cg

//Scan Line Polygon Fill Algorithm

#include<iostream.h>
#include<graphics.h>
#include<conio.h>
#include<stdio.h>
#include<dos.h>
struct data
{
 int x;
 int y;
};

void main()
{
  int side,i,j,gm,gd=DETECT,ctr=0;
  int maxy,maxx,miny,minx;
  data arr[20];
  initgraph(&gd,&gm,"c:\\tc\\bgi");

  cleardevice();
  printf("\n\nEnter the no of sides of polygon:");
  scanf("%d",&side);
  printf("\nEnter the x & y co-ordinate");
  for(i=0;i<side;i++)
   {
    printf("\n\t x[%d] : ",i+1);
    scanf("%d",&arr[i].x);
    printf("\t y[%d] : ",i+1);
    scanf("%d",&arr[i].y);
   }
  arr[i].x=arr[0].x;
  arr[i].y=arr[0].y;
  cleardevice();

  setcolor(RED);       //draw poly
  for(i=0;i<side;i++)
   {
     line(arr[i].x,arr[i].y,arr[i+1].x,arr[i+1].y);
   }
  //to search min & max y coordinate  and max x coordinate

  miny=arr[0].y;
  maxy=arr[0].y;
  maxx=arr[0].x;
  minx=arr[0].x;
  setcolor(YELLOW);

  for(i=0;i<side;i++)
   {
     if(miny>arr[i].y)
      miny=arr[i].y;
     if(maxy<arr[i].y)
      maxy=arr[i].y;
     if(maxx<arr[i].x)
      maxx=arr[i].x;
     if(minx>arr[i].x)
      minx=arr[i].x;
   }

  for(j=miny+1;j<maxy;j++)     // fill poly
    {
      ctr=0;
      delay(20);
      for(i=minx-1;i<=maxx;i++)
    {
      if(getpixel(i,j)!=0)
         {
           arr[ctr].x=i;
           arr[ctr].y=j;
           ctr++;
         }

      if(ctr==2)
         {
           delay(20);
           line(arr[0].x+1,arr[0].y,arr[1].x-1,arr[1].y);
           ctr=0;

         }
    }
    }
 getch();
}


//midpoint of a circle

#include<graphics.h>
#include<stdio.h>
#include<conio.h>
#include<dos.h>
#include<math.h>

void main()
{
    int gd=DETECT,gm,xc,yc,x,y,r,pk;
    initgraph(&gd,&gm,"c:\\tc\\bgi");
    printf("Enter co-ordinates of centre: ");
    scanf("%d%d",&xc,&yc);
    printf("Enter radius: ");
    scanf("%d",&r);
    x=0;
    y=r;
    putpixel(xc+x,yc+y,WHITE);
    pk=1-r;
    while(x<y)
    {
        if(pk<0)
        {
            x=x+1;
            pk=pk+(2*x)+1;
        }
        else
        {
            x=x+1;
            y=y-1;
            pk=pk+(2*x)-(2*y)+1;
        }
        putpixel(xc+x,yc+y,WHITE);
        putpixel(xc+y,yc+x,WHITE);
        putpixel(xc-y,yc+x,WHITE);
        putpixel(xc+x,yc-y,WHITE);
        putpixel(xc-x,yc-y,WHITE);
        putpixel(xc-y,yc-x,WHITE);
        putpixel(xc+y,yc-x,WHITE);
        putpixel(xc-x,yc+y,WHITE);
    }
    getch();
    closegraph();
}

//bressenham's line generation algorithm

#include<graphics.h>
#include<stdio.h>
#include<conio.h>
#include<dos.h>
#include<math.h>

void main()
{
    int gd=DETECT,gm,x1,x2,y1,y2,dx,dy,p0,pk,x,y;
    float xinc,yinc;
    initgraph(&gd,&gm,"c:\\tc\\bgi");
    printf("Enter end point co-ordinates of line: ");
    scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
    dx=x2-x1;
    dy=y2-y1;
    x=x1;
    y=y1;
    putpixel(x,y,WHITE);
    if(abs(dx)>=abs(dy))
    {
    pk=2*abs(dy)-abs(dx);
    while(x!=x2||y!=y2)
    {
        if (pk<0)
        {
            xinc=dx/abs(dx);
            yinc=0;
            pk=pk+2*abs(dy);
        }
        else
        {
            xinc=dx/abs(dx);
            yinc=dy/abs(dy);
            pk=pk+(2*abs(dy))-(2*abs(dx));
        }
        x=x+xinc;
        y=y+yinc;
        putpixel(x,y,WHITE);
    }
    }
    else
    {
    pk=2*abs(dx)-abs(dy);
    while(x!=x2||y!=y2)
    {
        if (pk<0)
        {
            xinc=0;
            yinc=dy/abs(dy);
            pk=pk+2*abs(dx);
        }
        else
        {
            xinc=dx/abs(dx);
            yinc=dy/abs(dy);
            pk=pk+(2*abs(dx))-(2*abs(dy));
        }
        x=x+xinc;
        y=y+yinc;
        putpixel(x,y,WHITE);
    }
    }
    getch();
    closegraph();
}

//dda line drawing algorithm

#include<graphics.h>
#include<stdio.h>
#include<conio.h>
#include<dos.h>
#include<math.h>

void main()
{
    int gd=DETECT,gm,x1,y1,x2,y2,step,dx,dy,x,y;
    float xinc,yinc;
    initgraph(&gd,&gm,"C:\\TC\\BGI");
    printf("Enter end pt co-ordinates of line as x1 y1 x2 y2: ");
    scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
    dx=x2-x1;
    dy=y2-y1;
    if(abs(dx)>=abs(dy))
        step=abs(dx);
    else
        step=abs(dy);
    xinc=dx/step;
    yinc=dy/step;
    putpixel(x1,y1,WHITE);
    x=x1;
    y=y1;
    while(x!=x2||y!=y2)
    {
        x=x+xinc;
        y=y+yinc;
        putpixel(x,y,WHITE);
    }
    getch();
    closegraph();
}
//2d

#include<stdio.h>

#include<graphics.h>

#include<conio.h>

#include<math.h>



int x[20],y[20],dx[20],dy[20],ch,n,i,sx,sy,tx,ty;

float rad,angle;



void draw()

{

    for(i=0;i<n-1;i++)

        line(x[i],y[i],x[i+1],y[i+1]);

    line(x[i],y[i],x[0],y[0]);

}





void accept()

{

    printf("Enter no. of vertices: \n");

    scanf("%d",&n);

    for(i=0;i<n;i++)

    {

        printf("Enter coordinates of vertice %d ",i+1);

        scanf("%d %d",&x[i],&y[i]);

    }

    cleardevice();

    draw();

}



void scaling()

{

    printf("Enter scaling factor Sx and Sy: \n");

    scanf("%d %d",&sx,&sy);

    for(i=0;i<n;i++)

    {

        x[i]*=sx;

        y[i]*=sy;

    }

    cleardevice();

    draw();

    }



void rotation()

{

    printf("Enter rotation angle\n");

    scanf("%d",&angle);

    rad=3.14/angle*180;

    for(i=0;i<n;i++)

    {

        x[i]=dx[i];

        y[i]=dy[i];

    }

    for(i=1;i<n;i++)

    {

        x[i]=(int)(dx[i]*cos(rad)-dy[i]*sin(rad));



        y[i]=(int)(dx[i]*sin(rad)+dy[i]*cos(rad));

    }

    cleardevice();

    draw();

}



void translation()

{

    printf("Enter Tx and Ty factor\n");

    scanf("%d %d",&tx,ty);

    for(i=0;i<n;i++)

    {

        x[i]+=tx;

        y[i]+=ty;

    }

    cleardevice();

    draw();

}



void main()

{

    int gd,gm;

    detectgraph(&gd,&gm);

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

    while(1)

    {

        printf("Enter choice:\n1.Accept\n2.Scaling\n3.Rotation\n4.Translation\n5.Exit\n");

        scanf("%d",&ch);

        if(ch==5)

            break;

        switch(ch)

        {

            case 1: accept();

                break;

            case 2: scaling();

                break;

            case 3: rotation();

                break;

            case 4: translation();

                break;

            default:printf("Invalid input\n");

                break;

        }

    }

}

//bezier

#include<stdio.h>

#include<conio.h>

#include<graphics.h>



int i;

float xxx[4][2],temp1,temp2;



void line1(float xb,float yb)

{

    line(xxx[0][0],xxx[0][1],xb,yb);

    xxx[0][0]=xb;

    xxx[0][1]=yb;

}



void bezier(float x2,float y2,float x3,float y3,float x4,float y4,int n)

{

    float x12,y12,x23,y23,x34,y34;

    float x123,y123,x234,y234;

    float x1234,y1234;

    if(n==0)

    {

        line1(x2,y2);

        line1(x3,y3);

        line1(x4,y4);

    }

    else

    {

        x12=(xxx[0][0]+x2)/2;

        y12=(xxx[0][1]+y2)/2;

        x23=(x2+x3)/2;

        y23=(y2+y3)/2;

        x34=(x3+x4)/2;

        y34=(y3+y4)/2;

        x123=(x12+x23)/2;

        y123=(y12+y23)/2;

        x234=(x23+x34)/2;

        y234=(y23+y34)/2;

        x1234=(x123+x234)/2;

        y1234=(y123+y234)/2;

        n=n-1;

        bezier(x12,y12,x123,y123,x1234,y1234,n);

        bezier(x234,y234,x34,y34,x4,y4,n);

    }

}



void main()

{

    int gd,gm;

    detectgraph(&gd,&gm);

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

    for(i=0;i<4;i++)

    {

        printf("Enter coordinates of point %d ",i+1);

        scanf("%f %f",&temp1,&temp2);

        xxx[i][0]=temp1;

        xxx[i][1]=temp2;

    }

    bezier(xxx[1][0],xxx[1][1],xxx[2][0],xxx[2][1],xxx[3][0],xxx[3][1],8);

    getch();

    closegraph();

}

//boundary fill

#include<stdio.h>

#include<conio.h>

#include<graphics.h>



void b_fill(int x,int y,int f_col,int b_col)

{

    if(getpixel(x,y)!=f_col && getpixel(x,y)!=b_col)

    {

        putpixel(x,y,f_col);

        b_fill(x+1,y,f_col,b_col);

        b_fill(x-1,y,f_col,b_col);

        b_fill(x,y+1,f_col,b_col);

        b_fill(x,y-1,f_col,b_col);

    }

}



void main()

{

    int gd,gm;

    int a[20][2],i,n,x,y;

    detectgraph(&gd,&gm);

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

    printf("Enter no. of edges: ");

    scanf("%d",&n);

    for(i=0;i<n;i++)

    {

        printf("\nEnter coordinates for edge %d ",i+1);

        scanf("%d %d",&a[i][0],&a[i][1]);

    }

    a[n][0]=a[0][0];

    a[n][1]=a[0][1];

    cleardevice();

    for(i=0;i<n;i++)

        line(a[i][0],a[i][1],a[i+1][0],a[i+1][1]);

    printf("\nEnter seed point: ");

    scanf("%d %d",&x,&y);

    b_fill(x,y,BLUE,15);

    getch();

}

//bresenham

#include <stdio.h>

#include <conio.h>

#include <graphics.h>

#include <math.h>



void bresenham(int x1,int y1,int x2,int y2)

{

    int xk,yk,e,s1,s2,dx,dy,xi,yi,i;

    xk=x1;

    yk=y1;

    dx=x2-x1;

    dy=y2-y1;

    putpixel(x1,y1,WHITE);

    if(dx==0 && dy==0)

        return;

    if(x2>x1)

        s1=1;

    else    s1=-1;

    if(y2>y1)

        s2=1;

    else    s2=-1;

    if(dx>dy)

    {

        e=2*dy-dx;

        for(i=0;i<=dx;i++)

        {

            if(e>0)

            {

                yk=yk+s2;

                e=e-2*dx;

            }

            xk=xk+s1;

            e=e+2*dy;

            putpixel(xk,yk,WHITE);

        }

    }

    else

    {

        e=2*dx-dy;

        for(i=0;i<=dy;i++)

        {

            if(e>=0)

            {

                xk=xk+s1;

                e=e-2*dy;

            }

            yk=yk+s2;

            e=e+2*dx;

            putpixel(xk,yk,WHITE);

        }

    }

}



void main()

{

    int gd,gm,x1,y1,x2,y2;

    detectgraph(&gd,&gm);

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

    printf("Enter starting co-ordinates\n");

    scanf("%d %d",&x1,&y1);

    printf("Enter ending co-ordinates\n");

    scanf("%d %d",&x2,&y2);

    bresenham(x1,y1,x2,y2);

    getch();

    closegraph();

}

//midpoint circle

#include<stdio.h>

#include <conio.h>

#include <math.h>

#include <graphics.h>



void display(int x1,int y1,int x,int y)

{

    putpixel(x1+x,y1+y,WHITE);

    putpixel(x1+x,y1-y,WHITE);

    putpixel(x1-x,y1+y,WHITE);

    putpixel(x1-x,y1-y,WHITE);

    putpixel(x1+y,y1+x,WHITE);

    putpixel(x1+y,y1-x,WHITE);

    putpixel(x1-y,y1+x,WHITE);

    putpixel(x1-y,y1-x,WHITE);

}



void midpointcircle(int x1,int y1,int r)

{

    int x,y;

    float p;

    x=0;

    y=r;

    p=1-r;

    while(x<=y)

    {

        if(p<=0)

        {

            x++;

            p=p+2*x+1;

        }

        else

        {

            x++;

            y--;

            p=p+2*(x-y)+1;

        }

        display(x1,y1,x,y);

    }

}



void main()

{

    int x1,y1,r,gd,gm;

    gd=DETECT;

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

    printf("Enter center co-ordiantes\n");

    scanf("%d %d",&x1,&y1);

    printf("Enter radius\n");

    scanf("%d",&r);

    midpointcircle(x1,y1,r);

    getch();

    closegraph();

}

//dda

#include <stdio.h>

#include <conio.h>

#include <graphics.h>

#include <math.h>



void dda(int x1,int y1,int x2,int y2)

{

    int xk,yk,step,dx,dy,xi,yi,i;

    xk=x1;

    yk=y1;

    dx=x2-x1;

    dy=y2-y1;

    if(abs(dx)>=abs(dy))

        step=abs(dx);

    else    step=abs(dy);

    xi=float(dx)/step;

    yi=float(dy)/step;

    for(i=0;i<=step;i++)

    {

        xk=xk+xi;

        yk=yk+yi;

        putpixel(int xk,int yk,WHITE);

        delay(2);

    }

}



void main()

{

    int gd,gm,x1,y1,x2,y2;

    detectgraph(&gd,&gm);

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

    printf("Enter starting co-ordinates\n");

    scanf("%d %d",&x1,&y1);

    printf("Enter ending co-ordinates\n");

    scanf("%d %d",&x2,&y2);

    dda(x1,y1,x2,y2);

    getch();

    closegraph();

}

//floodfill

#include<stdio.h>

#include<conio.h>

#include<graphics.h>



void f_fill(int x,int y,int f_col)

{

    if(getpixel(x,y)!=f_col)

    {

        putpixel(x,y,f_col);

        f_fill(x,y+1,f_col);

        f_fill(x,y-1,f_col);

        f_fill(x-1,y,f_col);

        f_fill(x+1,y,f_col);

    }

}



void main()

{

    int gd,gm;

    int a[20][2],i,n,x,y;

    detectgraph(&gd,&gm);

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

    printf("Enter no. of edges: ");

    scanf("%d",&n);

    for(i=0;i<n;i++)

    {

        printf("\nEnter coordinates for edge %d ",i+1);

        scanf("%d %d",&a[i][0],&a[i][1]);

    }

    a[n][0]=a[0][0];

    a[n][1]=a[0][1];

    cleardevice();

    for(i=0;i<n;i++)

        line(a[i][0],a[i][1],a[i+1][0],a[i+1][1]);

    printf("\nEnter seed point: ");

    scanf("%d %d",&x,&y);

    f_fill(x,y,BLUE);

    getch();

}

//piechart

#include<stdio.h>

#include<conio.h>

#include<graphics.h>

#include<math.h>



struct piechart

{

    float x,y;

}pts[2];



int i,n,xc,yc;

float r,data[5];



void piechart(int xc,int yc,int r)

{

    int x2=540,y2=240;

    float is,theta=0,total=0;

    circle(xc,yc,r);

    for(i=0;i<n;i++)

        total+=data[i];

    pts[0].x=xc;

    pts[0].y=yc;

    line(xc,yc,x2,480-y2);

    for(i=0;i<n-1;i++)

    {

        theta+=2*3.14*data[i]/total;

        pts[i].x=xc+r*cos(theta);

        pts[i].y=yc+r*sin(theta);

        x2=pts[i].x;

        y2=pts[i].y;

        setcolor(2);

        line(xc,480-yc,x2,480-y2);

    }

}





void main()

{

    int gd,gm;

    detectgraph(&gd,&gm);

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

    printf("Enter no. of points\n");

    scanf("%d",&n);

    printf("Enter data\n");

    for(i=0;i<n;i++)

        scanf("%f",&data[i]);

    xc=640/2;

    yc=480/2;

    r=200;

    piechart(xc,yc,r);

    getch();

}

//scanline

#include<stdio.h>

#include<conio.h>

#include<graphics.h>



int isvertex(int x,int y,int a[20][2],int n)

{

    int i;

    for(i=0;i<n;i++)

        if(a[i][0]==x)

            if(a[i][1]==y)

                return 1;

    return 0;

}



void main()

{

    int gd,gm;

    int a[20][2],k,n,left=640,right=0,top=480,bottom=0,i,j;

    detectgraph(&gd,&gm);

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

    printf("Enter no. of vertices\n");

    scanf("%d",&n);

    for(i=0;i<n;i++)

    {

        printf("Enter co-ordinates for vertice %d ",i+1);

        scanf("%d %d",&a[i][0],&a[i][1]);

        if(a[i][0]<left)

            left=a[i][0];

        if(a[i][0]>right)

            right=a[i][0];

        if(a[i][1]<top)

            top=a[i][1];

        if(a[i][1]>bottom)

            bottom=a[i][1];

    }

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

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

    cleardevice();

    for(i=0;i<n;i++)

        line(a[i][0],a[i][1],a[i+1][0],a[i+1][1]);

    for(j=top;j<bottom;j++)

    {

        k=0;

        for(i=left;i<right;i++)

        {

            if(getpixel(i,j)==15 && getpixel(i+1,j)!=15)

            {

                if(isvertex(i,j,a,n)==1)

                    k++;

                k++;

            }

            if(k%2==1)

                putpixel(i,j,15);

        }

    }

    getch();

}