C++ Programming Blog

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

 class WindowCoordinates
    {
       public:
      int x_min;
      int y_min;
      int x_max;
      int y_max;

      WindowCoordinates(const int x1,const int y1,const int x2,const int y2)
         {
        x_min=x1;
        y_min=y1;
        x_max=x2;
        y_max=y2;
         }
    };


 void show_screen( );

 const int clip_point(const WindowCoordinates,const int,const int);

 void Rectangle(const int,const int,const int,const int);
 void Line(const int,const int,const int,const int);


 int main( )
    {
       int driver=VGA;
       int mode=VGAHI;

       initgraph(&driver,&mode,\"..\\\\Bgi\");

       show_screen( );

       WindowCoordinates WC(180,140,470,340);

       setcolor(15);
     Rectangle(WC.x_min,WC.y_min,WC.x_max,WC.y_max);

       int points[12][2]={ {160,160} , {155,300} , {200,200} , {320,240} ,
               {225,175} , {400,150} , {275,325} , {450,320} ,
               {300,120} , {500,225} , {350,350} , {500,360} };

       for(int count_1=0;count_1<12;count_1++)
      putpixel(points[count_1][0],points[count_1][1],7);

       char Key=NULL;

       do
      {
         Key=getch( );
      }
       while(Key!=\'C\' && Key!=\'c\');

       settextstyle(0,0,1);
     setcolor(0);
       outtextxy(163,450,\"  Press \'C\' to see the Clipped Points. \");

    setcolor(15);
       outtextxy(165,450,\"------                          -------\");

     setcolor(12);
       outtextxy(213,450,\"  Press any Key to exit.  \");

       for(int count_2=0;count_2<12;count_2++)
      {
         if(clip_point(WC,points[count_2][0],points[count_2][1]))
         putpixel(points[count_2][0],points[count_2][1],10);
      }

       getch( );
       return 0;
    }



 //---------------------------  clip_point( )  ---------------------------//


 const int clip_point(const WindowCoordinates wc,const int x,const int y)
    {
       if((x>=wc.x_min && x<=wc.x_max) && (y>=wc.y_min && y<=wc.y_max))
      return 1;

       return 0;
    }


 //---------------------------  Rectangle( )  ----------------------------//


 void Rectangle(const int x_1,const int y_1,const int x_2,const int y_2)
    {
       Line(x_1,y_1,x_2,y_1);
       Line(x_2,y_1,x_2,y_2);
       Line(x_2,y_2,x_1,y_2);
       Line(x_1,y_2,x_1,y_1);
    }


 //-------------------------------  Line( )  -----------------------------//


 void Line(const int x_1,const int y_1,const int x_2,const int y_2)
    {
       int color=getcolor( );

       int x1=x_1;
       int y1=y_1;

       int x2=x_2;
       int y2=y_2;

       if(x_1>x_2)
      {
         x1=x_2;
         y1=y_2;

         x2=x_1;
         y2=y_1;
      }

       int dx=abs(x2-x1);
       int dy=abs(y2-y1);
       int inc_dec=((y2>=y1)?1:-1);

       if(dx>dy)
      {
         int two_dy=(2*dy);
         int two_dy_dx=(2*(dy-dx));
         int p=((2*dy)-dx);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(x<x2)
        {
           x++;

           if(p<0)
              p+=two_dy;

           else
              {
             y+=inc_dec;
             p+=two_dy_dx;
              }

           putpixel(x,y,color);
        }
      }

       else
      {
         int two_dx=(2*dx);
         int two_dx_dy=(2*(dx-dy));
         int p=((2*dx)-dy);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(y!=y2)
        {
           y+=inc_dec;

           if(p<0)
              p+=two_dx;

           else
              {
             x++;
             p+=two_dx_dy;
              }

           putpixel(x,y,color);
        }
      }
    }


 //--------------------------  show_screen( )  ---------------------------//


 void show_screen( )
    {
       setfillstyle(1,1);
     bar(247,26,380,38);

       settextstyle(0,0,1);
     setcolor(15);
       outtextxy(5,5,\"******************************************************************************\");
       outtextxy(5,17,\"*-**************************************************************************-*\");
       outtextxy(5,29,\"*----------------------------                   -----------------------------*\");
       outtextxy(5,41,\"*-**************************************************************************-*\");
       outtextxy(5,53,\"*-**************************************************************************-*\");

     setcolor(11);
       outtextxy(256,29,\"Point Clipping\");

     setcolor(15);

       for(int count=0;count<=30;count++)
          outtextxy(5,(65+(count*12)),\"*-*                                                                        *-*\");

       outtextxy(5,438,\"*-**************************************************************************-*\");
       outtextxy(5,450,\"*-------------------                                       ------------------*\");
       outtextxy(5,462,\"******************************************************************************\");

     setcolor(12);
       outtextxy(163,450,\"  Press \'C\' to see the Clipped Points. \");
    }

 
 
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