View source for Sprite bank file

{{ParentArticle|[[File formats]]}}
A sprite bank file is used to store multiple [[Sprite file]] in a very efficient manner. All sprites in a BNK file are compressed using [[Team17 compression]] and they all share one palette.

BNK files are used both by Worms World Party and Worms World Party Aqua in their gfx.dir and water.dir files.

== File Format ==
{| border="1" cellspacing="0" class="wikitable"
!Size
!Type
!Description
|-
| 4 || int32
| '''Signature'''. The [[w: Magic number (programming)|magic number]] used to identify the BNK file. [[w: Hexadecimal|Hex]]: 0x424E4B1A, [[w: ASCII|ASCII]]: "BNK\1A"
|-
| 4 || int32
| '''File Length''' The total length of the file.
|-
| 2 || int16
| '''Palette Count''' The number of palette entries, excluding back color.
|-
| 3 * i || byte[,]
| '''Palette''' The palette used for all frames in the file. Each palette entry is 3 bytes long, stored in BGR format. (sized as ''new byte[PaletteCount, 3]'')
|-
| 0 to 3 || byte[]
| '''Padding''' Padding is added to put the data in 4 byte position. (pos + 2) % 4
|-
| 4 || int32
| '''Sprite Count''' The total number of sprites stored in the file.
|-
| 12 * i || Sprite[]
| '''Sprite Info''' The data explaining how to get and display the sprite animations. (sized as ''new Sprite[SpriteCount]'')
|-
| 4 || int32
| '''Frame Count''' The total number of frames stored in the file.
|-
| 12 * i || Frame[]
| '''Frame Info''' The data explaining how to get and display the individual frames of a sprite animation. (sized as ''new Frame[FrameCount]'')
|-
| 4 || int32
| '''Stream Count''' The total number of compressed data streams stored in the file.
|-
| 12 * i || Stream[]
| '''Stream Info''' The data explaining how to get and decompress the image data streams. (sized as ''new Stream[StreamCount]]'')
|-
| var || Stream[]
| '''Stream Data''' The compressed image data streams.
|}

== The Sprite Struct ==
{| border="1" cellspacing="0" class="wikitable"
!Size
!Type
!Description
|-
| 2 || int16
| '''Flags''' The play back settings.
|-
| 2 || int16
| '''Width''' The cell width of the animation.
|-
| 2 || int16
| '''Height''' The cell height of the animation.
|-
| 2 || int16
| '''Frame Start''' The starting frame number for the animation.
|-
| 2 || int16
| '''Frame Count''' The total number of frames for the animation.
|-
| 1 || byte
| '''Unknown''' Unknown, but important.
|-
| 1 || byte
| '''Frame Rate''' The tick delay between frames.
|-
|}

== The Frame Struct ==
{| border="1" cellspacing="0" class="wikitable"
!Size
!Type
!Description
|-
| 2 || int16
| '''Stream''' The stream number that the frame image data is stored in.
|-
| 2 || int16
| '''Data Position''' The starting position of the frame image data in the decompressed stream.
|-
| 2 || int16
| '''Left Offset''' The left offset of the image data relative to the sprite cell.
|-
| 2 || int16
| '''Up Offset''' The up offset of the image data relative to the sprite cell.
|-
| 2 || int16
| '''Right Offset''' The right offset of the image data relative to the sprite cell.
|-
| 2 || int16
| '''Down Offset''' The down offset of the image data relative to the sprite cell.
|-
|}

== The Stream Struct ==
{| border="1" cellspacing="0" class="wikitable"
!Size
!Type
!Description
|-
| 4 || int32
| '''Compressed Position''' The starting position of the compressed data stream.
|-
| 4 || int32
| '''Decompressed Length''' The total length of the decompressed data stream.
|-
| 4 || int32
| '''Unknown''' Unknown, most likely useless.
|-
| var || byte[]
| '''Compressed Image Data''' The compressed data stream's binary data. (see Decompression Routine in [[Team17 compression]])
|-
|}