The Texas thing is really weird. It’s kind of a primary/caucus state. I haven’t been able to figure it out.
Half delegates to the State convention are chosen by direct vote, the other half are chosen by party caucuses right after the polls close (7:15 CST)
If you voted Dem, then you are eligible to go to the caucus too after the polls close at your precinct.
Delegates are proportional for Repubs and Dems and the Dems further split delegates by the popular vote and the caucus.
If you crossover as a Republican for example, and one of the Repub candidates down ticket have a tie or need a revote, you cannot cross back over for that vote.
Again, there is no caucus for Repubs.