FF8/FileFormat X

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Revision as of 21:45, 3 May 2016 by my_wiki>MaKiPL (→‎Texture page calculation: Corrected info and lame code not using bitwise)

By MaKiPL. Thanks for help in research for: shakotay2 (XeNTaX), Halfer, Yagami Light. Complete list of original battle stages by Kaspar01: List of battle stages

Contents

Info

.X file is uncompressed 3D stage model with texture embedeed. The file contains unused info (not used by FF8 engine), camera data, movement, translations and geometry data.

Battle stages DOES NOT contain pointers to next sections. All pointers are HARDCODED in FF8.EXE. Click me for battle stage pointer list

Name Usually starting with: Description
Unused data E8 FF BD 27 01 00 02 This data is unused by FF8 Engine
Camera data + movement 02 00 08 00 20 00 Camera animations, movement (pre-keyed)
Geometry 01 00 01 00 (See geometry section info) Divides to object (group) and it's sub-objects + vert/triangle grouping
Texture 01 00 00 00 09 (Always) Contains one .TIM texture

How is this file handled by the engine?

FF8 loads specific file and reads it from hardcoded (written in FF8 code) position. This hardcoded position points to camera data. Camera data has size uint16, which is calculated and relative jump is made. Just after camera, a typical section based file handling is made.

Offset Length Description
0 uint32 Number of sections
4 uint32 Objects group #1 (NULL?)
8 uint32 Objects group #2
12 uint32 Objects group #3
16 uint32 Objects group #4
20 uint32 Texture [unused in code]
24 uint32 Texture
28 uint32 Relative to EOF

Objects group:

Offset Length Description
0 uint32 Number of sections
4 uint32 Pointer to Settings #1
8 uint32 Pointer to ObjectsList
12 uint32 Pointer to Settings #2
16 uint32 Relative to end_of_group

Objects list:

Offset Length Description
0 uint32 Number of objects
Num_of_obj*4 uint32 Relative pointer to segment (one .obj file) [01 00 01 00]

Settings 1:

Offset Length Description
0 uint16 Unknown, fixed 2?
2 sint16 (probably, or uint16) Scale (01 is the smallest)
4 4 bytes PADDING
8 4 bytes Nothing?
12 4 bytes Nothing?
16 2 bytes if not FF FF, then model vanishes
18 sint16 X or Z Axis rot origin (Translation)
20 44 bytes Left null for storing some engine data AFTER loaded in-game
64 2 bytes if not FF FF or 00 00, then model vanishes
66 2 bytes Nothing?
68 ...up to end Left null for storing some engine data AFTER loaded in-game

This might look difficult, but it's like multi-pointer file that starts at different location given by executable. See list at the beginning of this wiki to see which stages camera starts at which position (where FF8.exe really starts to read file as BattleStage) [FF8 stores whole file, even with useless data before camera] If this still makes trouble, see this video: TODO

Camera data

Starts at ~0x5d4 (see How the engine handles this file?). [.text:00509820]

Offset Length Description
0 uInt16 Fixed 02 00 (Unused in code)
2 uInt16 Relative jump to CameraSetting
4 uInt16 Relative jump to CameraAnimation
6 uInt16 Camera data size (starting from 0) [unused in code]
8 24 bytes Camera Settings
32 ?? bytes Cameras

Camera Setting:

Offset Length Description
0 char (based on disassembly) CameraAnimMode?
1 byte? StopEnemyBeforeAnim?
2 Bitfield? (1B) UHM?
3 ??? DefaultEndofCameraPosition_Zoom?
4 ??? ???

Cameras:

Offset Length Description
0 uint16 NumberOfCameras
2 *(Camera) uint16 Relative pointer to camera animation
2 *(Camera)+ 2 uint16 Relative pointer to EOF
2 *(Camera) + 4 CameraAnimation CameraAnimation

Camera Animation:


Offset Length Description
0 uint16 NumOfKeypoints
2 *(KeypointID) uint16 Relative pointer to camera Keypoint
2 *(NumOfKeypoints)+ 2 16 bytes? (NumOfKeypoints * 2)? UNKNOWN
KeypointPointer Keyframe Keyframe

Keyframe:

Offset Length Description
0 UNKNOWN UNKNOWN

Geometry

Geometry contains groups, that contains Triangles and/or quads poligons. Models always stars at 01 00 01 00, and needs to be after camera data, either it's not model itself, but some other data.

Group

Offset Length Description
0 4 bytes Always 01 00 01 00 / Header of object
4 2 bytes Uint16 / number of vertices.
6 Number of vertices * 6 Vertex data, short X; short Y; short Z;
6 + (Number of vertices *6) (AbsolutePosition MOD 4) + 2 Padding
varies (just after above) 2 bytes uint16 / number of triangles
varies (just after above) 2 bytes uint16 / number of quads
varies (just after above) 4 bytes padding
varies (just after above) number of triangles * 20 Triangle data. If NumOfTriangles = 0, then instead of any triangle data, there's quad data.
varies (just after above) number of quads * 24 Triangle data. If NumOfQuads = 0, then instead of any quad data, there's either next header 01 00 01 00, or end of group.
Triangle
Name Type Description
F1 (A) uint16 A of face indice
F2 (B) uint16 B of face indice
F3 (C) uint16 C of face indice
U1 Byte U of first texture coordinate
V1 Byte V of first texture coordinate
U2 Byte U of second texture coordinate
V2 Byte V of second texture coordinate
CLUT_ID UInt16 (BIT operated)* Index to CLUT_ID operated by BIT (see below)
U3 Byte U of third texture coordinate
V3 Byte V of third texture coordinate
Special (see below / After QUAD table) 8 Byte See below (after QUAD table)
Hide Byte/Bool Bool. Hides or shows texture
Red Byte Texture colourization (Red)
Green Byte Texture colourization (Green)
Blue Byte Texture colourization (Blue)
PSone GPU related Byte PSOne instruction
Quad
Name Type Description
F1 (A) uint16 A of face indice
F2 (B) uint16 B of face indice
F3 (C) uint16 C of face indice
F4 (D) uint16 D of face indice
U1 Byte U of first texture coordinate
V1 Byte V of first texture coordinate
CLUT_ID UInt16 (BIT operated)* Index to CLUT_ID operated by BIT (see below)
U2 Byte U of second texture coordinate
V2 Byte V of second texture coordinate
Special (see below) 8 Byte See below (after table)
Hide Byte/Bool Bool. Hides or shows texture
U3 Byte U of third texture coordinate
V3 Byte V of third texture coordinate
U4 Byte U of fourth texture coordinate
V4 Byte V of fourth texture coordinate
Red Byte Texture colourization (Red)
Green Byte Texture colourization (Green)
Blue Byte Texture colourization (Blue)
PSone GPU related Byte PSOne instruction

Special Byte: This byte, needs to be divided to two bytes. So, for example, a 0xE5 needs to be treated like two bytes: 0x0E 0x05 Other way is to treat first one as 6 BIT's, and second one as 2 BIT.

Singular of char Example Description
First char/ 4 BIT B2 --> 0B Unknown
Second char / 4 BIT B2 --> 02 Texture page number

CLUT ID

The most important bit's are the first two on one byte, and last two on last byte. Example: 00000000 00111100 (00 3C) should be read like this: 00111100 00000000 (3C 00) And the CLUT ID is revealed by watching this four bits: 001111[00 00]000000

Same applies to reading CLUT colors (16bits) where they are: 1b-T, 5b-B, 5b-G, 5b-R (Or RGBT if reordered as shown above)

Complete list (without replacing bit order - as is in HEX editor/memory):

CLUT ID BIT HEX
#1 00000000 00111100 00 3C
#2 01000000 00111100 40 3C
#3 10000000 00111100 80 3C
#4 11000000 00111100 C0 3C
#5 00000000 00111101 00 3D
#6 01000000 00111101 40 3D
#7 10000000 00111101 80 3D
#8 11000000 00111101 C0 3D
#9 00000000 00111110 00 3E
#10 01000000 00111110 40 3E
#11 10000000 00111110 80 3E
#12 11000000 00111110 C0 3E
#13 00000000 00111111 00 3F
#14 01000000 00111111 40 3F
#15 10000000 00111111 80 3F
#16 11000000 00111111 C0 3F

Texture

Contains one TIMs with various size 512x256, 673x256, 768x256 (8BPP).

UV calculation algorithm

Float U = (float)U_Byte / (float)(TIM_Texture_Width * 2) + ((float)Texture_Page/(TIM_Texture_Width * 2));

Texture page calculation

               Byte TPage = InputBytes[TexturePage_index] & 0F; //Bitwise TPage byte AND 0F, to delete first 4 bits
               int TPageINT = TPage * 128; //For 16 bit TIM's, the texture page is 128 sized

Example: 0xB2 byte is: 2*128 = 256

TIM Texture width/height resolving

           //Updated - 19.07.2015 by MaKiPL
           
           Byte[] Stage = File.ReadAllBytes(@"PATH TO .X stage file"); //Load file to memory
           Byte[] TIMtexture = { 0x10, 0x00, 0x00, 0x00, 0x09 }; //Initialize 8BPP header
           int TIMoffset = ByteSearch(Stage, TIMtexture, 0); //Search in Stage for TIM header
           int TIMoffsetCLUTetc = TIM + 18; // Logic pass
           UInt16 CLUTsize = BitConverter.ToUInt16(Stage, TIMoffsetCLUTetc); //GET CLUT size to UInt16
           TIMoffsetCLUTetc += 2 + (CLUTsize * 512) + 8; // Logic pass - pass CLUT offset, to get to sensitive data
           UInt16 szerU = BitConverter.ToUInt16(Stage, TIMoffsetCLUTetc); //Get raw UInt16 value of width from texture data
           UInt16 wysoU = BitConverter.ToUInt16(Stage, TIMoffsetCLUTetc + 2); //Get raw UInt16 height value from texture data (real)
           int width = szerU * 2; //Calculate real texture width (For 8BPP = width*2)

Face order / Translation/ triangulation

1.Quad wing order: 

 ABCD ---> ABDC
 example:
  f 1 2 3 4
 to:
  f 1 2 4 3

2.Quad triangulation face order 

 ABDC > ABD
        ACD (same for VT)
 example:
 f 1 2 4 3
 to:
 f 1 2 4
 f 1 3 4

3.Triangles VT order: 

 A/T1 > A/T2
 B/T2 > B/T3
 C/T3 > C/T1
 Example:
 (Also with quad triangulation face order!)
 f 1/1 2/2 7/4 6/3
 to:
 f 1/1 2/2 7/4
 f 1/1 6/3 7/4
 where:
 A=1 B=2 C=6 D=7
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