truchet_2.py

# !/usr/bin/env python3
# Nicolas Seriot
# 2022-06-14
# https://seriot.ch/visualization/truchet_2.png
# loosely inspired by https://www.fxhash.xyz/gentk/slug/dirty-interlaced-truchet-tiles-18

import cairo
import math
import random

NB_COLS = 16
NB_ROWS = 16

W = 32

GRID = False

BKG = (241/255., 196./255., 89/255.)
EXT = (169/255., 89/255, 55/255.)
INT = BKG

W_L = 14
W_M = 8
W_S = 4

def draw_arcs(c, rotate):

    c.save()
    
    if rotate:
        c.translate(W, 0)
        c.rotate(math.pi/2.)

    for o, a in [(0, 0), (W, math.pi)]:
        for (width, color) in [(W_L, EXT), (W_M, INT), (W_S, EXT)]:
                               
            c.set_line_width(width)
            c.set_source_rgb(*color)
    
            c.arc(o, o, W/2., a, a+math.pi/2.)
            c.stroke()
        
    c.restore()    

def draw_bridge(c, rotate):

    c.save()
        
    if rotate:
        c.translate(W, 0)
        c.rotate(math.pi/2.0)
    
    for (x1, y1, x2, y2) in [(W/2., 0, W/2., W), (0, W/2., W, W/2.)]:
        for (width, color) in [(W_L, EXT), (W_M, INT), (W_S, EXT)]:
        
            c.set_line_width(width)
            c.set_source_rgb(*color)
        
            c.move_to(x1, y1)
            c.line_to(x2, y2)
            c.stroke()
    
    c.restore()    

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

c.set_source_rgb(*BKG)
c.paint()

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

        c.save()
        
        c.translate(col*W, row*W)

        arcs_else_bridge = random.choice([True, False])
        rotate = random.choice([True, False])
        
        if arcs_else_bridge:
            draw_arcs(c, rotate)
        else:
            draw_bridge(c, rotate)
            
        c.restore()
        
        if GRID:
            c.rectangle(col*W, row*W, W, W)
            c.stroke()
        
surface.write_to_png("truchet_2.png")