The TEXTURE1 and TEXTURE2 lumps define how wall patches from the WAD file should combine to form wall textures.
In other words, a texture is decomposed into smaller textures in such a way that repeating areas are only stored once. At startup time (to be precise, during "R_Init: Init DOOM refresh daemon"), the patches inside the WAD are read and combined into Wall Textures, or how the source code refers to, 'map textures'.
Binary data[]
The binary contents of the TEXTURE1 and TEXTURE2 lumps start with a header of flexible size, followed by all of the map textures.
TEXTURE1 or TEXTURE2 | |||
---|---|---|---|
Offset | Length | Name | Content |
0x00 | 4 | numtextures | An integer holding a the number of map textures. |
0x04 | 4 * numtextures | offset[] | An array of integers containing the offsets to the map textures in this lump. |
offset[0] offset[1] ... |
Flexible | mtexture[] | An array with the map texture structures. (see next table) |
All integers are 4 bytes long in x86-style little-endian order. Their values can never exceed 231-1, since Doom reads them as signed ints. Short integers are 2 bytes long and are otherwise equal to integers.
Map textures structure, binary data[]
The binary contents of the maptexture_t structure starts with a header of 22 bytes, followed by all the the map patches.
maptexture_t | |||
---|---|---|---|
Offset | Length | Name | Content |
0x00 | 8 | name | An ASCII string defining the name of the map texture. Only the characters A-Z (uppercase), 0-9, and [] - _ should be used in lump names. When a string is less than 8 bytes long, it should be null-padded to the eighth byte. |
0x08 | 4 | masked | A boolean (0=false, 1=true) defining ? |
0x0C | 2 | width | A short integer defining the total width of the map texture. |
0x0E | 2 | height | A short integer defining the total height of the map texture. |
0x10 | 4 | columndirectory | Obsolete, ignored by all DOOM versions |
0x14 | 2 | patchcount | the number of map patches that make up this map texture |
0x16 | 10 * patchcount | patches[] | array with the map patch structures for this texture. (see next table) |
Map patches structure, binary data[]
The binary contents of the mappatch_t structure contains 10 bytes defining how the patch should be drawn inside the texture.
mappatch_t | |||
---|---|---|---|
Offset | Length | Name | Content |
0x00 | 2 | originx | A short int defining the horizontal offset of the patch relative to the upper-left of the texture |
0x02 | 2 | originy | A short int defining the vertical offset of the patch relative to the upper-left of the texture |
0x04 | 2 | patch | A short int defining the patch number (as listed in PNAMES) to draw |
0x06 | 2 | stepdir | A short int defining ? |
0x08 | 2 | colormap | A short int defining ? |
Other formats[]
The TEXTUREx format above is used in the all versions of Doom since the the 0.5 alpha, Heretic, and Hexen, as well as the "teaser" and 1.0 versions of Strife.
The earlier alpha versions of Doom and v1.1 of the Strife IWAD have different formats.
Doom 0.2[]
This version has no TEXTUREx lump at all; and instead displays patches directly on the walls.
Doom 0.4[]
This version has a single TEXTURES lump with a "nameless" format.
maptexture04_t | |||
---|---|---|---|
Offset | Length | Name | Content |
0x00 | 4 | masked | A boolean (0=false, 1=true) defining ? |
0x04 | 2 | width | A short integer defining the total width of the map texture. |
0x06 | 2 | height | A short integer defining the total height of the map texture. |
0x08 | 4 | columndirectory | Obsolete, ignored by all DOOM versions |
0x0C | 2 | patchcount | the number of map patches that make up this map texture |
0x0E | 10 * patchcount | patches[] | array with the map patch structures for this texture. |
Strife 1.1 and above[]
These have a shortened format with unused bits removed.
maptexturestrife11_t | |||
---|---|---|---|
Offset | Length | Name | Content |
0x00 | 8 | name | An ASCII string defining the name of the map texture. Only the characters A-Z (uppercase), 0-9, and [] - _ should be used in lump names. When a string is less than 8 bytes long, it should be null-padded to the eighth byte. |
0x08 | 4 | masked | A boolean (0=false, 1=true) defining ? |
0x0C | 2 | width | A short integer defining the total width of the map texture. |
0x0E | 2 | height | A short integer defining the total height of the map texture. |
0x10 | 2 | patchcount | the number of map patches that make up this map texture |
0x12 | 6 * patchcount | patches[] | array with the shortened map patch structures for this texture. (see next table) |
mappatchstrife11_t | |||
---|---|---|---|
Offset | Length | Name | Content |
0x00 | 2 | originx | A short int defining the horizontal offset of the patch relative to the upper-left of the texture |
0x02 | 2 | originy | A short int defining the vertical offset of the patch relative to the upper-left of the texture |
0x04 | 2 | patch | A short int defining the patch number (as listed in PNAMES) to draw |
Text formats[]
DeuTex uses a combined PNAMES + TEXTUREx format to output extracted textures or recreate a texture lump. The format is simple:
;Comment TextureNameWidthHeight *PatchNameXoffsetYoffset
If a line starts with a name, it is a new texture. If it starts with an asterisk, it is a patch to add to the last texture. If it starts with a semi-colon, it is ignored as a comment. Patch names are used directly and the PNAMES table is then rebuilt by numbering them in order of appearance. The numbers that follow a texture names are understood as its dimensions, while the numbers that follow a patch name are understood as its offsets.
Doom source ports such as Doomsday and ZDoom have introduced new text based formats for textures which allows many additional effects to be performed, such as patch rotation or mirroring, as well as altering colors with a translation or a blending.