IsWalkable function

function isWalkable(pos, creature, proj, pz)-- by Nord
    if getTileThingByPos({x = pos.x, y = pos.y, z = pos.z, stackpos = 0}).itemid == 0 then return false end
    if getTopCreature(pos).uid > 0 and creature then return false end
    if getTileInfo(pos).protection and pz then return false, true end
    local n = not proj and 3 or 2
    for i = 0, 255 do
        pos.stackpos = i
        local tile = getTileThingByPos(pos)
        if tile.itemid ~= 0 and not isCreature(tile.uid) then
            if hasProperty(tile.uid, n) or hasProperty(tile.uid, 7) then
                return false
            end
        end
    end
    return true
end