CHAPTER : Floor and Ceiling Textures
All the names for these textures are in the directory between the
F_START and F_END entries. There is no look-up or meta-structure as with the
walls. Each texture is 4096 raw bytes, making a square 64 by 64 pixels, which
is pasted onto a floor or ceiling, with the same orientation as the automap
would imply, i.e. the first byte is the color at the NW corner, etc. The
blocks in the grid are 128 by 128, so four floor tiles will fit in each
The data in F_SKY1 isn't even used since the game engine interprets
that special ceiling as see-through to the SKY texture beyond. So the F_SKY1
entry can have zero length.
As discussed in chapter , replacement and/or new-name floors don't
work right from pwad files, only in the main IWAD.
You can change all the floors and ceilings you want by constructing a
new DOOM.WAD, but you have to make sure no floor or ceiling uses an entry
name which isn't in your F_ section. And you have to include these four entries,
although you can change their contents (pictures): FLOOR4_8, SFLR6_1,
MFLR8_4, and FLOOR7_2. The first three are needed as backgrounds for the
episode end texts. The last is what is displayed "outside" the display window
if the display is not full-screen.
[6-1]: Animated floors
See Chapter [8-4-1] for a discussion of how the animated walls and
floors work. Unfortunately, the fact that the floors all need to be lumped
together in one wad file means that its not possible to change the animations
via a pwad file, unless it contains ALL the floors, which amounts to several
hundred k. Plus you can't distribute the original data, so if you want to
pass your modification around, it must either have all the floors all-new,
or you must create some sort of program which will construct the wad from
the original DOOM.WAD plus your additions.