Tables

Functions for working with ecs_table_t. More...

Collaboration diagram for Tables:

Functions
const ecs_type_t *	ecs_table_get_type (const ecs_table_t *table)
	Get type for table.
int32_t	ecs_table_get_type_index (const ecs_world_t *world, const ecs_table_t *table, ecs_id_t id)
	Get type index for id.
int32_t	ecs_table_get_column_index (const ecs_world_t *world, const ecs_table_t *table, ecs_id_t id)
	Get column index for id.
int32_t	ecs_table_column_count (const ecs_table_t *table)
	Return number of columns in table.
int32_t	ecs_table_type_to_column_index (const ecs_table_t *table, int32_t index)
	Convert type index to column index.
int32_t	ecs_table_column_to_type_index (const ecs_table_t *table, int32_t index)
	Convert column index to type index.
void *	ecs_table_get_column (const ecs_table_t *table, int32_t index, int32_t offset)
	Get column from table by column index.
void *	ecs_table_get_id (const ecs_world_t *world, const ecs_table_t *table, ecs_id_t id, int32_t offset)
	Get column from table by component id.
size_t	ecs_table_get_column_size (const ecs_table_t *table, int32_t index)
	Get column size from table.
int32_t	ecs_table_count (const ecs_table_t *table)
	Returns the number of entities in the table.
int32_t	ecs_table_size (const ecs_table_t *table)
	Returns allocated size of table.
const ecs_entity_t *	ecs_table_entities (const ecs_table_t *table)
	Returns array with entity ids for table.
bool	ecs_table_has_id (const ecs_world_t *world, const ecs_table_t *table, ecs_id_t id)
	Test if table has id.
int32_t	ecs_table_get_depth (const ecs_world_t *world, const ecs_table_t *table, ecs_entity_t rel)
	Return depth for table in tree for relationship rel.
ecs_table_t *	ecs_table_add_id (ecs_world_t *world, ecs_table_t *table, ecs_id_t id)
	Get table that has all components of current table plus the specified id.
ecs_table_t *	ecs_table_find (ecs_world_t *world, const ecs_id_t *ids, int32_t id_count)
	Find table from id array.
ecs_table_t *	ecs_table_remove_id (ecs_world_t *world, ecs_table_t *table, ecs_id_t id)
	Get table that has all components of current table minus the specified id.
void	ecs_table_lock (ecs_world_t *world, ecs_table_t *table)
	Lock a table.
void	ecs_table_unlock (ecs_world_t *world, ecs_table_t *table)
	Unlock a table.
bool	ecs_table_has_flags (ecs_table_t *table, ecs_flags32_t flags)
	Test table for flags.
void	ecs_table_swap_rows (ecs_world_t *world, ecs_table_t *table, int32_t row_1, int32_t row_2)
	Swaps two elements inside the table.
bool	ecs_commit (ecs_world_t *world, ecs_entity_t entity, ecs_record_t *record, ecs_table_t *table, const ecs_type_t *added, const ecs_type_t *removed)
	Commit (move) entity to a table.
int32_t	ecs_search (const ecs_world_t *world, const ecs_table_t *table, ecs_id_t id, ecs_id_t *id_out)
	Search for component id in table type.
int32_t	ecs_search_offset (const ecs_world_t *world, const ecs_table_t *table, int32_t offset, ecs_id_t id, ecs_id_t *id_out)
	Search for component id in table type starting from an offset.
int32_t	ecs_search_relation (const ecs_world_t *world, const ecs_table_t *table, int32_t offset, ecs_id_t id, ecs_entity_t rel, ecs_flags64_t flags, ecs_entity_t *subject_out, ecs_id_t *id_out, struct ecs_table_record_t **tr_out)
	Search for component/relationship id in table type starting from an offset.
void	ecs_table_clear_entities (ecs_world_t *world, ecs_table_t *table)
	Remove all entities in a table.

Detailed Description

Functions for working with ecs_table_t.

Function Documentation

ecs_commit()

bool ecs_commit	(	ecs_world_t *	world,
		ecs_entity_t	entity,
		ecs_record_t *	record,
		ecs_table_t *	table,
		const ecs_type_t *	added,
		const ecs_type_t *	removed )

Commit (move) entity to a table.

This operation moves an entity from its current table to the specified table. This may cause the following actions:

• Ctor for each component in the target table
• Move for each overlapping component
• Dtor for each component in the source table.
• OnAdd triggers for non-overlapping components in the target table
• OnRemove triggers for non-overlapping components in the source table.

This operation is a faster than adding/removing components individually.

The application must explicitly provide the difference in components between tables as the added/removed parameters. This can usually be derived directly from the result of ecs_table_add_id() and ecs_table_remove_id(). These arrays are required to properly execute OnAdd/OnRemove triggers.

Parameters

world	The world.
entity	The entity to commit.
record	The entity's record (optional, providing it saves a lookup).
table	The table to commit the entity to.

Returns

True if the entity got moved, false otherwise.

ecs_search()

int32_t ecs_search	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		ecs_id_t	id,
		ecs_id_t *	id_out )

Search for component id in table type.

This operation returns the index of first occurrence of the id in the table type. The id may be a wildcard.

When id_out is provided, the function will assign it with the found id. The found id may be different from the provided id if it is a wildcard.

This is a constant time operation.

Parameters

world	The world.
table	The table.
id	The id to search for.
id_out	If provided, it will be set to the found id (optional).

Returns

The index of the id in the table type.

See also

ecs_search_offset()

ecs_search_relation()

ecs_search_offset()

int32_t ecs_search_offset	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		int32_t	offset,
		ecs_id_t	id,
		ecs_id_t *	id_out )

Search for component id in table type starting from an offset.

This operation is the same as ecs_search(), but starts searching from an offset in the table type.

This operation is typically called in a loop where the resulting index is used in the next iteration as offset:

int32_t index = -1;
while ((index = ecs_search_offset(world, table, offset, id, NULL))) {
  // do stuff
}

Depending on how the operation is used it is either linear or constant time. When the id has the form (id) or (rel, *) and the operation is invoked as in the above example, it is guaranteed to be constant time.

If the provided id has the form (*, tgt) the operation takes linear time. The reason for this is that ids for an target are not packed together, as they are sorted relationship first.

If the id at the offset does not match the provided id, the operation will do a linear search to find a matching id.

Parameters

world	The world.
table	The table.
offset	Offset from where to start searching.
id	The id to search for.
id_out	If provided, it will be set to the found id (optional).

Returns

The index of the id in the table type.

See also

ecs_search()

ecs_search_relation()

ecs_search_relation()

int32_t ecs_search_relation	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		int32_t	offset,
		ecs_id_t	id,
		ecs_entity_t	rel,
		ecs_flags64_t	flags,
		ecs_entity_t *	subject_out,
		ecs_id_t *	id_out,
		struct ecs_table_record_t **	tr_out )

Search for component/relationship id in table type starting from an offset.

This operation is the same as ecs_search_offset(), but has the additional capability of traversing relationships to find a component. For example, if an application wants to find a component for either the provided table or a prefab (using the IsA relationship) of that table, it could use the operation like this:

int32_t index = ecs_search_relation(
  world,            // the world
  table,            // the table
  0,                // offset 0
  ecs_id(Position), // the component id
  EcsIsA,           // the relationship to traverse
  0,                // start at depth 0 (the table itself)
  0,                // no depth limit
  NULL,             // (optional) entity on which component was found
  NULL,             // see above
  NULL);            // internal type with information about matched id

The operation searches depth first. If a table type has 2 IsA relationships, the operation will first search the IsA tree of the first relationship.

When choosing between ecs_search(), ecs_search_offset() and ecs_search_relation(), the simpler the function the better its performance.

Parameters

world	The world.
table	The table.
offset	Offset from where to start searching.
id	The id to search for.
rel	The relationship to traverse (optional).
flags	Whether to search EcsSelf and/or EcsUp.
subject_out	If provided, it will be set to the matched entity.
id_out	If provided, it will be set to the found id (optional).
tr_out	Internal datatype.

Returns

The index of the id in the table type.

See also

ecs_search()

ecs_search_offset()

ecs_table_add_id()

ecs_table_t * ecs_table_add_id	(	ecs_world_t *	world,
		ecs_table_t *	table,
		ecs_id_t	id )

Get table that has all components of current table plus the specified id.

If the provided table already has the provided id, the operation will return the provided table.

Parameters

world	The world.
table	The table.
id	The id to add.

Returns

The resulting table.

ecs_table_clear_entities()

void ecs_table_clear_entities	(	ecs_world_t *	world,
		ecs_table_t *	table )

Remove all entities in a table.

Does not deallocate table memory. Retaining table memory can be efficient when planning to refill the table with operations like ecs_bulk_init

Parameters

world	The world.
table	The table to clear.

ecs_table_column_count()

int32_t ecs_table_column_count

(

const ecs_table_t *

table

)

Return number of columns in table.

Similar to ecs_table_get_type(table)->count, except that the column count only counts the number of components in a table.

Parameters

table

The table.

Returns

The number of columns in the table.

ecs_table_column_to_type_index()

int32_t ecs_table_column_to_type_index	(	const ecs_table_t *	table,
		int32_t	index )

Convert column index to type index.

Same as ecs_table_type_to_column_index(), but converts from an index in the column array to an index in the table type.

Parameters

table	The table.
index	The column index.

Returns

The index in the table type.

ecs_table_count()

int32_t ecs_table_count

(

const ecs_table_t *

table

)

Returns the number of entities in the table.

This operation returns the number of entities in the table.

Parameters

table

The table.

Returns

The number of entities in the table.

ecs_table_entities()

const ecs_entity_t * ecs_table_entities

(

const ecs_table_t *

table

)

Returns array with entity ids for table.

The size of the returned array is the result of ecs_table_count().

Parameters

table

The table.

Returns

Array with entity ids for table.

ecs_table_find()

ecs_table_t * ecs_table_find	(	ecs_world_t *	world,
		const ecs_id_t *	ids,
		int32_t	id_count )

Find table from id array.

This operation finds or creates a table with the specified array of (component) ids. The ids in the array must be sorted, and it may not contain duplicate elements.

Parameters

world	The world.
ids	The id array.
id_count	The number of elements in the id array.

Returns

The table with the specified (component) ids.

ecs_table_get_column()

void * ecs_table_get_column	(	const ecs_table_t *	table,
		int32_t	index,
		int32_t	offset )

Get column from table by column index.

This operation returns the component array for the provided index.

Parameters

table	The table.
index	The column index.
offset	The index of the first row to return (0 for entire column).

Returns

The component array, or NULL if the index is not a component.

ecs_table_get_column_index()

int32_t ecs_table_get_column_index	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		ecs_id_t	id )

Get column index for id.

This operation returns the column index for an id in the table's type. If the id is not a component, the function will return -1.

Parameters

world	The world.
table	The table.
id	The component id.

Returns

The column index of the id, or -1 if not found/not a component.

ecs_table_get_column_size()

size_t ecs_table_get_column_size	(	const ecs_table_t *	table,
		int32_t	index )

Get column size from table.

This operation returns the component size for the provided index.

Parameters

table	The table.
index	The column index.

Returns

The component size, or 0 if the index is not a component.

ecs_table_get_depth()

int32_t ecs_table_get_depth	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		ecs_entity_t	rel )

Return depth for table in tree for relationship rel.

Depth is determined by counting the number of targets encountered while traversing up the relationship tree for rel. Only acyclic relationships are supported.

Parameters

world	The world.
table	The table.
rel	The relationship.

Returns

The depth of the table in the tree.

ecs_table_get_id()

void * ecs_table_get_id	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		ecs_id_t	id,
		int32_t	offset )

Get column from table by component id.

This operation returns the component array for the provided component id.

Parameters

world	The world.
table	The table.
id	The component id for the column.
offset	The index of the first row to return (0 for entire column).

Returns

The component array, or NULL if the index is not a component.

ecs_table_get_type()

const ecs_type_t * ecs_table_get_type

(

const ecs_table_t *

table

)

Get type for table.

The table type is a vector that contains all component, tag and pair ids.

Parameters

table

The table.

Returns

The type of the table.

ecs_table_get_type_index()

int32_t ecs_table_get_type_index	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		ecs_id_t	id )

Get type index for id.

This operation returns the index for an id in the table's type.

Parameters

world	The world.
table	The table.
id	The id.

Returns

The index of the id in the table type, or -1 if not found.

See also

ecs_table_has_id()

ecs_table_has_flags()

bool ecs_table_has_flags	(	ecs_table_t *	table,
		ecs_flags32_t	flags )

Test table for flags.

Test if table has all of the provided flags. See include/flecs/private/api_flags.h for a list of table flags that can be used with this function.

Parameters

table	The table.
flags	The flags to test for.

Returns

Whether the specified flags are set for the table.

ecs_table_has_id()

bool ecs_table_has_id	(	const ecs_world_t *	world,
		const ecs_table_t *	table,
		ecs_id_t	id )

Test if table has id.

Same as ecs_table_get_type_index(world, table, id) != -1.

Parameters

world	The world.
table	The table.
id	The id.

Returns

True if the table has the id, false if the table doesn't.

See also

ecs_table_get_type_index()

ecs_table_lock()

void ecs_table_lock	(	ecs_world_t *	world,
		ecs_table_t *	table )

Lock a table.

When a table is locked, modifications to it will throw an assert. When the table is locked recursively, it will take an equal amount of unlock operations to actually unlock the table.

Table locks can be used to build safe iterators where it is guaranteed that the contents of a table are not modified while it is being iterated.

The operation only works when called on the world, and has no side effects when called on a stage. The assumption is that when called on a stage, operations are deferred already.

Parameters

world	The world.
table	The table to lock.

ecs_table_remove_id()

ecs_table_t * ecs_table_remove_id	(	ecs_world_t *	world,
		ecs_table_t *	table,
		ecs_id_t	id )

Get table that has all components of current table minus the specified id.

If the provided table doesn't have the provided id, the operation will return the provided table.

Parameters

world	The world.
table	The table.
id	The id to remove.

Returns

The resulting table.

ecs_table_size()

int32_t ecs_table_size

(

const ecs_table_t *

table

)

Returns allocated size of table.

This operation returns the number of elements allocated in the table per column.

Parameters

table

The table.

Returns

The number of allocated elements in the table.

ecs_table_swap_rows()

void ecs_table_swap_rows	(	ecs_world_t *	world,
		ecs_table_t *	table,
		int32_t	row_1,
		int32_t	row_2 )

Swaps two elements inside the table.

This is useful for implementing custom table sorting algorithms.

Parameters

world	The world
table	The table to swap elements in
row_1	Table element to swap with row_2
row_2	Table element to swap with row_1

ecs_table_type_to_column_index()

int32_t ecs_table_type_to_column_index	(	const ecs_table_t *	table,
		int32_t	index )

Convert type index to column index.

Tables have an array of columns for each component in the table. This array does not include elements for tags, which means that the index for a component in the table type is not necessarily the same as the index in the column array. This operation converts from an index in the table type to an index in the column array.

Parameters

table	The table.
index	The index in the table type.

Returns

The index in the table column array.

See also

ecs_table_column_to_type_index()

ecs_table_unlock()

void ecs_table_unlock	(	ecs_world_t *	world,
		ecs_table_t *	table )

Unlock a table.

Must be called after calling ecs_table_lock().

Parameters

world	The world.
table	The table to unlock.