https://statutes.capitol.texas.gov/Docs/PE/htm/PE.9.htmSec. 9.04. THREATS AS JUSTIFIABLE FORCE. The threat of force is justified when the use of force is justified by this chapter. For purposes of this section, a threat to cause death or serious bodily injury by the production of a weapon or otherwise, as long as the actor's purpose is limited to creating an apprehension that he will use deadly force if necessary, does not constitute the use of deadly force.
And a Texas lawyer says:
https://www.youtube.com/watch?v=zINtaXThtpY
Obviously, the wisdom of such a tactic is subject to debate. Opinions differ. Texas law remains clear. TPC 9.04 sets the requirements under which you can use your firearm in a way that does not "constitute the use of deadly force."