function Canal::_GetUsedTiles(from, to, is_aqueduct)
{
	local used_list = AIList();
	local offset = AIMap.GetTileX(from) == AIMap.GetTileX(to) ? this._map_size_x : 1;

	local dir;
	if (offset == 1) {
		dir = 1; // Axis X
	} else if (offset == this._map_size_x) {
		dir = 2; // Axis Y
	}

	local ramp = 4;
	local head = 8;

	local complement = is_aqueduct ? head : (head | ramp);
	used_list.AddItem(from, dir | complement);
	used_list.AddItem(to, dir | complement);

	if (from > to) {
		local swap = from;
		from = to;
		to = swap;
	}

	if (is_aqueduct) {
		complement = ramp;
	}
	local tile_offset = from + offset;
	while (tile_offset != to) {
		used_list.AddItem(tile_offset, dir | complement);
		tile_offset += offset;
	}

	return used_list;
}