Texas state residency question?

OK, so i want to go to a texas university and i live in missouri. I want to go live in texas for a year so i can get residency. The problem is i was claimed as a dependent by my parents this year when they filled taxes and i am now a resident of missouri. I want to claim myself next year, while i live in texas but how long after i claim myself will i have to live in texas to be a resident there? I need to be a resident to qualify for my father's hazelwood act. I checked the texas website about it, and it only confused me more. Could someone please explain this to me, it's really important.