Dawson

#include<iostream.h>
#include<conio.h>
#include<math.h>
#include<graphics.h>
#include<dos.h>
#include<process.h>

int pixels[2][4];
float xn1,xn2,yn1,yn2,x3,y3,m;


void show_quadrant()
 {
 cleardevice();
 rectangle(120,40,320,240);
 rectangle(320,40,520,240);
 rectangle(120,240,320,440);
 rectangle(320,240,520,440);
 for(int i=130;i<=510;i+=10)
 {
 if(i==320)
 continue;
 outtextxy(i,237,"+");
 }
 for(i=50;i<=430;i+=10)
 {
 if(i==240)
 continue;
 outtextxy(317,i,"-");
 }
 outtextxy(310,230,"O");
 outtextxy(530,240,"X");
 outtextxy(320,450,"-Y");
 outtextxy(100,240,"-X");
 outtextxy(320,30,"Y");
 }

void su_co(int x1,int y1,int x2,int y2,int xmin,int ymin,int xmax,int ymax)
 {
 int i,j,fl;
 for(i=0;i<2;i++)
 for(j=0;j<4;j++)
 pixels[i][j]=0;
 if(y1>ymax)
 pixels[0][0]=1;
 if(y1<ymin)
 pixels[0][1]=1;
 if(x1>xmax)
 pixels[0][2]=1;
 if(x1<xmin)
 pixels[0][3]=1;
 if(y2>ymax)
 pixels[1][0]=1;
 if(y2<ymin)
 pixels[1][1]=1;
 if(x2>xmax)
 pixels[1][2]=1;
 if(x2<xmin)
 pixels[1][3]=1;

 for(j=0;j<4;j++)
 {
 if(pixels[0][j]==0&&pixels[1][j]==0)
 continue;
 if(pixels[0][j]==1&&pixels[1][j]==1)
 {
 fl=3;
 break;
 }
 fl=2;
 }
 switch(fl)
 {
 case 1:
 line(320+x1,240-y1,320+x2,240-y2);
 break;

 case 3:
 cout<<" a" Line Is Not Visible...:-(";
 break;

 case 2:
 m=(y2-y1)/(x2-x1);
 xn1=x1;
 yn1=y1;
 xn2=x2;
 yn2=y2;
 if(pixels[0][0]==1)
 {
 xn1=x1+(ymax-y1)/m;
 yn1=ymax;
 }
 if(pixels[0][1]==1)
 {
 xn1=x1+(ymin-y1)/m;
 yn1=ymin;
 }
 if(pixels[0][2]==1)
 {
 yn1=y1+(xmax-x1)*m;
 xn1=xmax;
 }
 if(pixels[0][3]==1)
 {
 yn1=y1+(xmin-x1)*m;
 xn1=xmin;
 }
 if(pixels[1][0]==1)
 {
 xn2=x2+(ymax-y2)/m;
 yn2=ymax;
 }
 if(pixels[1][1]==1)
 {
 xn2=x2+(ymin-y2)/m;
 yn2=ymin;
 }
 if(pixels[1][2]==1)
 {
 yn2=y2+(xmax-x2)*m;
 xn2=xmax;
 }
 if(pixels[1][3]==1)
 {
 yn2=y2+(xmin-x2)*m;
 xn2=xmin;
 }
 line(320+xn1,240-yn1,320+xn2,240-yn2);
 break;
 }
 }


void midpt(int x1,int y1,int x2,int y2,int xmin,int ymin,int xmax,int ymax)
 {
 int fl=1;
 int i,j;
 int ox1=x1,ox2=x2,oy1=y1,oy2=y2;
 for(i=0;i<2;i++)
 for(j=0;j<4;j++)
 pixels[i][j]=0;

 if(y1>ymax)
 pixels[0][0]=1;
 if(y1<ymin)
 pixels[0][1]=1;
 if(x1>xmax)
 pixels[0][2]=1;
 if(x1<xmin)
 pixels[0][3]=1;
 if(y2>ymax)
 pixels[1][0]=1;
 if(y2<ymin)
 pixels[1][1]=1;
 if(x2>xmax)
 pixels[1][2]=1;
 if(x2<xmin)
 pixels[1][3]=1;

 for(j=0;j<4;j++)
 {
 if(pixels[0][j]==0&&pixels[1][j]==0)
 continue;

 if(pixels[0][j]==1&&pixels[1][j]==1)
 {
 fl=3;
 break;
 }
 fl=2;
 }
 switch(fl)
 {
 case 1:
 line(320+x1,240-y1,320+x2,240-y2);
 break;

 case 3:
 cout<<" a" Line Is Not Visible...:-(";
 break;

 case 2:
 xn1=x1;
 yn1=y1;
 xn2=x2;
 yn2=y2;
 fl=0;
 x3=x1;
 y3=y1;
 while(1)
 {
 if(!(y1>ymax || y1<ymin || x1>xmax || x1<xmin) && (x3 || y3)!=0.1)
 break;
 x3=(x1+x2)/2;
 y3=(y1+y2)/2;
 if(!(y3>ymax || y3<ymin || x3>xmax || x3<xmin))
 fl=1;
 else
 fl=0;
 if(fl)
 {
 x2=x3;
 y2=y3;
 }
 else
 {
 x1=x3;
 y1=y3;
 }
 }
 xn1=x3;
 yn1=y3;
 fl=0;
 x1=ox1;
 x2=ox2;
 y1=oy1;
 y2=oy2;
 x3=x2;
 y3=y2;
 while(1)
 {
 if(!(y2>ymax || y2<ymin || x2>xmax || x2<xmin) && (x3 || y3)!=0.1)
 break;
 x3=(x1+x2)/2;
 y3=(y1+y2)/2;

 if(!(y3>ymax || y3<ymin || x3>xmax || x3<xmin))
 fl=1;
 else
 fl=0;

 if(fl)
 {
 x1=x3;
 y1=y3;
 }
 else
 {
 x2=x3;
 y2=y3;
 }
 }
 xn2=x3;
 yn2=y3;
 line(320+xn1,240-yn1,320+xn2,240-yn2);
 break;
 }
 }

void show_message()
 {
 char *mess[]={"-","=","["," ","L","i","n","e"," ","C","l","i",
 "p","p","i","n","g"," ","]","=","-",};
 int xx=29,xxx=50,i,j;
 _setcursortype(_NOCURSOR);
 for(i=0,j=21;i<13,j>=11;i++,j--)
 {
 gotoxy(xx,1);
 cout<<mess[i];
 xx++;
 gotoxy(xxx,1);
 cout<<mess[j];
 xxx--;
 delay(50);
 }
 _setcursortype(_NORMALCURSOR);
 }


void main()
 {
 clrscr();
 int gd=DETECT,gm,i,j;
 int xmin,ymin,xmax,ymax,x1,y1,x2,y2;
 int choice,ed[20],num;
 show_message();
 cout<<" " Enter The Co-Ordinates Of The Clipping Window."";
 cout<<" " Enter X(min) & Y(min) ":=";
 cin>>xmin>>ymin;
 cout<<" " Enter X(max) & Y(max) ":=";
 cin>>xmax>>ymax;

 cout<<" " Enter The Co-Ordinates Of The Line."";
 cout<<" " Enter X(1) & Y(1) ":=";
 cin>>x1>>y1;
 cout<<" " Enter X(2) & Y(2) ":=";
 cin>>x2>>y2;
 clrscr();
 show_message();
 cout<<" 1:==>" Sutherland-Cohen "";
 cout<<" 2:==>" Mid-Point Method "";
 cout<<" 3:==>" Exit "";
 cout<<" " Enter Your Choice ":=";
 cin>>choice;
 switch(choice)
 {
 case 1:
 initgraph(&gd,&gm,"..bgi");
 clearviewport();
 show_quadrant();
 line(320+xmin,240-ymin,320+xmin,240-ymax);
 line(320+xmin,240-ymax,320+xmax,240-ymax);
 line(320+xmax,240-ymax,320+xmax,240-ymin);
 line(320+xmax,240-ymin,320+xmin,240-ymin);
 line (320+x1,240-y1,320+x2,240-y2);
 getch();
 cleardevice();
 show_quadrant();
 line(320+xmin,240-ymin,320+xmin,240-ymax);
 line(320+xmin,240-ymax,320+xmax,240-ymax);
 line(320+xmax,240-ymax,320+xmax,240-ymin);
 line(320+xmax,240-ymin,320+xmin,240-ymin);
 su_co(x1,y1,x2,y2,xmin,ymin,xmax,ymax);
 getch();
 break;

 case 2:
 initgraph(&gd,&gm,"..bgi");
 clearviewport();
 show_quadrant();
 line(320+xmin,240-ymin,320+xmin,240-ymax);
 line(320+xmin,240-ymax,320+xmax,240-ymax);
 line(320+xmax,240-ymax,320+xmax,240-ymin);
 line(320+xmax,240-ymin,320+xmin,240-ymin);
 line (320+x1,240-y1,320+x2,240-y2);
 getch();
 cleardevice();
 show_quadrant();
 line(320+xmin,240-ymin,320+xmin,240-ymax);
 line(320+xmin,240-ymax,320+xmax,240-ymax);
 line(320+xmax,240-ymax,320+xmax,240-ymin);
 line(320+xmax,240-ymin,320+xmin,240-ymin);
 midpt(x1,y1,x2,y2,xmin,ymin,xmax,ymax);
 getch();
 break;

 case 3:
 exit(0);

 default:
 cout<<" a" Press A Valid Key...!!! "";
 getch();
 main();
 break;
 }
 closegraph();
 }