Probable Cause is not required in Texas. The bar is lower than that.
Be aware that courts have ruled that motorists stopped for less than probable cause (reasonable / articulable suspicion) may be required to identify themselves for the sake of officer safety. Failing to do so can lead to arrest for failure to ID.
See: United States v. Villagrana-Flores, 467 F.3d 1269 (10th Cir. November 7, 2006).
We explained in Holt that ‘the justification for detaining a motorist to obtain a criminal history check is, in part, officer safety’ because ‘by determining whether a detained motorist has a criminal record or outstanding warrants, an officer will be better apprized of whether the detained motorist might engage in violent activity during the stop.’” As long as the detention is for a short period, “the government’s strong interest in officer safety outweighs the motorist’s interests
Apparently the same pertains to pedestrian stops.
To me, this means that the current state of affairs is that as long as LEOs have a articulable reason (less than probable cause) to stop you, you could be arrested if you failed to identify yourself. Without that articulation, they cannot force you to identify yourself nor can they arrest you for not providing it. LEOs are under no obligation to tell you what they are investigating, articulate what they are doing, nor are they required to differentiate between requesting and demanding, so you'll get to guess if they've got enough to make you identify yourself.
Good luck.