A thorough code review/overhaul of QuickMUD / ROM 2.4b6 for starting your MUD

BaseMUD is a work-in-progress fork of QuickMUD that has been heavily reorganized, refactored, and cleaned-up for clarity and easy extendability. This project has two main goals:

1. Provide an easy-to-modify codebase for those who want to play around with their own stock ROM mud, and
2. Provide a transitional project for porting the ROM codebase to C++ or another high-level language.

To compile and run:

cd src
make
cd ..
./run.sh

To play:

telnet localhost 4000

BaseMUD comes packaged with a level 60 "Implementor" account. The name is Admin and the password is Admin. Change the password and, if you'd like, create your own god character and raise them to level 60.

BaseMUD is based on QuickMUD, which is based on the ROM 2.4 beta version of Merc 2.1 base code, which is in turn based on DikuMUD. Credits in licenses:

ROM 2.4 copyright (c) 1993-1995 Russ Taylor.
MERC 2.1 code by Hatchet, Furey, and Kahn.
DikuMUD by Hans Staerfeldt, Katja Nyboe, Tom Madsen, Michael Seifert, and Sebastian Hammer

If you wish to use BaseMUD, you must comply with the following licenses:

• doc/license.doc: DikuMUD license
• doc/license.txt: Merc Release 2.1 license
• doc/rom.license: ROM 2.4 license

As with QuickMUD, BaseMUD is packaged with the following code (which has been integrated into the source code more thoroughly):

• OLC 1.81
• Lope's Color 2.0
• Erwin's Copyover
• Erwin's Noteboard
• Color Login

This project is still very rough. I've been testing things as I go, but I've been haphazardly moving large swaths of code around under the premise that everything will be thoroughly tested later. Hopefully the resulting code will be modular enough that some sort of unit testing environment will be possible.

Despite the heavy refactoring, BaseMUD strives to be a pure version of ROM 2.4. However, in the process of sifting through all this code, sometimes I just can't help myself. Some small changes and additions have been made, which can be enabled by commenting out the line #define VANILLA in src/basemud.h. Changes that I've considered bugfixes, typo / spelling error fixes, or patches to small oversights (i.e, fixing spells that have no casting message) will be left in.

Most of the code has been manually linted for better readability and brevity. Some changes are subject to taste, but much care has been spent to make the code consistent and easy to read. Here are some general style changes:

• Vertical space is prioritized highly - two-line if() statements are bountiful.
• Horizontal space is also cherished. Some lines exceed the old standard 80 character limit just barely to avoid some ugliness.
• Several giant tables, such as spells, races, and classes, go WAY over the line so they can be read and modified as tabular data.
• Redundant comments have been removed for the most part in favor of renaming functions, parameters, and variables to be more self-evident. The author comments have been preserved out of respect and to comply with licenses.
• All tabs have been removed and replaced with spaces. Everywhere.

Some changes may also be temporarilly regressive as a staging step for some larger refactoring. In other words, some things are a mess because I'm still cleaning it :) The affect code, for example, had all of its easy-to-read assignments replaced with incomprehensible one-liner functions. The long-term plan, in this case, is to move all of the affects to a table, at which point this will be fixed.

Note: OLC and Copyover code is also largely untested, and may even crash! D:

Deployment:

• The rom executable is now in the /bin directory and run from the root directory. For convenience, you can use run.sh in the root directory.
• The Dockerfile has been temporarilly removed until some of the structural changes are accounted for.

Code Reorganization:

• Files have been split and rearranged so there is (hopefully) less time spent hunting for functions or data tables.
• All do_*() functions are in appropriate act_*.c or wiz_*.c files.
• Introduced do_filter*() functions whose role is to break out of code flow in do_*() functions with appropriate messages.
• Several functions have been renamed to follow the same naming scheme for consistency's sake.
• More data has been moved from functions to tables to facilitate easy modification, addition, or removal of features.
• Integrated board and OLC features into the main code.
• handler.c has been seperated out into chars.c, objs.c, rooms.c, and find.c.
• Mob / object materials are now stored in a table rather than as a simple string.
• Unused flags in flag / type have been added to their respective tables so they're accounted for.
• Moved "day of the week", "months of the year", "weather", and "sun position" values to a tables in tables.c.
• Weather change calculations have been made easier to understand (but could still be better).
• Merged db2.c into db.c and separated old database functions into db_old.c.
• The wear command now uses a table for looking up wear slots, as does char_wear_obj(). This is a big improvement from copy+pasted "You wear ___ on ___" code for each possible slot.
• Separated descriptor functions in comm.c into new file descs.c.
• Moved some game loop functions from comm.c to main.c.

Code Reduction:

• LOTS of redundant code has been swapped up with small helper functions or... (gulp) macros. Macros are indeed ugly and bad - they'll be replaced with something better in a later iteration of refactoring, potentially using C++.
• Common shared code between do_*() functions have been separated out and moved to do_sub.c.
• Extremely common code patterns were replaced with macros for brevity. Most significant is BAIL_IF(cond, msg, ch) to replace if (cond) { send_to_char(msg, ch); return; } found in 99% of do_*() functions.
• Common linked-list code has been replaced with helper macros. This is a stepping-stone to a more reliable set of helper structs and functions to manage all lists.
• get, put, drop, and give have been refactored to use a lot of shared code.
• NPC breath attacks now use a shared perform_breath_attack() function.
• Replaced is_safe() and is_safe_spell() with consolidated do_filter_can_attack_real(). Added shorter functions: do_filter_can_attack(), do_filter_can_attack_spell(), can_attack(), and can_attack_spell().
• Merged code for displaying exits in look, exits, and exits in the prompt.

Code Changes:

• Several systems have been overhauled completely, namely: the color system, recycleable objects, and the "lookup" functions.
• Separated mob- and player-specific flags (ACT_*) into separate MOB_* and PLR_* flags, with separate variables. This should prevent a lot of bugs.
• act_new() now uses flags instead of an int type variable to determine recipients. Target #defines have been appropriately renamed to be more accurate. Flags could potentially be extended to have flags regarding visibility for blindness, deafness, or other options.
• Introduced functions act2() (messages to char + room) and act3() (messages to char + target + room).
• Replaced some groups of act() to CHAR/NOTCHAR and CHAR/VICT/OTHERS to act2() and act3() respectively.
• Some spells (like 'blindness') now can be invoked with or without messages so other spells that use cause the affect won't give "spell failed" messages. (A better solution would be a way to 'scope' functions like this to have their messages suppressed. C doesn't have anything like that, so perhaps a global stack-based system?)
• Exits between areas are tracked internally using a "portal" system that link exits/rooms together with keywords. This doesn't change anything for gameplay or .are files, but will (eventually) make building easier by defining links between areas without writing in specific vnums (e.g, link midgaard_west to midennir_east).
• Introduced dam_type classes DAM_PHYSICAL and DAM_MAGICAL for determining immunity.

There are some higher-level abstractions that have likely caused a slight performance hit or a little more memory usage, but this is hardly an issue in 2019 ;) Some profiling will likely happen later on down the line.

Some small changes have been made, most of which are small quality-of-life improvements, some of which are personal preferences that will eventually be phased out or at least optional. A handful of changes were just for fun.

Bugfixes:

• The scan command now checks for mob visibility in rooms based on room light level.
• scan doesn't peek through doors anymore.
• Doors are now properly closed and locked and both sides when loading zones. This fixes some resets as well.
• Getting hit by fire or ice breath no longer makes you less hungry or thirsty. Whoops!
• 'Word of recall' now writes "Spell failed." to the caster rather than the victim.
• 'Heat metal' would drop an item more if the opponent had more dexterity - this is fixed, but still needs balancing.
• In most cases, finding characters and objects by '1.thing', '2.thing', etc. will now count correctly when searching multiple locations (e.g, check the room, then the rest of the world). This is done by a find_continue_count() call preceding the next check.
• Checks for immune/resistant/vulnerable flags completely ignored default weapon/magic imm/res/vuln flags, despite existing code with implied behavior. Resistance no longer overrides default immunity, and vulnerability now properly downgrades the default status (imm->res, res->normal, normal->vuln).
• When wearing an item, all potential slots are now checked, not just related slots (e.g, a ring can now be held as well as worn on a finger).

Patched Oversights:

• scan <dir> only checks two rooms ahead rather than four. To see that far, you'll need to use the "farsight" spell :)
• Tweaked some stat tables very slightly to allow for steady progression in areas that looked like oversights. (Maximum weight capacity did not increase steadily where it easily could have.)
• You can no longer trip targets without feet or legs.
• Looking for doors by name now works the same way as looking for anything else. You can now find a door by number - for example, if you're carrying "a portable door", and there are two "door"s in the room, you can now say open 3.door to open the room's second door.
• Clean-ups and bugfixes to OLC to ensure stock zones are saved exactly as they are loaded. (Confirmed using diff comparisons on .are files and one gargantuan everything.json file containing the entire world in JSON format)
• Certain messages from shopkeepers, trainers, etc. would try to look and act like the tell command, but it wasn't consistent and generally unecessary. Now they're just simple messages. Hopefully this doesn't break any mob scripting or anything like that.

Quality-of-Life Features:

• Current position can be shown in prompt.
• Exits in the prompt now show open/closed status (!VANILLA).
• Stunned / incapacitated / mortally wounded / dead state checks are now based on percentage of max hit points.
• The 'lore' command has been implemented. It works like the 'identify' spell, but hand-picks information based on your skill percentage. What the player knows about is random, seeded by the player's name and the object's vnum. It currently cannot be practiced beyond 75%.
• Some, but not all, simple "Ok." messages have been replaced with useful things.
• Lots and lots of warning messages for mismatched doors or keys when loading zones. This produces some warning messages from the stock zones (which are warranted).
• New messages for passing through doors (for both sides).
• Drunkeness, thirst, hunger, and fullness now gives you more useful messages when the state changes via drink/eat.
• If standing on/at/in something, The stand command without any argument will now step off/out.

Gameplay Changes:

• Door open / closed(!VANILLA) status is visible in the "exits" command.
• Beds, tents, stools, etc. have automatic flags for STAND_IN, STAND_AT, etc. in addition to some standard hit and move regeneration bonuses.
• Bashing / tripping was effectively useless because combatants were automatically moved back to standing position in violence_update(). This is now a bit smarter, with cooldown rates.
• You cannot change position while in a daze / cooldown state. You can still issue several commands while knocked down, but you can't get back up!
• Standing up in combat is automatic once the cooldown period has been reached. This is essentially the same as before where you would always stand up during combat when attacked, but now it's no longer instant.
• Form / parts for races have been reviewed and tweaked slightly (consistency between canids). It makes no gameplay difference, but may in the future.
• Tiny balance changes have been made to certain skills and stat regen amounts.
• Fast healing is only active when sitting, resting, or sleeping.
• Meditation is only active when sitting or resting.
• As a bonus feature, booting the MUD currently outputs several files to JSON format in the json/ directory. In time, the MUD will be able to read these files instead or in addition to the standard ".are" files. This is to help develop editing software other than notepad or OLC.

Optional Features (disabled by default - enable by uncommenting #define VANILLA in basemud.h):

• More status noficiations in addition to 'excellent', 'nasty wounds', etc.
• Room titles are now colored based on their terrain type.
• The "pixie" race has been added just for fun. They can fly, and they're small, but boy are they frail! (this will undoubtedly get rolled back at some point...)
• The score command now shows your current hit/mana/move rates. This was a debug feature that I felt was nice enough to have.
• Hits and misses have additional adjectives to show their power in addition to the verb that shows percentage of max hit points. Example: "You wound a scary beholder with your excellent slash."
• Attacks from successful enhanced damage rolls are now displayed as "heavy ". Example: "You scratch a lich with your epic heavy pierce."
• Open and closed doors are now visible in auto exits. This reveals some otherwise hidden exits but makes exploring sooo much nicer.
• Hit / mana / move generation now happens on every pulse rather than in singular giant ticks. This is undoubtedly a CPU hog, and will need to be improved in some way! In the meantime, it's very luxurious :)
• When a character arrives in the room via standard movement, you will now see in what direction they came from.
• The (Glowing), (White Aura), (Red Aura) etc. tags have appropriate colors.
• Added (Golden Aura) and (Black Aura) for extreme good/evil characters.
• Added the disengage command to let spellcasters stop fighting and recover mana. Doesn't work if they're being targetted by anyone in the room.
• You can no longer sacrifice worthless objects.
• Added @ command as a shortcut for order all.
• Added abilities command, which shows both skills and spells.
• NPCs can no longer bash, trip, kick, etc. while they're on the ground.
• When affects are joined, the duration will stack as before, but the modifier will cap out at the min/max between the two affects. For example: Suppose the 'giant strength' spell could be stacked. Casting 'giant strength' with a +3 str bonus onto a target who already has a 'giant strength' +2 str bonus will result in a +3 str bonus (the maximum of the two) rather the a +5 str bonus (the sum of the two). The same applies for negative bonuses like for 'chill touch' and 'plague'.
• Object / character materials can now be shown with the 'materials' command.
• Mobs can now be in stunned, incapacitated, and mortally wounded states.
• Caster mobs now say their spells when casting just like players.

Enjoy!

-- Synival