#include <u.h>
#include <libc.h>
#include <draw.h>
Point o;
Image *px;
uchar bgr[3] = {0, 0, 255};
int rad;
void
spot(int n, int r){
	Point p;
	int t;
	bgr[1] = ~r;
	loadimage(px, px->r, bgr, 3);
	r = r * rad >> 8;
	switch(n){
	case 0: p = Pt(o.x, o.y - rad + r); break;
	case 1:
		t = sqrt((rad - r) * (rad - r) >> 1);
		p = Pt(o.x + t, o.y - t);
		break;
	case 2: p = Pt(o.x + rad - r, o.y); break;
	case 3:
		t = sqrt((rad - r) * (rad - r) >> 1);
		p = Pt(o.x + t, o.y + t);
		break;
	case 4: p = Pt(o.x, o.y + rad - r); break;
	case 5:
		t = sqrt((rad - r) * (rad - r) >> 1);
		p = Pt(o.x - t, o.y + t);
		break;
	case 6: p = Pt(o.x - rad + r, o.y); break;
	case 7:
		t = sqrt((rad - r) * (rad - r) >> 1);
		p = Pt(o.x - t, o.y - t);
		break;
	}
	fillellipse(screen, p, r, r, px, ZP);
}
void
main(int, char**){
	int r, n, i;
	if(initdraw(nil, nil, ".oO") < 0)
		sysfatal("initdraw: %r");
	px = allocimage(display, Rect(0, 0, 1, 1), RGB24, 1, DNofill);
	if(px == nil)
		sysfatal("allocimage: %r");
	rad = Dx(screen->r) < Dy(screen->r) ? Dx(screen->r) / 2 : Dy(screen->r) / 2;
	o.x = screen->r.min.x + screen->r.max.x >> 1;
	o.y = screen->r.min.y + screen->r.max.y >> 1;
	while(9){
		for(n = 0; n < 8; n++)
			for(r = 0; r < 32; r++){
				bgr[1] = 0;
				loadimage(px, px->r, bgr, 3);
				draw(screen, screen->r, px, nil, ZP);
				for(i = 7; i >= 0; i--)
					spot(n - i & 7, i << 5 | r);
				flushimage(display, 1);
//				sleep(50);
			}
	}
}