Dynamically Adding Entities to a geWorld

[QuestOfDreams]

The following code allows to add an entity to a geWorld at runtime. The entity can be of any class that is available in the editor
(as all entity class definitions are stored in the bsp file even if there is actually no entity of a specific type). All you have to pass to
the function is the current world, the name of the entity class, a name for the entity to identify it and the user data for that entity.
On success the function returns a pointer to the created geEntity, otherwise it returns a NULL pointer.

in Genesis.h add

Code: Select all

GENESISAPI geEntity* geWorld_AddEntity(
		geWorld		*World,
		const char	*ClassName,
		const char	*EntityName,
		void		*UserData)

in World.c add

Code: Select all

//========================================================================================
//	geWorld_AddEntity
//========================================================================================
GENESISAPI geEntity* geWorld_AddEntity(
		geWorld		*World,
		const char	*ClassName,
		const char	*EntityName,
		void		*UserData)
{
	geWorld_EntClassSet	*WSets;
	int32				i;
	geEntity			*Entity;
	geEntity_Class		*Class;
	
	assert(World);

	// No classname, just return
	if(!ClassName || !EntityName ||!UserData)
	{
		return NULL;
	}

	WSets = World->EntClassSets;
	
	Entity = geEntity_Create();
	if(!Entity)
	{
		return NULL;
	}

	// Add it to the main set
	if(!geEntity_EntitySetAddEntity(WSets[0].Set, Entity))
	{
		geEntity_Destroy(Entity);
		return NULL;
	}

	// create Epair for name (every entity needs one - should be unique but we don't check for it here)
	{
		geEntity_Epair *EntityNameEpair = geEntity_EpairCreate();
		
		EntityNameEpair->Key = geRam_Allocate(strlen("%Name%")+1);
		strcpy(EntityNameEpair->Key, "%Name%");
		
		EntityNameEpair->Value = geRam_Allocate(strlen(EntityName)+1);
		strcpy(EntityNameEpair->Value, EntityName);
		
		geEntity_AddEpair(Entity, EntityNameEpair);
	}

	// remember type class
	Class = geEntity_EntitySetFindClassByName(WSets[0].Set, ClassName);
	if(!Class)
	{
		geEntity_Destroy(Entity);
		return NULL;
	}

	Entity->Class = Class;

	// allocate space for user data
	Entity->UserData = GE_RAM_ALLOCATE_ARRAY(char, Entity->Class->FieldSize);
	if(!Entity->UserData)
	{
		geEntity_Destroy(Entity);
		return NULL;
	}
	memcpy(Entity->UserData, UserData, Entity->Class->FieldSize);
	
	// check all fields and look if there are any strings in this entity class
	// if so, add a new Epair, copy the string to the Epair->Value and
	// set the char pointer in the UserData to point to Epair->Value
	{
		geEntity_Field	*Field;
		char			*UData = Entity->UserData;
		
		for(Field=Class->Fields; Field; Field=Field->Next)
		{
			if(Field->TypeClass->Type == TYPE_STRING)
			{
				if(*(char**)(UData + Field->Offset) != NULL)
				{
					geEntity_Epair *Epair = geEntity_EpairCreate();

					// get fieldname
					Epair->Key = geRam_Allocate(strlen(Field->Name)+1);
					strcpy(Epair->Key, Field->Name);
				
					// copy string
					Epair->Value = geRam_Allocate(strlen(*(char**)(UData + Field->Offset))+1);
					strcpy(Epair->Value, *(char**)(UData + Field->Offset));
					*(char**)(UData + Field->Offset) = Epair->Value;

					// add epair to entity
					geEntity_AddEpair(Entity, Epair);
				}
			}
		}
	}
	
	// insert entity in class list
	for(i=1; i<World->NumEntClassSets; i++)
	{
		assert(WSets[i].Set);

		if(!stricmp(WSets[i].ClassName, ClassName))
		{			
			geEntity_EntitySetAddEntity(WSets[i].Set, Entity);
			return Entity;
		}
	}

	if(i >= MAX_WORLD_ENT_CLASS_SETS)
	{
		geEntity_Destroy(Entity);
		return NULL;					// oh well...
	}

	// Create a new entity set
	WSets[i].Set = geEntity_EntitySetCreate();

	// Insert the entity into a new class set
	WSets[i].ClassName = Entity->Class->Name;
	geEntity_EntitySetAddEntity(WSets[i].Set, Entity);

	World->NumEntClassSets++;

	return Entity;
}

[zany_001]

so you can create lights etc. in the middle of the game?cool.

[QuestOfDreams]

Yes, that's an example, although this special case would have been doable before. First feature I'm using it for is to spawn an Attribute entity when dropping a weapon so you can pick it up again later.

[Juutis]

Sounds great! I can see plenty of new possibilities with this feature.

Thanks QoD.

[zany_001]

yah tnks a lot.

[federico]

hoping to join the Physics release with the official RF, I will add this command to my genesis3d source, including my new command to globally rotate bones...

[darksmaster923]

will this be in the neu rf release??

[federico]

The question should be: what will contain the new version of RF?
Anyway I added this command to the genesis3d source I packed for the physics release.