Ellipse¶
This demo shows a dynamic grid of ellipses whose horizontal and vertical dimensions are continuously swapped over time.
The class Canva subclasses anim.plane.canva and updates each ellipse in update using np.cos(t.step/20)
so alternating cells animate in opposite deformation directions.
Full Code¶
1'''
22D ellipse demo
3'''
4
5import numpy as np
6import anim
7
8# ═══ 2D Animation canva ═══════════════════════════════════════════════════
9
10class Canva(anim.plane.canva):
11
12 # ────────────────────────────────────────────────────────────────────────
13 def __init__(self, window, **kwargs):
14
15 super().__init__(window,
16 boundaries = [[0, 1],[0,1]],
17 display_boundaries = True,
18 **kwargs)
19
20 # Number of ellipse per axis
21 self.a = 10
22
23 # Mesh size
24 self.b = 1/(self.a-1)
25
26 for i in range(self.a):
27 for j in range(self.a):
28
29 self.item[f'ellipse_{i}_{j}'] = anim.plane.ellipse(
30 position = [i*self.b, j*self.b],
31 dimension = [0,0],
32 color = 'cyan' if (i+j)%2 else 'blue'
33 )
34
35 # ────────────────────────────────────────────────────────────────────────
36 def update(self, t):
37
38 for i in range(self.a):
39 for j in range(self.a):
40
41 L = self.b*(1 + np.cos(t.step/20)/2)
42 self.item[f'ellipse_{i}_{j}'].dimension = [L, 2*self.b-L] if (i+j)%2 else [2*self.b-L, L]
43
44 # Confirm update
45 super().update(t)
46
47# ═══ Main ═════════════════════════════════════════════════════════════════
48
49W = anim.window('Ellipse animation')
50
51# Add animation
52W.add(Canva)
53
54# Allow backward animation
55W.allow_backward = True
56W.allow_negative_time = True
57
58W.show()