How to make new Kill Frenzies by editing the MISSION.INI file

By Michael Mendelsohn

There is a text version available. It may be put up on other web sites as long as it remains unchanged.

Before you can add a kill frenzy of your own, you should know how one works.

A kill frenzy in GTA usually starts when you pick up a special powerup crate.

From the object code section of MISSION.INI (mission [1] Easy Liberty City):

492 (6,1,4) POWERUP 2 500 
493 (47,214,4) POWERUP 2 500 
494 (224,103,4) POWERUP 2 500 
495 (224,231,4) POWERUP 2 700 
496 (158,77,4) POWERUP 2 700 

The powerup at 493 will be our example. This is a machine gun powerup with a time limit. A few lines later, we find a TRIGGER in the same location:

497 1 (6,1,4) TRIGGER 9160 0 
498 1 (47,214,4) TRIGGER 9240 0 
499 1 (224,103,4) TRIGGER 9320 0 
500 1 (224,231,4) TRIGGER 9400 0 
501 1 (158,77,4) TRIGGER 10000 0 

This trigger will activate when we take the powerup since it has the same (x,y,z) coordinates. It starts program code at 9240.
Notice that each trigger starts different code!

Now here is the program code for this one:

9240 DISABLE 498 0 0 0 0                

turn off trigger that started the code so it won't be started again

9242 KF_PROCESS 0 0 -1 -1 0             

???

9245 DECCOUNT 553 0 0 0 0               

decrement secret mission counter,
see 553 1 (0,0,0) SECRET_MISSION_COUNTER 7 0
change 7 to a higher number if you add new frenzies!

9246 IS_POWERUP_DONE 493 0 9260 200 0 

wait for the POWERUP process to finish to make sure the player has the weapon. Start 9260 if after 200 time units the powerup has not been taken.
Note: the mission counter will be decremented regardless, so this probably never happens.

9247 MESSAGE_BRIEF 0 0 0 0 2503 

Display FXT file message [2503]KILL FRENZY!

9250 FRENZY_BRIEF 0 0 0 24 1426 

After 24 time units, display FXT file message [1426]Move! Get 1,000 points in time for a whale of a bonus!

9252 FRENZY_SET 9270 0 -1 -1 0 

???

9254 KICKSTART 9270 0 -1 -1 0 

start code at line 9270 as a new process

9256 KICKSTART 9280 0 -1 -1 0 

start code at line 9280 as a new process

9258 KICKSTART 9290 -1 -1 -1 0 

start code at line 9290 as a new process and stop (first -1 means stop)

Now this process is done, but 3 new processes are running at the same time.

9260 ENABLE 498 -1 -1 0 0 

This gets called if the player stepped on the tile where the powerup is but didn't take it.
The TRIGGER gets turned on again in case the player takes the powerup later. The program stops (first -1).

9270 FRENZY_CHECK 1000 0 9270 0 30000 

Go to 9270 until player has reached 1000 points
???? 30000

9272 MESSAGE_BRIEF 0 0 0 0 4000 

Display FXT file message [4000]YOU GOT IT!

9274 STOP_FRENZY 493 0 0 0 0 

Turn weapon that resulted from 493 POWERUP off

9276 RESET_KF 0 0 0 0 0 

??? some relation to KF_PROCESS earlier

9278 DROP_WANTED_LEVEL 0 -1 -1 0 0 

drops wanted level; should also stop, but no first -1 ????

9280 SURVIVE 0 0 0 400 0 

wait 400 time units; exact meaning of SURVIVE still unclear

9282 MESSAGE_BRIEF 0 0 0 0 2504 

Display FXT file message [2504]FRENZY FAILED!

9284 STOP_FRENZY 493 0 0 0 0 

Turn weapon that resulted from 493 POWERUP off

9286 RESET_KF 0 -1 -1 0 0 

??? some relation to KF_PROCESS earlier
??? should also stop, but no first -1 ????

9290 DEAD_ARRESTED 294 0 9290 0 0 

go to 9290 until the player is dead or arrested
see 294 1 (105,119,4) PLAYER 293 256

9292 MESSAGE_BRIEF 0 0 0 0 2504 

display FXT file message [2504]FRENZY FAILED!

9294 STOP_FRENZY 493 0 0 0 0 

Turn weapon that resulted from 493 POWERUP off

9296 RESET_KF 0 -1 -1 0 0 

??? some relation to KF_PROCESS earlier
??? should also stop, but no first -1 ????

Concermimg the KF statements, my guess is that KF_PROCESS sets up a process group that contains the process that calls it and all subsequentprocesses KICKSTARTed from it; RESET_KF 0 -1 -1 0 0 then terminates all processes in the group, and RESET_KF 0 0 0 0 0 terminates all other processes in the group but keeps the one that executed RESET_KF running.

It should by now have become clear what the "right" way to add a frenzy is!

1) Add a POWERUP with the second parameter > 100.
You do not need to use a DUMMY line, just use any unused object line number. You can place the new line anywhere in the object section regardless of line number (a good choice would be to place it where the other frenzies are), although it helps finding your way around the file if you keep them in order.

2) Add a TRIGGER at the same (x,y,z) as the POWERUP. Have it trigger an unused linenumber.

3) Copy the code from an existing frenzy. Change the line numbers so they start at the unused line number the TRIGGER points to. Be sure to adjust parameters that reference these line numbers, too!

4) Decide whether you want your frenzy to be a secret mission; if you do, increase the SECRET_MISSION_COUNTER object; if you don't, remove the DECCOUNT statement.

5) You can write comments in the MISSION.INI; use any blank line (or make yourself one). It might be wise not to start your comment with a number! Place a comment where you made your additions so you can find them later.

That's it!

If you notice any errors or have any additional comments, please contact me.
It would be groovy if you could send in a formula for the frenzy time!

In the near future, the GTA editor project will make a tool available that allows you to distribute "just the changes" versions of missions; this helps you avoid copyright infringements you probably incur when distributing MISSION.INIs that contain DMA code. It also keeps file sizes small which is a decidied advantage for downloading! Look on http://www.informatik.uni-bremen.de/~mendel/gta/ for this!

Have frenzied fun!

Michael