/* Program 1.13 */
/* simple rectangle animation */
/* hint: use the cursors to move the funky rectangle, press 'q' to quit */
/* Used header files */

/* header files */
#include <stdio.h>
#include <stdlib.h>
#include <ext.h>
#include <graphics.h>

/* !!! This is important part - the variables must be declared before they are used !!!! */

int r_x_pos=0;			/* starting x position of rectangle*/
int r_y_pos=0; 			/* starting y position of rectangle*/ 
int r_height=100; 		/* rectangle height*/
int r_width=100; 		/* rectangle width */
int delta_x=0; 			/* in which x direction our rectangle will be moving x-axis*/
int delta_y=0; 			/* how many pixels our rectangle will be moving on y-axis */

/* declaration of used functions */
void draw_rectangle(int colour);

/* implementation of user defined functions */

void draw_rectangle(int colour)
{
setcolor(colour);
moveto(r_x_pos,r_y_pos);
lineto(r_x_pos+r_width,r_y_pos);
lineto(r_x_pos+r_width,r_y_pos+r_height);
lineto(r_x_pos,r_y_pos+r_height);
lineto(r_x_pos,r_y_pos);

}  	/* end of function(or procedure with parameter you naughty pascal Ý$%&%*!) draw_rectangle */


/* Main function - our program starts here*/
int main(void)
{
/* initialization of variables */

int driver,mode,err=0;
int kod_znaku=0;

driver = VDI;
mode = VDIMODE;
  
initgraph(&driver, &mode, "");		/* Damn, still no drivers for Atari! Why !? ;))))))*/
  err = graphresult();
  if(err) {
    puts(grapherrormsg(err));
    return(err);
   }
              
while(1==1)
 {
  draw_rectangle(BLUE);

  /* Now, we are checking if the key was pressed */
  if (kod_znaku=getch())
   {
    switch (kod_znaku) /* switch on :))) */
    {
     case 72:			/* arrow up pressed */
      {delta_y=-10;delta_x=0;break;} 
     
	  case 80:			/* arrow down pressed */
      {delta_y=10;delta_x=0;break;}
     
     case 75:			/* left arrow pressed */
      {delta_x=-10;delta_y=0;break;}
     
     case 77:			/* right arrow pressed */
      {delta_x=10;delta_y=0;break;}
     
     case 113:			/* if 'q' pressed quit proggy */
      {
       closegraph();
       printf("You have quitted the program. See ya!!");
       return(0);
       }

     } /* end of switch (switch it off ;)))) ) */

} /* end of if */


/* Moving of the rectangle*/
if ( ((r_x_pos + delta_x) > -10) && ((r_x_pos + delta_x) < (getmaxx()-r_width)) )
 r_x_pos=r_x_pos + delta_x;

if (((r_y_pos+delta_y)>-10)&&((r_y_pos+delta_y)<(getmaxy()-r_height)))
r_y_pos=r_y_pos+delta_y; 

cleardevice(); /* clear the whole screen */
} /* end of while loop */

} /* our main program ends here */