This **is not a solution to the question**. But I thought you all might enjoy seeing another nice Truchet example.

```
# Translated to Processing Python mode from the Java example at
# "Processing: Creative Coding and Generative Art in Processing 2" by Ira Greenberg, Dianna Xu, Deepak Kumar
from random import choice
tile_size = 50
rows = 50
cols = 50
tiles = [[None] * rows for _ in range(cols)]
ic = color(100, 125, 0) # orange # ic = color(100, 125, 0)
oc = color(20, 150, 255) # blue # oc = color(20, 150, 255)
def setup():
size(1000, 1000)
smooth()
for i in range(rows):
for j in range(cols):
tiles[i][j] = Tile(j * tile_size, i * tile_size, tile_size, ic, oc)
color_swap(i, j)
tiles[i][j].display()
def color_swap(i, j):
if i > 0 and j == 0: # first tile of a row, starting from the 2nd row
# same orientation as tile directly above
if tiles[i-1][0].orientation == tiles[i][0].orientation:
# set to opposite coloring of my neighbor above
tiles[i][0].swapped_colors = not tiles[i-1][0].swapped_colors
else:
# set to same coloring of my neighbor above
tiles[i][0].swapped_colors = tiles[i-1][0].swapped_colors
if j > 0: # subsequent tiles in a row, including the first
# same orientation as tile to the left
if tiles[i][j-1].orientation == tiles[i][j].orientation:
# set to opposite coloring of my neighbor to the left
tiles[i][j].swapped_colors = not tiles[i][j-1].swapped_colors
else:
# set to same coloring of my neighbor to the left
tiles[i][j].swapped_colors = tiles[i][j-1].swapped_colors
class Tile:
def __init__(self, x, y, w, ic, oc):
self.x, self.y = x, y # x, y coords of top left corner of tile
self.sz = w # size of tile
self.ic = ic # inside – fill of arc if swapColor is False
# outside – fill of background square if swapColor is False
self.oc = oc
self.orientation = choice((0, 1)) # orientation of tile
# whether we should swap inside and outside colors
self.swapped_colors = False
def display(self):
pushMatrix()
# move to tile's x-y location (upper left corner)
translate(self.x, self.y)
noStroke()
if (self.swapped_colors):
fill(self.ic)
else:
fill(self.oc)
rect(0, 0, self.sz, self.sz) # draw background square
translate(self.sz / 2, self.sz / 2) # move to the center of the tile
rotate(self.orientation * PI / 2) # rotate by the appropriate angle
translate(-self.sz / 2, -self.sz / 2) # back to the upper left corner
stroke(255)
strokeWeight(3)
if self.swapped_colors:
fill(self.oc)
else:
fill(self.ic)
arc(0, 0, self.sz, self.sz, 0, PI / 2)
arc(self.sz, self.sz, self.sz, self.sz, PI, 3 * PI / 2)
popMatrix()
```