====== Activation requirements (XG) ======

An [[xg:line_type|Line Type]] can specify several requirements that must be met for the [[activation]] or [[deactivation]] of the line to succeed. These include for instance event type, a counter (as in "line can be activated N times"), activator type (player, missile, etc.) and any combination of keys possessed by the activator.


===== Requirements =====


To set the requirements for activation and deactivation within a [[line_type|Line Type]] definition, use the Flags property of the definition.

  Flags = flaga | flagb | flagc

Example: 

  Flags = mobj_gone | activator_type


==== mobj_gone ====

The line will only be activated if there are no THINGS of a certain type with health > 0 at the time of testing. Thing type is specified using the **Thing type** flag eg:
  Thing type = POSSESSED

==== no_other_use_secret ====

Only players can activate this line if it's marked as secret.

==== activator_type ====

The line can only be activated by THINGS of a certain type. Thing type is specified using the **Thing type** flag eg:
  Thing type = POSSESSED


===== Extended requirements =====


To set the extended requirements for (De)activation within an Line Class definition use Flags2 eg:

  Flags2 = flaga | flagb | flagc etc

Example: 

  Flags2 = key1 | health_above


==== when_act ====

The function of the line is executed when the line changes state from inactive to active, i.e. it's activated.

==== when_deact ====

The function of the line is executed when the line changes state from active to inactive, i.e. it's deactivated.

==== when_last ====

The function of the line can only be executed when the line's counter changes to one (1) from another value. Otherwise the function won't be processed at all.

==== while_act ====

The function of the line is executed repeatedly while the line is active. Controlled with "Ticker start time", "Ticker end time" and "Ticker tics".

==== while_inact ====

The function of the line is executed repeatedly while the line is inactive. Controlled with "Ticker start time", "Ticker end time" and "Ticker tics".

==== key_1 ====

The activator must be a player who has key 1 (Doom: blue keycard, Heretic: yellow key). If the player doesn't have the key the message "You need a [key]." will be shown.

==== key_2 ====

The activator must be a player who has key 2 (Doom: yellow keycard, Heretic: green key). If the player doesn't have the key the message "You need a [key]." will be shown.

==== key_3 ====

The activator must be a player who has key 3 (Doom: red keycard, Heretic: blue key). If the player doesn't have the key the message "You need a [key]." will be shown.

==== key_4 ====

The activator must be a player who has key 4 (Doom: blue skull key, Heretic: not used). If the player doesn't have the key the message "You need a [key]." will be shown.

==== key_5 ====

The activator must be a player who has key 5 (Doom: yellow skull key, Heretic: not used). If the player doesn't have the key the message "You need a [key]." will be shown.

==== key_6 ====

The activator must be a player who has key 6 (Doom: red skull key, Heretic: not used). If the player doesn't have the key the message "You need a [key]." will be shown.

==== line_act ====

All the lines referenced with must be **active** or the event-based activation and deactivation of the line will fail. An example would be a door that is unlocked by a remote switch. The lines to check are specified with "Line act lref" (Ap4) using a [[lref]] and "Line act lrefd" (Ap5) eg:

  Line act lref = lref_line_tagged

==== line_inact ====

All the lines referenced with must be **inactive** or the event-based activation and deactivation of the line will fail. An example would be a door that is unlocked by a remote switch. The lines to check are specified with "Line inact lref" (Ap6) using a [[lref]] and "Line inact lrefd" (Ap7) eg:
  Line inact lref = lref_tagged
     Line inact lrefd = 8

==== color ====

The activator of the line must be of the color specified or the activation and deactivation of the line will fail. The activator color is specified with Color (Ap8) eg:
  Color = 1

==== health_above ====

Health of the line's activator must be **above** the value specified or the activation and deactivation of the line will fail. Health below limit is set with Health above (Ap0) eg:
  Health above = 100

==== health_bellow ====

Health of the line's activator must be **below** the value specified or the activation and deactivation of the line will fail. Health below limit is set with Health below (Ap1) eg:
  Health below = 100

==== power_above ====

The line's activator must be a player whose armor level is **above** the value specified or the activation and deactivation of the line will fail. Power below limit is set with Power above (Ap2) eg:
  Power above = 20

==== power_below ====

The line's activator must be a player whose armor level is **below** the value specified or the activation and deactivation of the line will fail. Power below limit is set with Power below (Ap3) eg:
  Power below = 80

==== single_player ====

The line can be activated and deactivated in single-player games.

==== cooperative ====

The line can be activated and deactivated in co-operative multiplayer games.

==== deathmatch ====

The line can be activated and deactivated in deathmatch multiplayer games.

==== any_mode ====

(singleplayer, cooperative and deathmatch combined). The line can be activated and deactivated regardless of game mode.

==== easy ====

The line can be activated and deactivated in easy skill levels (1 and 2).

==== med ====

The line can be activated and deactivated in the medium skill level (3).

==== hard ====

The line can be activated and deactivated in hard skill levels (4 and 5).

==== any_skill ====

(easy, med and hard combined). The line can be activated and deactivated regardless of the skill level.

==== any ====

(any_mode and any_skill combined). The line can be activated and deactivated regardless of game mode or skill level.