squirrel-battle/squirrelbattle/mapgeneration/randomwalk.py

118 lines
3.9 KiB
Python

# Copyright (C) 2020 by ÿnérant, eichhornchen, nicomarg, charlse
# SPDX-License-Identifier: GPL-3.0-or-later
from enum import auto, Enum
from random import choice, random, randint
from typing import Tuple
from ..interfaces import Map, Tile
DEFAULT_PARAMS = {
"split_chance": .15,
"turn_chance": .5,
"death_chance": .1,
"max_walkers": 15,
"width": 100,
"height": 100,
"fill": .4,
"no_lone_walls": False,
}
class Directions(Enum):
up = auto()
down = auto()
left = auto()
right = auto()
class Walker:
def __init__(self, x: int, y: int):
self.x = x
self.y = y
self.dir = choice(list(Directions))
def random_turn(self) -> None:
self.dir = choice(list(Directions))
def next_pos(self) -> Tuple[int, int]:
if self.dir == Directions.up:
return self.x, self.y + 1
elif self.dir == Directions.down:
return self.x, self.y - 1
elif self.dir == Directions.right:
return self.x + 1, self.y
elif self.dir == Directions.left:
return self.x - 1, self.y
def move_in_bounds(self, width: int, height: int) -> None:
nx, ny = self.next_pos()
if 0 < nx < width and 0 < ny < height:
self.x, self.y = nx, ny
def split(self) -> "Walker":
child = Walker(self.x, self.y)
child.dir = self.dir
return child
class Generator:
def __init__(self, params: dict = None):
if params is None:
params = DEFAULT_PARAMS
self.params = params
def run(self) -> Map:
width, height = self.params["width"], self.params["height"]
walkers = [Walker(width // 2, height // 2)]
grid = [[Tile.EMPTY for _ in range(width)] for _ in range(height)]
count = 0
while count < self.params["fill"] * width * height:
# because we can't add or remove walkers while looping over the pop
# we need lists to keep track of what will be the walkers for the
# next iteration of the main loop
next_walker_pop = []
for walker in walkers:
if grid[walker.y][walker.x] == Tile.EMPTY:
count += 1
grid[walker.y][walker.x] = Tile.FLOOR
if random() < self.params["turn_chance"]:
walker.random_turn()
walker.move_in_bounds(width, height)
if random() > self.params["death_chance"]:
next_walker_pop.append(walker)
# we make sure to never kill all walkers
if not next_walker_pop:
next_walker_pop.append(choice(walkers))
# we use a second loop for spliting so we're not bothered by cases
# like a walker not spliting because we hit the population cap even
# though the next one would have died and freed a place
# not a big if it happened though
for walker in walkers:
if len(next_walker_pop) < self.params["max_walkers"]:
if random() < self.params["split_chance"]:
next_walker_pop.append(walker.split())
walkers = next_walker_pop
start_x, start_y = randint(0, width - 1), randint(0, height - 1)
while grid[start_y][start_x] != Tile.FLOOR:
start_x, start_y = randint(0, width - 1), randint(0, height - 1)
result = Map(width, height, grid, start_y, start_x)
# post-processing: add walls
for x in range(width):
for y in range(height):
if grid[y][x] == Tile.EMPTY:
c = sum([1 if grid[j][i] == Tile.FLOOR else 0 for j, i in result.neighbourhood(y, x, large=True)])
if c == 4 and self.params["no_lone_walls"]:
result.tiles[y][x] = Tile.FLOOR
elif c > 0:
result.tiles[y][x] = Tile.WALL
return result