Left 4 Dead 2/Script Functions/AddThinkToEnt

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Turns a function of an entity's script into a think function, which then the function automatically calls itself in an interval set by number returns if they exist, otherwise the sv_script_think_interval cvar is used (0.1 seconds by default). There can only be one think function for each entity at a time, so you can't chain think functions.

To remove think functions, call this function with null as an argument under the funcname parameter. See this sub-section of the Entity Scripts page to know more about think functions.

Parameters

void AddThinkToEnt(CBaseEntity entity,string funcname)

Type Name Description
CBaseEntity entity Target entity to be applied a think function.
string funcname Given the string, find the function of the exact same name (no brackets allowed!). Passnullto remove it.

Code Samples

Fastest Rethink Rate

L4D2ScriptFunctions AddThinkToEnt-FastestRethinkRate.png

When ran, an info_target will be spawned with a think function that automatically uses the fastest possible rethink rate (that's capped). The think function uses ClientPrint() and fills the chatbox about how long the game has been running. When it has sent the messages 30 times, the entity will then delete itself, thus halting the think function.

Since Left 4 Dead 2 runs on 30 ticks by default, think functions can never run faster than 0.03333... seconds. See this sub-section of the Entity Scripts page to know more about think functions.

local timethinker = SpawnEntityFromTable("info_target", { targetname = "timethinker" } )
if( timethinker.ValidateScriptScope() )
{
	const MAX_PRINT_TIMES = 30
	timethinker.GetScriptScope()["PrintCount"] <- 0
	timethinker.GetScriptScope()["Think"] <- function()
	{
		if( timethinker.GetScriptScope()["PrintCount"] < MAX_PRINT_TIMES )
		{
			ClientPrint(null, DirectorScript.HUD_PRINTTALK, "\x04"+"Current Time: "+"\x05"+Time().tostring())
			timethinker.GetScriptScope()["PrintCount"]++
			return 0.01	// can't actually rethink this fast; quick way to ensure it rethinks at the rethink rate cap
		}
		else
		{
			ClientPrint(null, DirectorScript.HUD_PRINTTALK, "\x03"+"We printed enough times already.")
			self.Kill()
		}
	}
	AddThinkToEnt(timethinker, "Think")
}

Survivor Health Decay

Look at Rochelle, Ellis and Coach's health.

This script applies a slow think function onto all players, which will then slowly decay their normal health, and turn it into temporary health. It also implements a buffer system, a period where health decay attempts will not be allowed.

const HEALTH_DECAY_TIME = 2
const HEALTH_DECAY_BUFFERCOUNT = 5
local player = null
while( player = Entities.FindByClassname(player,"player") )
{
	// Team 4 is the L4D1 Passing Survivors; they're invincible!
	if( player.IsSurvivor() && NetProps.GetPropInt(player, "m_iTeamNum") != 4 )
	{
		if( player.ValidateScriptScope() )
		{
			local player_entityscript = player.GetScriptScope()
			player_entityscript["HealthDecayBufferCount"] <- HEALTH_DECAY_BUFFERCOUNT
			player_entityscript["HealthDecay"] <- function()
			{
				if( player_entityscript["HealthDecayBufferCount"] < 0 )
				{
					// Bots lose the think function when they die, anyways
					if( !self.IsIncapacitated() && !self.IsDead() && !self.IsHangingFromLedge() )
					{
						if( self.GetHealth() > 1 )
						{
							self.SetHealth( self.GetHealth()-1 )
							self.SetHealthBuffer( self.GetHealthBuffer()+1 )
							printl(GetCharacterDisplayName(self)+" is decaying health!")
						}
						else
							printl(GetCharacterDisplayName(self)+" isn't able to decay health anymore.")
					}
					else
						printl(GetCharacterDisplayName(self)+" is currently not allowed to decay health.")
				}
				else
				{
					player_entityscript["HealthDecayBufferCount"] -= 1
					printl(GetCharacterDisplayName(self)+" is in health decay buffer")
				}
				return HEALTH_DECAY_TIME
			}
		}
	}
	AddThinkToEnt(player, "HealthDecay")
	printl("Applied health decaying to "+player)
}