Sutherland PolyGon CLipping

Code:

#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#define round(a) ((int)(a+0.5))
int k;
float xmin,ymin,xmax,ymax,arr[20],m;
void clipl(float x1,float y1,float x2,float y2)
{
    if(x2-x1)
        m=(y2-y1)/(x2-x1);
    else
        m=100000;
    if(x1 >= xmin && x2 >= xmin)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(x1 < xmin && x2 >= xmin)
    {
        arr[k]=xmin;
        arr[k+1]=y1+m*(xmin-x1);
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(x1 >= xmin  && x2 < xmin)
    {
        arr[k]=xmin;
        arr[k+1]=y1+m*(xmin-x1);
        k+=2;
    }
}

void clipt(float x1,float y1,float x2,float y2)
{
    if(y2-y1)
        m=(x2-x1)/(y2-y1);
    else
        m=100000;
    if(y1 <= ymax && y2 <= ymax)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(y1 > ymax && y2 <= ymax)
    {
        arr[k]=x1+m*(ymax-y1);
        arr[k+1]=ymax;
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(y1 <= ymax  && y2 > ymax)
    {
        arr[k]=x1+m*(ymax-y1);
        arr[k+1]=ymax;
        k+=2;
    }
}

void clipr(float x1,float y1,float x2,float y2)
{
    if(x2-x1)
        m=(y2-y1)/(x2-x1);
    else
        m=100000;
    if(x1 <= xmax && x2 <= xmax)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(x1 > xmax && x2 <= xmax)
    {
        arr[k]=xmax;
        arr[k+1]=y1+m*(xmax-x1);
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(x1 <= xmax  && x2 > xmax)
    {
        arr[k]=xmax;
        arr[k+1]=y1+m*(xmax-x1);
        k+=2;
    }
}

void clipb(float x1,float y1,float x2,float y2)
{
    if(y2-y1)
        m=(x2-x1)/(y2-y1);
    else
        m=100000;
    if(y1 >= ymin && y2 >= ymin)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(y1 < ymin && y2 >= ymin)
    {
        arr[k]=x1+m*(ymin-y1);
        arr[k+1]=ymin;
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(y1 >= ymin  && y2 < ymin)
    {
        arr[k]=x1+m*(ymin-y1);
        arr[k+1]=ymin;
        k+=2;
    }
}

void main()
{
    int gdriver=DETECT,gmode,n,poly[20];
    float xi,yi,xf,yf,polyy[20];
    clrscr();
    cout<<"Coordinates of rectangular clip window :\nxmin,ymin             :";
    cin>>xmin>>ymin;
    cout<<"xmax,ymax             :";
    cin>>xmax>>ymax;
    cout<<"\n\nPolygon to be clipped :\nNumber of sides       :";
    cin>>n;
    cout<<"Enter the coordinates :";
    for(int i=0;i < 2*n;i++)
    cin>>polyy[i];
    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    for(i=0;i < 2*n+2;i++)
    poly[i]=round(polyy[i]);
    initgraph(&gdriver,&gmode,"C:\\TURBOC3\\BGI");
    setcolor(RED);
    rectangle(xmin,ymax,xmax,ymin);
    cout<<"\t\tUNCLIPPED POLYGON";
    setcolor(WHITE);
    fillpoly(n,poly);
  getch();
    cleardevice();
    k=0;
    for(i=0;i < 2*n;i+=2)
    clipl(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    n=k/2;
    for(i=0;i < k;i++)
    polyy[i]=arr[i];
    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    k=0;
    for(i=0;i < 2*n;i+=2)
    clipt(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    n=k/2;
    for(i=0;i < k;i++)
    polyy[i]=arr[i];
    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    k=0;
    for(i=0;i < 2*n;i+=2)
    clipr(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    n=k/2;
    for(i=0;i < k;i++)
    polyy[i]=arr[i];
    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    k=0;
    for(i=0;i < 2*n;i+=2)
    clipb(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    for(i=0;i < k;i++)
    poly[i]=round(arr[i]);
    if(k)
    fillpoly(k/2,poly);
    setcolor(RED);
    rectangle(xmin,ymax,xmax,ymin);
    cout<<"\tCLIPPED POLYGON";
    getch();
    closegraph();
}

Output:

This Program is taken from pracspedia.com we at gndecprogramming do not believe in copying but this is done because of less time.....

Mid Point Eclipse Drawing Algoritm

Code:

#include<stdio.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
void disp();
float x,y;
int xc,yc;
void main()
{
int gd=DETECT,gm;
int a,b;
float p1,p2;
clrscr();
initgraph(&gd,&gm,"");
scanf("%d%d",&xc,&yc);
scanf("%d%d",&a,&b);
x=0;y=b;
disp();
p1=(b*b)-(a*a*b)+(a*a)/4;
while((2.0*b*b*x)<=(2.0*a*a*y))
{
x++;
if(p1<=0)
p1=p1+(2.0*b*b*x)+(b*b);
else
{
y--;
p1=p1+(2.0*b*b*x)+(b*b)-(2.0*a*a*y);
}
disp();
x=-x;
disp();
x=-x;
}
x=a;
y=0;
disp();
p2=(a*a)+2.0*(b*b*a)+(b*b)/4;
while((2.0*b*b*x)>(2.0*a*a*y))
{
y++;
if(p2>0)
p2=p2+(a*a)-(2.0*a*a*y);
else
{
x--;
p2=p2+(2.0*b*b*x)-(2.0*a*a*y)+(a*a);
}
disp();
y=-y;
disp();
y=-y;
}
getch();
closegraph();
}
void disp()
{
putpixel(xc+x,yc+y,10);
putpixel(xc-x,yc+y,10);
putpixel(xc+x,yc-y,10);
putpixel(xc+x,yc-y,10);
}

Output:

This Program is Taken from Studentcpu.com, We at gndecprogramming donot believe in copying but this time we did it because of less time .....

Transformation Computer Graphics

Question:
Write a program to draw any 2-D object and perform the transformations on it according to the input parameters from the user, namely: Translation, Rotation or Scaling

Code:

#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>
void main(){

    int g=DETECT,gmode;
    initgraph(&g,&gmode,"C://TURBOC3//BGI");
    line(200,300,300,200);
    int x;
    cout<<"Enter Your Choice\nPress 1 For Translation\n2 For Rotation\n3 For Scaling\n";
    cin>>x;

    if(x==1){
cleardevice();
int tx,ty;
line(200,300,300,200);
cout<<"Enter Translation Along x and y\n";
cout<<"Tx =";
cin>>tx;
cout<<"Ty =";
cin>>ty;
line(200+tx,300+ty,300+tx,200+ty);
    }else if(x==2){
cleardevice();
line(200,300,300,200);
cout<<"Enter Rotation Angle:\n";
cout<<"a=";
float a;
cin>>a;
a=a*(3.142/180);
cout<<200*cos(a)-300*sin(a)<<","<<200*sin(a)+300*cos(a)<<","<<300*cos(a)-200*sin(a)<<","<<300*sin(a)+200*cos(a);
//line((int)200*cos(a)-300*sin(a),(int)200*sin(a)+300*cos(a),(int)300*cos(a)-200*sin(a),(int)300*sin(a)+200*cos(a));
line(200*cos(a)-300*sin(a),200*sin(a)+300*cos(a),300*cos(a)-200*sin(a),300*sin(a)+200*cos(a));
    }else{
cleardevice();
float sx,sy;
line(200,300,300,200);
cout<<"Enter Scaling along x and y\n";
cout<<"Sx =";
cin>>sx;
cout<<"Sy =";
cin>>sy;
line(200*sx,300*sy,300*sx,200*sy);
    }

    getch();
}

Output:

MidPoint Circle Generation Algorithm

Question: Write a program to generate a complete moving wheel using Midpoint circle drawing algorithm and DDA line drawing algorithm.

Code:

#include<iostream.h>

#include<conio.h>

#include<stdio.h>

#include<graphics.h>

#include<dos.h>

#include<math.h>

int u=1;

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

  int s, dx, dy, m;

  float xi, yi, x, y;

  dx = x2 - x1;

  dy = y2 - y1;

  if (abs(dx) > abs(dy))

    s = abs(dx); else

    s = abs(dy);

  xi = dx / (float) s;

  yi = dy / (float) s;

  x = x1;

  y = y1;

  putpixel(x1 + 0.5, y1 + 0.5, 15);

  for (m = 0; m < s; m++) {

    x += xi;

    y += yi;

    putpixel(x + 0.5, y + 0.5, 15);

  }

}

void main(){

    int g=DETECT,gmode;

    initgraph(&g,&gmode,"C://TURBOC3//BGI");

    int r;

    cout<<"Enter Radius \n";

    cin>>r;

    int x=0,y=r;

    int p=1-r;

    int xc=50,yc=200;

    while(xc<750)

    {  cleardevice();

       x=0;y=r;p=1-r;

      while(x<y){

      if(p<=0){

p=p+2*x+3;

      }else{

p=p+2*(x-y)+5;

y--;

      }

      x++;

      putpixel(xc+x,yc+y,10);

      putpixel(xc+y,yc+x,10);

      putpixel(xc+x,yc-y,10);

      putpixel(xc-y,yc+x,10);

      putpixel(xc-x,yc-y,10);

      putpixel(xc+y,yc-x,10);

      putpixel(xc-x,yc+y,10);

      putpixel(xc-y,yc-x,10);

      if(u%20==0){

      dda(xc-x,yc+y,xc+x,yc-y);

      dda(xc+x,yc+y,xc-x,yc-y);

      dda(xc+y,yc+x,xc-y,yc-x);

      dda(xc-y,yc+x,xc+y,yc-x);

    }u++;

  }

  xc=xc+5;

  delay(90);

  }

getch();

}

Output:

Bresenham VS DDA

Write a program to input the line coordinates from the user to generate a line using Bresenham’s method and DDA algorithm. Compare the lines for their values on theplotted line.

Code:


#include<iostream.h>
#include<conio.h>
#include<graphics.h>
void main(){

    int g=DETECT,gmode;
    initgraph(&g,&gmode,"C://TURBOC3//BGI");
    float x1,x2,y1,y2;
    cout<<"Enter coordinates\n";
    cout<<"x1:";
    cin>>x1;
    cout<<"y1:";
    cin>>y1;
    cout<<"x2:";
    cin>>x2;
    cout<<"y2:";
    cin>>y2;
    int x3=x1+100;
    int x4=x2+100;
    int y3=y1,y4=y2;
    int y=y2-y1;
    int x=x2-x1;
    float m=y/x;
    int d=2*y-x;
    putpixel(x1,y1,10);
    if(m<=1){
    while(x1!=x2){
      if(d>0){
y1++;
d=d+2*(y-x);
      }else{
      d=d+2*y;
      }
      x1++;
      putpixel(x1,y1,10);
    }}else{
      while(y1!=y2){
      if(d>0){
x1++;
d=d+2*(y-x);
      }else{
      d=d+2*y;
      }
      y1++;
      putpixel(x1,y1,10);
    }
    }
    if(m<=1){
    while(x3!=x4){
    x3++;
    y3=y3+m;
    putpixel(x3,y3,10);
    }
    }else{
    while(y3!=y4){
    y3++;
    x3=x3+1/m;
    putpixel(x3,y3,10);
    }

    }
    setcolor(15);
    settextstyle(1,HORIZ_DIR,2);
    outtextxy(x2+15,y2,"Bresenham");
    outtextxy(x2+135,y2,"DDA");
    getch();
}

   Output:

DDA(Digital Differential Algorithm)

Code:

#include<iostream.h>
#include<conio.h>
#include<graphics.h>
void main(){

    int g=DETECT,gmode;
    initgraph(&g,&gmode,"C://TURBOC3//BGI");
    float x1,x2,y1,y2;
    cout<<"Enter coordinates\n";
    cout<<"x1:";
    cin>>x1;
    cout<<"y1:";
    cin>>y1;
    cout<<"x2:";
    cin>>x2;
    cout<<"y2:";
    cin>>y2;
    float m=(y2-y1)/(x2-x1);
    putpixel(x1,y1,10);
    if(m<=1){
    while(x1!=x2){
    x1++;
    y1=y1+m;
    putpixel(x1,y1,10);
    }
    }else{
    while(y1!=y2){
    y1++;
    x1=x1+1/m;
    putpixel(x1,y1,10);
    }

    }
    getch();
}

Output:

CG3

Code:

#include<iostream.h>
#include<conio.h>
#include<graphics.h>
void main(){

    int g=DETECT,gmode;
    initgraph(&g,&gmode,"C://TURBOC3//BGI");
    setcolor(10);
    setbkcolor(15);
    settextstyle(SANS_SERIF_FONT,HORIZ_DIR,5);
    outtextxy(100,100,"HELLO WORLD!");
    setcolor(20);
    settextstyle(DEFAULT_FONT,HORIZ_DIR,5);
    outtextxy(100,200,"HELLO WORLD!");
    setcolor(25);
    settextstyle(BOLD_FONT,HORIZ_DIR,5);
    outtextxy(100,300,"HELLO WORLD!");
    getch();
}

Output: