lines_1.py

#!/usr/bin/env python3
# 2021-10-09
# Emilien & Nicolas Seriot 
# https://seriot.ch/visualization/lines_1.png

import cairo
import random

WIDTH = 800
HEIGHT = 600
MARGIN = 20
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, WIDTH, HEIGHT)
c = cairo.Context(surface)

c.set_source_rgb(0.85,0.85,0.85)
c.paint()

c.set_line_width(2)

c.set_line_join(cairo.LINE_JOIN_ROUND)
c.set_line_cap(cairo.LINE_CAP_ROUND)

x = WIDTH / 2
y = HEIGHT / 2

for i in range(400):

    c.move_to(x, y)

    n = random.randint(0,3)
    l = random.choice([20, 50, 100])
    
    if n == 0:
        x = x + l
    elif n == 1:
        y = y + l
    elif n == 2:
        y = y - l
    elif n == 3:
        x = x - l
    
    x = max(min(WIDTH - MARGIN, x), MARGIN)
    y = max(min(HEIGHT - MARGIN, y), MARGIN)

    c.set_source_rgb(0,0,0)
    c.line_to(x, y)
    c.stroke()

surface.write_to_png("lines_1.png")