Texas code is very long. I'll post the code and a link to a site that breaks it down. Here the main part/an exerpt;
Texas Trespassing Laws: What You Need to Know
Laws and Regulations / By Tom Marlowe
https://www.survivalsullivan.com/texas-trespassing-laws/
Now, on to the heart of the statutes with section 30.05:
Section 30.05. Criminal Trespass
(a) A person commits an offense if the person enters or remains on or in property of another, including residential land, agricultural land, a recreational vehicle park, a building, or an aircraft or other vehicle, without effective consent and the person:
(1) had notice that the entry was forbidden; or
(2) received notice to depart but failed to do so.
Starting out, it is clear that entering or remaining upon any kind of property of another person without effective consent, and with notice that entry is forbidden or in disregard of any notice to depart, is a violation. (a) qualifies the rest of this section, which we get to immediately.
(b) For purposes of this section:
(1) “Entry” means the intrusion of the entire body.
(2) “Notice” means:
(A) oral or written communication by the owner or someone with apparent authority to act for the owner;
(B) fencing or other enclosure obviously designed to exclude intruders or to contain livestock;
(C) a sign or signs posted on the property or at the entrance to the building, reasonably likely to come to the attention of intruders, indicating that entry is forbidden;
There are five forms of notice against entry in the state of Texas. The first is a verbal or written communication by the owner or the owner’s agent to a specific person or persons the entry on to the land, onto the premises or into the building is not allowed.
The second is fencing or some other enclosure or barrier that is obviously designed to exclude intruders from the property or to contain animals within the bounds of the property.
The third is any number of signs posted on the property at entrances or along the perimeter in a manner that is reasonably likely to come to the attention of potential intruders and describes the prohibited activity.
We will look at the fourth and fifth form of notice, identifying markings, just below.
(D) the placement of identifying purple paint marks on trees or posts on the property, provided that the marks are:
(i) vertical lines of not less than eight inches in length and not less than one inch in width;
(ii) placed so that the bottom of the mark is not less than three feet from the ground or more than five feet from the ground; and
(iii) placed at locations that are readily visible to any person approaching the property and no more than:
(a) 100 feet apart on forest land; or
(b) 1,000 feet apart on land other than forest land; or
(E) the visible presence on the property of a crop grown for human consumption that is under cultivation, in the process of being harvested, or marketable if harvested at the time of entry.
The placing of purple painted markings on posts or trees is a broadly standard method of marking land or property against trespassing throughout the U.S., but to have the force of law in Texas it must be done according to the standards described in (D).
Interestingly, the fifth form of notice is simply the visible growth of crops or the cultivation thereof on the property in question. If someone is growing crops and you enter upon that land without authority and consent you are trespassing.
https://www.survivalsullivan.com/texas-trespassing-laws/
See also;
https://statutes.capitol.texas.gov/docs/PE/htm/PE.30.htm