Each iterator

Collaboration diagram for Each iterator:

Functions
ecs_iter_t	ecs_each_id (const ecs_world_t *world, ecs_id_t id)
	Iterate all entities with specified (component id).
bool	ecs_each_next (ecs_iter_t *it)
	Progress an iterator created with ecs_each_id().
ecs_iter_t	ecs_children (const ecs_world_t *world, ecs_entity_t parent)
	Iterate children of parent.
bool	ecs_children_next (ecs_iter_t *it)
	Progress an iterator created with ecs_children().

Detailed Description

Find all entities that have a single (component) id.

Function Documentation

ecs_children()

ecs_iter_t ecs_children	(	const ecs_world_t *	world,
		ecs_entity_t	parent )

Iterate children of parent.

Equivalent to:

ecs_iter_t it = ecs_each_id(world, ecs_pair(EcsChildOf, parent));

Parameters

world	The world.
parent	The parent.

Returns

An iterator that iterates all children of the parent.

See also

ecs_each_id()

ecs_children_next()

bool ecs_children_next

(

ecs_iter_t *

it

)

Progress an iterator created with ecs_children().

Parameters

it	The iterator.

Returns

True if the iterator has more results, false if not.

ecs_each_id()

ecs_iter_t ecs_each_id	(	const ecs_world_t *	world,
		ecs_id_t	id )

Iterate all entities with specified (component id).

This returns an iterator that yields all entities with a single specified component. This is a much lighter weight operation than creating and iterating a query.

Usage:

ecs_iter_t it = ecs_each(world, Player);
while (ecs_each_next(&it)) {
  for (int i = 0; i < it.count; i ++) {
    // Iterate as usual.
  }
}

If the specified id is a component, it is possible to access the component pointer with ecs_field just like with regular queries:

ecs_iter_t it = ecs_each(world, Position);
while (ecs_each_next(&it)) {
  Position *p = ecs_field(&it, Position, 0);
  for (int i = 0; i < it.count; i ++) {
    // Iterate as usual.
  }
}

Parameters

world	The world.
id	The (component) id to iterate.

Returns

An iterator that iterates all entities with the (component) id.

ecs_each_next()

bool ecs_each_next

(

ecs_iter_t *

it

)

Progress an iterator created with ecs_each_id().

Parameters

it	The iterator.

Returns

True if the iterator has more results, false if not.