SAND_NUMBER = 10
sand = [Sand.random(9e-1, 11e-1) for i in range(SAND_NUMBER)]
window = Window()
plane = Plane(offset=[window.w/2, window.h/2], zoom=min(window.size)/10)
angle = 0
while window.open:
window.check()
window.clear(mycolors.WHITE)
angle += 0.01
angle %= 2*math.pi
xoffset = math.cos(angle)
yoffset = math.sin(angle)
for grain in sand:
x, y = plane.getToScreen(grain.center)
x += xoffset*plane.zoom
y -= yoffset*plane.zoom
grain_pixel = Sand([int(x), int(y)], radius=grain.radius*plane.zoom)
grain_pixel.show(window)
window.flip()
