// circles.cxx
// draws random circles on the screen

#include <winbgim.h>    // for graphics functions
#include <stdlib.h>		// for random()
const int XDIM = 500;
const int YDIM = 500;

void main(void)
{
    int xcenter, ycenter;// center of circle
    int radius;       	 // radius of circle
    int col;

    initwindow(XDIM, YDIM); // open a graphics window 

    while (!kbhit()) { // loop until any key is hit on the keyboard
        do { // pick a random location and radius for the circle
           xcenter = random(XDIM-1);	// random number for x center
           ycenter = random(YDIM-1);	// random number for y center
           radius = random(101) + 50;	// random number in range 50-150
        } while (xcenter+radius >= XDIM  || xcenter-radius < 0 ||
                 ycenter+radius >= YDIM  || ycenter-radius < 0);
	        // make sure circle lies entirely on screen
 
        col = random(16); // choose a random color
		setcolor(col); // set color for circle
        circle(xcenter, ycenter, radius);  // draw unfilled circle
        //delay(100 /* milliseconds */);
    }
}