paa.ksy

meta:
  id: paa
  file-extension: paa
  endian: le

seq:
  - id: type
    type: u2
    enum: pax_type
  - id: tags
    type: tag
    repeat: until
    repeat-until: _.next_signature != "GGAT"
  - id: palette
    type: palette
  - id: mipmaps
    type: mipmap
    repeat: until
    repeat-until: _.next_mipmap_width == 0

types:
  mipmap:
    seq:
      - id: width
        type: u2
      - id: height
        type: u2
      - id: size12
        type: u2
      - id: size3
        type: u1
      - id: data
        size: size
    instances:
      size:
        value: 'size12 | (size3 << 16)'
      next_mipmap_width:
        pos: _io.pos
        type: u2
        
  palette:
    seq:
      - id: triplets
        type: u2
  tag:
    seq:
      - id: signature
        type: str
        size: 4
        encoding: ASCII
      - id: type
        type: str
        size: 4
        encoding: ASCII
      - id: data_len
        type: u4
      - id: data
        size: data_len
    instances:
      next_signature:
        pos: _io.pos
        type: str
        size: 4
        encoding: ASCII

enums:
  pax_type:
    0x8080: gray_w_alpha
    0xFF01: dxt1