Sprite sheet

Most sprite sheets are located at SUBDATA.DAT/START.DAT/ANM000.DAT and each sprite sheets is made of 8 parts:

1. Header + 4 data pointers
2. Animations
3. Layers
4. Sprite sheets informations
5. Keyframes
6. Cutouts
7. Color table
8. Sprite sheet images

1. Header

Type	Size	Description
uShort	2 byte	Number of animations
uShort	2 byte	Number of layers
uShort	2 byte	Number of colortable sets?
uShort	2 byte	Number of sprite sheets
uShort	2 byte	Number of keyframes
uShort	2 byte	Number of cutouts
uShort	2 byte	Number of color tabels, is always 1?
uShort	2 byte	Number of sprite sheets?

The four data pointers:

Type	Size	Description
uInt	4 byte	Points to keyframes
uInt	4 byte	Points to cutouts
uInt	4 byte	Points to the color tables
uInt	4 byte	Points to the image data

2. Animations

For each animations:

Type	Size	Description
uShort	2 byte	Start keyframe index
uShort	2 byte	Animation ID (like a name)

The end keyframe of an animation is the next animation starting keyframe.

3. Layers

A Layer is a set of cutouts, which get rendered in order.

For each layer:

Type	Size	Description
uShort	2 byte	Start cutout index
uShort	2 byte	Number of cutouts

4. Sprite sheet informations

At start there is a uInt (4 byte) with the size of the color table.

This contains the infomations about each sprite sheet. The width and height can be any number but the game matches them to the given power (2^x). So the sizes should be 16,32,64,128,256,512,1024 so on.

'The power of color table' determine the encoding of the ID sprite sheet. If the power is biger then 4 (16 colors) then each ID is saved as a uChar 1 byte.

For each sheet:

Type	Size	Description
uInt	4 byte	Pointer to the image
uShort	2 byte	Width
uShort	2 byte	Height
uChar	1 byte	The power of color table
uChar	1 byte	image swizzled (not used on PC)
uChar	1 byte	The power of width
uChar	1 byte	The power of height

5. Keyframes

For each Keyframe:

Type	Size	Description
uShort	4 byte	Layer index
uChar	2 byte	Delay (ns?, s?)
uChar	2 byte	Type: 1 - Start, 0 - Continue, 2 - End (End keyframe is not displayed?), 3 - effect marker?
uShort	4 byte	ingame x offset? (mostly 0)
uShort	4 byte	ingame y offset? (mostly 0)

Changed blinking keyframes, the delay has been increased and the end keyframe has been moved forward.

6. Cutouts

A cutout is a part of sprite sheet, which is build with a given color table.

For each cutout:

Type	Size	Description
uShort	2 byte	External sheet ID, if not 0 then the keyframe references a outside file
uChar	1 byte	Sprite sheet index
uChar	1 byte	Color table offset
Short	2 byte	Anchor X, point of rotation and mirror
Short	2 byte	Anchor Y, point of rotation and mirror
uShort	2 byte	X
uShort	2 byte	Y
uShort	2 byte	Width
uShort	2 byte	Height
Short	2 byte	Scale X (0 - 100)
Short	2 byte	Scale Y (0 - 100)
Short	2 byte	Offset X, from the anchor point
Short	2 byte	Offset Y, from the anchor point
Short	2 byte	Rotation is degree
uChar	1 byte	Transparency (0-128)
uChar	1 byte	0x10-Mirror horizontally, 0x08-Mirror vertically, 0x04 - Blend mode

Left, 'scale X' was set from 100 to 50. Right, 'colortable index' was set from 0 to 2 (this color table is used for the character portrait).

7. Color table

The color table is build out if sets of 16 BGRA pixels. The size is 'size'*16*4

> Color table example.

8. Sprite sheet images

The image data holds a offset to a color table value, to this is also added a starting offset, which is defined in the cutouts. This means to fully reconstruct the colors you also need to use the cutouts.

There are two known fromats:

16 or less colors:

This is the most common format, in which each byte holds two indexes for a color table => two pixels.

const char c = reader.readChar();
unsigned char index1 = c & 0x0F;
unsigned char index2 = (c >> 4) & 0x0F;

XKeeper custom sprite sheet. Left, the image IDs 0-32. Right, color image build with two separate color tables, one for the character and one for the portrait.

up to 256 colors:

Each byte is one offset. This is used if used color table has more then 16 colors.

/*
 * colortabels - every color table as one long array
 * cut - the cutout information
 * cut.colortable - the colortable with cutout uses (start offset)
 * IDImage - the 16 or 256 ID image (offset)
 */
rgbaImage[i] = colortabels[cut.colortable*16 + IDImage[i]];