truchet_simple.py

# !/usr/bin/env python3
# Nicolas Seriot
# 2022-06-10
# https://seriot.ch/visualization/truchet_simple.png

import cairo
import math
import random

NB_COLS = 8
NB_ROWS = 8

W = 32

GRID = True

surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, W*NB_COLS, W*NB_ROWS)
c = cairo.Context(surface)

c.set_source_rgb(1,1,1)
c.paint()

c.set_source_rgb(0,0,0)

for col in range(NB_COLS):
    for row in range(NB_ROWS):

        c.save()
        
        c.translate(col*W, row*W)
        
        # rotate if needed
        if random.choice([True, False]):
            c.translate(W, 0)
            c.rotate(math.pi/2.0)
        
        # draw two arc quarters
        for o, a in [(0, 0), (W, math.pi)]:
            c.arc(o, o, W/2.0, a, a+math.pi/2.0)
            c.stroke()
            
        c.restore()
        
        if GRID:
            c.rectangle(col*W, row*W, W, W)
            c.stroke()
        
surface.write_to_png("truchet_simple.png")