Computer Graphics lesson's

Basic's of how to draw a line in TurboC....

#include<iostream.h>

#include<conio.h>

#include<stdio.h>

#include<dos.h>

#include<graphics.h>

#include<math.h>

void main()

{

 clrscr();

 float x,y,x1,x2,y1,y2,dx,dy,lenght;

 int i,gd,gm;

 cout<<"enter x1 and y1"<<endl;

 cin>>x1>>y2;

 cout<<"enter x2 and y2"<<endl;

 cin>>x2>>y2;

 detectgraph(&gd,&gm);

 initgraph(&gd,&gm,"C:\\TC\\BGI");

 dx=abs(x2-x1);

 dy=abs(y2-y1);

 if(dx>=dy)

 { lenght=dx;}

 else

 {lenght=dy;}

 dx=(x2-x1)/lenght;

 dy=(y2-y1)/lenght;

 x=x1+0.5 ;

 y=y1+0.5;

 i=1;

 while(i<=lenght)

 {

  putpixel(x,y,15);

  x=x+dx;

  y=y+dy;

  i++;

 }

 delay(100);

 getch();

 closegraph();

}

Second basic's of drawing a line......

#include<iostream.h>

#include<conio.h>

#include<stdio.h>

#include<dos.h>

#include<graphics.h>

#include<math.h>

void main()

{

 clrscr();

 float x,y,x1,x2,y1,y2,dx,dy,e;

 int i,gd,gm;

 cout<<"enter x1 and y1"<<endl;

 cin>>x1>>y2;

 cout<<"enter x2 and y2"<<endl;

 cin>>x2>>y2;

 detectgraph(&gd,&gm);

 initgraph(&gd,&gm,"C:\\TC\\BGI");

 dx=abs(x2-x1);

 dy=abs(y2-y1);

 x=x1;

 y=y1;

 e=2*dy-dx;

 i=1;

 do

 {

  putpixel(x,y,15);

  while(e<=0)

  {

   y=y+1;

   e=e+2*dx;

  }

  x=x+1;

  e=e+2*dy;

  i++;

 }while(i<=dx);

 getch();

 closegraph();

}

How to make a smilee face .....

#include<iostream.h>
#include<graphics.h>
#include<conio.h>
void main()
{
 int gd,gm;
 detectgraph(&gd,&gm);
 initgraph(&gd,&gm,"C:\\tc\\bgi");
 circle(300,250,150);
 circle(250,200,25);
 circle(350,200,25);
 line(300,225,300,275);
 line(300,225,300,275);
 arc(300,250,240,300,75);
 getch();

}