Textureinformation Crash 2/3

## Introduction

In Crash 2/3, *texture information* contains information about a 3D model's UV coordinates, (animated) textures and colorpalettes. The *texture information* can also be used by *'extended information'* . Extended information can loop through multiple 12-byte structures to make animated textures, or provide settings for textures with different LOD's (Levels of Detail).

## Texture information

Texture information information is stored in 12-byte structures in the 4th item of scenery and model entries. The format for the 12-byte structure consists of 3 consequent 32-bit integers and is as follows:

**YYYYYYYY YYYYXXXX BBBBBBBB AAAAAAAA**

**TTTTTTTT FMM0SSSS DDDDDDDD CCCCCCCC**

**HHHHHHHH GGGGGGGG FFFFFFFF EEEEEEEE**

The contents represent the following:

**AAAAAAAA**

Model entry: for triangle type “AA” and “BB”, UV point 3 x, for triangle type “CC”, UV point 1 x

Scenery entry: UV point 1 x

**BBBBBBBB**

Model entry: for triangle type “AA” and “BB”, UV point 3 y, for triangle type “CC”, UV point 1 y

Scenery entry: UV point 1 y

XXXX

CLUT-line origin x coordinate (CLUT: Color LookUp Table, contain the colors for a specific texture)

**YYYYYYYYYYYY**

CLUT-line origin y coordinate

The origin [x,y] for the CLUT-line is placed in a 16-bit interpretation of the texturechunk.

4-bit textures can have 2^4 = 16 different colors. Therefore the corresponding CLUT-line should always be 16 pixels long (in 16-bit!).

8-bit textures can have 2^8 = 256 different colors. Therefore the corresponding CLUT-line should always be 256 pixels long (in 16-bit!).

**CCCCCCCC**

 Scenery/model entry: UV point 2 x

**DDDDDDDD**

 Scenery/model entry: UV point 2 y

**F**

Flag determined to define a 8 or 4-bit texture. 0 = 4-bit, 1 = 8-bit.

**MM**

The colormode instructs how the texture should interpret the CLUT-colors (formatted as 'SBBBBBGGGGGRRRRR').

 1 (additive face)
 2 (subtractive face)
 3 (standard/opaque face)

**0**

Unused?

**SSSS**

Texturechunk segment index (0, 1, 2 or 3)

Each texturechunk in the original Crash games consists out of 4
segments.

The 16-bit size of a texturechunk is 256 x 128

The 8-bit size of a texturechunk is 512 x 128

The 4-bit size of a texturechunk is 1024 x 128

Therefore, the segments in 16-, 8- and 4-bit mode are respectively:

- 64 x 128,

- 128 x 128

- 256 x 128

The segment index refers to the origin of the segment. The UV points work relative from this origin. Note that the values of the UV points are not effected by 8- or 4-bit mode. The x,y values range from
0 to 255 and are fixed.

**TTTTTTTT**

 Model entry: refers to an offset from 0x0C in the header, for which textureslot to use (0-7 (i.e. 0x0 – 0x40 ) )

 Scenery entry: refers to an offset from 0x2C in the header, for which textureslot to use (0-7 (i.e. 0x0 – 0x40 ) )

**EEEEEEEE**

Model entry: for triangle type “AA” and “BB”, UV point 1 x, for triangle type “CC”, UV point 3 x

Scenery/model entry: UV point 3 x

**FFFFFFFF**

Model entry: for triangle type “AA” and “BB”, UV point 1 y, for triangle type “CC”, UV point  3 y

Scenery/model entry: UV point 3 y

**GGGGGGGG**

Scenery entry: UV point  4 y (applies to quads only)

**HHHHHHHH**

Scenery entry: UV point  4 x (applies to quads only)

## Extended information

Extended information is in the 7th item in scenery entries and/or the 5th item in model entries. It is stored as 32-bit integers and can have 2 different formats according to flag 'F':

**F???????? ???????? ?????OOO OOOOOOOO**

**OOOOOOOOOOO**

Starting offset (in 12-byte structures) in the item for *texture information*. The first structure is indexed by 1, not 0. 0 is reserved for non-textured!

### Texture information with LOD

If flag 'F' is set, the extended information will serve as *texture information* with 8 customizable LOD-settings according to camera distance, ranging from close (AA) to further away (II).

**1AABBCCDDE EFFGGHHI I0000OOO OOOOOOOO**

**AA, BB, CC, DD, EE, FF, GG, HH, II**

LOD-settings. Since each texture has a maximum of 4 LOD's (respectively from hi- to lo-res), each one of these 8 settings can be set from 00 (hi-res) to II (lo-res) in binary.

**0000**

Unused?

### Animated texture information

If flag 'F' is not set, the extended information will serve as *animated* *texture information.* The LOD-distances are standardized. This extended information will define a *128-frame loop* ranging from 0 to 127, starting at the *starting offset*.

**00000000 0000MMMM MMMMLOOO OOOOOOOO**

**MMMMMMMM**

Loopmask. Each frame in the 128-sized loop will be masked by this value. For example, a value of 0x3 would result in a subloop of 4 frames that is repeated 32 times within the 128 frame-sized loop:

There is a great variety of loops to be made with this mechanism.

**L**

Leapflag: when set, this flag makes the offset refer to another 32-bit structure inside the 7th item in scenery and/or the 5th item in models. The eventual texture uses the offset of the structure that does not refer to another one, like a childnode relating to a leafnode.

**000000000000**

Unused?