[Exult-general] TFA.DAT

[Marzo J. <ma...@ya...>]

    Hello all,

    I just discovered something about which I want to
ask to see if anyone knowns anything about it: namely,
that the TFA.DAT file (in both BG and SI) have a
512-byte tailer which is not at all read by Exult
(assuming you do not read part of that data in SI for
the skin shapes). I was shocked to discover that.
Doubly so since it seems to contain animation data!

    Thanks to hex editing and DOSBox, this is what I
know for sure:

    It is a nibble-field -- each byte has 4 bits for
each shape. Thus, the shapes take the data at offset
0xC00 + shape/2, the high nibble being for the odd
shape. The shape nibbles do not seem to be bit fields.

    For animating shapes, the nibbles mean the
following:

============
BG
Nibble    Meaning
--------------------------
0, 1      Continuous, looping animation
2         Unused like 0 or 1, but frames seem to
          advance randomly (maybe with 1/4 chance)
3         Mistery. Some shapes animate to the end then
          keep alternating between the last two
frames,
          other shapes reverse direction of animation
          at the end then back at the beginning.
          Present only for strength tester, which is
          not animated.
4         Mystery, unused. Frames advance randomly,
          like in 2, but with some of the behaviour of
          3. Maybe 1/4 chance to advance as per 3?
5         Like the random loops I recently added;
stops
          at frame 0 for random periods of time, then
          animates as per 0 or 1.
6         Seems to select one frame at random from the
          animation. Used for wounded man.
7         Present only in slimes. When used for an
          animated shape, toggles bit 0 of frame at
          random time intervals with a low chance.
8         Sundials; frame = hour of day.
9         Fire/sleep fields. Resumes animation from
8th
          frame from last (i.e., frame 24 if shape has
          32-frames, like the wounded man).
A         Poison field. Like 9, but using the 6th
frame
          from last instead.
B         Doesn't animate first frame; all other
frames
          form a single looping cycle (e.g., shafts).
C         Like 1, but animation is slower; maybe 1/4
of
          normal speed. Used only for guillotine and
          wedding ring, which don't animate.
D         Energy field: animates normally but stops at
          the last frame.
E         Grandfather clocks; slower animation. Maybe
          time-synched?
F         Unused; does not animate at all.

============
SI
Nibble    Meaning
--------------------------
0 to E    Exactly like their BG counterparts
F         Animation happens in groups of 6 frames or
          less. Thus, a shape with 13 frames would
have
          3 cycles: 0-5, 6-11 and 12 (non-animating).

    In any case, the current system in Exult is far
more capable than the original system. Methinks I will
just use this new data to finish adding data in
shape_info.txt for BG and SI and fix the TFA reader to
ignore those last 512 bytes. Maybe add some of the
extra capabilities like those from nibbles 6 and 7.

    Any thoughts?


-- 

Marzo Sette Torres Junior
ma...@fi...
ma...@ya...
ma...@ta...


 
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