Search:

C++ Programming Articles

Submit Article

Home » Articles » C++ Programming » Computer Graphics

RSS Feeds

Program to show the implementation of Window-to-Viewport Transformaton

Posted By: Easy Tutor Category: C++ Programming Views: 3361

Write a program to show the implementation of Window-to-Viewport Transformaton.

Download Sourcecode for Program to show the implementation of Window-to-Viewport Transformaton (Size: 3.34 KB)

Code for Program to show the implementation of Window-to-Viewport Transformaton in C++ Programming

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

 class PointCoordinates
    {
       public:
      float x;
      float y;

      PointCoordinates( )
         {
        x=0;
        y=0;
         }
    };


 class LineCoordinates
    {
       public:
      float x_1;
      float y_1;
      float x_2;
      float y_2;

      LineCoordinates( )
         {
        x_1=0;
        y_1=0;
        x_2=0;
        y_2=0;
         }

      LineCoordinates(constfloat x1,constfloat y1,
                          constfloat x2,constfloat y2)
         {
        x_1=x1;
        y_1=y1;
        x_2=x2;
        y_2=y2;
         }
    };

 /*************************************************************************///--------------------  RectangularCoordinates  -------------------------///*************************************************************************/class RectangularCoordinates
    {
       public:
      float x_min;
      float y_min;
      float x_max;
      float y_max;

      RectangularCoordinates(constfloat x1,constfloat y1,
                          constfloat x2,constfloat y2)
         {
        x_min=x1;
        y_min=y1;
        x_max=x2;
        y_max=y2;
         }
    };


 void show_screen( );

 void apply_window_to_viewport_coordinate_transformation(
                      const RectangularCoordinates,
                        const RectangularCoordinates,
                                int &,int &);

 void clip_polygon(const RectangularCoordinates,constint,constint []);

 constint check_line(const LineCoordinates,const LineCoordinates);
 constint check_point(const LineCoordinates,constfloat,constfloat);

 const PointCoordinates get_intersection_point(LineCoordinates,
                                LineCoordinates);

 void Polygon(constint,constint []);
 void Rectangle(constint,constint,constint,constint);
 void Line(constint,constint,constint,constint);
 void Dashed_line(constint,constint,constint,constint,constint=0);


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

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

       show_screen( );

       setcolor(15);
     Line(90,150,90,390);
     Line(50,350,320,350);

     Line(400,150,400,390);
     Line(360,350,580,350);

       RectangularCoordinates WC(130,180,290,300);
       RectangularCoordinates VC(440,230,550,300);

       setcolor(15);
     Line(90,180,95,180);
     Line(90,300,95,300);

     Line(130,345,130,350);
     Line(290,345,290,350);

     Line(400,230,405,230);
     Line(400,300,405,300);

     Line(440,345,440,350);
     Line(550,345,550,350);

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

       int n=8;

       int polygon_vertices[18]={ 60,320 , 320,320 , 250,190 , 235,210 ,
                  230,195 , 215,220 , 200,200 , 60,320 };

       setcolor(7);
     Polygon(n,polygon_vertices);

       setcolor(15);
     settextstyle(0,0,1);
       outtextxy(50,175,"YW");
       outtextxy(50,295,"YW");
       outtextxy(110,360,"XW");
       outtextxy(280,360,"XW");

       outtextxy(360,225,"YV");
       outtextxy(360,295,"YV");
       outtextxy(420,360,"XV");
       outtextxy(530,360,"XV");

       outtextxy(182,170,"Window");
       outtextxy(140,390,"World Coordinates");

       outtextxy(462,220,"Viewport");
       outtextxy(420,390,"Device Coordinates");

     settextstyle(2,0,4);
       outtextxy(67,175,"min");
       outtextxy(67,295,"max");
       outtextxy(127,360,"min");
       outtextxy(297,360,"max");

       outtextxy(377,225,"min");
       outtextxy(377,295,"max");
       outtextxy(437,360,"min");
       outtextxy(547,360,"max");

       char Key=NULL;

       do
      {
         Key=getch( );
      }
       while(Key!='T' && Key!='t');

       settextstyle(0,0,1);
     setcolor(0);
       outtextxy(90,450,"  Press 'T' to see the Window-to-Viewport Transformation.  ");

    setcolor(15);
       outtextxy(85,450,"----------------                          -----------------");

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

       for(int count=0;count<n;count++)
      apply_window_to_viewport_coordinate_transformation(WC,VC,
                       polygon_vertices[(count*2)],
                       polygon_vertices[((count*2)+1)]);

       clip_polygon(VC,n,polygon_vertices);

       getch( );
       return 0;
    }


 /*************************************************************************///------  apply_window_to_viewport_coordinate_transformation( )  --------///*************************************************************************/void apply_window_to_viewport_coordinate_transformation(
                   const RectangularCoordinates wc,
                       const RectangularCoordinates vc,
                                  int &x,int &y)
    {
       float Sx=((vc.x_max-vc.x_min)/(wc.x_max-wc.x_min));
       float Sy=((vc.y_max-vc.y_min)/(wc.y_max-wc.y_min));
       float Tx=vc.x_min;
       float Ty=vc.y_min;

       x=(Tx+(Sx*(x-wc.x_min)));
       y=(Ty+(Sy*(y-wc.y_min)));
    }

 /*************************************************************************///--------------------------  clip_polygon( )  --------------------------///*************************************************************************/void clip_polygon(const RectangularCoordinates wc,constint n,
                           constint polygon_edges[])
    {
       int edges_counter;
       int number_of_edges=n;

       int *edges=newint[(n*4)];
       int *clipped_edges=newint[(n*4)];

       for(int count_1=0;count_1<(n*2);count_1++)
      edges[count_1]=polygon_edges[count_1];

       LineCoordinates window_line;

       for(int count_2=1;count_2<=4;count_2++)
      {
         edges_counter=1;

         for(int count_3=0;count_3<(number_of_edges*4);count_3++)
        clipped_edges[count_3]=0;

         if(count_2==1)
        {
           window_line.x_1=wc.x_min;
           window_line.y_1=wc.y_max;
           window_line.x_2=wc.x_max;
           window_line.y_2=wc.y_max;
        }

         elseif(count_2==2)
        {
           window_line.x_1=wc.x_max;
           window_line.y_1=wc.y_max;
           window_line.x_2=wc.x_max;
           window_line.y_2=wc.y_min;
        }

         elseif(count_2==3)
        {
           window_line.x_1=wc.x_max;
           window_line.y_1=wc.y_min;
           window_line.x_2=wc.x_min;
           window_line.y_2=wc.y_min;
        }

         elseif(count_2==4)
        {
           window_line.x_1=wc.x_min;
           window_line.y_1=wc.y_min;
           window_line.x_2=wc.x_min;
           window_line.y_2=wc.y_max;
        }

         int rule_no;

         PointCoordinates point;

         for(int count_4=1;count_4<number_of_edges;count_4++)
        {
           LineCoordinates line(edges[((count_4*2)-2)],
                    edges[((count_4*2)-1)],
                    edges[(count_4*2)],
                    edges[((count_4*2)+1)]);

           rule_no=check_line(window_line,line);

           switch(rule_no)
              {
             case 1 : clipped_edges[(edges_counter*2)]=
                             (int)(line.x_2+0.5);
                  clipped_edges[((edges_counter*2)+1)]=
                             (int)(line.y_2+0.5);
                  edges_counter++;
                  break;

             case 2 : break;

             case 3 : point=
                    get_intersection_point(window_line,line);

                  clipped_edges[(edges_counter*2)]=
                              (int)(point.x+0.5);
                  clipped_edges[((edges_counter*2)+1)]=
                              (int)(point.y+0.5);
                  edges_counter++;
                  break;

             case 4 : point=
                    get_intersection_point(window_line,line);

                  clipped_edges[(edges_counter*2)]=
                              (int)(point.x+0.5);
                  clipped_edges[((edges_counter*2)+1)]=
                              (int)(point.y+0.5);
                  edges_counter++;

                  clipped_edges[(edges_counter*2)]=
                             (int)(line.x_2+0.5);
                  clipped_edges[((edges_counter*2)+1)]=
                             (int)(line.y_2+0.5);
                  edges_counter++;
                  break;
              }
        }

         clipped_edges[0]=clipped_edges[((edges_counter*2)-2)];
         clipped_edges[1]=clipped_edges[((edges_counter*2)-1)];

         for(int count_5=0;count_5<(edges_counter*2);count_5++)
        edges[count_5]=0;

         number_of_edges=edges_counter;

         for(int count_6=0;count_6<(edges_counter*2);count_6++)
        edges[count_6]=clipped_edges[count_6];
     }

       setcolor(10);
     Polygon(number_of_edges,edges);

       delete edges;
       delete clipped_edges;
    }

 /*************************************************************************///----------------------------  check_line( )  --------------------------///*************************************************************************/constint check_line(const LineCoordinates line,const LineCoordinates edge)
    {
       int rule_number=0;
       int point_1=check_point(line,edge.x_1,edge.y_1);
       int point_2=check_point(line,edge.x_2,edge.y_2);

       if(point_1==1 && point_2==1)
      rule_number=1;

       elseif(point_1!=1 && point_2!=1)
      rule_number=2;

       elseif(point_1==1 && point_2!=1)
      rule_number=3;

       elseif(point_1!=1 && point_2==1)
      rule_number=4;

       return rule_number;
    }

 /*************************************************************************///----------------------------  check_point( )  -------------------------///*************************************************************************/constint check_point(const LineCoordinates lc,constfloat x,constfloat y)
    {
       float c=(((lc.x_2-lc.x_1)*(y-lc.y_1))-((lc.y_2-lc.y_1)*(x-lc.x_1)));

       if(c<=0)
      return 1;

       elsereturn 0;
    }

 /*************************************************************************///----------------------  get_intersection_point( )  --------------------///*************************************************************************/const PointCoordinates get_intersection_point(LineCoordinates lc1,
                            LineCoordinates lc2)
    {
       float x_min=lc1.x_1;
       float x_max=lc1.x_2;
       float y_min=lc1.y_1;
       float y_max=lc1.y_2;

       if(lc1.x_1==lc1.x_2)
      {
         if(lc2.y_2>=lc2.y_1 && lc2.y_2>y_max)
        y_max=lc2.y_2;

         elseif(lc2.y_1>lc2.y_2 && lc2.y_1>y_max)
        y_max=lc2.y_1;

         if(lc2.y_1<=lc2.y_2 && lc2.y_1<y_min)
        y_min=lc2.y_1;

         elseif(lc2.y_2<lc2.y_1 && lc2.y_2<y_min)
        y_min=lc2.y_2;
      }

       elseif(lc1.y_1==lc1.y_2)
      {
         if(lc2.x_2>=lc2.x_1 && lc2.x_2>x_max)
        x_max=lc2.x_2;

         elseif(lc2.x_2<lc2.x_1 && lc2.x_1>x_max)
        x_max=lc2.x_1;

         if(lc2.x_1<=lc2.x_2 && lc2.x_1<x_min)
        x_min=lc2.x_1;

         elseif(lc2.x_2<lc2.x_1 && lc2.x_2<x_min)
        x_min=lc2.x_2;
      }

       float x_mid;
       float y_mid;

       if(lc2.y_1>y_max)
      {
         while(lc2.y_1!=y_max)
        {
           x_mid=((lc2.x_1+lc2.x_2)/2);
           y_mid=((lc2.y_1+lc2.y_2)/2);

           if(y_mid>=y_max)
              {
             lc2.x_1=x_mid;
             lc2.y_1=y_mid;
              }

           else
              {
             lc2.x_2=x_mid;
             lc2.y_2=y_mid;
              }
        }
      }

       elseif(lc2.y_1<y_min)
      {
         while(lc2.y_1!=y_min)
        {
           x_mid=((lc2.x_1+lc2.x_2)/2);
           y_mid=((lc2.y_1+lc2.y_2)/2);

           if(y_mid<=y_min)
              {
             lc2.x_1=x_mid;
             lc2.y_1=y_mid;
              }

           else
              {
             lc2.x_2=x_mid;
             lc2.y_2=y_mid;
              }
        }
      }

       if(lc2.x_1>x_max)
      {
         while(lc2.x_1!=x_max)
        {
           x_mid=((lc2.x_1+lc2.x_2)/2);
           y_mid=((lc2.y_1+lc2.y_2)/2);

           if(x_mid>=x_max)
              {
             lc2.x_1=x_mid;
             lc2.y_1=y_mid;
              }

           else
              {
             lc2.x_2=x_mid;
             lc2.y_2=y_mid;
              }
        }
      }

       elseif(lc2.x_1<x_min)
      {
         while(lc2.x_1!=x_min)
        {
           x_mid=((lc2.x_1+lc2.x_2)/2);
           y_mid=((lc2.y_1+lc2.y_2)/2);

           if(x_mid<=x_min)
              {
             lc2.x_1=x_mid;
             lc2.y_1=y_mid;
              }

           else
              {
             lc2.x_2=x_mid;
             lc2.y_2=y_mid;
              }
        }
      }

       PointCoordinates ipt;

       ipt.x=lc2.x_1;
       ipt.y=lc2.y_1;

       return ipt;
    }


 /*************************************************************************///---------------------------  Rectangle( )  ----------------------------///*************************************************************************/void Rectangle(constint x_1,constint y_1,constint x_2,constint y_2)
    {
       Dashed_line(x_1,y_1,x_2,y_1,1);
       Dashed_line(x_2,y_1,x_2,y_2,1);
       Dashed_line(x_2,y_2,x_1,y_2,1);
       Dashed_line(x_1,y_2,x_1,y_1,1);
    }

 /*************************************************************************///-----------------------------  Polygon( )  ----------------------------///*************************************************************************/void Polygon(constint n,constint coordinates[])
    {
       if(n>=2)
      {
         Line(coordinates[0],coordinates[1],
                         coordinates[2],coordinates[3]);

         for(int count=1;count<(n-1);count++)
        Line(coordinates[(count*2)],coordinates[((count*2)+1)],
                        coordinates[((count+1)*2)],
                        coordinates[(((count+1)*2)+1)]);
      }
    }

 /*************************************************************************///--------------------------  Line( )  ------------------------///*************************************************************************/void Line(constint x_1,constint y_1,constint x_2,constint 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);
        }
      }
    }

 /*************************************************************************///---------------------------  Dashed_line( )  --------------------------///*************************************************************************/void Dashed_line(constint x_1,constint y_1,constint x_2,
                      constint y_2,constint line_type)
    {
       int count=0;
       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;
              }

           if((count%2)!=0 && line_type==0)
              putpixel(x,y,color);

           elseif((count%5)!=4 && line_type==1)
              putpixel(x,y,color);

           elseif((count%10)!=8 && (count%10)!=9 && line_type==2)
              putpixel(x,y,color);

           elseif((count%20)!=18 && (count%20)!=19 && line_type==3)
              putpixel(x,y,color);

           elseif((count%12)!=7 && (count%12)!=8 &&
                (count%12)!=10 && (count%12)!=11 && line_type==4)
              putpixel(x,y,color);

           count++;
        }
      }

       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;
              }

           if((count%2)!=0 && line_type==0)
              putpixel(x,y,color);

           elseif((count%5)!=4 && line_type==1)
              putpixel(x,y,color);

           elseif((count%10)!=8 && (count%10)!=9 && line_type==2)
              putpixel(x,y,color);

           elseif((count%20)!=18 && (count%20)!=19 && line_type==3)
              putpixel(x,y,color);

           elseif((count%12)!=7 && (count%12)!=8 &&
                (count%12)!=10 && (count%12)!=11 && line_type==4)
              putpixel(x,y,color);

           count++;
        }
      }
    }

 /*************************************************************************///--------------------------  show_screen( )  ---------------------------///*************************************************************************/void show_screen( )
    {
       setfillstyle(1,1);
     bar(180,26,460,38);

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

     setcolor(11);
       outtextxy(190,29,"Window-to-Viewport Transformation");

     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(90,450,"  Press 'T' to see the Window-to-Viewport Transformation.  ");
    }

Previous Post:

Program to show the implementation of Sutherland-Hodgeman Polygon Clipping Algorithm

Next Post:

Program to show the implementation of None-or-All String Clipping Strategy (Text Clipping Example)

Didn't find what you were looking for? Find more on Program to show the implementation of Window-to-Viewport Transformaton Or get search suggestion and latest updates.

Easy Tutor author of Program to show the implementation of Window-to-Viewport Transformaton is from United States. Easy Tutor says

Hello Friends,

I am Free Lance Tutor, who helped student in completing their homework.

I have 4 Years of hands on experience on helping student in completing their homework. I also guide them in doing their final year projects.

I have share many programs on this website for everyone to use freely, if you need further assistance, than please contact me on easytutor.2ya [at the rate] gmail [dot] com

I have special discount scheme for providing tutor services. I am providing tutor service to students from various contries, currently most of my students are from United States, India, Australia, Pakistan, Germany, UK and Canada.

I am also here to expand my technical network to receive more opportunity in my career, make friends to help them in resolving their technical problem, learn and share my knowledge, If you like to be my friend, Please send me friend request.

Thanks,
Happy Programming :)

View All Articles

RSS Feeds:	Articles \| Forum \| New Users \| Activities \| Interview FAQ \| Poll \| Hotlinks
Social Networking:	Hall of Fame \| Facebook \| Twitter \| LinkedIn
Terms:	Terms of Use \| Privacy Policy \| Contact us

C++ Programming Articles

Program to show the implementation of Window-to-Viewport Transformaton

Write a program to show the implementation of Window-to-Viewport Transformaton.

Code for Program to show the implementation of Window-to-Viewport Transformaton in C++ Programming

Related Articles and Code:

Other Interesting Articles in C++ Programming:

Please enter your Comment ** Comment should be atleast 30 Characters. Please put code inside [Code] your code [/Code]. Please login to post comment

No Comment Found, Be the First to post comment!