Tex. Code of Criminal Procedure § 44.33

(a) The Court of Criminal Appeals shall make rules of posttrial and appellate procedure as to the hearing of criminal actions not inconsistent with this Code. After the record is filed in the Court of Appeals or the Court of Criminal Appeals the parties may file such supplemental briefs as they may desire before the case is submitted to the court. Each party, upon filing any such supplemental brief, shall promptly cause true copy thereof to be delivered to the opposing party or to the latter's counsel. In every case at least two counsel for the defendant shall be heard in the Court of Appeals if such be desired by defendant. In every case heard by the Court of Criminal Appeals at least two counsel for the defendant shall be permitted oral argument if desired by the appellant.

(b) Appellant's failure to file his brief in the time prescribed shall not authorize a dismissal of the appeal by the Court of Appeals or the Court of Criminal Appeals, nor shall the Court of Appeals or the Court of Criminal Appeals, for such reason, refuse to consider appellant's case on appeal.