C program to generate CAPTCHA using C graphics.h

This program generates captcha, a captcha is a random code generated using some algorithm. We will use random function in our code. These are used in typing tutors and in website to check whether a human is operating on a website.

C programming code

#include<stdlib.h>
#include<dos.h>
#include<graphics.h>
 
main()
{
   int i = 0, key, num, midx, gd = DETECT, gm;
   char a[10];
 
   initgraph(&gd,&gm,"C:\\TC\\BGI");
 
   midx = getmaxx()/2;
 
   settextstyle(SCRIPT_FONT,HORIZ_DIR,5);
   settextjustify(CENTER_TEXT,CENTER_TEXT);
   setcolor(GREEN);
   outtextxy(midx,20,"CAPTCHA");
   settextstyle(SCRIPT_FONT,HORIZ_DIR,2);
   outtextxy(midx,125,"Press any key to change the generated random code \"captcha\"");
   outtextxy(midx,150,"Press escape key to exit...");
 
   setcolor(WHITE);
   setviewport(100,200,600,400,1);
   setcolor(RED);
   randomize();
 
   while(1)
   {
      while(i<6)
      {
         num = random(3);
 
         if ( num == 0 )
            a[i] = 65 + random(26);     /* 65 is the ASCII value of A */
         else if ( num == 1)
            a[i] = 97 + random(26);     /* 97 is the ASCII value of a */
         else
            a[i] = 48 + random(10);     /* 48 is the ASCII value of 0 */
         i++;
      }
      a[i] = '\0';
      outtextxy(210,100,a);
      key = getch();
 
      if( key == 27 )                     /* escape key*/
         exit(0);
      clearviewport();
      i = 0;
   }
}

C Program for SMILING FACE ANIMATION using C graphics.h

This animation using c draws a smiling face which appears at random position on screen. See output below the code, it will help you in understanding the code easily.

C programming code

#include<graphics.h>
#include<conio.h>
#include<stdlib.h>
 
main()
{
   int gd = DETECT, gm, area, temp1, temp2, left = 25, top = 75;
   void *p;
 
   initgraph(&gd,&gm,"C:\\TC\\BGI");
 
   setcolor(YELLOW);
   circle(50,100,25);
   setfillstyle(SOLID_FILL,YELLOW);
   floodfill(50,100,YELLOW);
 
   setcolor(BLACK);
   setfillstyle(SOLID_FILL,BLACK);
   fillellipse(44,85,2,6);
   fillellipse(56,85,2,6);
 
   ellipse(50,100,205,335,20,9);
   ellipse(50,100,205,335,20,10);
   ellipse(50,100,205,335,20,11);
 
   area = imagesize(left, top, left + 50, top + 50);
   p = malloc(area);
 
   setcolor(WHITE);
   settextstyle(SANS_SERIF_FONT,HORIZ_DIR,2);
   outtextxy(155,451,"Smiling Face Animation");
 
   setcolor(BLUE);
   rectangle(0,0,639,449);
 
   while(!kbhit())
   {
      temp1 = 1 + random ( 588 );
      temp2 = 1 + random ( 380 );
 
      getimage(left, top, left + 50, top + 50, p);
      putimage(left, top, p, XOR_PUT);
      putimage(temp1 , temp2, p, XOR_PUT);
      delay(100);
      left = temp1;
      top = temp2;
   }
 
   getch();
   closegraph();
   return 0;
}