Rectangle¶
This demo presents the rectangle scene in 2D and shows how the animation state evolves over time with lib-anim. The script defines a canva, adds the corresponding items, and updates them frame by frame to produce the final motion.
Full Code¶
1'''
22D rectangle demo
3'''
4
5import numpy as np
6import matplotlib as mpl
7import anim
8
9# ═══ 2D Animation canva ═══════════════════════════════════════════════════
10
11class Canva(anim.plane.canva):
12
13 # ────────────────────────────────────────────────────────────────────────
14 def __init__(self, window):
15
16 super().__init__(window)
17
18 self.item.rect_0 = anim.plane.rectangle(
19 position = [0.5, 0.5],
20 dimension = [0, 0]
21 )
22
23 self.colormap = mpl.colormaps['hsv'].resampled(100)
24
25 # ────────────────────────────────────────────────────────────────────────
26 def update(self, t):
27
28 # Geometry
29 self.item.rect_0.Lx = (np.sin(t.step/10) + 1)*0.3 + 0.2
30 self.item.rect_0.Ly = (np.cos(t.step/23) + 1)*0.2 + 0.3
31 self.item.rect_0.orientation = t.step/40
32
33 # Color
34 self.item.rect_0.color = self.colormap(t.step % self.colormap.N)
35
36 # Confirm update
37 super().update(t)
38
39# ═══ Main ═════════════════════════════════════════════════════════════════
40
41W = anim.window('2D rectangle demo')
42
43# Add animation
44W.add(Canva)
45
46# Allow backward animation
47W.allow_backward = True
48W.allow_negative_time = True
49
50# Display
51W.show()