def on(grid: Grid) -> Grid:
unvisited = []
for cell in grid.each_cell():
unvisited.append(cell)
first_cell = choice(unvisited)
unvisited.remove(first_cell)
while len(unvisited) > 0:
# start a walk
cell = choice(unvisited)
path = [cell]
while cell in unvisited:
cell = choice(cell.neighbors)
try:
position = path.index(cell)
# already walked, perform loop-erase. e.g. A -> B -> C -> D -> B becomes A -> B
path = path[:position + 1]
except ValueError:
path.append(cell)
# Passage carving once has found a valid path
for index in range(len(path) - 1):
path[index].link(path[index + 1])
unvisited.remove(path[index])
return grid
def _render(grid: Grid, cell_size: int = 4, coloring: bool = False) -> Image:
wall_color = (0, 0, 0)
image_width = cell_size * grid.columns
image_height = cell_size * grid.rows
image = Image.new("RGBA", (image_width + 1, image_height + 1), (255, 255, 255))
draw = ImageDraw.Draw(image)
for draw_pass in range(2):
for cell in grid.each_cell():
x1 = cell.column * cell_size
y1 = cell.row * cell_size
x2 = (cell.column + 1) * cell_size
y2 = (cell.row + 1) * cell_size
if draw_pass == STEP_BACKGROUND and coloring:
if coloring:
color = cast(ColoredGrid, grid).background_color_for(cell)
else:
color = (255, 255, 255)
draw.rectangle((x1, y1, x2, y2), fill=color)
else:
if not cell.north:
draw.line((x1, y1, x2, y1), fill=wall_color, width=1)
if not cell.west:
draw.line((x1, y1, x1, y2), fill=wall_color, width=1)
if not cell.linked_to(cell.east):
draw.line((x2, y1, x2, y2), fill=wall_color, width=1)
if not cell.linked_to(cell.south):
draw.line((x1, y2, x2, y2), fill=wall_color, width=1)
return image
def on(grid: Grid) -> Grid:
for cell in grid.each_cell():
neighbors = []
if cell.north:
neighbors.append(cell.north)
if cell.east:
neighbors.append(cell.east)
if len(neighbors) > 0:
cell.link(choice(neighbors))
return grid
def on(self, grid: Grid) -> None:
for cell in grid.each_cell():
neighbors = []
if cell.north:
neighbors.append(cell.north)
if cell.east:
neighbors.append(cell.east)
if len(neighbors) > 0:
neighbor = choice(neighbors)
cell += neighbor
def on(self, grid: Grid) -> None:
current_cell: Optional[Cell] = grid.random_cell()
while current_cell is not None:
unvisited_neighbors = [neighbor for neighbor in current_cell.neighbors if len(neighbor.links) == 0]
if len(unvisited_neighbors) > 0:
# as int as there are unvisited paths, walk them
neighbor = choice(unvisited_neighbors)
current_cell += neighbor
current_cell = neighbor
else:
# enter hunt mode, find first unvisited cell near any visited cell
current_cell = None
for cell in grid.each_cell():
visited_neighbors = [neighbor for neighbor in cell.neighbors if len(neighbor.links) > 0]
if len(cell.links) == 0 and len(visited_neighbors) > 0:
current_cell = cast(Cell, cell) # outside of Mypy it's a mere assignment
neighbor = choice(visited_neighbors)
current_cell += neighbor
break
def on(grid: Grid) -> Grid:
current_cell = grid.random_cell() # type: Optional[Cell]
while current_cell is not None:
unvisited_neighbors = \
[neighbor for neighbor in current_cell.neighbors if len(neighbor.links) == 0]
if len(unvisited_neighbors) > 0:
# as long as there are unvisited paths, walk them
neighbor = choice(unvisited_neighbors)
current_cell.link(neighbor)
current_cell = neighbor
else:
# enter hunt mode, find first unvisited cell near any visited cell
current_cell = None
for cell in grid.each_cell():
visited_neighbors = [neighbor for neighbor in cell.neighbors if len(neighbor.links) > 0]
if len(cell.links) == 0 and len(visited_neighbors) > 0:
current_cell = cast(Cell, cell)
neighbor = choice(visited_neighbors)
current_cell.link(neighbor)
break
return grid
