It is, and like SC, is also proportional based on winning congressional districts.
Texas Republican Delegation 2016
108 district delegates for 36 congressional districts. 50% gets all 3, 20% gets 2 from each district.
47 at large delegates for the state as a whole. 50% gets all of them, 20% entitles one to a proportional share.
I think Trump, Cruz and Rubio each get some share of the delegates from Texas.