Editing Thinggroup

'''thinggroup''' is an [[EDF]] block which groups separate [[thingtype]]s into categories and gives them special flags, without also subjecting them to inheritance. The original motivation for this flag was extending the hell knight and baron of hell 'alliance' behaviour, where they can't harm each other by projectiles, but others monsters of separate species are always affected.

==Syntax==

The syntax is as follows:
 thinggroup <name>
 {
   flags <flags>
   types { <thingtype1>, <thingtype2>, ... }
 }

''Name'' is the name of this category. Currently it's merely descriptive, but must be unique per '''thinggroup'''.

Each <thingtypeX> is the mnemonic of a [[thingtype]] already defined in EDF. In order for this definition to have any effect on gameplay, you must set '''flags''' to any of the following values, joined by | (as in EDF flag settings):
* '''PROJECTILEALLIANCE''': this prevents monsters from '''types''' from harming each other with projectiles. Hell knights and barons of hell have this flag set in the base things.edf.
* '''DAMAGEIGNORE''': monsters in the '''types''' list may be damaged by each other, but will not infight as a result. This generalizes the deprecated BOSSIGNORE '''thingtype''' flag. It will ''not'' prevent monsters from infighting others of the ''same'' species; for that, use a new thingtype flag (see below).
* '''INHERITED''': only has meaning if any of the other flags above is set. It makes it so any thingtypes inheriting the ones from the list are also included in this group. By default they don't inherit.

'''Types''' don't have to be monsters specifically; any thingtype will do.

==Example==
The following EDF makes imps and cacodemons immune to each other's attacks:
 thinggroup ClassicDevils  // name can be anything but must be unique
 {
   flags ProjectileAlliance
   types { DoomImp, Cacodemon }
 }

==Other infighting-related properties==
As infighting is a rather complex rule in Doom and related games, there are also other means to customize it:
* '''thingtype''' damagefactor attribute "immune". Unlike "damagefactor ''Xyz'', 0", this also prevents pain, thrusting and retaliation. Useful to prevent friendly fire and infighting for arbitrary [[damage types]] (means of death) between monsters. Example:
 thingdelta
 {
   name Zombieman
   mod ZombiemanMOD  // their default MOD is "unknown"; it needs to be set to a custom one.
   damagefactor ZombiemanMOD, immune
 }
 damagetype ZombiemanMOD { num 100 }  // MOD definition: use a number that doesn't conflict with the stock ones.

* new '''thingtype''' flags:
:*'''NOSPECIESINFIGHT''', which, in addition to '''DAMAGEIGNORE''' from '''thinggroup''', also prevents monsters from the same species from infighting due to damage.
:*'''HARMSPECIESMISSILE''', which allows monsters of the same species to be affected by each other's projectiles, overriding the default immunity from classic Doom.
:*'''FRIENDFOEMISSILE''', which makes projectiles shot by friends harm enemies of the same species, and viceversa. Default [[MBF]] behaviour makes them immune due to being the same species.