Creation & Deletion

Collaboration diagram for Creation & Deletion:

Classes
struct	ecs_entities_t
	Type returned by ecs_get_entities(). More...

Typedefs
typedef struct ecs_entities_t	ecs_entities_t
	Type returned by ecs_get_entities().

Functions
ecs_world_t *	ecs_init (void)
	Create a new world.
ecs_world_t *	ecs_mini (void)
	Create a new world with just the core module.
ecs_world_t *	ecs_init_w_args (int argc, char *argv[])
	Create a new world with arguments.
int	ecs_fini (ecs_world_t *world)
	Delete a world.
bool	ecs_is_fini (const ecs_world_t *world)
	Returns whether the world is being deleted.
void	ecs_atfini (ecs_world_t *world, ecs_fini_action_t action, void *ctx)
	Register action to be executed when world is destroyed.
ecs_entities_t	ecs_get_entities (const ecs_world_t *world)
	Return entity identifiers in world.

Detailed Description

Function Documentation

ecs_atfini()

void ecs_atfini	(	ecs_world_t *	world,
		ecs_fini_action_t	action,
		void *	ctx )

Register action to be executed when world is destroyed.

Fini actions are typically used when a module needs to clean up before a world shuts down.

Parameters

world	The world.
action	The function to execute.
ctx	Userdata to pass to the function

ecs_fini()

int ecs_fini

(

ecs_world_t *

world

)

Delete a world.

This operation deletes the world, and everything it contains.

Parameters

world

The world to delete.

Returns

Zero if successful, non-zero if failed.

ecs_get_entities()

ecs_entities_t ecs_get_entities

(

const ecs_world_t *

world

)

Return entity identifiers in world.

This operation returns an array with all entity ids that exist in the world. Note that the returned array will change and may get invalidated as a result of entity creation & deletion.

To iterate all alive entity ids, do:

ecs_entities_t entities = ecs_get_entities(world);
for (int i = 0; i < entities.alive_count; i ++) {
  ecs_entity_t id = entities.ids[i];
}

To iterate not-alive ids, do:

for (int i = entities.alive_count + 1; i < entities.count; i ++) {
  ecs_entity_t id = entities.ids[i];
}

The returned array does not need to be freed. Mutating the returned array will return in undefined behavior (and likely crashes).

Parameters

world

The world.

Returns

Struct with entity id array.

ecs_init()

ecs_world_t * ecs_init

(

void

)

Create a new world.

This operation automatically imports modules from addons Flecs has been built with, except when the module specifies otherwise.

Returns

A new world

ecs_init_w_args()

ecs_world_t * ecs_init_w_args	(	int	argc,
		char *	argv[] )

Create a new world with arguments.

Same as ecs_init(), but allows passing in command line arguments. Command line arguments are used to:

• automatically derive the name of the application from argv[0]

Returns

A new world

ecs_is_fini()

bool ecs_is_fini

(

const ecs_world_t *

world

)

Returns whether the world is being deleted.

This operation can be used in callbacks like type hooks or observers to detect if they are invoked while the world is being deleted.

Parameters

world

The world.

Returns

True if being deleted, false if not.

ecs_mini()

ecs_world_t * ecs_mini

(

void

)

Create a new world with just the core module.

Same as ecs_init(), but doesn't import modules from addons. This operation is faster than ecs_init() and results in less memory utilization.

Returns

A new tiny world