Sutherland-Hodgeman Polygon Clipping C Programming Coding Computer Graphics Lab

This program is for implementing Sutherland-Hodgeman Polygon Clipping .

#include"stdio.h"

#include"conio.h"

#include"graphics.h"

#include"math.h"

void dda(int,int,int,int,int,int,int,int);

void dda(int x1,int y1,int x2,int y2,int xmin,int ymin,int xmax,int ymax)

{

            float dx,dy;

            float steps,x=x1,y=y1;

            int i=0;

            dx=x2-x1;

            dy=y2-y1;

            if(abs(dx)>=abs(dy))

                        steps=abs(dx);

            else

                        steps=abs(dy);

            dx=dx/steps;

            dy=dy/steps;

            while(i++<=steps)

            {

            if(x>=xmin && x<=xmax && y>=ymin && y<=ymax)

            {

                        line(x,y,x2,y2);

                        return;

            }

                        x=x+dx;

                        y=y+dy;

            }

}

void main()

{

            int n,gd,gm,x1,x2,y1,y2,xRec,yRec,b1,b2,b3,b4,l,b,yMin,yMax,xMin,xMax;

            float m;

            int a[10][4],i,j, flag=0,in=0;

            gd=DETECT;

            gm=DETECT;

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

            printf("Enter the length and breadth of the clipping window:\n");

            scanf("%d%d",&l,&b);

            printf("Enter the starting co-ord of the rectangle\n");

            scanf("%d%d",&xRec,&yRec);

            clrscr();

            rectangle(xRec,yRec,xRec+l,yRec+b);

            getch();

            clrscr();

            printf("Enter the no of lines\n");

            scanf("%d",&n);

            for(i=0;i<n;i++)

            {

                        printf("Enter the co-ord of line %d\n",i+1);

                        for(j=0;j<2;j++)

                        {

                                    scanf("%d",&a[i][j]);

                        }

                        a[i][2]=a[0][0];

                        a[i][3]=a[0][1];

                        if(i!=0)

                        {

                               a[i-1][2]=a[i][0];

                               a[i-1][3]=a[i][1];

                        }

            }

            clrscr();

            rectangle(xRec,yRec,xRec+l,yRec+b);

            for(i=0;i<n;i++)

            {

                        line(a[i][0],a[i][1],a[i][2],a[i][3]);

            }

            getch();

            clrscr();

            rectangle(xRec,yRec,xRec+l,yRec+b);

            xMin=xRec;

            yMin=yRec;

            xMax=xRec+l;

            yMax=yRec+b;

            for(i=0;i<n;i++)

            {

                        flag=0;

                        x1=a[i][0];

                        x2=a[i][2];

                        y1=a[i][1];

                        y2=a[i][3];

                        if(x1>=xMin && x1<=xMax && y1>=yMin && y1<=yMax)

                                    flag++;

                        if(x2>=xMin && x2<=xMax && y2>=yMin && y2<=yMax)

                                    flag++;

                        switch(flag)

                        {

                                    case 0:

                                                break;

case 1: if(x2>=xMin && x2<=xMax && y2>=yMin &&    y2<=yMax)

                                                {

                                                            dda(x1,y1,x2,y2,xMin,yMin,xMax,yMax);

                                                }

                                                else

                                                {

                                                            dda(x2,y2,x1,y1,xMin,yMin,xMax,yMax);

                                                }

                                                break;

                                    case 2: line(x1,y1,x2,y2);

                                                break;

                        }

            }

            getch();

            closegraph();

}

--

Don't ever give up.

Even when it seems impossible,

Something will always

pull you through.

The hardest times get even

worse when you lose hope.

As long as you believe you can do it, You can.

But When you give up,

You lose !

I DONT GIVE UP.....!!!

with regards

prem sasi kumar arivukalanjiam