Difference between revisions of "Replay file"

Revision as of 12:20, 4 November 2009

Replay (.WAgame) files were introduced to Worms Armageddon with Deadcode's 3.6.19.7 beta update, which was released on 9 February, 2004. The files represent self-contained recordings of games, which can be played on any computer with the corresponding software updates installed.

Recordings of all games played (including offline, mission and training games) are saved automatically to the User\Games folder. File names consist of a date/time stamp, the game type, and the participating players.

The files contain all the information needed to play the replay flawlessly. This includes the game version which was emulated during the game, the map and the scheme, the participating teams (including the custom flags and graves), and the random seed used for random in-game events (such as random initial placement of worms and objects).

File format

A typical replay file consists of a 4-byte header, a map chunk, a settings chunk, and the message (user input) stream.

The file header consists of two signature bytes ("WA"), after which follows a word with the file version. W:A 3.6.26.5 saves replays in the version 12 format (0x000C).

After the header is the map chunk. The map chunk represents a DWORD which represents the chunk's contents' length (chunk length-4, or map length+4), followed by the chunk data. The first DWORD of the chunk's data specifies the map type - it can be 1 for Monochrome map (.bit), 2 for Seed-generated monochrome map, or 3 for Colour map. The map data follows, its length being the chunk's length - 4.

Following the map data is the settings (initialization) chunk. Its structure:

• 3 usually null bytes
• the replay file version (see header), a 2nd time (WORD)
• the replay date/time in time_t format
• a null byte
• game engine version to emulate (0x30 represents 3.6.26.5; 0x4C represents 3.6.28) (DWORD)
• game type (normal=1, mission=2, training=3) (byte)
• scheme type (usually 0xFF, positive value for intrinsic schemes) (byte)
• the scheme - see Game scheme file (length is determined by the scheme file format version)

• initial logic (random) seed (DWORD)
• blood amount (byte)
• rope knocking (byte)
• the game ID (Pascal string)
• local machine ID (byte)

This is followed by the data about connected machines, and teams.

User Input

Generalities

After the padding mentioned above, the game starts with a 09 xx xx xx xx 00. The four xx bytes are still to be determined. Each new turn is initiated by that 00 byte, and before advancing, the game engine will wait until all pending actions are stabilized (Mines triggered, flames falling, animals running, ...). Each turn is divided in frames, at a rate of 50 frames per second. Those frames are seperated by a 02 byte. A frame can be empty, or contain the actions taken at that very moment. Each 25 frames, the word 0C 1E is inserted. Its purpose is yet unknown, and it is sometimes followed by a byte ranging from 03 to 07, for unknown reasons too. Each time an weapon is used, a checksum gets inserted into the following frame.

Actions

Actions are usually constituted by 2 Bytes, the first one coding for the action, and the second one coding for the active team (01-06). However, it is not possible to change the "Active team" byte to move another worm while it's not his turn. For example, the action 1E corresponds to the left arrow ; the action 21 to the down arrow. If the active worm is in the third team, the frame will look like "02 1E 03 21 03" (New frame, pressing left and pressing up). Some actions are more complex, and require therefore additional arguments. Those are typically inserted before or after the "Active team" byte. Here is a list of actions codes, along with their arguments when applicable.

Tables

Related to action 0F : Game chat. xx and yy represent sender and receiver (Not sure about that anymore)

Related to action 32 : Mouse click. zz determines the action for which the click is for.

Related to action 33 : Weapon selection. zz determines weapon selected. Those weapons indices are in the same order than visible in right-click menu, starting from Bazooka and with utilities being sent at the end. Note that Super sheep and aqua sheep are 2 different weapons (F5 line has 6 columns, even if only 5 of them are visible)

Security

The format incorporates periodic checksums, embedded into specific actions. This allows to detect modifications to the replay, causing warning messages during playback.

The tool-assisted versions of W:A save replays in an encrypted format, which is playable only with the tool-assisted version. Only Deadcode can decrypt them, thus making them playable with normal versions of W:A.

Export Log

A log file can be extracted from a replay file to give a text representation of what happens in the replay. The log file includes:

• The date and time that the game was played, GMT
• The game version with which the game was played
• Mission number and name, if applicable
• A list of the players involved, the colours they played as, the names of the teams they used, and any CPU teams involved (and their skill levels)
• A chronologically-ordered list of things that happened in the game, including:
  • Comments made by players in the chat window
  • Turn starts
  • Weapon shots (with some details e.g. herd number; fuse time; bounce; jetpack fuel used etc.)
  • Health deductions (not including poison)
  • Turn endings (including time used and retreat time used)
  • End of game
• Total time used by each team, split into turn time and retreat time
• Mission result, if applicable
• Round number
• Round time
• Total game time
• Total worms killed
• Total health lost
• Name of the team which won the game
• Name of the "worm of the round"
• Name of the worm that dealt the most damage with one shot
• Match awards