[DGD] Shadows issue

[Kamil Niechajewicz]

Hello all,
I just recently discovered DGD mudlib and it looks reallypromising and
interesting. My experience as MUD developer started with Diku type
MUDs, but I quickly dumped them in favor of LpMUDs, and spent most of
my coding time with LPC & CD driver for Genesis LPMUD.

I haven't really done anything in LPC in last 6-7 years but recenly I
regained my interest in MUDs and decided to try and write my own
mudlib based on DGD driver (even if I never finish it, it may be a
good fun to try :). So far I really like what DGD offers and most of
the design decisions made by its authors, but with one thing I
encountered some "theoretical" problems. As I'm used to functions that
CD offered, I wonder what is the best way to achieve effect that
"shadowing" had in mudlibs based on CD.

Just to remind - shadows in CD mudlibs were mostly used for things
like guild membership - player inherited pre-defined empty methods
that described guild titles, taxes and other things and when he joined
a guild he was given a shadow that masked those methods, so they
started to return proper guild title, tax etc. Same for stuff like
changing appearance, lets say we want to give player a chance to
become an undead - I think the easiest way it was done in CD was to
give him some kind of "undead" shadow that overriden all necessary
methods like player description, player shorts, even how he
enters/leaves the room, how he acts in combat etc. etc. Same for
"fluff" like mounts if I remember well - it was all based on shadowing
certain methods, and by doing it achieving very varied effects. Also
this method didn't force coders to design and imagine every possible
change that should be allowed in certain objects - they could always
mask these methods by using shadows (unless it was prevented for that
object).

I hope I described the uses of shadows I'm interested in good enough,
if not please say so and I will try to provide some sample code or
something :) I searched for this topic before writing this mail, but
haven't found too much information. There was even attempt to mimic
shadows behavior in mudlib by overriding call_other, but I'm not sure
I should use this method if whole shadow thing was skipped in driver
(there was some reason I guess).

Maybe you know different approaches to code things that I described
(some nice new way to do this "modern" way), so: guild membership,
changing user behavior or even whole user "living" object so it
becomes undead creature or some super-monster etc. I guess it could be
achieved by changing body object to different one, but how to do it
when its already inherited by player? Is it possible to change
inherited objecy "on the fly"? So if player is inheriting LIVING_BODY
we change it for UNDEAD_BODY and he automatically receives proper
methods changing his descriptions, behaviour etc? This must be done
without relogging player of course.

Any help is appreciated, I'm a bit "rusty" if it comes to designing
these things nowdays, but I'm reading alot and trying to find best
possible design solutions, but some things like the ones above are not
covered too much in any documentation & manuals. So far most of
discussions here covered more low-level things about mudlib design,
and my problem lies more in that "higher" tier of programming mudlib
where you code guilds, mounts, advanced changes to player behavior /
body, things that affect combat etc.

Thanks,

KN