Logic script

Class hierarchy
CLogicScript ↳CPointEntity ↳CBaseEntity

logic_script is a point entity available in all Source games since Left 4 Dead 2. It is also available in Team Fortress 2 branch, and Mapbase.

This entity functions as a container for VScripts. In Left 4 Dead 2, for example, it is used extensively for the logic in "carnival games" found in the Dark Carnival campaign, such as Peanut Gallery, Strongman Contest, Whack-a-Stach, etc.

KeyValues

Name (targetname) <string>[ Edit ]

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

EntityGroup[0] (Group00) to EntityGroup[15] (Group15) <targetname>

All specified entity names will be searched for upon this entity spawning and their script handles are added to an array named EntityGroup in logic_script's script scope. EntityGroup[0] contains handle of entity with name specified in EntityGroup[0] property etc. If multiple entities with the given named exists, handle of first found will be used.

Table MyEntityGroup is also created which contains the handles with keys being the names. (for some reason there is also MyEntityGroupArray which is same as EntityGroup)

VScript run internally to achieve this

The following VScript is run in logic_script scope when it spawns. __AppendToScriptGroup is then called with each name specified by Group00-Group15 keyvalues. EntityGroup <- []; MyEntityGroup <- {}; MyEntityGroupArray <- EntityGroup; function __AppendToScriptGroup( name ) { if ( name.len() == 0 ) { EntityGroup.append( null ); } else { local ent = Entities.FindByName( null, name ); EntityGroup.append( ent ); if ( ent != null ) { ent.ValidateScriptScope(); MyEntityGroup[name] <- ent; ent.GetScriptScope().EntityGroup <- EntityGroup; } } }

Note:For other VScript keyvalues notable for this entity like vscripts, thinkfunction and inputs like RunScriptCode, CallScriptFunction see Generic Keyvalues, Inputs and Outputs

See also

• L4D2 VScripts
• Left 4 Dead 2 Tool Updates

External links

• It's the VScripting documentation FAQ! (Steam Forums)
• Scripting for Left 4 Dead 2 (Leeland.net) - Example uses of logic_script