Method _move_backward

src/engine/engine.cpp:609–731

			_ctx.game->state->set_player_prev_depth(
				_ctx.game->state->get_depth());
			_ctx.game->state->set_depth(to_level);
			_set_tile_explored(_ctx.game->state->get_player_pos());

			_ctx.controller->unset_flag("want_take_stairs_down");
		}
	}

	_ctx.controller->unset_flag("want_take_stairs_up");
}

auto Sorcery::Engine::_move_backward() -> bool {

	// Work out our new position
	auto at_loc{_ctx.game->state->get_player_pos()};
	auto x_d{at_loc.x};
	auto y_d{at_loc.y};

	switch (_ctx.game->state->get_player_facing()) {
		using enum Enums::Map::Direction;
	case NORTH:
		--y_d;
		break;
	case SOUTH:
		++y_d;
		break;
	case EAST:
		--x_d;
		break;
	case WEST:
		++x_d;
		break;
	default:
		break;
	}

	if (x_d < 0)
		x_d = MAP_SIZE - 1;
	else if (x_d > MAP_SIZE - 1)
		x_d = 0;
	if (y_d < 0)
		y_d = MAP_SIZE - 1;
	else if (y_d > MAP_SIZE - 1)
		y_d = 0;

	const auto next_loc{Coordinate{x_d, y_d}};

	// Check for walls etc between current square and new square
	auto this_tile{_ctx.game->state->level->at(at_loc)};
	const auto &next_tile{_ctx.game->state->level->at(next_loc)};

	auto this_wall_to_check{Enums::Map::Direction::NO_DIRECTION};
	switch (_ctx.game->state->get_player_facing()) {
		using enum Enums::Map::Direction;
	case NORTH:
		this_wall_to_check = SOUTH;
		break;
	case SOUTH:
		this_wall_to_check = NORTH;