#include <xsimple.h>

#include <xsimple.h>
#include <stdlib.h>
#include <unistd.h>
#include <time.h>
#include <sys/time.h>

#define RND ((double)rand() / RAND_MAX)

#define WIN_X 110
#define WIN_Y 75
#define WIN_W 800
#define WIN_H 600

#define HZ 30

#define NBALLS 5

typedef struct {
int x, y;
int oldx, oldy;
int dx, dy;
int color;
} BALL;

BALL ball[NBALLS] = {
{300, 100, -1, -1, 10, -5, 58},
{100, 300, -1, -1, -5, -10, 59},
{130, 200, -1, -1, -10, 10, 60},
{350, 370, -1, -1, 10, 5, 61},
{600, 350, -1, -1, -5, 10, 62}
};

static int itstime(struct timeval *t)
{
struct timeval now;
double s1, s2;

gettimeofday(&now, NULL);
s1 = (double)t->tv_sec + (double)t->tv_usec / 1000000;
s2 = (double)now.tv_sec + (double)now.tv_usec / 1000000;
if (s2 - s1 >= 1./HZ) {
*t = now;
return 1;
}
return 0;
}

static void do_balls(void)
{
int i;

for (i = 0; i < NBALLS; i++) {
if (ball[i].oldx != -1)
fillellipse(ball[i].oldx, ball[i].oldy, 50, 50, BLACK);
}

for (i = 0; i < NBALLS; i++)
fillellipse(ball[i].x, ball[i].y, 50, 50,
xv.egacolor[ball[i].color]);

update(0, 0, 0, 0);

for (i = 0; i < NBALLS; i++) {
ball[i].oldx = ball[i].x; ball[i].oldy = ball[i].y;

ball[i].x += ball[i].dx; ball[i].y += ball[i].dy;
if (ball[i].x == WIN_W - 50 || ball[i].x == 0)
ball[i].dx = -ball[i].dx;
if (ball[i].y == WIN_H - 50 || ball[i].y == 0)
ball[i].dy = -ball[i].dy;
}
}

int main(int argc, char **argv)
{
struct timeval t;

srand(time(NULL));

xinit("balls", "Balls", "Bouncing Balls", WIN_X, WIN_Y, WIN_W, WIN_H, 0,
"black", "black", 0);

gettimeofday(&t, NULL);

cls(BLACK);

for (;;) {
XEvent e;

if (itstime(&t))
do_balls();

while (getevent(&e)) {
switch (e.type) {
case KeyPress:
switch (XLookupKeysym((XKeyEvent *)&e, 0)) {
int i;
case XK_Down:
for (i = 0; i < NBALLS; i++)
ball[i].color = (int)(1 + RND * 15);
break;
case XK_q:
exit(0);
}
break;
}
}
}
}