def on(self, grid: Grid) -> None:
unvisited = []
for cell in grid.eachCell():
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 = cell.randomNeighbour() # type: ignore
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)
self.step()
# Passage carving once has found a valid path
for index in range(len(path) - 1):
path[index] += (path[index + 1])
unvisited.remove(path[index])
self.step()
def _prepareLogGrid(self, grid: Grid) -> None:
''' Prepare the grid for logging the algorithm '''
if not self.log: return
# 'visit' : List of steps on which the cell was visited
# 'links' : Directions of the links made by the cell (NOT to the cell)
data = {'visit': [], 'links': []} # type: Dict
key = self.name # type: str
for cell in grid.eachCell():
cell.data[key] = data
def on(self, grid: Grid) -> Grid:
grid_type = type(grid)
# row i becomes col n-i when rotating 90 degrees clockwise
rotated_grid = grid_type(rows=grid.cols, cols=grid.rows)
for old_cell in grid.eachCell():
row, column = self._rotated_coordinates(old_cell, rotated_grid)
new_cell = rotated_grid[row, column]
if new_cell is None:
raise IndexError('Cell not found at row {} column {}'.format(
row, column))
self._rotate_cell_neighbors(new_cell, old_cell, rotated_grid)
return rotated_grid
def on(self, grid: Grid) -> None:
self._prepareLogGrid(grid)
for cell in grid.eachCell():
self._logVisit(cell)
neighbours = []
if cell.north: neighbours.append(cell.north)
if cell.east: neighbours.append(cell.east)
if len(neighbours) > 0:
neighbour = choice(neighbours)
cell += neighbour
self._logLink(cell, neighbour)
self.step()
def _render(grid: Grid, cell_size: int=4, coloring: bool=False) -> Image:
''' Rendering core '''
wall_color = (0, 0, 0)
image = Image.new('RGBA', (cell_size * grid.cols + 1, cell_size * grid.rows + 1), (255, 255, 255))
draw = ImageDraw.Draw(image)
for draw_pass in range(2):
for cell in grid.eachCell():
x1 = cell.col * cell_size
y1 = cell.row * cell_size
x2 = (cell.col + 1) * cell_size
y2 = (cell.row + 1) * cell_size
if draw_pass == 0:
color = grid.color(cell) if coloring else (255, 255, 255) # type: ignore
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 & cell.east: draw.line((x2, y1, x2, y2), fill=wall_color, width=1)
if not cell & cell.south: draw.line((x1, y2, x2, y2), fill=wall_color, width=1)
return image