full_screen = True
window_size = (1024, 768)

import sys, random, pygame
from pygame.locals import *
from math import *

circles = ((0, 1),)
circle_scale = 0.3
circle_radius = 8
n_grid = 3
grid_spacing = 0.2
grid_length = 0.05
grid_width = 2
fix_radius = 8
rotation_speed = pi/2
bg_color = (0, 0, 0)
grid_color = (100, 100, 255)
circle_color = (255, 255, 0)
disapp_frames = 1

window_center = (window_size[0]/2.0, window_size[1]/2.0)
window_scale = min(window_size)/2.0
def coord(real):
    """takes real coordinates, returns pixel coordinates"""
    return (int(round(real[0]*window_scale + window_center[0])),\
            int(round(-real[1]*window_scale + window_center[1])))

g_cos, g_sin = 1, 0
def set_rotation(angle):
    """sets up rotation"""
    global g_cos, g_sin
    g_cos, g_sin = cos(angle), sin(angle)
def rotate(point):
    """rotates a 3D point about the Z-axis by given angle set by set_rotation()"""
    return (g_cos*point[0] + g_sin*point[1], -g_sin*point[0] + g_cos*point[1])

# graphics initializations
frames, show = 0, True
try:
    pygame.init()
    if full_screen:
        surf = pygame.display.set_mode(window_size, HWSURFACE | FULLSCREEN | DOUBLEBUF)
    else:
        surf = pygame.display.set_mode(window_size)

    t0 = pygame.time.get_ticks()
    while True:
        for event in pygame.event.get():
            if event.type in (QUIT, KEYDOWN): raise Exception()
            elif event.type == MOUSEBUTTONDOWN: frames, show = 0, False
            elif event.type == MOUSEBUTTONUP: frames, show = 0, True

        surf.fill(bg_color)
        t = (pygame.time.get_ticks() - t0)/1000.0
        set_rotation(rotation_speed*t)
        for i in range(-n_grid, +n_grid + 1):
            for j in range(-n_grid, +n_grid + 1):
                center = (grid_spacing*i, grid_spacing*j)
                fr = rotate((center[0] - grid_length, center[1]))
                to = rotate((center[0] + grid_length, center[1]))
                pygame.draw.line(surf, grid_color, coord(fr), coord(to), grid_width)
                fr = rotate((center[0], center[1] - grid_length))
                to = rotate((center[0], center[1] + grid_length))
                pygame.draw.line(surf, grid_color, coord(fr), coord(to), grid_width)
        for circ in circles:
            c = (circle_scale*circ[0], circle_scale*circ[1])
            if show:
                col = (150, 150, 0)
                pygame.draw.circle(surf, col, coord(c), circle_radius, 0)
            else:
                step = 150/disapp_frames
                lev = max(0, 150 - frames*step)
                col = (lev, lev, 0)
                if lev > 0:
                    pygame.draw.circle(surf, col, coord(c), circle_radius, 0)
        pygame.draw.circle(surf, grid_color, coord((0, 0)), fix_radius)
        pygame.display.flip()
        frames += 1
finally: pygame.quit()