Function UpdateVehicleTileHash

src/vehicle.cpp:592–621

}

static void UpdateVehicleTileHash(Vehicle *v, bool remove)
{
	Vehicle **old_hash = v->hash_tile_current;
	Vehicle **new_hash;

	if (remove) {
		new_hash = nullptr;
	} else {
		new_hash = &_vehicle_tile_hash[GetTileHash(TileX(v->tile), TileY(v->tile))];
	}

	if (old_hash == new_hash) return;

	/* Remove from the old position in the hash table */
	if (old_hash != nullptr) {
		if (v->hash_tile_next != nullptr) v->hash_tile_next->hash_tile_prev = v->hash_tile_prev;
		*v->hash_tile_prev = v->hash_tile_next;
	}

	/* Insert vehicle at beginning of the new position in the hash table */
	if (new_hash != nullptr) {
		v->hash_tile_next = *new_hash;
		if (v->hash_tile_next != nullptr) v->hash_tile_next->hash_tile_prev = &v->hash_tile_next;
		v->hash_tile_prev = new_hash;
		*new_hash = v;
	}

	/* Remember current hash position */
	v->hash_tile_current = new_hash;
}

static std::array<Vehicle *, 1 << (GEN_HASHX_BITS + GEN_HASHY_BITS)> _vehicle_viewport_hash{};