Files
snake-python/snakes/engine/spatial.py
T
daniel156161 3a9af3f54d feat(snake): modularize engine and add tournament tools
- Split active strategies, reusable engine code, core classes, and legacy snakes.
- Replace implicit snake imports with explicit module registrations.
- Extract Prism duel, spatial, and survival behavior into focused mixins.
- Improve duel scoring with food races, pressure, caches, and depth metrics.
- Add deterministic arena scenarios and paired seeded engine tournaments.
- Expand benchmark telemetry and bump Prism to version 1.3.0.
- Update documentation and tests for the new package layout and tooling.
2026-08-01 20:25:07 +02:00

217 lines
8.0 KiB
Python

"""Bitboard-backed spatial primitives shared by competitive snakes."""
from __future__ import annotations
from snakes.engine.bitboard import BitBoard
class BitboardSpatialMixin:
def _get_bb(self, width: int, height: int) -> BitBoard:
"""Return (possibly cached) BitBoard for the current dimensions."""
if self._bb is None or width != self._bb_w or height != self._bb_h:
self._bb = BitBoard(width, height)
self._bb_w = width
self._bb_h = height
return self._bb
def _blocked_to_bits(self, blocked: set[tuple[int, int]], width: int, height: int) -> int:
"""Convert blocked cells to bits without stale identity-based caching."""
return self._get_bb(width, height).set_to_bits(blocked)
def _flood_fill_count(self, start: tuple, blocked: set, width: int, height: int) -> int:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
start_idx = bb.idx(start[0], start[1])
# A7/E2: per-turn transposition cache (kept from Apex)
cache_key = (start_idx, blocked_bits, width, height)
cached = self._bfs_cache.get(cache_key)
if cached is not None:
return cached
result = bb.flood_count(start_idx, blocked_bits)
if len(self._bfs_cache) < self._bfs_cache_max:
self._bfs_cache[cache_key] = result
return result
def _territory_fast(
self, my_pos: tuple, blocked: set, width: int, height: int,
deadline: float | None = None,
) -> int:
if not self._enemy_heads:
return 0
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
my_idx = bb.idx(my_pos[0], my_pos[1])
enemy_idxs = [bb.idx(eh[0], eh[1]) for eh in self._enemy_heads]
return bb.territory(my_idx, enemy_idxs, blocked_bits)
def _articulation_penalty(
self, point: tuple, blocked: set, width: int, height: int, required_space: int,
) -> float:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
point_idx = bb.idx(point[0], point[1])
sizes = bb.partition_sizes(point_idx, blocked_bits)
if not sizes:
return 0.0
min_size = min(sizes)
if min_size < required_space:
return 1500.0
elif min_size < required_space * 2:
return 400.0
else:
return 85.0
def _bounded_bfs(self, start: tuple, blocked: set, width: int, height: int, limit: int) -> set:
"""Bitboard-accelerated bounded BFS. Returns a set for API compatibility."""
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
start_idx = bb.idx(start[0], start[1])
reachable_bits = bb.flood_fill(start_idx, blocked_bits)
result: set[tuple[int, int]] = set()
temp = reachable_bits
w = bb.width
while temp:
bit = temp & (-temp)
idx = bit.bit_length() - 1
result.add((idx % w, idx // w))
temp ^= bit
if len(result) >= limit:
break
return result
def _distance_map(self, start: tuple, blocked: set, width: int, height: int) -> dict:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
start_idx = bb.idx(start[0], start[1])
idx_dmap = bb.distance_map(start_idx, blocked_bits)
w = bb.width
return {(idx % w, idx // w): d for idx, d in idx_dmap.items()}
def _path_distance(
self, start: tuple, goal: tuple, blocked: set, width: int, height: int,
) -> int | None:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
return bb.path_distance(
bb.idx(start[0], start[1]),
bb.idx(goal[0], goal[1]),
blocked_bits,
)
def _nearest_food_info(
self, start: tuple, food_set: set, blocked: set, width: int, height: int,
) -> tuple[int | None, tuple | None]:
if not food_set:
return None, None
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
food_bits = bb.set_to_bits(food_set)
start_idx = bb.idx(start[0], start[1])
dist, cell_idx = bb.nearest_food(start_idx, food_bits, blocked_bits)
if dist is None or cell_idx is None:
return None, None
return dist, bb.coord(cell_idx)
def _open_neighbor_count(self, start: tuple, blocked: set, width: int, height: int) -> int:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
return bb.open_neighbor_count(bb.idx(start[0], start[1]), blocked_bits)
def _next_turn_options(self, head: dict, blocked: set, width: int, height: int) -> int:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
return bb.open_neighbor_count(bb.idx(head["x"], head["y"]), blocked_bits)
def _legal_moves(
self, my_head, my_body: list, other_snakes: list,
food_set: set, is_constrictor: bool, width: int, height: int,
enemy_can_grow: dict | None = None,
):
"""S10: Bitboard-accelerated legal move generation."""
bb = self._get_bb(width, height)
w = bb.width
# Build occupied bitboard
occupied = 0
for seg in my_body:
occupied |= 1 << (seg["y"] * w + seg["x"])
for snake in other_snakes:
for seg in snake["body"]:
occupied |= 1 << (seg["y"] * w + seg["x"])
hx, hy = my_head["x"], my_head["y"]
head_idx = hy * w + hx
# Own tail can be stepped on
passable = 0
if not is_constrictor and len(my_body) >= 2:
t, t2 = my_body[-1], my_body[-2]
if not (t["x"] == t2["x"] and t["y"] == t2["y"]):
passable |= 1 << (t["y"] * w + t["x"])
# Enemy tails that will vacate
if not is_constrictor:
for snake in other_snakes:
sbody = snake["body"]
if len(sbody) < 2:
continue
st, st2 = sbody[-1], sbody[-2]
if st["x"] == st2["x"] and st["y"] == st2["y"]:
continue # stacked
sid = snake.get("id")
can_grow = None
if enemy_can_grow is not None and sid is not None:
can_grow = enemy_can_grow.get(sid)
if can_grow is None:
can_grow = self._enemy_can_grow_this_turn(snake, food_set)
if not can_grow:
passable |= 1 << (st["y"] * w + st["x"])
legal = bb._neighbor_masks[head_idx] & ((~occupied & bb.board_mask) | passable)
safe: dict[str, dict[str, int]] = {}
for name, (dx, dy) in self.DIRECTIONS.items():
nx, ny = hx + dx, hy + dy
if 0 <= nx < w and 0 <= ny < bb.height:
if (1 << (ny * w + nx)) & legal:
safe[name] = {"x": nx, "y": ny}
return safe
def _enemy_confinement_metrics(
self, enemy_head: tuple, blocked: set, width: int, height: int,
) -> tuple[int, int]:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
eh_idx = bb.idx(enemy_head[0], enemy_head[1])
eb_bits = blocked_bits & ~(1 << eh_idx)
space = bb.flood_count(eh_idx, eb_bits)
options = bb.open_neighbor_count(eh_idx, eb_bits)
return space, options
def _enemy_constrictor_projection(
self, other_snakes: list, blocked: set, width: int, height: int,
) -> tuple[int, int]:
bb = self._get_bb(width, height)
blocked_bits = self._blocked_to_bits(blocked, width, height)
best_space = 0
total_opts = 0
for enemy in other_snakes:
eh = (enemy["head"]["x"], enemy["head"]["y"])
eh_idx = bb.idx(eh[0], eh[1])
nb = bb.neighbors_of(eh_idx) & ~blocked_bits & bb.board_mask
temp = nb
while temp:
total_opts += 1
bit = temp & (-temp)
n_idx = bit.bit_length() - 1
sp = bb.flood_count(n_idx, blocked_bits | bit)
if sp > best_space:
best_space = sp
temp ^= bit
return best_space, total_opts