Claiming a child in Texas DIVORCED parents

Our Texas paperwork from the court mentions NO DETAILS AT ALL covering who can claim our one child. I have extended modifed visitation to see him as much as the law allows but he live with her most of the time other than 1 month out of the summer ect...and other court appointed time such as spring break/holidays. Since it doesn't state can I claim him? I pay the child support ect. Since it doesn't say which parent by law don't I have as much right to file since we are joint conservators? I don't think I can be in trouble with the court since my contract doesn't mention it. Therefore I can claim him and split it with or claim him and tell her we can rotate everywhere and by law she can't do anything since our contract doesn't state guidelines for this?