OBD talk:TXMP

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Revision as of 10:16, 13 February 2007 by Ssg (talk | contribs) (→‎Store type: anthing else)
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Complete and accurate knowledge on the TXMP format is badly needed.
For one thing, incomplete/inaccurate knowledge may be a reason why repacking (with OUP) fails.
Also, import and export lack a few features (alpha, env maps) and may get colors slightly wrong.
Basically, the incomplete/inaccurate information is related to the three bytes below, and to the associated RAW/SEP formats.
One not-too-comfortable aspect is that apparently contradictory settings for the 3 bytes are somehow interpreted by Oni.
geyser 21:09, 3 February 2007 (CET)
Option Value Meaning
MIP-mapping types 00 off
01 on
11 unknown
1C unknown (used for skyboxes, works with 00 too)
Color depths 10 16 bit
12 16 bit + shade vertex
14 16 bit + 4 bits for the alpha channel
20 32 bit
Store types 00 uncompressed, with alpha blending
01 uncompressed, without alpha blending
02 unknown
03 unknown
08 32 bit uncompressed (used for skyboxes)
09 compressed
0A unknown
0B unknown

Bitsets or indices

Store type
probably an index
MIP mapping
not sure
maybe they are not only MIP mapping options
(in that case almost certainly a set of flags)
Color depth
It's not just the color depth
(actually, quite little to do with color depth)
so almost certainly a bitset.

MIP mapping

0x01
This one "just" turns mip mapping on and off.
For uncompressed pictures, resampling is trivial. ==> They are "pre-resampled". It's not done at runtime.
what about compressed ones.
0x02
unknown
0x04
Enabled for skyboxes (anything special about the format?)
0x08
unknown
0x10
This one is enabled for env-mapped textures and env maps themselves.
Also enabled for skyboxes?
0x20
if you use this bit, you get always a white image; never used in Oni (IIRC)
0x40
unknown
0x80
unknown
Anything else?
There aren't so many values: 0, 1, 17, 28. It's hard to decide against an ID.
A bitset does make some sense because both 1 and 17 use MIP mapping...
Well, IMO they're bitsets. I fixed that a long time ago. Ssg 10:59, 13 February 2007 (CET)

Color depth

Actually, the colors are parsed according to the store type.
This one only sets the depth for miscellaneous extras (alpha, env map, etc)
0x01
Used when again?
0x02
Reads the high byte as env map (0x00 is "little", 0xFF is "much")
Sometimes used in conjunction with 5x5x5 textures, i.e. if it really
reads the whole byte, the 3 lower bits will be garbage. Not sure...
0x04
Reads the high byte as alpha (0x00 is transparent, 0xFF is opaque)
0x08
Used when again?
0x10
On if there are 16 bits per uncompressed pixel (color depth etc may vary) ==> no changes ==> Oni reads it directly from the raw file
0x20
On if there are 32 bits per uncompressed pixel (color depth etc may vary) (or may they?)
IIRC, that bit is never used in Oni. If you use it, Oni chrashes.
0x40
Looks like TXAN looping ON/OFF. Somebody please check somehow ^^
0x80
16 bit blue (?) - only SHIELD use it

The first two bits of the next bitset are used too:

0x01
16 bit alpha (?) - only INVIS use it
0x02
16 bit red (?) - only DAODAN_SHIELD use it Ssg 11:06, 13 February 2007 (CET)

Store type

Data per pixel, uncompressed unless mentioned otherwise

0
(4,4,4) RGB, 4 bits extra (interpreted as alpha or env map blending)
1
(5,5,5) RGB and 1 bit extra, or (5,6,5) RGB?
2
(5,5,5) RGB, 1 bit extra
8
(8,8,8) RGB?
9
compressed (four times) (algorithm detailed elsewhere)
Anything else?
No. Uups... I mean, yes.
The "mac exe" contains the following stuff in the image section (image.c or somthing like that):
rgb555, rgb565, rgba5551, argb1555, argb4444, rgba4444, rgba8888, s3, compressed, i8, i1, i4a4
(r=red, g=green, b=blue, a=alpha, i=intensity; see http://www.cg.tuwien.ac.at/~wimmer/view3dx/TEXUS.html too)