TXI (Texture Extensions)

TXI files (or TPC appended arrays) are highly forgiving plain-text metadata blocks applied adjacent to graphical files to enforce custom mipmap, bumpmap, or animation shaders.

At a Glance

File Structure

One directive per line: a command token, then whatever arguments it takes. There is no header, no terminator, and no required ordering.

<command> <args...>
<command> <args...>
upperleftcoords <count>
  <u> <v> <w>
  ...
lowerrightcoords <count>
  <u> <v> <w>
  ...

Two commands break the one-line rule. upperleftcoords and lowerrightcoords declare a count and are followed by that many coordinate triples on their own lines, which is the only place the format has structure beyond a flat list. A list here takes either that counted form or an endlist terminator, which is the one format in the manual that does both; see counted, terminated, or neither.

Empty lines are ignored, and command matching is case-insensitive. Text is Windows-1252. Rakata offers two write modes: a policy-normalised one that lowercases the command token, and a source-preserving one that keeps whatever casing the input used, for round-tripping someone else’s file without editorialising it. Neither mode consults a list of known commands, because there is no such list: the reader is deliberately a tolerant key-and-arguments parser, matching the engine, which as the audit below records bypasses anything it does not recognise without complaint.

The recognised vocabulary

Three layers run for every line, in order. A directive matching none of them is silently discarded.

Texture directives, matched directly:

Font directives, delegated on every line regardless of what already matched: numchars, fontheight, baselineheight, texturewidth, spacingR, spacingB, plus the two coordinate lists.

Procedural-controller directives, delegated only once a proceduretype line has appeared earlier in the same file. proceduretype takes one of eight values, each constructing a controller and destroying any previous one, so the last proceduretype line in a file is the one that counts.

Every controller accepts the same base set:

Three of the eight add directives of their own, and the other five add nothing:

A directive from the wrong controller’s set is not an error. It falls through to the same silent discard as any unrecognised token, so waterwidth under proceduretype arturo does exactly nothing and says exactly nothing.

Important

Four multi-line lists have a second terminator, not two upperleftcoords, lowerrightcoords, channelscale and channeltranslate all normally take a count and then that many lines. If the token after the command fails to parse as an integer, the parser instead reads lines until it meets one whose first word is endlist. So a file can legitimately use either form for any of the four, and a reader that only implements the counted one will consume the rest of the file as list entries when it meets the other.

Tip

An unknown directive is not an error anywhere in the chain The engine bypasses commands it does not recognise without logging or failing the texture load, as the audit below records. That makes TXI unusually safe to extend and unusually easy to get silently wrong: a typo’d command name behaves exactly like a command that does nothing, with no diagnostic on either side. The boolean-parsing note further down is the sharpest case of this.

Engine Audits & Decompilation

Read from CAurTextureBasic::ParseField at 0x00422390 in swkotor.exe. Provenance: derived, not attested unless a claim says otherwise: the rows have not been separately re-derived, so they sit on the reverse-engineering queue. Individual claims below may carry a level of their own, and where one does it overrides this line for that claim.

Note

Boolean Parsing Nuance Modding documentation often warns against specific formats or keywords (like decal). Decompilation reveals the universal behavior applied to all boolean flags:

• Missing Space: Keys merged with their arguments (e.g. "decal1", "mipmap0") silently abort. The firstword() extractor pulls the merged string, completely failing the target evaluation list.
• Separated Numbers: Space-separated numbers (e.g. "decal 1") are completely structurally valid. firstword() pulls "decal" and hands " 1" off to Parse_bool(). An sscanf strips the whitespace and evaluates "1" to true.
• Argument-less Flags: Passing just a flag ("decal") triggers the branch, but Parse_bool physically finds no argument. It fails to match "true", "false", "1", or "0", silently safely leaving the boolean integer unchanged from its previous memory allocation.