Is there s state flag allowed to be raised as high as the USA flag?

I was told recently that when Texas entered the union, one of the conditions was that their state flag would be flown equal to the USA flag. Our state flag is flown about 1 foot lower, and I have seen other states do the same, but haven't been to Texas. Can someone let me know if this is true, or this Texan is just making this up! Thanx