Computer Graphics

#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
int main(void)
{
/* request auto detection */
  int gdriver = DETECT, gmode, errorcode;
/* initialize graphics mode */
  initgraph(&gdriver, &gmode, "");
/* read result of initialization */
  errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
  {
    printf("Graphics error: %s\n", grapherrormsg(errorcode));
    printf("Press any key to halt:");
    getch();
    exit(1); /* return with error code */
  }
/* draw a line */
  line(0, 0, getmaxx(), getmaxy());
/* clean up */
  getch();
  closegraph();
  return 0;
}

The graphics programming in c language is discussed in brief to provide an over view to the beginner.

/* Sample program to draw a circle*/
#include<graphics.h>
#include<conio.h>
main()
{
  int gd=DETECT,gm;
  initgraph(&gd,&gm,""); /* initialization of graphic mode */
  circle(150,150,100);
  getch();
  closegraph(); /* Restore orignal screen mode */
}
/* End of program */

Normally the screen which u view in DOS is in the text mode which means it is meant for text. And for graphics u need to initialize graphics mode. And for this to happen u need to include graphics.h?.

circle(x coordinate ,y coordinate , radius);


The circle command takes a X coordinate which means Vertical axis and Y coordinate which means Horizontal axis. And the last one is the radius of the circle. closegraph();

With out this function the screen mode will still remain in graphic mode and when u come out, to DOS u will see a different screen, which is not in the text mode.

/*A program to draw a space with stars*/
#include<graphics.h>
main()
{
  int gd=DETECT,gm;
  int i,x,y;
  initgraph(&gd,&gm,"");
  line(0,0,640,0);
  line(0,0,0,480);
  line(639,0,639,480);
  line(639,479,0,479);
  for(i=0;i<=1000;i++)
  {
    x=rand()%639;
    y=rand()%480;
    putpixel(x,y,15);
  }
  getch();
  closegraph();
}
/* End of program */

*Here a sample program to illustrate how to use BARS which are used for visual statistics */
#include<graphics.h>
main() {
  int gd=DETECT,gm,maxx,maxy,x,y,button;
  initgraph(&gd,&gm,"");
  line(80,150,200,150);
  line(80,150,80,50);
  settextstyle(1,HORIZ_DIR,1);
  outtextxy(100,153,"<-X axis");
  settextstyle(1,VERT_DIR,1);
  outtextxy(60,50,"<-Y axis");
  bar(100,100,120,150);
  bar(130,120,150,150);
  getch();
  closegraph();
}