TEXTURE1, TEXTURE2 and PNAMES is a system developped by idSoftwareare to create textures from socalled patches. All three lumps may be present in a pwad. Patches are those images which are placed between P_ markers (P_START and P_END).

In the original DOOM games, this namespace is further broken down into separate P1_, P2_ and P2_ spaces, probably to separate images into themes.

One might wonder why such a system was applied. The reasoning was to contain the textures memory footprint as small as possible. Consider that DOOM was programmed at a times when Most PCs had only 640 KB of memory, so having a lot of full blown textures to deal with ate up a lot of that memory space. A few small textures (patches) were employed to piece together a large number of textures.

TEXTUREx

• TEXTURE1
  is used for the original DOOM/2/U games to catalog the patches used which compose the textures.
  When making a PWAD with new textures, it is required that TEXTURE1 includes the new textures plus the ones from the base resource of DOOM2.wad. Remember that TEXTURE1 lumps will not concatenate, meaning a new TEXTURE1 will overwrite an older TEXTURE1. For example when loading several pwads, each having a TEXTURE1 lump.


• TEXTURE2
  can be used in new pwads, representing the new textures.
  When used, there is a definite division between the original textures in TEXTURE1 and the new textures in TEXTURE2.


• PNAMES
  is the database of all patches, for DOOM2 plus new ones, defined by either TEXTURE1 or TEXTURE2.