u1>0.0)

                                                            {

                                                                        x1+=u1*dx;

                                                                        y1+=u1*dy;

                                                            }

                                                            line(x1,y1,x2,y2);

                                                }

                        }

}

void main()

{

            int gdriver=DETECT,gmode,x1,y1,x2,y2,minx,miny,maxx,maxy;

            initgraph(&gdriver,&gmode,"");

            clrscr();

            printf("Enter the min & max x values: ");

            scanf("%d %d",&minx,&maxx);

            printf("Enter the min & max y values: ");

            scanf("%d %d",&miny,&maxy);

            printf("Enter the first endpoint: ");

            scanf("%d %d",&x1,&y1);

            printf("Enter the second endpoint: ");

            scanf("%d %d",&x2,&y2);

            clrscr();

            printf("Before Clipping");

            line(x1,y1,x2,y2);

            rectangle(minx,maxy,maxx,miny);

            getch();

            clrscr();

            printf("After Clipping");

            clipline(minx,miny,maxx,maxy,x1,y1,x2,y2);

            rectangle(minx,maxy,maxx,miny);

            getch();

}

OUTPUT:-

            Enter the min & max x values:: 300  400

            Enter the min & max x values:: 300  400

            Enter the first endpoint  : 275  300

            Enter the second endpoint : 350  420

            Before Clipping

           

                                                                               

 After Clipping                            

                                                                                                                                     

                                                                       

                                                      

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DRAW A CIRCLE USING MIDPOINT ALGORITHM

DRAW A CIRCLE USING MIDPOINT ALGORITHM

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#include<dos.h>

void main()

{

   /* request auto detection */

   int gdriver = DETECT, gmode, errorcode;

   int x1,x2,x3,x4,xc,yc,r,y1,y2;

   char msg[15];

   /* initialize graphics and local variables */

   initgraph(&gdriver, &gmode, "");

   /* read result of initialization */

   errorcode = graphresult();

   /* an error occurred */

   if (errorcode != grOk)

   {

      printf("Graphics error: %s\n", grapherrormsg(errorcode));

      printf("Press any key to halt:");

      getch();

      exit(1);

   }

   printf("Enter the value for xc,yc,r:");

   scanf("%d%d%d",&xc,&yc,&r);

   circlemidpoint(xc,yc,r);

   getch();

   closegraph();

}

void circlemidpoint(int xc,int yc,int r)

{

int x=0,y=r,p=1-r;

void circleplotpoints(int,int,int,int);

circleplotpoints(xc,yc,x,y);

while(x<y)

{

x++;

if(p<0)

p+=2*x+1;

else

{

y--;

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

}

circleplotpoints(xc,yc,x,y);

}

}

 void circleplotpoints(int xc,int yc,int x,int y)

{

putpixel(xc+x,yc+y,YELLOW);

putpixel(xc-x,yc+y,YELLOW);

putpixel(xc+x,yc-y,GREEN);

putpixel(xc-x,yc-y,GREEN);

putpixel(xc+y,yc+x,GREEN);

putpixel(xc-y,yc+x,RED);

putpixel(xc+y,yc-x,RED);

putpixel(xc-y,yc-x,RED);

}

OUTPUT:-

Enter the value for xc, yc, r:

250

150

125

         

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DRAW A LINE USING DDA ALGORITHM

DRAW A LINE USING DDA ALGORITHM

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#include<dos.h>

#define ROUND(a)((int)(a+0.5))

int main(void)

{

   /* request auto detection */

   int gdriver = DETECT, gmode, errorcode;

   int xa,xb,ya,yb;

  // int y=0,x=0,i;

   char msg[25];

   /* initialize graphics and local variables */

   initgraph(&gdriver, &gmode, "");

   /* read result of initialization */

   errorcode = graphresult();

   /* an error occurred */

   if (errorcode != grOk)

  {

       printf("Graphics error: %s\n", grapherrormsg(errorcode));

      printf("Press any key to halt:");

      getch();

      exit(1);

  }

 printf("Enter the value for x1,y1:\n");

 scanf("%d%d",&xa,&ya);

 printf("Enter the value for x2,y2:\n");

 scanf("%d%d",&xb,&yb);

 linedda(xa,ya,xb,yb);

 getch();

 closegraph();

  return 0;

}

void linedda(int xa,int ya,int xb,int yb)

{

int dx=xb-xa,dy=yb-ya,steps,k;

float xincr,yincr,x=xa,y=ya;

if(abs(dx)>abs(dy))

steps=abs(dy);

else

steps=abs(dy);

xincr=dx/(float)steps;

yincr=dy/(float)steps;

putpixel(ROUND(x),ROUND(y),GREEN);

for(k=0;k<steps;k++)

{

x+=xincr;

y+=yincr;

putpixel(ROUND(x),ROUND(y),GREEN);

}

}

OUTPUT:-

Enter the value for x1,y1:

100

100

Enter the value for x2,y2:

250

300

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DRAW A LINE USING BRESENHAM ALGORITHM

DRAW A LINE USING BRESENHAM ALGORITHM

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#include<dos.h>

void main()

{

   /* request auto detection */

   int gdriver = DETECT, gmode, errorcode;

   int xa,xb,ya,yb,x,y;

   char msg[25];

   /* initialize graphics and local variables */

   initgraph(&gdriver, &gmode, "");

   /* read result of initialization */

   errorcode = graphresult();

   /* an error occurred */

   if (errorcode != grOk)

   {

      printf("Graphics error: %s\n", grapherrormsg(errorcode));

      printf("Press any key to halt:");

      getch();

      exit(1);

  }

  printf("Enter the x1 and y1 value:\n");

  scanf("%d%d",&xa,&ya);

  printf("Enter the x2 and y2 value:\n");

  scanf("%d%d",&xb,&yb);

  linebres(xa,ya,xb,yb);

  getch();

  closegraph();

}

           

 void linebres(int xa,int ya,int xb,int yb)

{

            int dx=abs(xa-xb),dy=abs(ya-yb);

            int p=2*dy-dx;

            int twody=2*dy,twodxdy=2*(dy-dx);

            int x,y,xend;

            if(xa>xb)

            {

                    x=xb;y=yb;xend=xa;

            }

           

            else

            {

                        x=xa;y=ya;xend=xb;

            }

            putpixel(x,y,YELLOW);

            while(x<xend)

            {

                        x++;

                        if(p<0)

                                    p+=twody;

                        else

                        {

                                    y++;

                                    p+=twodxdy;

                        }

                        putpixel(x,y,YELLOW);

            }

}

OUTPUT:-

Enter the x1 and y1 value:

100

100

Enter the x2 and y2value:

250

300

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