Difference between revisions of "Save Game Format (.CHR)"

Latest revision as of 21:50, 4 January 2013

The CHR format is required for storing the user's saved game from Tournament mode. It is a XOR encoded file identified by a DWORD having the value 0xafaeadad (0x00000001 after XOR decoding). The format consists of a number of sections.

Encoding

The encoding is a simple XOR mask + iteration scheme. An XOR mask is known or computed for the first byte in each block, and is incremented to produce the XOR mask for the next byte, and so on.

The first 448 bytes are encoded with a XOR mask starting with 0xac. This covers the Player and Tournament sections. The Opponents section uses a XOR mask starting with the low BYTE of the size of the Opponents block. This can be determined by multiplying the value stored at offset 246 by 68.

The Player's photo is not XOR encoded.

Player

Starting at offset 4 for the user (with an XOR mask of 0xb0) and offset 448 for the first opponent (with an XOR mask determined by the explanation above):

Description															Size in Bytes
Pilot name															16
Wins															2
Loses															2
Rank															1
HAR															1
Arm\|Blade\|Flail Power, Leg Power, Arm\|Flame\|Blade\|Flail Speed															2 (5 bits per attribute)
Leg\|Flame Speed\|Arm Power(Flail), Armour, Stun Resistance															2 (5 bits per attribute)
Power & Agility															2 (7 bits per attribute)
Endurance															1 (7 bits per attribute)
Credits															4
Ternary HAR colour															1
Secondary HAR colour															1
Primary HAR colour															1

The HAR is determined from the following table:

HAR															Value
Jaguar															0x0
Shadow															0x1
Thorn															0x2
Pyros															0x3
Electra															0x4
Katana															0x5
Shredder															0x6
Flail															0x7
Gargoyle															0x8
Chronos															0x9
Nova															0xa

Tournament

This section stores a limited set of details relating to the tournament that the user is competing in. Starting at offset 47 (XOR mask will be 0xdb) and consuming 56 bytes of data:

Offset (Size in Bytes)	47–59 (12)												60-90 (30)																														91-103 (12)
Description	Tournament file name. MS-DOS 8+3 + '\0'												Tournament Description. 29 + '\0'.																														Tournament image file name. MS-DOS 8+3 + '\0'

There is an entire section devoted to the Tournament. It has not been completely de-mystified as yet. Some parts of the section store data on the user's wins or losses against un-ranked challengers, and if any HAR enhancement was won.

Offset	Bytes	Description
155	1	Difficulty Level
246	4	Number of opponents, including un-ranked challengers.
248	4	Number of opponents, excluding un-ranked challengers.

Values for the difficulty level

Mode	Value
Aluminium (Easy)	0x0
Iron (Medium)	0x08
Steel (Hard)	0x10
Heavy Metal	0x18

HAR enhancements

This section occupies 11 consecutive bytes, and for the user is stored from offset 166 to 176. For the Opponents the section is stored directly following the format of the Player section.

HAR															Offset
Jaguar															+0
Shadow															+1
Thorn															+2
Pyros															+3
Electra															+4
Katana															+5
Shredder															+6
Flail															+7
Gargoyle															+8
Chronos															+9
Nova															+10

Enhancements follow a 0x0, 0x1, 0x2 for each upgrade. For example a value of 0x2 for the Jaguar would mean all upgrades enabled. This has not fully been evaluated.

Opponents

This section occupies 68 bytes per opponent and follows the format of Player + HAR enhancements. The first opponent will be stored at offset 448. Opponents are stored by Rank, highest to lowest (that is, rank 1 followed by rank 2 ...). Following is the un-ranked or hidden challengers.

Player's photo

An image stored in the OMF2097 sprite format.

Contributors

Alastair Hogge
Carl Manzi
chaosbm (Richard ...)
Michael Nicolella
Mighty Wombat
Ray Kirkland
Todd Copeland

@@ Line 1: / Line 1: @@
-The CHR format is required for storing the user's saved game from Tournament mode. It is a XOR encoded file identified by a DWORD having the value 0xafaeadad. The format consists of a number of sections.
+The CHR format is required for storing the user's saved game from Tournament mode. It is a XOR encoded file identified by a DWORD having the value 0xafaeadad (0x00000001 after XOR decoding). The format consists of a number of sections.
 == Encoding ==
-The encoding is a simple XOR mask + iteration scheme. The first 448 bytes are coded with a XOR mask of 0xac. This covers the [[Save_Game_Format_(.CHR)|Player]] & [[Save_Game_Format_(.CHR)|Tournament]] sections. The [[Save_Game_Format_(.CHR)|Opponents]] section uses a XOR mask determined from the value stored at offset 246. This value contains the the number of opponents of in the Tournament.
+The encoding is a simple XOR mask + iteration scheme. An XOR mask is known or computed for the first byte in each block, and is incremented to produce the XOR mask for the next byte, and so on.
-<code>
+The first 448 bytes are encoded with a XOR mask starting with 0xac. This covers the [[#Player|Player]] and [[#Tournament|Tournament]] sections. The [[#Opponents|Opponents]] section uses a XOR mask starting with the low BYTE of the size of the [[#Opponents|Opponents]] block. This can be determined by multiplying the value stored at offset 246 by 68.
- int GetOppXOR(int no)
- {
-    return (no - (((no / 256) * 256)));
- }
-</code>
-The [[Save_Game_Format_(.CHR)|Player's photo]] is not XOR encoded.
+The [[#Player's photo|Player's photo]] is not XOR encoded.
 == Player ==
-Starting at offset 4 for the user(with a XOR mask of 0xb0) & offset 448 for the first opponent(with a XOR mask determined with the code above):
+Starting at offset 4 for the user (with an XOR mask of 0xb0) and offset 448 for the first opponent (with an XOR mask determined by the explanation above):
 {| border="1" style="text-align:center"
@@ Line 117: / Line 111: @@
 |}
-There is an entire section devoted to the Tournament. It has no been completely de-mystified as yet. Some parts of the section store data on the user's win or lose against un-ranked challengers, and if any HAR enhancement was won.
+There is an entire section devoted to the Tournament. It has not been completely de-mystified as yet. Some parts of the section store data on the user's wins or losses against un-ranked challengers, and if any HAR enhancement was won.
 {| border="1" style="text-align:center
@@ Line 156: / Line 150: @@
 == HAR enhancements ==
-This section occupies 11 consecutive bytes, and for the user is stored from offset 166 to 176. For the [[Save_Game_Format_(.CHR)|Opponents]] the section is stored directly following the format of the [[Save_Game_Format_(.CHR)|Player]] section.
+This section occupies 11 consecutive bytes, and for the user is stored from offset 166 to 176. For the [[#Opponents|Opponents]] the section is stored directly following the format of the [[#Player|Player]] section.
 {| border="1" style="text-align:center"
@@ Line 200: / Line 194: @@
 == Opponents ==
-This section occupies 68 bytes and follows the format of [[Save_Game_Format_(.CHR)|Player]] + [[Save_Game_Format_(.CHR)|HAR enhancements]]. The first opponent will be stored at offset 448. Opponents are stored by Rank, highest to lowest (that is, rank 1 followed by rank 2 ...). Following is the un-ranked or hidden challengers.
+This section occupies 68 bytes per opponent and follows the format of [[#Player|Player]] + [[#HAR enhancements|HAR enhancements]]. The first opponent will be stored at offset 448. Opponents are stored by Rank, highest to lowest (that is, rank 1 followed by rank 2 ...). Following is the un-ranked or hidden challengers.
 == Player's photo ==
-Raw 8bit pelleted One Must Fall 2097 image format.
+An image stored in the OMF2097 [[Sprite format#Sprite Data|sprite format]].
 == Contributors ==