1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
| import Tkinter as tk
import time
DEBUG = True
def debug(s):
if DEBUG: print(s)
COUNT = 4
Y_MAX = X_MAX = 400
RADIUS = 20
DELAY = 20
centers = [ (50, 50), (300, 50), (50, 300), (300, 300), ]
deltas = [ (10, 10) ] * COUNT
colors = ['red','blue','green','yellow' ]
idents = [ 0 ] * COUNT
timer = None
def check_wall_collision(v, du, MIN, MAX):
dv = du
if not (MIN <= v <= MAX):
if v < MIN:
b = MIN
else:
b = MAX
v = 2 * b - v
dv = -du
return v, dv
last_move = time.clock()
def move():
global timer, last_move
for i in range(COUNT):
x0, y0 = centers[i]
dx, dy = deltas[i]
x1, dx = check_wall_collision(x0 + dx, dx, RADIUS, X_MAX - RADIUS)
y1, dy = check_wall_collision(y0 + dy, dy, RADIUS, Y_MAX - RADIUS)
assert RADIUS <= x1 <= X_MAX - RADIUS, 'fatal: x1 out of range: (%d, %d)' % (x0, x1)
assert RADIUS <= y1 <= Y_MAX - RADIUS, 'fatal: y1 out of range: (%d, %d)' % (y0, y1)
iid = idents[i]
canvas.move(iid, x1-x0, y1-y0)
centers[i] = x1, y1
deltas[i] = dx, dy
now = time.clock()
debug('delta: %.3f' % (now - last_move))
last_move = now
timer = app.after(DELAY, move)
def do_start():
if timer is None:
move()
def do_stop():
global timer
if timer is not None:
app.after_cancel(timer)
timer = None
if __name__ == '__main__':
app = tk.Tk()
canvas = tk.Canvas(width=X_MAX,height=Y_MAX,bg='dark grey')
canvas.grid(row=1,column=1,rowspan=3)
for i in range(COUNT):
cx, cy = centers[i]
color = colors[i]
coords = (cx - RADIUS, cy - RADIUS,
cx + RADIUS, cy + RADIUS,)
idents[i] = canvas.create_oval(coords, fill=color)
tk.Button(text='Go!',command=do_start).grid(row=1,column=2)
tk.Button(text='Stop!',command=do_stop).grid(row=2,column=2)
tk.Button(text='Quitter',command=app.quit).grid(row=3,column=2)
tk.mainloop() |
