Level Data Format

Format

The object data pointer contains the following (each section detailed below):

  Header (10 bytes)
  Object Data (4-5 bytes per object)
  $FF
  Screen Exit Data (5 bytes per exit)
  $FF

Sprite data has a separate pointer which contains 3-byte entries and ends with $FFFF.

Header

The level header contains information that is used to set up the level's graphics, music, items, and scrolling. It uses a bitpacked format that can be summarized as follows:

  ccccc111 1ppppp22 222ppppp p333333p pppppsss sssspppp dddddaaa aaappppp rrrrrmmm miiuuuuu
  c = background color
  1 2 3 = BG# tileset
  p = palette (for preceding tileset)
  s = sprite tileset
  d = level mode
  a = animation tileset
  r = BG scroll rate
  m = music
  i = item memory
  u = unused

Type	Packed Length (bits)	RAM Address Destination
BG Color	5	$7E0134
BG 1 Tileset	4	$7E0136
BG 1 Palette	5	$7E0138
BG 2 Tileset	5	$7E013A
BG 2 Palette	6	$7E013C
BG 3 Tileset	6	$7E013E
BG 3 Palette	6	$7E0140
Sprite Tileset	7	$7E0142
Sprite Palette	4	$7E0144
Level Mode	5	$7E0146
Animation Tileset	6	$7E0148
Animation Palette	5	$7E014A
BG Scrolling Rate	5	$7E014C
Music	4	$7E014E
Item Memory	2	$7E0150
Unused	5	$7E0152

Object Data

Objects can be 3 types: 4-byte, 4-byte extended, or 5-byte. The first byte of the object governs which type it shall be. $00 indicates extended, otherwise the first byte is the ID which governs whether to read in just length or width & height (4 vs. 5). The $1284EC table is what governs 4 vs. 5; the ID is used to index into it, and if the first 2 bits of the byte that's retrieved from the table are equal to 00 or 01 (binary), then it is 4-byte; otherwise, 5.

5-Byte Objects:
  IIIIIIII       ID (can't be 00/FF)
  XXXXYYYY       High X and High Y
  xxxxyyyy       Low X and Low Y
  WWWWWWWW       Width - 1, signed
  HHHHHHHH       Height - 1, signed

4-Byte Objects:
  IIIIIIII       ID (can't be 00/FF)
  XXXXYYYY       High X and High Y
  xxxxyyyy       Low X and Low Y
  LLLLLLLL       Length - 1, signed

4-Byte Extended Objects
  00000000
  XXXXYYYY       High X and High Y
  xxxxyyyy       Low X and Low Y
  IIIIIIII       ID

Screen Exit Data

Screen exits may be two types; each are 5 bytes.

Level warp:
  TTTTTTTT       Target page (between 00 and 7F)
  LLLLLLLL       Destination Level (between 00 and DD)
  XXXXXXXX       Destination X-Coordinate
  YYYYYYYY       Destination Y-Coordinate
  EEEEEEEE       Destination Entrance Type (between 00 and 0A)

Minibattle:
  TTTTTTTT       Target page (between 00 and 7F)
  MMMMMMMM       Destination Minibattle (between DE and E9)
  XXXXXXXX       Return X-Coordinate
  YYYYYYYY       Return Y-Coordinate
  LLLLLLLL       Return Level (between 00 and E9)

Sprite Data

  iiiiiiii       Low ID
  YYYYYYYI       High ID and Y Tile Coordinate
  XXXXXXXX       X Tile Coordinate