New pathfinding that avoids most of the mobs getting stuck, closes #35

This commit is contained in:
Nicolas Margulies 2020-12-10 22:21:09 +01:00
parent 50d806cdcf
commit cc6033e8e4
3 changed files with 74 additions and 48 deletions

View File

@ -3,7 +3,6 @@
from squirrelbattle.interfaces import Map
from .display import Display
from squirrelbattle.entities.player import Player
class MapDisplay(Display):
@ -23,24 +22,27 @@ class MapDisplay(Display):
for e in self.map.entities:
self.addstr(self.pad, e.y, self.pack.tile_width * e.x,
self.pack[e.name.upper()], self.color_pair(2))
players = [ p for p in self.map.entities if isinstance(p,Player) ]
player = players[0] if len(players) > 0 else None
if player:
for x in range(self.map.width):
for y in range(self.map.height):
if (y,x) in player.paths:
deltay, deltax = (y - player.paths[(y, x)][0],
x - player.paths[(y, x)][1])
if (deltay, deltax) == (-1, 0):
character = ''
elif (deltay, deltax) == (1, 0):
character = ''
elif (deltay, deltax) == (0, -1):
character = ''
else:
character = ''
self.addstr(self.pad, y, self.pack.tile_width * x,
character, self.color_pair(1))
# Display Path map for deubg purposes
# from squirrelbattle.entities.player import Player
# players = [ p for p in self.map.entities if isinstance(p,Player) ]
# player = players[0] if len(players) > 0 else None
# if player:
# for x in range(self.map.width):
# for y in range(self.map.height):
# if (y,x) in player.paths:
# deltay, deltax = (y - player.paths[(y, x)][0],
# x - player.paths[(y, x)][1])
# if (deltay, deltax) == (-1, 0):
# character = '↓'
# elif (deltay, deltax) == (1, 0):
# character = '↑'
# elif (deltay, deltax) == (0, -1):
# character = '→'
# else:
# character = '←'
# self.addstr(self.pad, y, self.pack.tile_width * x,
# character, self.color_pair(1))
def display(self) -> None:
y, x = self.map.currenty, self.pack.tile_width * self.map.currentx

View File

@ -43,11 +43,14 @@ class Monster(FightingEntity):
# If they can't move and they are already close to the player,
# They hit.
if target and (self.y, self.x) in target.paths:
# Move to target player
next_y, next_x = target.paths[(self.y, self.x)]
moved = self.check_move(next_y, next_x, True)
if not moved and self.distance_squared(target) <= 1:
self.map.logs.add_message(self.hit(target))
# Move to target player by choosing the best avaliable path
for next_y, next_x in target.paths[(self.y, self.x)]:
moved = self.check_move(next_y, next_x, True)
if moved:
break
if self.distance_squared(target) <= 1:
self.map.logs.add_message(self.hit(target))
break
else:
# Move in a random direction
# If the direction is not available, try another one

View File

@ -1,9 +1,10 @@
# Copyright (C) 2020 by ÿnérant, eichhornchen, nicomarg, charlse
# SPDX-License-Identifier: GPL-3.0-or-later
from functools import reduce
from queue import PriorityQueue
from random import randint
from typing import Dict, Tuple
from queue import PriorityQueue
from ..interfaces import FightingEntity
@ -93,32 +94,52 @@ class Player(FightingEntity):
def recalculate_paths(self, max_distance: int = 8) -> None:
"""
Use Dijkstra algorithm to calculate best paths
for monsters to go to the player.
Use Dijkstra algorithm to calculate best paths for monsters to go to
the player. Actually, the paths are computed for each tile adjacent to
the player then for each step the monsters use the best path avaliable.
"""
queue = PriorityQueue()
queue.put((0, (self.y, self.x)))
visited = []
distances = {(self.y, self.x): 0}
predecessors = {}
while not queue.empty():
dist, (y, x) = queue.get()
if dist >= max_distance or (y,x) in visited:
distances = []
predecessors = []
# four Dijkstras, one for each adjacent tile
for dir_y, dir_x in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
queue = PriorityQueue()
new_y, new_x = self.y + dir_y, self.x + dir_x
if not 0 <= new_y < self.map.height or \
not 0 <= new_x < self.map.width or \
not self.map.tiles[new_y][new_x].can_walk():
continue
visited.append((y, x))
for diff_y, diff_x in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
new_y, new_x = y + diff_y, x + diff_x
if not 0 <= new_y < self.map.height or \
not 0 <= new_x < self.map.width or \
not self.map.tiles[new_y][new_x].can_walk():
queue.put(((1, 0), (new_y, new_x)))
visited = [(self.y, self.x)]
distances.append({(self.y, self.x): (0, 0), (new_y, new_x): (1, 0)})
predecessors.append({(new_y, new_x): (self.y, self.x)})
while not queue.empty():
dist, (y, x) = queue.get()
if dist[0] >= max_distance or (y, x) in visited:
continue
new_distance = dist + 1
if not (new_y, new_x) in distances or \
distances[(new_y, new_x)] > new_distance:
predecessors[(new_y, new_x)] = (y, x)
distances[(new_y, new_x)] = new_distance
queue.put((new_distance, (new_y, new_x)))
self.paths = predecessors
visited.append((y, x))
for diff_y, diff_x in [(1, 0), (-1, 0), (0, 1), (0, -1)]:
new_y, new_x = y + diff_y, x + diff_x
if not 0 <= new_y < self.map.height or \
not 0 <= new_x < self.map.width or \
not self.map.tiles[new_y][new_x].can_walk():
continue
new_distance = (dist[0] + 1,
dist[1] + (not self.map.is_free(y, x)))
if not (new_y, new_x) in distances[-1] or \
distances[-1][(new_y, new_x)] > new_distance:
predecessors[-1][(new_y, new_x)] = (y, x)
distances[-1][(new_y, new_x)] = new_distance
queue.put((new_distance, (new_y, new_x)))
# For each tile that is reached by at least one Dijkstra, sort the
# different paths by distance to the player. For the technical bits :
# The reduce function is a fold starting on the first element of the
# iterable, and we associate the points to their distance, sort
# along the distance, then only keep the points.
self.paths = {}
for y, x in reduce(set.union, [set(p.keys()) for p in predecessors]):
self.paths[(y, x)] = [p for d, p in sorted(
[(distances[i][(y, x)], predecessors[i][(y, x)])
for i in range(len(distances)) if (y, x) in predecessors[i]])]
def save_state(self) -> dict:
"""