Data Descriptions

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Template:Otherlang2 Data description tables contain metadata. They have many uses, but the most common is to define what internal information about a class should be stored when the game is saved.

Note.pngNote:The Preprocessor directive USES_SAVERESTORE may be required for data descriptions (and the save/restore system in general) to function. It is included by default.

Usage

A Datadesc table must be declared in the constructor with DECLARE_DATADESC();. Table elements are then declared between BEGIN_DATADESC and END_DATADESC, outside any functions: 

BEGIN_DATADESC( CMyClass )

   DEFINE_FIELD( ... ),
   DEFINE_FIELD( ... ),

END_DATADESC()

Note the absence of semicolons.

Warning.pngWarning:Take extra care to get your Datadesc syntax right. The compiler sees only the code behind the macros, so any errors it throws may not make much sense!

Example

For npc_barnacle: 

BEGIN_DATADESC( CNPC_Barnacle )

	DEFINE_FIELD( m_flAltitude, FIELD_FLOAT ),
	DEFINE_FIELD( m_cGibs, FIELD_INTEGER ),// barnacle loads up on gibs each time it kills something.
	DEFINE_FIELD( m_bLiftingPrey, FIELD_BOOLEAN ),
	DEFINE_FIELD( m_bSwallowingPrey, FIELD_BOOLEAN ),
	DEFINE_FIELD( m_flDigestFinish, FIELD_TIME ),
	DEFINE_FIELD( m_bPlayedPullSound, FIELD_BOOLEAN ),
	DEFINE_FIELD( m_bPlayerWasStanding, FIELD_BOOLEAN ),
	DEFINE_FIELD( m_flVictimHeight, FIELD_FLOAT ),
	DEFINE_FIELD( m_iGrabbedBoneIndex, FIELD_INTEGER ),

	DEFINE_FIELD( m_vecRoot, FIELD_POSITION_VECTOR ),
	DEFINE_FIELD( m_vecTip, FIELD_POSITION_VECTOR ),
	DEFINE_FIELD( m_hTongueRoot, FIELD_EHANDLE ),
	DEFINE_FIELD( m_hTongueTip, FIELD_EHANDLE ),
	DEFINE_FIELD( m_hRagdoll, FIELD_EHANDLE ),
	DEFINE_AUTO_ARRAY( m_pRagdollBones, FIELD_MATRIX3X4_WORLDSPACE ),
	DEFINE_PHYSPTR( m_pConstraint ),
	DEFINE_KEYFIELD( m_flRestUnitsAboveGround, FIELD_FLOAT, "RestDist" ),
	DEFINE_FIELD( m_nSpitAttachment, FIELD_INTEGER ),
	DEFINE_FIELD( m_hLastSpitEnemy, FIELD_EHANDLE ),
	DEFINE_FIELD( m_nShakeCount, FIELD_INTEGER ),
	DEFINE_FIELD( m_flNextBloodTime, FIELD_TIME ),
#ifndef _XBOX
	DEFINE_FIELD( m_nBloodColor, FIELD_INTEGER ),
#endif
	DEFINE_FIELD( m_vecBloodPos, FIELD_POSITION_VECTOR ),
	DEFINE_FIELD( m_flBarnaclePullSpeed, FIELD_FLOAT ),
	DEFINE_FIELD( m_flLocalTimer, FIELD_TIME ),
	DEFINE_FIELD( m_vLastEnemyPos, FIELD_POSITION_VECTOR ),
	DEFINE_FIELD( m_flLastPull, FIELD_FLOAT ),
	DEFINE_EMBEDDED( m_StuckTimer ),

	DEFINE_INPUTFUNC( FIELD_VOID, "DropTongue", InputDropTongue ),
	DEFINE_INPUTFUNC( FIELD_INTEGER, "SetDropTongueSpeed", InputSetDropTongueSpeed ),

#ifdef HL2_EPISODIC
	DEFINE_INPUTFUNC( FIELD_VOID, "LetGo", InputLetGo ),
	DEFINE_OUTPUT( m_OnGrab,     "OnGrab" ),
	DEFINE_OUTPUT( m_OnRelease, "OnRelease" ),
#endif

	// Function pointers
	DEFINE_THINKFUNC( BarnacleThink ),
	DEFINE_THINKFUNC( WaitTillDead ),

	DEFINE_FIELD( m_bSwallowingBomb, FIELD_BOOLEAN ),

END_DATADESC()

Elements

DEFINE_FIELD

Tells the engine to store a variable in saved games. 

DEFINE_FIELD( variable, field_type )

The available field types are:

FIELD_VOID
No type or value (used for function parameters)
FIELD_FLOAT
Any floating point value
FIELD_STRING
A string ID (return from ALLOC_STRING)
FIELD_VECTOR
Any vector, QAngle, or AngularImpulse
FIELD_QUATERNION
A quaternion value
FIELD_INTEGER
Any integer or enum value
FIELD_BOOLEAN
Boolean value (represented as an integer)
FIELD_SHORT
2 byte integer
FIELD_CHARACTER
One byte
FIELD_COLOR32
8-bit per channel [R,G,B,A] (32-bit color)
FIELD_EMBEDDED
An embedded object with a data description, recursively traverse and embedded | class/structure based on an additional type description
FIELD_CUSTOM
A special type that contains function pointers to its read/write/parse functions
FIELD_CLASSPTR
CBaseEntity pointer
FIELD_EHANDLE
CHandle or EHANDLE
FIELD_EDICT
edict_t pointer
FIELD_POSITION_VECTOR
A world coordinate value, which is fixed up across level-transitions automatically
FIELD_TIME
A floating point time value, which is fixed up across level-transitions automatically
FIELD_TICK
An integer tick count, which is fixed up similarly to FIELD_TIME
FIELD_MODELNAME
Engine string that is a model name (Must be precached)
FIELD_SOUNDNAME
Engine string that is a sound name (Must be precached)
FIELD_INPUT
A list of inputted data fields, all derived from CMultiInputVar
FIELD_FUNCTION
A class function pointer (Think, Use, etc.)
FIELD_VMATRIX
A VMatrix
Note.pngNote:Output coordinates are NOT worldspace
FIELD_VMATRIX_WORLDSPACE
A VMatrix that maps some localspace to worldspace (translation is fixed up on level-transitions)
FIELD_MATRIX3X4_WORLDSPACE
matrix3x4_t that maps some localspace to worldspace (translation is fixed up on level-transitions)
FIELD_INTERVAL
A start and range floating point interval ( e.g., 3.2->3.6 == 3.2 and 0.4 )
FIELD_MODELINDEX
A model index
FIELD_MATERIALINDEX
A material index (using the material precache string table)

DEFINE_KEYFIELD and DEFINE_KEYFIELD_NOT_SAVED

Both link a variable to a FGD keyvalue, allowing it to be configured by mappers in Hammer (i.e. read from the entity lump). Depending on which you use, the value will or will not be embedded in saved games. Arguments are the same in either case: 

DEFINE_KEYFIELD( variable, field_type, "HammerName" )
Note.pngNote:HammerName is case insensitive.
Tip.pngTip:To get an entity from Hammer, define a char* and FIELD_STRING, then use gEntList.FindEntityByName() in Spawn() to get a pointer.

DEFINE_CUSTOM_FIELD

Allows custom interpretation of a variable with regards to how it is saved and restored. By passing in the reference to a handler class, the user is able to handle serialization of the data entirely.

The handler class must descend from the CClassPtrSaveRestoreOps class; it uses the Save() and Restore() functions for serialization.

For more information, see uses of CClassPtrSaveRestoreOps within the code base.

DEFINE_OUTPUT

Links an output event to a named identifier used by Hammer. 

DEFINE_OUTPUT( COutputEvent, "HammerOutputName")

DEFINE_INPUTFUNC

This macro is used to link named inputs from Hammer to functions in the engine. This also defines the type of parameter being passed in to the function from the Entity I/O system. The macro is defined as: 

DEFINE_INPUTFUNC( parameterType, "inputName", InputFunction )

The parameterType can be any of the following FIELD_ types:

  • FIELD_VOID
  • FIELD_INTEGER
  • FIELD_FLOAT
  • FIELD_STRING
  • FIELD_VECTOR
  • FIELD_COLOR32
  • FIELD_BOOLEAN

DEFINE_INPUT

This macro is a shorthand version of DEFINE_INPUTFUNC. It automatically sets the described data member to the parameter passed in from the Input() function. This bypasses the need to create an input function whose sole purpose is to set a data member to a passed value. The macro is declared as: 

DEFINE_INPUT( variableName, variableType, "keyvalueName" )

DEFINE_ARRAY and DEFINE_AUTO_ARRAY

As their names suggest, these macros deal with saving and restoring array values. The number of elements in the array must be declared when using DEFINE_ARRAY, whereas DEFINE_AUTO_ARRAY will cause the code to automatically determine the size of the array at compile time.

The macros are declared as: 

DEFINE_ARRAY( variable, variableType, numElements )

DEFINE_AUTO_ARRAY( variable, variableType )

DEFINE_THINKFUNC

Entities with a custom think function must declare it: 

DEFINE_THINKFUNC( MyThink )

Think functions must be void.

DEFINE_ENTITYFUNC

Entities using a custom touch function must declare that function via this macro declaration.

Touch functions must be of the type: 

typedef void (CBaseEntity::*ENTITYFUNCPTR)(CBaseEntity *pOther );

DEFINE_USEFUNC

Entities using a custom use function must declare that function via this macro declaration.

Use functions must be of the type: 

typedef void (*UseFunc)(
	CBaseEntity *pActivator,
	CBaseEntity *pCaller,
	USE_TYPE useType,
	float value
);

Others

  • dlls\simtimer.h
  • game_shared\physics_saverestore.h
    • DEFINE_PHYSPTR - Define a physics pointer
    • DEFINE_PHYSPTR_ARRAY - Define a physics pointer array
  • game_shared\saverestore_bitstring.h
  • game_shared\saverestore_utlmap.h
  • game_shared\saverestore_utlrbtree.h
  • game_shared\saverestore_utlvector.h
  • game_shared\soundenvelope.h
    • DEFINE_SOUNDPATCH
  • public\saverestore.h
    • DEFINE_KEYFIELD_NOT_SAVED
    • DEFINE_ENTITY_FIELD
    • DEFINE_ENTITY_GLOBAL_FIELD
    • DEFINE_GLOBAL_FIELD
    • DEFINE_GLOBAL_KEYFIELD
    • DEFINE_CUSTOM_FIELD
    • DEFINE_CUSTOM_KEYFIELD
    • DEFINE_AUTO_ARRAY2D
    • DEFINE_EMBEDDED
    • DEFINE_EMBEDDED_OVERRIDE
    • DEFINE_EMBEDDEDBYREF
    • DEFINE_EMBEDDED_ARRAY
    • DEFINE_EMBEDDED_AUTO_ARRAY
    • DEFINE_PRED_TYPEDESCRIPTION
    • DEFINE_PRED_TYPEDESCRIPTION_PTR
    • DEFINE_PRED_FIELD
    • DEFINE_PRED_ARRAY
    • DEFINE_FIELD_NAME
    • DEFINE_PRED_FIELD_TOL
    • DEFINE_PRED_ARRAY_TOL
    • DEFINE_FIELD_NAME_TOL
  • public\stdstring.h
    • DEFINE_STDSTRING
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