Getting and Setting

Functions for getting and setting components. More...

Collaboration diagram for Getting and Setting:

Functions
const void *	ecs_get_id (const ecs_world_t *world, ecs_entity_t entity, ecs_id_t component)
	Get an immutable pointer to a component.
void *	ecs_get_mut_id (const ecs_world_t *world, ecs_entity_t entity, ecs_id_t component)
	Get a mutable pointer to a component.
void *	ecs_ensure_id (ecs_world_t *world, ecs_entity_t entity, ecs_id_t component, size_t size)
	Ensure an entity has a component and return a pointer.
ecs_ref_t	ecs_ref_init_id (const ecs_world_t *world, ecs_entity_t entity, ecs_id_t component)
	Create a component ref.
void *	ecs_ref_get_id (const ecs_world_t *world, ecs_ref_t *ref, ecs_id_t component)
	Get a component from a ref.
void	ecs_ref_update (const ecs_world_t *world, ecs_ref_t *ref)
	Update a ref.
void *	ecs_emplace_id (ecs_world_t *world, ecs_entity_t entity, ecs_id_t component, size_t size, bool *is_new)
	Emplace a component.
void	ecs_modified_id (ecs_world_t *world, ecs_entity_t entity, ecs_id_t component)
	Signal that a component has been modified.
void	ecs_set_id (ecs_world_t *world, ecs_entity_t entity, ecs_id_t component, size_t size, const void *ptr)
	Set the value of a component.

Detailed Description

Functions for getting and setting components.

Function Documentation

ecs_emplace_id()

void * ecs_emplace_id	(	ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_id_t	component,
		size_t	size,
		bool *	is_new )

Emplace a component.

Emplace is similar to ecs_ensure_id() except that the component constructor is not invoked for the returned pointer, allowing the component to be constructed directly in the storage.

When the is_new parameter is not provided, the operation will assert when the component already exists. When the is_new parameter is provided, it will indicate whether the returned storage has been constructed.

When is_new indicates that the storage has not yet been constructed, it must be constructed by the code invoking this operation. Not constructing the component will result in undefined behavior.

Parameters

world	The world.
entity	The entity.
component	The component to get or add.
size	The component size.
is_new	Whether this is an existing or new component.

Returns

The (uninitialized) component pointer.

ecs_ensure_id()

void * ecs_ensure_id	(	ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_id_t	component,
		size_t	size )

Ensure an entity has a component and return a pointer.

This operation returns a mutable pointer to a component. If the entity did not yet have the component, it will be added.

If ensure() is called when the world is in deferred or read-only mode, the function will:

• return a pointer to temporary storage if the component does not yet exist, or
• return a pointer to the existing component if it exists

Parameters

world	The world.
entity	The entity.
component	The component to get or add.
size	The size of the component.

Returns

The component pointer.

See also

ecs_emplace_id()

ecs_get_id()

const void * ecs_get_id	(	const ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_id_t	component )

Get an immutable pointer to a component.

This operation obtains a const pointer to the requested component. The operation accepts the component entity ID.

This operation can return inherited components reachable through an IsA relationship.

Parameters

world	The world.
entity	The entity.
component	The component to get.

Returns

The component pointer, NULL if the entity does not have the component.

See also

ecs_get_mut_id()

ecs_get_mut_id()

void * ecs_get_mut_id	(	const ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_id_t	component )

Get a mutable pointer to a component.

This operation obtains a mutable pointer to the requested component. The operation accepts the component entity ID.

Unlike ecs_get_id(), this operation does not return inherited components. This is to prevent errors where an application accidentally resolves an inherited component shared with many entities and modifies it, while thinking it is modifying an owned component.

Parameters

world	The world.
entity	The entity.
component	The component to get.

Returns

The component pointer, NULL if the entity does not have the component.

ecs_modified_id()

void ecs_modified_id	(	ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_id_t	component )

Signal that a component has been modified.

This operation is usually used after modifying a component value obtained by ecs_ensure_id(). The operation will mark the component as dirty, and invoke OnSet observers and hooks.

Parameters

world	The world.
entity	The entity.
component	The component that was modified.

ecs_ref_get_id()

void * ecs_ref_get_id	(	const ecs_world_t *	world,
		ecs_ref_t *	ref,
		ecs_id_t	component )

Get a component from a ref.

Get a component pointer from a ref. The ref must be created with ecs_ref_init(). The specified component must match the component with which the ref was created.

Parameters

world	The world.
ref	The ref.
component	The component to get.

Returns

The component pointer, NULL if the entity does not have the component.

ecs_ref_init_id()

ecs_ref_t ecs_ref_init_id	(	const ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_id_t	component )

Create a component ref.

A ref is a handle to an entity and component pair, which caches a small amount of data to reduce the overhead of repeatedly accessing the component. Use ecs_ref_get() to get the component data.

Parameters

world	The world.
entity	The entity.
component	The component to create a ref for.

Returns

The reference.

ecs_ref_update()

void ecs_ref_update	(	const ecs_world_t *	world,
		ecs_ref_t *	ref )

Update a ref.

Ensure the contents of a ref are up to date. Same as ecs_ref_get_id(), but does not return a pointer to the component.

Parameters

world	The world.
ref	The ref.

ecs_set_id()

void ecs_set_id	(	ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_id_t	component,
		size_t	size,
		const void *	ptr )

Set the value of a component.

This operation allows an application to set the value of a component. The operation is equivalent to calling ecs_ensure_id() followed by ecs_modified_id(). The operation will not modify the value of the passed-in component. If the component has a copy hook registered, it will be used to copy in the component.

If the provided entity is 0, a new entity will be created.

Parameters

world	The world.
entity	The entity.
component	The component to set.
size	The size of the pointed-to value.
ptr	The pointer to the value.