Block diagram
This page hosts a formal specification of .wad file format of id Tech 1 using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
meta:
id: doom_wad
application: id Tech 1
file-extension: wad
xref:
justsolve: Doom_WAD
mime: application/x-doom
wikidata: Q1936828
license: CC0-1.0
endian: le
seq:
- id: magic
type: str
size: 4
encoding: ASCII
- id: num_index_entries
type: s4
doc: Number of entries in the lump index
- id: index_offset
type: s4
doc: Offset to the start of the index
types:
index_entry:
seq:
- id: offset
type: s4
- id: size
type: s4
- id: name
type: str
size: 8
encoding: ASCII
pad-right: 0
instances:
contents:
io: _root._io
pos: offset
size: size
type:
switch-on: name
cases:
'"THINGS"': things
'"LINEDEFS"': linedefs
'"SIDEDEFS"': sidedefs
'"VERTEXES"': vertexes
'"BLOCKMAP"': blockmap
'"SECTORS"': sectors
'"TEXTURE1"': texture12
'"TEXTURE2"': texture12
'"PNAMES"': pnames
things:
seq:
- id: entries
type: thing
repeat: eos
thing:
seq:
- id: x
type: s2
- id: y
type: s2
- id: angle
type: u2
- id: type
type: u2
- id: flags
type: u2
linedefs:
seq:
- id: entries
type: linedef
repeat: eos
linedef:
seq:
- id: vertex_start_idx
type: u2
- id: vertex_end_idx
type: u2
- id: flags
type: u2
- id: line_type
type: u2
- id: sector_tag
type: u2
- id: sidedef_right_idx
type: u2
- id: sidedef_left_idx
type: u2
sidedefs:
seq:
- id: entries
type: sidedef
repeat: eos
sidedef:
seq:
- id: offset_x
type: s2
- id: offset_y
type: s2
- id: upper_texture_name
type: str
size: 8
encoding: ASCII
- id: lower_texture_name
type: str
size: 8
encoding: ASCII
- id: normal_texture_name
type: str
size: 8
encoding: ASCII
- id: sector_id
type: s2
vertexes:
seq:
- id: entries
type: vertex
repeat: eos
vertex:
seq:
- id: x
type: s2
- id: y
type: s2
blockmap:
seq:
- id: origin_x
type: s2
doc: Grid origin, X coord
- id: origin_y
type: s2
doc: Grid origin, Y coord
- id: num_cols
type: s2
doc: Number of columns
- id: num_rows
type: s2
doc: Number of rows
- id: linedefs_in_block
type: blocklist
repeat: expr
repeat-expr: num_cols * num_rows
doc: Lists of linedefs for every block
types:
blocklist:
seq:
- id: offset
type: u2
doc: Offset to the list of linedefs
instances:
linedefs:
pos: offset * 2
type: s2
repeat: until
repeat-until: _ == -1
doc: List of linedefs found in this block
sectors:
seq:
- id: entries
type: sector
repeat: eos
sector:
seq:
- id: floor_z
type: s2
- id: ceil_z
type: s2
- id: floor_flat
type: str
size: 8
encoding: ASCII
- id: ceil_flat
type: str
size: 8
encoding: ASCII
- id: light
type: s2
doc: |
Light level of the sector [0..255]. Original engine uses
COLORMAP to render lighting, so only 32 actual levels are
available (i.e. 0..7, 8..15, etc).
- id: special_type
type: u2
enum: special_sector
- id: tag
type: u2
doc: |
Tag number. When the linedef with the same tag number is
activated, some effect will be triggered in this sector.
enums:
special_sector:
0: normal
1: d_light_flicker
2: d_light_strobe_fast
3: d_light_strobe_slow
4: d_light_strobe_hurt
5: d_damage_hellslime
7: d_damage_nukage
8: d_light_glow
9: secret
10: d_sector_door_close_in_30
11: d_damage_end
12: d_light_strobe_slow_sync
13: d_light_strobe_fast_sync
14: d_sector_door_raise_in_5_mins
15: d_friction_low
16: d_damage_super_hellslime
17: d_light_fire_flicker
18: d_damage_lava_wimpy
19: d_damage_lava_hefty
20: d_scroll_east_lava_damage
21: light_phased
22: light_sequence_start
23: light_sequence_special1
24: light_sequence_special2
texture12:
doc: |
Used for TEXTURE1 and TEXTURE2 lumps, which designate how to
combine wall patches to make wall textures. This essentially
provides a very simple form of image compression, allowing
certain elements ("patches") to be reused / recombined on
different textures for more variety in the game.
doc-ref: https://doom.fandom.com/wiki/TEXTURE1_and_TEXTURE2
seq:
- id: num_textures
type: s4
doc: Number of wall textures
- id: textures
type: texture_index
repeat: expr
repeat-expr: num_textures
types:
texture_index:
seq:
- id: offset
type: s4
instances:
body:
pos: offset
type: texture_body
texture_body:
-orig-id: maptexture_t
seq:
- id: name
type: str
size: 8
pad-right: 0
encoding: ASCII
doc: Name of a texture, only `A-Z`, `0-9`, `[]_-` are valid
- id: masked
type: u4
- id: width
type: u2
- id: height
type: u2
- id: column_directory
type: u4
doc: Obsolete, ignored by all DOOM versions
- id: num_patches
type: u2
doc: Number of patches that are used in a texture
- id: patches
type: patch
repeat: expr
repeat-expr: num_patches
patch:
-orig-id: mappatch_t
seq:
- id: origin_x
type: s2
doc: X offset to draw a patch at (pixels from left boundary of a texture)
- id: origin_y
type: s2
doc: Y offset to draw a patch at (pixels from upper boundary of a texture)
- id: patch_id
type: u2
doc: Identifier of a patch (as listed in PNAMES lump) to draw
- id: step_dir
type: u2
- id: colormap
type: u2
pnames:
doc-ref: https://doom.fandom.com/wiki/PNAMES
seq:
- id: num_patches
type: u4
doc: Number of patches registered in this global game directory
- id: names
type: str
size: 8
encoding: ASCII
pad-right: 0
repeat: expr
repeat-expr: num_patches
instances:
index:
pos: index_offset
type: index_entry
repeat: expr
repeat-expr: num_index_entries