# Object Scripts

Object Scripts
Object scripts control the complex behaviour of an object. For details on scripting see the C4Script documentation.
Creation
For every object, the engine calls the function Initialize in the object script when it is created and completed.
func Initialize() { CreateContents(Rock); }
An object with this script will be given a rock right after it has been created. The Initialize function is called only when the object has reached full size (a building only when its construction has been completed and a living being only when it is fully grown).
ActMap
An active object can also define activity script calls in its ActMap. The defined StartCall is made whenever an action begins (or repeats), an EndCall is made at the end of each activity. PhaseCall is called at each animation phase step and should only be used for very short animations. The call frequency of PhaseCalls is determined by the speed of the animation.
#include
An object script can also include the functionality of another script.
#include Clonk
At this position the complete script of the specified object definition (that of the clonk, in this case) is inserted, including all scripts that that script includes or got via #appendto. The only exception is that every script is included only once, so including both the Clonk script and a script that is included by the Clonk script doesn't include that script twice. Other Obviously, the included definition must be valid and loaded. Declared functions can be overloaded by functions of the same name that occur later in the script. Also see inherited().
Interaction from other scripts
Other scripts can call functions of an object `obj` with the `->` and `->~` operators.
var obj = CreateObject(Flint); obj->Hit();
Object calls made by the engine
The engine calls the following functions is objects at the given time.

Function
Parameter
Description
Initialize
When the object is completed (Con >= 100).
Construction
object by_object
When the object is created. The parameter is a pointer to the object the script of which has created this object. Also see Construction
Destruction
When the object is removed.
Hit
When the object collides with the landscape or is collected at high velocity (>=15).
Hit2
Like Hit, with speeds >= 20 (see OCF_HitSpeed2).
Hit3
Like Hit, with speeds >= 60 (see OCF_HitSpeed3).
Grab
object target, bool grab
When the object grabs or lets go of another object.
Grabbed
object by_object, bool grab
When the object is grabbed or let go by another object.
Get
object target
When the object takes another object from a container.
Put
When the object puts another object into a container.
Damage
int change, int cause, int by_player
When the object is damaged. See Fx*Damagefor `cause` values.
DeepBreath
When a living being surfaces after having used up more than half of its breath.
Incineration
int by_player
When the object is incinerated. Notice: with objects changing their definition via BurnTo, this call is made to the burned version!
IncinerationEx
int by_player
When the object is incinerated in and immediately extinguished by a surrounding liquid. Otherwise as Incineration.
Death
When a living being dies.
Activate
object by_object
Activation by double dig. Only applies to collected items or directly controlled crew objects. Called after internal handling of the double dig command has been completed (e.g. chopping of trees etc.)
Contact_
When the object collides with the landscape. See CNAT - Contact Attachment.
Control_
object by_object
When the object is controlled from the outside. See Control Functions.
Contained_
object by_object
When the object is controlled from the inside. See Control Functions.
ControlCommand
string command, object target, int x, int y, object target2, int data, object command_object
When the object has received a command to be independently executed. See Control functions.
ControlCommandFinished
string command, object target, int x, int y, object target2, any Data
When the object has completed a command or execution of a command has failed.
ControlTransfer
object obj, int x, int y
When an object (obj) using the internal pathfinding algorithm is trying to pass the transfer zone of this object on its way to point x/y. The transfer function can then help the object along by giving special script commands and returning `true`. Also see SetTransferZone().
UpdateTransferZone
When an object is loaded from a savegame or network synchronization is performed. Objects with a transfer zone should reset the zone in this call. Also see SetTransferZone().
MenuQueryCancel
int selection, object menu_object
When the player wants to close a user defined object menu. Return value `true` will keep the menu open.
IsFulfilled
Only in game goal objects. A return value `true` indicates that this goal is fulfilled.
ControlContents
id target
When a new inventory object is selected. See Control Functions.
Selection
object container
When the object is selected in an inventory change. If you are processing this event, the function should play its own selection sound.
CatchBlow
int level, object by
When the object is hit or punched by another object.
QueryCatchBlow
object by
Called before the object is hit or punched by another object. By returning `true`, QueryCatchBlow can reject physical blows.
LineBreak
int cause
When a line object is broken. cause: 0 by movement, 1 because of a missing or incomplete target object.
BuildNeedsMaterial
id material_definition, int amount
When the object is building another object and building material is required. The parameters are the type and amount of the first needed material. If this function returns `true`, no material message is displayed above the object.
AttachTargetLost
When the object is in an ATTACH action and has lost its action target. At this time, the object's action has already been reset.
CrewSelection
bool deselect, bool cursor_only
When crew selection is changed. cursor_only specifies whether only that crew member has been selected which is also the cursor.
GetObject2Drop
object for_collection_of_object
Called to determine the least needed inventory object when a clonk tries to collect a new object and his inventory is full. The function should return the object to be dropped to gain space, or `nil` if none.
OnMenuSelection
int index, object menu_object
When an object menu entry is selected.
CalcValue
object in_base, int for_player
Calculates the value of an object. Also see GetValue().
CalcDefValue
object in_base, int for_player
Calculates the value of an object type available to buy. Also see GetValue().
CalcBuyValue
id item, int value
Returns the buying price of the object type.
CalcSellValue
object obj, int object_value
Returns the selling price of the object type.
LiftTop
When an object with LIFT action lifts its action target to the height specified in its DefCore or above.
Stuck
When the action target of the object's PUSH or LIFT action is stuck.
GrabLost
When the action target of the object's PUSH or PULL action is lost.
Collection
object obj, bool put
When the object has collected another object (obj) (by ingame collection or grabbing and getting).
Collection2
object obj
When the object has collected another object (obj) (in all cases, even in script controlled collection or entering).
ContentsDestruction
object destroyed
When an object contained in the object has been destroyed/removed. The object still exists when the callback is called, but will be destroyed afterwards.
Departure
object container
When this object has left another object (container).
Ejection
object obj
When another object (obj) has left the contents of this object (also see script command Exit).
Entrance
object container
When the object has entered another object (container).
ActivateEntrance
object by_object
When another object is trying to enter this object through the entrance.
RejectCollect
id def, object obj
Called before Collection. If RejectCollect returns `true`, the collection of the other object is prevented.
RejectEntrance
object into_object
Called before Entrance. If RejectEntrance returns `true`, then entrance of the other object is prevented.
InitializePlayer
int player
Called in game goals, rules, or environment objects after the joining of a new player and before the corresponding call in the scenario script.
SellTo
int by_player
When the object is sold. Should return `nil` or the id of the object type which is actually added to the player's homebase material.
Sale
int by_player
When the object is sold.
Purchase
int by_player, object buy_object
When the object is bought.
Recruitment
int player
When the objet is added to the crew of a player.
RejectTeamSwitch
int player, int new_team
Callback in game goal, rule, and environment objects and in the scenario script. If RejectTeamSwitch returns `true`, the team switch of a player can be prevented (see SetPlayerTeam).
OnTeamSwitch
int player, int new_team, int old_team
Callback in game goal, rule, and environment objects and in the scenario script. Called when a player has successfully switch from old_team to new_team (see SetPlayerTeam).

sulai
2003-11
Sven2
2004-02
matthes
2004-07
Clonkonaut
2008-04