This version is outdated by a newer approved version.DiffThis version (2017/09/04 02:33) was approved by zdimension.The Previously approved version (2017/07/19 15:11) is available.Diff

Scripting in TR4 and TR5

In this chapter we will describe full gameflow script specification for TR4/TR5 script file (usually called SCRIPT.DAT) and language file, which contains all the strings used in game for specific language (e.g., ENGLISH.DAT, FRENCH.DAT, and so on).

The Script File

The script is divided into several blocks (or headers), some of them are global (applicable to whole game instance), and some are per-level only.

This header contains general information not specific to particular level.

struct tr4_script_header // 9 bytes
{
    uint8_t  Options;
    uint8_t  Filler[3];     // Unused
    uint32_t InputTimeout;
    uint8_t  SecurityTag;
}

Options is a set of bit flags with several global game settings (name of the settings directly borrowed from original text scripts distributed with TRLE):

Hex Bit Description
0x0001 0 CheatEnabled – Enables debug fly mode activated by typing DOZY ingame.
0x0002 1 LoadSaveEnabled – When this bit is not set, load and save features are disabled. This option was used for demo versions.
0x0004 2 TitleEnabled – Specifies if title screen should be displayed or not. If not set, game will start right away after user has launched an application.
0x0008 3 PlayAnyLevel – Gives an access to any level from the title screen.
0x0070 4 Language – Chooses which loading picture (US, GR, FR or UK) is showed
5
6
0x0080 7 DemoDisc – Unknown feature, probably related to game versions deployed on promotional CDs.

InputTimeout: in early TR4 demos (for example, version dated September 15, 1999) this parameter specified time interval, after which game will engage pre-recorded rolling demo, in case there was no user input. This feature became useless in final version.

SecurityTag parameter meant to be a special “key” value used to encrypt script data. Encryption is done with simple XOR operation against the data. However, this value was never used, and instead, hardcoded one was specified. This matter will be discussed later.

Level Header

This section defines platform-specific information, such as file extensions used in PC an PlayStation versions of the game. All the mentioned strings are null-terminated.

struct tr4_script_levelheader
{
    uint8_t NumTotalLevels;
    uint8_t NumFilenames;
 
    uint8_t Filler;
 
    uint16_t LevelpathStringLen;
    uint16_t LevelBlockLen;
 
    uint8_t PSXLevelString [5];    //  typically ".PSX"
    uint8_t PSXFMVString   [5];    //  typically ".FMV"
    uint8_t PSXCutString   [5];    //  typically ".CUT"
    uint8_t Filler         [5];    //  Possibly for some additional extension type?
 
    uint8_t PCLevelString  [5];    //  typically ".TR4"
    uint8_t PCFMVString    [5];    //  typically ".BIK"
    uint8_t PCCutString    [5];    //  typically ".TR4"
    uint8_t Filler         [5];
}

NumTotalLevels is an amount of levels included in script. Title flyby is also counted.

LevelpathStringLen is a sum of lengths of all level path strings, including 0x00s (empty ones).

LevelBlockLen is a sum of lengths of each level script data length.

Level Listing Block

struct tr4_script_levellisting
{
    uint16_t OffsetsToLevelpathString[NumTotalLevels];
     uint8_t LevelpathStringBlock [LevelpathStringLen];
 
    uint16_t OffsetsToLevelData [NumTotalLevels];
}

Note that the offsets in the offset table themselves are not relative to the file address 0. The level-path offsets are relative to the first path string’s starting byte address (56 + NumTotalLevels * 2), while the level-data offsets are relative to the first level data’s starting byte address (56 + NumTotalLevels * 2 + LevelpathStringLen + NumTotalLevels * 2).

It is also worth noting that the level-path strings in SCRIPT.DAT are ordered the same way they were ordered in corresponding [Level] blocks in uncompiled SCRIPT.TXT. For example, if the first [Level] in SCRIPT.TXT defines Level=DATA\TEST1,101 and the second Level=DATA\TEST2,101 — then there will be 2 level-paths in SCRIPT.DAT, in the order such as this: DATA\\TEST1.DATA\\TEST2; where . is the null-terminator (0x00) byte.

To get to a certain level’s path within SCRIPT.DAT knowing only its number, just look-up at OffsetsToLevelpathString[LevelNum] and go to that offset (remember, it is not relative to file address 0!).

Level Block

Inside the level block, each level stores its own data describing certain parameters, such as level name, puzzle item names, load camera position, default background ambience soundtrack, and so on (the title level is no exception!).

While in SCRIPT.TXT each parameter was given its own line and position within the file itself, in SCRIPT.DAT this is not the case. Rather, bitfields are used for bool options (enabled/disabled; such as Lightning option) and the rest of the usually multi-byte data uses an opcode data structure.

That is, preceding a certain type of data you usually find a byte. That is the opcode byte — depending on its value, it can be determined what kind and how many arguments follow that need parsing. For example, chunk 0x81 indicates the level description opcode; with that info, the parser knows that 4 arguments follows: the string index, etc. This structure is somewhat akin to the AnimCommands structure of level files (see description above). The chunk order does matter; the original tomb4.exe binary seems to crash if something is not ordered the way it should be.

The title screen is special in that it uses the 0x82 opcode the indicate the level-name and audio track information and it, naturally, lacks the string index integer as the title level has no name associated with it.

struct tr4_script_leveldata
{
    uint8_t LevelData [LevelDataLen];
}

LevelData is all of the level’s data continuously stored in memory. Number of level data sections is equal to overall amount of levels in game, and overall size of all level data sections comprise Level Block.

To get to a certain level’s data section, follow that particular level’s offset from inside the offset table you loaded (described above). The data sections themselves are ordered the very same way levels were ordered in SCRIPT.TXT. For more info on the types of all available TR4 chunks and how to parse them, see the Script Opcodes section.

Language File Listing Block

After the level block follows a simple array of ASCII strings which define all the language files the game can choose from. There are, however, no offset tables for this one, so one must simply read until a null-byte is reached, and then take that as the string and repeat onwards until EOF. Therefore, the last byte of SCRIPT.DAT must always be the null-terminator (0x00).

This setup is valid only for standard TR4 scripts generated by original TRLE script utility. TRNG scripts have their own special footer and data block appended to the bottom of the file, which contain all the extra information it needs.

Script Opcodes

Here is a list of all available TR4 opcodes, their meaning and their corresponding arguments (order of arguments matters!):

It is important to note that the LoadCamera opcode has been removed in TR5, which means that all the other opcodes (>= 0x92) are shifted by 1).

TR4 TR5 Opcode Arguments
0x80 FMV uint8_t: 4 least significant bits represent the FMV index; 4 most significant bits (y) represent the FMV trigger bitfield as in y=1↔bit 8 set
0x81 Level uint8_t stringIndex uint16_t levelOptions uint8_t pathIndex uint8_t audio
0x82 [Title] Level uint8_t pathIndex uint16_t titleOptions uint8_t audio
0x83 LEVEL_DATA_END None – this opcode appears at the end of every level (incl. title) block
0x84 Cut uint8_t cutIndex
0x85 ResidentCut1 uint8_t cutIndex
0x86 ResidentCut2
0x87 ResidentCut3
0x88 ResidentCut4
0x89 Layer1 uint8_t red uint8_t green uint8_t blue int8_t speed
0x8A Layer2
0x8B UVrotate int8_t speed
0x8C Legend uint8_t stringIndex
0x8D LensFlare uint16_t yClicks bit16 zClicks uint16_t xClicks uint8_t red uint8_t green uint8_t blue
0x8E Mirror uint8_t room int32_t xAxis
0x8F Fog uint8_t red uint8_t green uint8_t blue
0x90 AnimatingMIP uint8_t: 4 least significant bits represent animatingObjectIndex - 1; 4 most significant bits represent the distance
0x91 XXX LoadCamera int32_t srcX int32_t srcY int32_t srcZ int32_t targX int32_t targY int32_t targZ uint8_t room
0x92 0x91 ResetHUB uint8_t levelIndex
0x93 0x92 KEY_ITEM1 uint16_t stringIndex uint16_t height uint16_t size uint16_t yAngle uint16_t zAngle uint16_t xAngle uint16_t unknown
0x94 0x93 KEY_ITEM2
0x95 0x94 KEY_ITEM3
0x96 0x95 KEY_ITEM4
0x97 0x96 KEY_ITEM5
0x98 0x97 KEY_ITEM6
0x99 0x98 KEY_ITEM7
0x9A 0x99 KEY_ITEM8
0x9B 0x9A KEY_ITEM9
0x9C 0x9B KEY_ITEM10
0x9D 0x9C KEY_ITEM11
0x9E 0x9D KEY_ITEM12
0x9F 0x9E PUZZLE_ITEM1
0xA0 0x9F PUZZLE_ITEM2
0xA1 0xA0 PUZZLE_ITEM3
0xA2 0xA1 PUZZLE_ITEM4
0xA3 0xA2 PUZZLE_ITEM5
0xA4 0xA3 PUZZLE_ITEM6
0xA5 0xA4 PUZZLE_ITEM7
0xA6 0xA5 PUZZLE_ITEM8
0xA7 0xA6 PUZZLE_ITEM9
0xA8 0xA7 PUZZLE_ITEM10
0xA9 0xA8 PUZZLE_ITEM11
0xAA 0xA9 PUZZLE_ITEM12
0xAB 0xAA PICKUP_ITEM1
0xAC 0xAB PICKUP_ITEM2
0xAD 0xAC PICKUP_ITEM3
0xAE 0xAD PICKUP_ITEM4
0xAF 0xAE EXAMINE1
0xB0 0xAF EXAMINE2
0xB1 0xB0 EXAMINE3
0xB2 0xB1 KEY_ITEM1_COMBO1
0xB3 0xB2 KEY_ITEM1_COMBO2
0xB4 0xB3 KEY_ITEM2_COMBO1
0xB5 0xB4 KEY_ITEM2_COMBO2
0xB6 0xB5 KEY_ITEM3_COMBO1
0xB7 0xB6 KEY_ITEM3_COMBO2
0xB8 0xB7 KEY_ITEM4_COMBO1
0xB9 0xB8 KEY_ITEM4_COMBO2
0xBA 0xB9 KEY_ITEM5_COMBO1
0xBB 0xBA KEY_ITEM5_COMBO2
0xBC 0xBB KEY_ITEM6_COMBO1
0xBD 0xBC KEY_ITEM6_COMBO2
0xBE 0xBD KEY_ITEM7_COMBO1
0xBF 0xBE KEY_ITEM7_COMBO2
0xC0 0xBF KEY_ITEM8_COMBO1
0xC1 0xC0 KEY_ITEM8_COMBO2
0xC2 0xC1 PUZZLE_ITEM1_COMBO1
0xC3 0xC2 PUZZLE_ITEM1_COMBO2
0xC4 0xC3 PUZZLE_ITEM2_COMBO1
0xC5 0xC4 PUZZLE_ITEM2_COMBO2
0xC6 0xC5 PUZZLE_ITEM3_COMBO1
0xC7 0xC6 PUZZLE_ITEM3_COMBO2
0xC8 0xC7 PUZZLE_ITEM4_COMBO1
0xC9 0xC8 PUZZLE_ITEM4_COMBO2
0xCA 0xC9 PUZZLE_ITEM5_COMBO1
0xCB 0xCA PUZZLE_ITEM5_COMBO2
0xCC 0xCB PUZZLE_ITEM6_COMBO1
0xCD 0xCC PUZZLE_ITEM6_COMBO2
0xCE 0xCD PUZZLE_ITEM7_COMBO1
0xCF 0xCE PUZZLE_ITEM7_COMBO2
0xD0 0xCF PUZZLE_ITEM8_COMBO1
0xD1 0xD0 PUZZLE_ITEM8_COMBO2
0xD2 0xD1 PICKUP_ITEM1_COMBO1
0xD3 0xD2 PICKUP_ITEM1_COMBO2
0xD4 0xD3 PICKUP_ITEM2_COMBO1
0xD5 0xD4 PICKUP_ITEM2_COMBO2
0xD6 0xD5 PICKUP_ITEM3_COMBO1
0xD7 0xD6 PICKUP_ITEM3_COMBO2
0xD8 0xD7 PICKUP_ITEM4_COMBO1
0xD9 0xD8 PICKUP_ITEM4_COMBO2
XXX 0xD9 GiveItemAtStartup uint16_t unknown
0xDA LoseItemAtStartup uint16_t unknown

The uint16_t values levelOptions and titleOptions are actually bit fields containing several boolean options, and are laid out as follows (per-bit description):

  • Bit 0 (0x0001) — YoungLara
  • Bit 1 (0x0002) — Weather
  • Bit 2 (0x0004) — Horizon
  • Bit 3 (0x0008) — Layer1 used
  • Bit 4 (0x0010) — Layer2 used
  • Bit 5 (0x0020) — Starfield
  • Bit 6 (0x0040) — Lightning
  • Bit 7 (0x0080) — Train
  • Bit 8 (0x0100) — Pulse
  • Bit 9 (0x0200) — ColAddHorizon
  • Bit 10 (0x0400) — ResetHUB used
  • Bit 11 (0x0800) — LensFlare used
  • Bit 12 (0x1000) — Timer
  • Bit 13 (0x2000) — Mirror used
  • Bit 14 (0x4000) — Remove Horus amulet from inventory
  • Bit 15 (0x8000) — NoLevel

The Language File

In contrary to TR2 and TR3, TR4 uses a more sophisticated language-handling scheme. Instead of storing the strings in SCRIPT.DAT for every different language, TR4 splits the string definition ({LANGUAGE}.DAT) and script definition (SCRIPT.DAT) data into the two mentioned files. This allows for smaller files, finer grain of selectivity and easy localization.

This means that, within SCRIPT.DAT, strings are always given as string indices, i.e. numbers that correspond to the array positions of the corresponding strings within {LANGUAGE}.DAT, where {LANGUAGE} can be any supported language filename.

From these files, the game will choose the first one that is available and use that as the string resource. See below for details on string selection.

Language File Priority

The number of supported language files depends on what was defined in SCRIPT.TXT, in the [Language] section. Also, the priority of loading is specified there (the first number before the comma). For example, if we have defined:

[Language]
File= 0,ENGLISH.TXT
File= 1,FRENCH.TXT
File= 2,GERMAN.TXT
File= 3,ITALIAN.TXT
File= 4,SPANISH.TXT
File= 5,US.TXT

…that would mean that the game will first look for ENGLISH.DAT for loading. If that’s not present, it will look for FRENCH.DAT. If not, it’ll look for GERMAN.DAT, and so on. If none of the files are present, the game will crash. In SCRIPT.DAT, these numbers reflect on the order of file name strings: in the above situation, the language file listing block at the end of SCRIPT.DAT would look like this (highest→lowest priority):

ENGLISH.DAT FRENCH.DAT GERMAN.DAT ITALIAN DAT SPANISH.DAT US.DAT.

…where the splitting space between filenames specifies the null-terminator (0x00) byte.

Language File Structure

The Header

The header of the language file follows this structure:

struct tr4_lang_header
{
    uint16_t NumGenericStrings;
    uint16_t NumPSXStrings;
    uint16_t NumPCStrings;
 
    uint16_t GenericStringsLen; //  including the null-terminator bytes
    uint16_t PSXStringsLen;     //  including the null-terminator bytes
    uint16_t PCStringsLen;      //  including the null-terminator bytes
 
    uint16_t StringOffsetTable[];
}

StringOffsetTable is a table holding offsets which point to corresponding strings. Therefore, its size is NumGenericStrings + NumPSXStrings + NumPCStrings.

Offsets in the offset table themselves are not relative to the file address 0! They are actually relative to the first string’s starting byte address!

In order to get an absolute offset of a string whose relative offset you retrieved from the offset table, do the following:

absoluteOffset = relativeOffset + sizeof(tr4_lang_header)

sizeof(tr4_lang_header) depends, of course, on the number of strings in each group. Therefore, the header size is sizeof(uint16_t) * 6 + sizeof(OffsetTable).

String Data

In the usual TR4 situation, there are typically 359 strings (that is, usually NumTotalStrings = NumGenericStrings + NumPSXStrings + NumPCStrings = 359) defined. This, however, is not a limit nor rule of any kind.

All the strings defined within {LANGUAGE}.DAT files are ASCII null-terminated strings. Every character (byte) contained in such a string is XOR-ed with byte 0xA5 (as mentioned above, it is done regardless of what byte was specified in SCRIPT.TXT under the Security option).

The null-termination byte is not being XOR-ed!

After the above defined header section goes an array of strings, in a predefined order: Generic → PSX → PC.

The length of this array of total (NumTotalStrings) strings is therefore TotalStringsLen = GenericStringsLen + PSXStringsLen + PCStringsLen.

Hence the string array has the following format:

struct tr4_lang_stringdata
{
    string_entry Strings[NumTotalStrings];
}

where string_entry is simply a char array, whose length depends on the corresponding string’s length. That can be calculated by subtracting the next string’s by the current string’s offset.

trs/scripting_tr4_tr5.txt · Last modified: 2017/11/17 12:21 (external edit)
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