ligo-comprehensive/scripts/sb.py

#!/usr/bin/env python3
from PIL import Image
from math import sin, pi


def main():
    bg = Image.open('../figures/bead_bg.png')
    left = Image.open('../figures/bead_left.png')
    right = Image.open('../figures/bead_right.png')

    size_x, size_y = bg.size

    n = 50
    def combine(t):
        A = 20
        w = 2*2*pi/n
        offset = int(A*sin(w*t))

        left_c = left.copy()
        right_c = right.copy()

        left_c.paste(left, box=(offset, 0))
        right_c.paste(right, box=(-offset, 0))

        left_mask = left_c.split()[0].point(lambda i: i != 0 and 255)
        right_mask = right_c.split()[0].point(lambda i: i != 0 and 255)

        bg_copy = bg.copy()
        bg_copy.paste(left_c, mask=left_mask)
        bg_copy.paste(right_c, mask=right_mask)

        # bg_copy.show()
        return bg_copy

    frames = [combine(i) for i in range(n)]

    frames[0].save('res.gif', save_all=True, append_images=frames[1:], duration=int(1000/30), loop=10)


if __name__ == '__main__':
    main()