Program to implement Polygon Filling Algorithm



Program to implement Polygon Filling Algorithm

#include<stdio.h>
#include<conio.h>
#include<iostream.h>
#include<graphics.h>
#include<dos.h>
#include<stdlib.h>

int gd=DETECT,gm;

class myStack
 {
        private:
 int arr[10000][2],top;
 public:
 myStack()
  {
  top=-1;
  }
 void push(int x,int y)
  {
  if(top>10000)
   {
   printf("
a " Stack Full...:-("");
   exit(0);
   }
  top++;
  arr[top][0]=x;
  arr[top][1]=y;
  }

 void pop(int &x,int &y)
  {
  x=arr[top][0];
  y=arr[top][1];
  top--;
  }

 int empty(void)
  {
  if(top==-1)
  return(1);
  else return(0);
  }
 };

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");
 }


int get_poly(int ed[20])
 {
 int edg,i,j;
 clearviewport();
        closegraph();
 cout<<"
 " Enter No. Of Edges ":=";
 cin>>edg;
 for(i=0,j=1;i<2*edg;i+=2,j++)
  {
  cout<<"
  " Enter Vertex No. "<<j<<" ":= ";
  flushall();
  cin>>ed[i]>>ed[i+1];
  ed[i]+=320;
  ed[i+1]=240-ed[i+1];
  }
 ed[i]=ed[0];
 ed[i+1]=ed[1];
 initgraph(&gd,&gm,"..\bgi");
 clearviewport();
 show_quadrant();
 drawpoly(edg+1,ed);
 return(edg);
 }

void get_y(int &min,int &max,int edge[20],int size)
 {
 int i;
 min=480;
 max=0;
 for(i=1;i<2*size;i+=2)
  {
  if(edge[i]>max)
  max=edge[i];
  if(edge[i]<min)
  min=edge[i];
  }
 }

void get_x(int &min,int &max,int edge[20],int size)
 {
 int i;
 min=480;
 max=0;
 for(i=0;i<2*size;i+=2)
  {
  if(edge[i]>max)
  max=edge[i];
  if(edge[i]<min)
  min=edge[i];
  }
 }

void fill_polygon(int x,int y,int fg,int bg)
 {
 myStack stack;
 int col;
 putpixel(x,y,fg);
 stack.push(x,y);
 while(!stack.empty())
  {
  stack.pop(x,y);
  col=getpixel(x,y);
  if(col!=bg&&col!=fg)
  putpixel(x,y,fg);
  col=getpixel(x,y+1);
  if(col!=bg&&col!=fg)
  stack.push(x,y+1);
  col=getpixel(x+1,y);
  if(col!=bg&&col!=fg)
  stack.push(x+1,y);
  col=getpixel(x-1,y);
  if(col!=bg&&col!=fg)
  stack.push(x-1,y);
  col=getpixel(x,y-1);
  if(col!=bg&&col!=fg)
  stack.push(x,y-1);
  }
 }


void flood_fill(int ed[20])
 {
 int i,j,x,y,num,bg,fg,col,k;
 clearviewport();
        closegraph();
 cout<<"
 " Enter No Of Edges ":= ";
 cin>>num;
 for(i=0,k=1;i<2*num;i+=2,k++)
  {
  cout<<"
 " Enter The Vertex No "<<k<<" ":=";
  flushall();
  cin>>ed[i]>>ed[i+1];
  ed[i]+=320;
  ed[i+1]=240-ed[i+1];
  }
 ed[i]=ed[0];
 ed[i+1]=ed[1];
 cout<<"
 " Enter The Seed Point (x,y) ":= ";
 cin>>x>>y;
 x+=320;
 y=240-y;
        initgraph(&gd,&gm,"..\bgi");
        cleardevice();
 show_quadrant();
 setcolor(1);
 drawpoly(num+1,ed);
 fill_polygon(x,y,15,1);
 }

int check_mid(int i,int ed[20],int k)
 {
 int max,min;
 if(ed[k+1]>ed[k+3])
  {
  max=ed[k+1];
  min=ed[k+3];
  }
 if(ed[k+1]<ed[k+3])
  {
  max=ed[k+3];
  min=ed[k+1];
  }
 if(i>min&&i<max)
 return(1);
 else
 return(0);
 }

void scan_poly(int ed[20],int num)
 {
 int i,j,k,xmax,xmin,ymax,ymin,p;
 void sort(float xi[10],int n);
 float xi[10];
 get_y(ymin,ymax,ed,num);
 get_x(xmin,xmax,ed,num);
 for(i=ymin;i<=ymax;i++)
  {
  p=0;
  for(k=0;k<2*num;k+=2)
   {
   if(ed[k+1]==ed[k+3])
   continue;
xi[p] = ed[k]+((double)((double)(i-ed[k+1])/(ed[k+1]-ed[k+3]))*(ed[k]-ed[k+2]));
   if(xi[p]>=xmin&&xi[p]<=xmax)
   p++;
   }
  sort(xi,p);
  for(j=0;j<p;j+=2)
  line(xi[j],i,xi[j+1],i);
  }
 }

void sort(float xi[10],int n)
 {
 int i,j;
 for(i=0;i<n-1;i++)
  {
  for(j=0;j<n-1;j++)
   {
   if(xi[j]>xi[j+1])
    {
    float temp;
    temp=xi[j];
    xi[j]=xi[j+1];
    xi[j+1]=temp;
    }
   }
        }
 }

void edge_fill(int ed[20],int num)
 {
 int i,j,k,xmax,xmin,ymax,ymin,col;
 double xint;
 get_y(ymin,ymax,ed,num);
 get_x(xmin,xmax,ed,num);
 for(k=0;k<2*num;k+=2)
  {
  for(i=ymin;i<=ymax;i++)
   {
   if(ed[k+1]==ed[k+3])
   continue;
   if(!check_mid(i,ed,k))
   continue;
xint = ed[k]+(((double)(i-ed[k+1])/(ed[k+1]-ed[k+3]))*(ed[k]-ed[k+2]));
   for(j=xmin;j<=xmax;j++)
    {
    if(j>xint)
     {
     col=getpixel(j,i);
     if(col==15)
     putpixel(j,i,0);
     if(col==0)
     putpixel(j,i,15);
     }
    }
   }
  }
 }

void main()
 {
 clrscr();
 char *mess[]={"-","=","["," ","P","o","l","y","g","o","n"," ",
        "F","i","l","l","i","n","g"," ","]","=","-",};
 int xx=28,xxx=51,i,j;
 _setcursortype(_NOCURSOR);
 for(i=0,j=22;i<13,j>=11;i++,j--)
  {
  gotoxy(xx,1);
  cout<<mess[i];
  xx++;
  gotoxy(xxx,1);
  cout<<mess[j];
  xxx--;
  delay(50);
  }
 xx=30;xxx=49;
        int choice,ed[20],num;
 _setcursortype(_NORMALCURSOR);
 cout<<"


  1:==>" Flood Fill "";
 cout<<"

  2:==>" Ordered Edge List Fill "";
 cout<<"

  3:==>" Edge Fill "";
 cout<<"

  4:==>" Exit "";
 cout<<"

  " Enter Your Choice ":=";
 cin>>choice;
 initgraph(&gd,&gm,"..\bgi");
 clearviewport();
 switch(choice)
  {
  case 1:
   flood_fill(ed);
   getch();
   break;

  case 2:
   num=get_poly(ed);
   scan_poly(ed,num);
   getch();
   break;

  case 3:
   num=get_poly(ed);
   edge_fill(ed,num);
   getch();
   break;

  case 4:
   exit(0);

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

Top Ad unit 728 × 90

Program to implement Polygon Filling Algorithm

About Silentstudent

No comments:

Like Us On FB

Contact Form
