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C

/**
* @file flecs.h
* @brief Flecs public API.
*
* This file contains the public API for Flecs.
*/
#ifndef FLECS_H
#define FLECS_H
/**
* @defgroup c C API
*
* @{
* @}
*/
/**
* @defgroup core Core
* @brief Core ECS functionality (entities, storage, queries).
*
* \ingroup c
* @{
*/
/**
* @defgroup options API defines
* @brief Defines for customizing compile time features.
* @{
*/
/** \def ecs_float_t
* Customizable precision for floating point operations */
#ifndef ecs_float_t
#define ecs_float_t float
#endif
/** \def ecs_ftime_t
* Customizable precision for scalar time values. Change to double precision for
* processes that can run for a long time (e.g. longer than a day). */
#ifndef ecs_ftime_t
#define ecs_ftime_t ecs_float_t
#endif
/** \def FLECS_LEGACY
* Define when building for C89
*/
// #define FLECS_LEGACY
/** \def FLECS_NO_DEPRECATED_WARNINGS
* disables deprecated warnings
*/
#define FLECS_NO_DEPRECATED_WARNINGS
/** \def FLECS_ACCURATE_COUNTERS
* Define to ensure that global counters used for statistics (such as the
* allocation counters in the OS API) are accurate in multithreaded
* applications, at the cost of increased overhead.
*/
// #define FLECS_ACCURATE_COUNTERS
/* Make sure provided configuration is valid */
#if defined(FLECS_DEBUG) && defined(FLECS_NDEBUG)
#error "invalid configuration: cannot both define FLECS_DEBUG and FLECS_NDEBUG"
#endif
#if defined(FLECS_DEBUG) && defined(NDEBUG)
#error "invalid configuration: cannot both define FLECS_DEBUG and NDEBUG"
#endif
/** \def FLECS_DEBUG
* Used for input parameter checking and cheap sanity checks. There are lots of
* asserts in every part of the code, so this will slow down applications.
*/
#if !defined(FLECS_DEBUG) && !defined(FLECS_NDEBUG)
#if defined(NDEBUG)
#define FLECS_NDEBUG
#else
#define FLECS_DEBUG
#endif
#endif
/** \def FLECS_SANITIZE
* Enables expensive checks that can detect issues early. Recommended for
* running tests or when debugging issues. This will severely slow down code.
*/
#ifdef FLECS_SANITIZE
#ifndef FLECS_DEBUG
#define FLECS_DEBUG /* If sanitized mode is enabled, so is debug mode */
#endif
#endif
/* Tip: if you see weird behavior that you think might be a bug, make sure to
* test with the FLECS_DEBUG or FLECS_SANITIZE flags enabled. There's a good
* chance that this gives you more information about the issue! */
/** \def FLECS_SOFT_ASSERT
* Define to not abort for recoverable errors, like invalid parameters. An error
* is still thrown to the console. This is recommended for when running inside a
* third party runtime, such as the Unreal editor.
*
* Note that internal sanity checks (ECS_INTERNAL_ERROR) will still abort a
* process, as this gives more information than a (likely) subsequent crash.
*
* When a soft assert occurs, the code will attempt to minimize the number of
* side effects of the failed operation, but this may not always be possible.
* Even though an application may still be able to continue running after a soft
* assert, it should be treated as if in an undefined state.
*/
// #define FLECS_SOFT_ASSERT
/** \def FLECS_KEEP_ASSERT
* By default asserts are disabled in release mode, when either FLECS_NDEBUG or
* NDEBUG is defined. Defining FLECS_KEEP_ASSERT ensures that asserts are not
* disabled. This define can be combined with FLECS_SOFT_ASSERT.
*/
// #define FLECS_KEEP_ASSERT
/** \def FLECS_CUSTOM_BUILD
* This macro lets you customize which addons to build flecs with.
* Without any addons Flecs is just a minimal ECS storage, but addons add
* features such as systems, scheduling and reflection. If an addon is disabled,
* it is excluded from the build, so that it consumes no resources. By default
* all addons are enabled.
*
* You can customize a build by either whitelisting or blacklisting addons. To
* whitelist addons, first define the FLECS_CUSTOM_BUILD macro, which disables
* all addons. You can then manually select the addons you need by defining
* their macro, like "FLECS_SYSTEM".
*
* To blacklist an addon, make sure to *not* define FLECS_CUSTOM_BUILD, and
* instead define the addons you don't need by defining FLECS_NO_<addon>, for
* example "FLECS_NO_SYSTEM". If there are any addons that depend on the
* blacklisted addon, an error will be thrown during the build.
*
* Note that addons can have dependencies on each other. Addons will
* automatically enable their dependencies. To see the list of addons that was
* compiled in a build, enable tracing before creating the world by doing:
* ecs_log_set_level(0);
* which outputs the full list of addons Flecs was compiled with.
*/
// #define FLECS_CUSTOM_BUILD
#ifndef FLECS_CUSTOM_BUILD
// #define FLECS_C /**< C API convenience macros, always enabled */
#define FLECS_CPP /**< C++ API */
#define FLECS_MODULE /**< Module support */
#define FLECS_PARSER /**< String parser for queries */
#define FLECS_PLECS /**< ECS data definition format */
#define FLECS_RULES /**< Constraint solver for advanced queries */
#define FLECS_SNAPSHOT /**< Snapshot & restore ECS data */
#define FLECS_STATS /**< Access runtime statistics */
#define FLECS_MONITOR /**< Track runtime statistics periodically */
#define FLECS_METRICS /**< Expose component data as statistics */
#define FLECS_ALERTS /**< Monitor conditions for errors */
#define FLECS_SYSTEM /**< System support */
#define FLECS_PIPELINE /**< Pipeline support */
#define FLECS_TIMER /**< Timer support */
#define FLECS_META /**< Reflection support */
#define FLECS_META_C /**< Utilities for populating reflection data */
#define FLECS_UNITS /**< Builtin standard units */
#define FLECS_EXPR /**< Parsing strings to/from component values */
#define FLECS_JSON /**< Parsing JSON to/from component values */
#define FLECS_DOC /**< Document entities & components */
#define FLECS_COREDOC /**< Documentation for core entities & components */
#define FLECS_LOG /**< When enabled ECS provides more detailed logs */
#define FLECS_APP /**< Application addon */
#define FLECS_OS_API_IMPL /**< Default implementation for OS API */
#define FLECS_HTTP /**< Tiny HTTP server for connecting to remote UI */
#define FLECS_REST /**< REST API for querying application data */
// #define FLECS_JOURNAL /**< Journaling addon (disabled by default) */
#endif // ifndef FLECS_CUSTOM_BUILD
/** \def FLECS_LOW_FOOTPRINT
* Set a number of constants to values that decrease memory footprint, at the
* cost of decreased performance. */
// #define FLECS_LOW_FOOTPRINT
#ifdef FLECS_LOW_FOOTPRINT
#define FLECS_HI_COMPONENT_ID (16)
#define FLECS_HI_ID_RECORD_ID (16)
#define FLECS_SPARSE_PAGE_BITS (6)
#define FLECS_ENTITY_PAGE_BITS (6)
#define FLECS_USE_OS_ALLOC
#endif
/** \def FLECS_HI_COMPONENT_ID
* This constant can be used to balance between performance and memory
* utilization. The constant is used in two ways:
* - Entity ids 0..FLECS_HI_COMPONENT_ID are reserved for component ids.
* - Used as lookup array size in table edges.
*
* Increasing this value increases the size of the lookup array, which allows
* fast table traversal, which improves performance of ECS add/remove
* operations. Component ids that fall outside of this range use a regular map
* lookup, which is slower but more memory efficient. */
#ifndef FLECS_HI_COMPONENT_ID
#define FLECS_HI_COMPONENT_ID (256)
#endif
/** \def FLECS_HI_ID_RECORD_ID
* This constant can be used to balance between performance and memory
* utilization. The constant is used to determine the size of the id record
* lookup array. Id values that fall outside of this range use a regular map
* lookup, which is slower but more memory efficient.
*/
#ifndef FLECS_HI_ID_RECORD_ID
#define FLECS_HI_ID_RECORD_ID (1024)
#endif
/** \def FLECS_SPARSE_PAGE_BITS
* This constant is used to determine the number of bits of an id that is used
* to determine the page index when used with a sparse set. The number of bits
* determines the page size, which is (1 << bits).
* Lower values decrease memory utilization, at the cost of more allocations. */
#ifndef FLECS_SPARSE_PAGE_BITS
#define FLECS_SPARSE_PAGE_BITS (12)
#endif
/** \def FLECS_ENTITY_PAGE_BITS
* Same as FLECS_SPARSE_PAGE_BITS, but for the entity index. */
#ifndef FLECS_ENTITY_PAGE_BITS
#define FLECS_ENTITY_PAGE_BITS (12)
#endif
/** \def FLECS_USE_OS_ALLOC
* When enabled, Flecs will use the OS allocator provided in the OS API directly
* instead of the builtin block allocator. This can decrease memory utilization
* as memory will be freed more often, at the cost of decreased performance. */
// #define FLECS_USE_OS_ALLOC
/** \def FLECS_ID_DESC_MAX
* Maximum number of ids to add ecs_entity_desc_t / ecs_bulk_desc_t */
#ifndef FLECS_ID_DESC_MAX
#define FLECS_ID_DESC_MAX (32)
#endif
/** \def FLECS_TERM_DESC_MAX
* Maximum number of terms in ecs_filter_desc_t */
#define FLECS_TERM_DESC_MAX (16)
/** \def FLECS_EVENT_DESC_MAX
* Maximum number of events in ecs_observer_desc_t */
#define FLECS_EVENT_DESC_MAX (8)
/** \def FLECS_VARIABLE_COUNT_MAX
* Maximum number of query variables per query */
#define FLECS_VARIABLE_COUNT_MAX (64)
/** \def FLECS_QUERY_SCOPE_NESTING_MAX
* Maximum nesting depth of query scopes */
#define FLECS_QUERY_SCOPE_NESTING_MAX (8)
/** @} */
#include "flecs/private/api_defines.h"
#include "flecs/private/vec.h" /* Vector datatype */
#include "flecs/private/sparse.h" /* Sparse set */
#include "flecs/private/block_allocator.h" /* Block allocator */
#include "flecs/private/map.h" /* Map */
#include "flecs/private/allocator.h" /* Allocator */
#include "flecs/private/strbuf.h" /* String builder */
#include "flecs/os_api.h" /* Abstraction for operating system functions */
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup api_types API types
* @brief Public API types.
* @{
*/
/**
* @defgroup core_types Core API Types
* @brief Types for core API objects.
* @{
*/
/** Ids are the things that can be added to an entity.
* An id can be an entity or pair, and can have optional id flags. */
typedef uint64_t ecs_id_t;
/** An entity identifier.
* Entity ids consist out of a number unique to the entity in the lower 32 bits,
* and a counter used to track entity liveliness in the upper 32 bits. When an
* id is recycled, its generation count is increased. This causes recycled ids
* to be very large (>4 billion), which is normal. */
typedef ecs_id_t ecs_entity_t;
/** A type is a list of (component) ids.
* Types are used to communicate the "type" of an entity. In most type systems a
* typeof operation returns a single type. In ECS however, an entity can have
* multiple components, which is why an ECS type consists of a vector of ids.
*
* The component ids of a type are sorted, which ensures that it doesn't matter
* in which order components are added to an entity. For example, if adding
* Position then Velocity would result in type [Position, Velocity], first
* adding Velocity then Position would also result in type [Position, Velocity].
*
* Entities are grouped together by type in the ECS storage in tables. The
* storage has exactly one table per unique type that is created by the
* application that stores all entities and components for that type. This is
* also referred to as an archetype.
*/
typedef struct {
ecs_id_t *array;
int32_t count;
} ecs_type_t;
/** A world is the container for all ECS data and supporting features.
* Applications can have multiple worlds, though in most cases will only need
* one. Worlds are isolated from each other, and can have separate sets of
* systems, components, modules etc.
*
* If an application has multiple worlds with overlapping components, it is
* common (though not strictly required) to use the same component ids across
* worlds, which can be achieved by declaring a global component id variable.
* To do this in the C API, see the entities/fwd_component_decl example. The
* C++ API automatically synchronizes component ids between worlds.
*
* Component id conflicts between worlds can occur when a world has already used
* an id for something else. There are a few ways to avoid this:
*
* - Ensure to register the same components in each world, in the same order.
* - Create a dummy world in which all components are preregistered which
* initializes the global id variables.
*
* In some use cases, typically when writing tests, multiple worlds are created
* and deleted with different components, registered in different order. To
* ensure isolation between tests, the C++ API has a `flecs::reset` function
* that forces the API to ignore the old component ids. */
typedef struct ecs_world_t ecs_world_t;
/** A table stores entities and components for a specific type. */
typedef struct ecs_table_t ecs_table_t;
/** A term is a single element in a query. */
typedef struct ecs_term_t ecs_term_t;
/** A filter is an iterable data structure that describes a query.
* Filters are used by the various query implementations in Flecs, like queries,
* observers and rules, to describe a query. Filters themselves can also be
* iterated. */
typedef struct ecs_filter_t ecs_filter_t;
/** A query that caches its results.
* Queries are the fastest mechanism for finding and iterating over entities.
* Queries cache results as a list of matching tables (vs. individual entities).
*
* This has several advantages:
* - Matching is only performed when new tables are created, which is infrequent
* - Iterating a query just walks over the cache, no actual searching is needed
* - Iteration is table-based, which allows for direct iteration of underlying
* component arrays, providing good cache locality.
*
* While queries are the fastest mechanism to iterate entiites, they are slower
* to create than other mechanisms, as a result of having to build the cache
* first. For this reason queries are best suited for use cases where a single
* query can be reused many times (like is the case for systems).
*
* For ad-hoc queries it is recommended to use filters or rules instead, which
* are slower to iterate, but much faster to create. Applications should at all
* times avoid frequent creation/deletion of queries. */
typedef struct ecs_query_t ecs_query_t;
/** A rule is a query with advanced graph traversal features.
* Rules are fast uncached queries with support for advanced graph features such
* as the usage of query variables. A simple example of a rule that matches all
* spaceship entities docked to a planet:
* SpaceShip, (DockedTo, $planet), Planet($planet)
*
* Here, the rule traverses the DockedTo relationship, and matches Planet on the
* target of this relationship. Through the usage of variables rules can match
* arbitrary patterns against entity graphs. Other features supported
* exclusively by rules are:
* - Component inheritance
* - Transitivity
*
* Rules have similar iteration performance to filters, but are slower than
* queries. Rules and filters will eventually be merged into a single query
* implementation. Features still lacking for rules are:
* - Up traversal
* - AndFrom, OrFrom, NotFrom operators
*/
typedef struct ecs_rule_t ecs_rule_t;
/** An observer is a system that is invoked when an event matches its query.
* Observers allow applications to respond to specific events, such as adding or
* removing a component. Observers are created by both specifying a query and
* a list of event kinds that should be listened for. An example of an observer
* that triggers when a Position component is added to an entity (in C++):
*
* world.observer<Position>()
* .event(flecs::OnAdd)
* .each([](Position& p) {
* // called when Position is added to an entity
* });
*
* Observer queries can be as complex as filters. Observers only trigger when
* the source of the event matches the full observer query. For example, an
* OnAdd observer for Position, Velocity will only trigger after both components
* have been added to the entity. */
typedef struct ecs_observer_t ecs_observer_t;
/** An observable produces events that can be listened for by an observer.
* Currently only the world is observable. In the future, queries will become
* observable objects as well. */
typedef struct ecs_observable_t ecs_observable_t;
/* Type used for iterating iterable objects.
* Iterators are a common interface across iterable objects (world, filters,
* rules, queries, systems, observers) to provide applications with information
* about the currently iterated result, and to store any state required for the
* iteration. */
typedef struct ecs_iter_t ecs_iter_t;
/** A ref is a fast way to fetch a component for a specific entity.
* Refs are a faster alternative to repeatedly calling ecs_get for the same
* entity/component combination. When comparing the performance of getting a ref
* to calling ecs_get, a ref is typically 3-5x faster.
*
* Refs achieve this performance by caching internal data structures associated
* with the entity and component on the ecs_ref_t object that otherwise would
* have to be looked up. */
typedef struct ecs_ref_t ecs_ref_t;
/** Type hooks are callbacks associated with component lifecycle events.
* Typical examples of lifecycle events are construction, destruction, copying
* and moving of components. */
typedef struct ecs_type_hooks_t ecs_type_hooks_t;
/** Type information.
* Contains information about a (component) type, such as its size and
* alignment and type hooks. */
typedef struct ecs_type_info_t ecs_type_info_t;
/** Information about an entity, like its table and row. */
typedef struct ecs_record_t ecs_record_t;
/** Information about a (component) id, such as type info and tables with the id */
typedef struct ecs_id_record_t ecs_id_record_t;
/** Information about where in a table a specific (component) id is stored. */
typedef struct ecs_table_record_t ecs_table_record_t;
/** A poly object.
* A poly (short for polymorph) object is an object that has a variable list of
* capabilities, determined by a mixin table. This is the current list of types
* in the flecs API that can be used as an ecs_poly_t:
*
* - ecs_world_t
* - ecs_stage_t
* - ecs_query_t
* - ecs_filter_t
* - ecs_rule_t
* - (more to come)
*
* Functions that accept an ecs_poly_t argument can accept objects of these
* types. If the object does not have the requested mixin the API will throw an
* assert.
*
* The poly/mixin framework enables partially overlapping features to be
* implemented once, and enables objects of different types to interact with
* each other depending on what mixins they have, rather than their type
* (in some ways it's like a mini-ECS). Additionally, each poly object has a
* header that enables the API to do sanity checking on the input arguments.
*/
typedef void ecs_poly_t;
/** Type that stores poly mixins */
typedef struct ecs_mixins_t ecs_mixins_t;
/** Header for ecs_poly_t objects. */
typedef struct ecs_header_t {
int32_t magic; /* Magic number verifying it's a flecs object */
int32_t type; /* Magic number indicating which type of flecs object */
ecs_mixins_t *mixins; /* Table with offsets to (optional) mixins */
} ecs_header_t;
/** @} */
/**
* @defgroup function_types Function types.
* @brief Function callback types.
* @{
*/
/** Function prototype for runnables (systems, observers).
* The run callback overrides the default behavior for iterating through the
* results of a runnable object.
*
* The default runnable iterates the iterator, and calls an iter_action (see
* below) for each returned result.
*
* @param it The iterator to be iterated by the runnable.
*/
typedef void (*ecs_run_action_t)(
ecs_iter_t *it);
/** Function prototype for iterables.
* A system may invoke a callback multiple times, typically once for each
* matched table.
*
* @param it The iterator containing the data for the current match.
*/
typedef void (*ecs_iter_action_t)(
ecs_iter_t *it);
/** Function prototype for creating an iterator from a poly.
* Used to create iterators from poly objects with the iterable mixin. When a
* filter is provided, an array of two iterators must be passed to the function.
* This allows the mixin implementation to create a chained iterator when
* necessary, which requires two iterator objects.
*
* @param world The world or stage for which to create the iterator.
* @param iterable An iterable poly object.
* @param it The iterator to create (out parameter)
* @param filter Optional term to filter results.
*/
typedef void (*ecs_iter_init_action_t)(
const ecs_world_t *world,
const ecs_poly_t *iterable,
ecs_iter_t *it,
ecs_term_t *filter);
/** Function prototype for iterating an iterator.
* Stored inside initialized iterators. This allows an application to * iterate
* an iterator without needing to know what created it.
*
* @param it The iterator to iterate.
* @return True if iterator has no more results, false if it does.
*/
typedef bool (*ecs_iter_next_action_t)(
ecs_iter_t *it);
/** Function prototype for freeing an iterator.
* Free iterator resources.
*
* @param it The iterator to free.
*/
typedef void (*ecs_iter_fini_action_t)(
ecs_iter_t *it);
/** Callback used for comparing components */
typedef int (*ecs_order_by_action_t)(
ecs_entity_t e1,
const void *ptr1,
ecs_entity_t e2,
const void *ptr2);
/** Callback used for sorting the entire table of components */
typedef void (*ecs_sort_table_action_t)(
ecs_world_t* world,
ecs_table_t* table,
ecs_entity_t* entities,
void* ptr,
int32_t size,
int32_t lo,
int32_t hi,
ecs_order_by_action_t order_by);
/** Callback used for grouping tables in a query */
typedef uint64_t (*ecs_group_by_action_t)(
ecs_world_t *world,
ecs_table_t *table,
ecs_id_t group_id,
void *ctx);
/* Callback invoked when a query creates a new group. */
typedef void* (*ecs_group_create_action_t)(
ecs_world_t *world,
uint64_t group_id,
void *group_by_ctx); /* from ecs_query_desc_t */
/* Callback invoked when a query deletes an existing group. */
typedef void (*ecs_group_delete_action_t)(
ecs_world_t *world,
uint64_t group_id,
void *group_ctx, /* return value from ecs_group_create_action_t */
void *group_by_ctx); /* from ecs_query_desc_t */
/** Initialization action for modules */
typedef void (*ecs_module_action_t)(
ecs_world_t *world);
/** Action callback on world exit */
typedef void (*ecs_fini_action_t)(
ecs_world_t *world,
void *ctx);
/** Function to cleanup context data */
typedef void (*ecs_ctx_free_t)(
void *ctx);
/** Callback used for sorting values */
typedef int (*ecs_compare_action_t)(
const void *ptr1,
const void *ptr2);
/** Callback used for hashing values */
typedef uint64_t (*ecs_hash_value_action_t)(
const void *ptr);
/** Constructor/destructor callback */
typedef void (*ecs_xtor_t)(
void *ptr,
int32_t count,
const ecs_type_info_t *type_info);
/** Copy is invoked when a component is copied into another component. */
typedef void (*ecs_copy_t)(
void *dst_ptr,
const void *src_ptr,
int32_t count,
const ecs_type_info_t *type_info);
/** Move is invoked when a component is moved to another component. */
typedef void (*ecs_move_t)(
void *dst_ptr,
void *src_ptr,
int32_t count,
const ecs_type_info_t *type_info);
/* Destructor function for poly objects */
typedef void (*ecs_poly_dtor_t)(
ecs_poly_t *poly);
/** @} */
/**
* @defgroup mixins Poly mixin types.
* @brief Mixin types for poly mechanism.
* @{
*/
/** Iterable mixin.
* Allows its container to be iterated. */
typedef struct ecs_iterable_t {
ecs_iter_init_action_t init; /**< Callback that creates iterator. */
} ecs_iterable_t;
/** @} */
/**
* @defgroup query_types Query descriptor types.
* @brief Types used to describe queries.
* @{
*/
/** Specify read/write access for term */
typedef enum ecs_inout_kind_t {
EcsInOutDefault, /**< InOut for regular terms, In for shared terms */
EcsInOutNone, /**< Term is neither read nor written */
EcsInOut, /**< Term is both read and written */
EcsIn, /**< Term is only read */
EcsOut, /**< Term is only written */
} ecs_inout_kind_t;
/** Specify operator for term */
typedef enum ecs_oper_kind_t {
EcsAnd, /**< The term must match */
EcsOr, /**< One of the terms in an or chain must match */
EcsNot, /**< The term must not match */
EcsOptional, /**< The term may match */
EcsAndFrom, /**< Term must match all components from term id */
EcsOrFrom, /**< Term must match at least one component from term id */
EcsNotFrom, /**< Term must match none of the components from term id */
} ecs_oper_kind_t;
/* Term id flags */
#define EcsSelf (1u << 1) /**< Match on self */
#define EcsUp (1u << 2) /**< Match by traversing upwards */
#define EcsDown (1u << 3) /**< Match by traversing downwards (derived, cannot be set) */
#define EcsTraverseAll (1u << 4) /**< Match all entities encountered through traversal */
#define EcsCascade (1u << 5) /**< Sort results breadth first */
#define EcsDesc (1u << 6) /**< Iterate groups in descending order */
#define EcsParent (1u << 7) /**< Short for up(ChildOf) */
#define EcsIsVariable (1u << 8) /**< Term id is a variable */
#define EcsIsEntity (1u << 9) /**< Term id is an entity */
#define EcsIsName (1u << 10) /**< Term id is a name (don't attempt to lookup as entity) */
#define EcsFilter (1u << 11) /**< Prevent observer from triggering on term */
#define EcsTraverseFlags (EcsUp|EcsDown|EcsTraverseAll|EcsSelf|EcsCascade|EcsDesc|EcsParent)
/* Term flags discovered & set during filter creation. Mostly used internally to
* store information relevant to queries. */
#define EcsTermMatchAny (1u << 0)
#define EcsTermMatchAnySrc (1u << 1)
#define EcsTermSrcFirstEq (1u << 2)
#define EcsTermSrcSecondEq (1u << 3)
#define EcsTermTransitive (1u << 4)
#define EcsTermReflexive (1u << 5)
#define EcsTermIdInherited (1u << 6)
/* Term flags used for term iteration */
#define EcsTermMatchDisabled (1u << 7)
#define EcsTermMatchPrefab (1u << 8)
/** Type that describes a single identifier in a term */
typedef struct ecs_term_id_t {
ecs_entity_t id; /**< Entity id. If left to 0 and flags does not
* specify whether id is an entity or a variable
* the id will be initialized to EcsThis.
* To explicitly set the id to 0, leave the id
* member to 0 and set EcsIsEntity in flags. */
const char *name; /**< Name. This can be either the variable name
* (when the EcsIsVariable flag is set) or an
* entity name. When ecs_term_t::move is true,
* the API assumes ownership over the string and
* will free it when the term is destroyed. */
ecs_entity_t trav; /**< Relationship to traverse when looking for the
* component. The relationship must have
* the Traversable property. Default is IsA. */
ecs_flags32_t flags; /**< Term flags */
} ecs_term_id_t;
/** Type that describes a term (single element in a query) */
struct ecs_term_t {
ecs_id_t id; /**< Component id to be matched by term. Can be
* set directly, or will be populated from the
* first/second members, which provide more
* flexibility. */
ecs_term_id_t src; /**< Source of term */
ecs_term_id_t first; /**< Component or first element of pair */
ecs_term_id_t second; /**< Second element of pair */
ecs_inout_kind_t inout; /**< Access to contents matched by term */
ecs_oper_kind_t oper; /**< Operator of term */
ecs_id_t id_flags; /**< Id flags of term id */
char *name; /**< Name of term */
int32_t field_index; /**< Index of field for term in iterator */
ecs_id_record_t *idr; /**< Cached pointer to internal index */
ecs_flags16_t flags; /**< Flags that help eval, set by ecs_filter_init */
bool move; /**< Used by internals */
};
/** Use $this variable to initialize user-allocated filter object */
FLECS_API extern ecs_filter_t ECS_FILTER_INIT;
/** Filters alllow for ad-hoc quick filtering of entity tables. */
struct ecs_filter_t {
ecs_header_t hdr;
ecs_term_t *terms; /**< Array containing terms for filter */
int32_t term_count; /**< Number of elements in terms array */
int32_t field_count; /**< Number of fields in iterator for filter */
bool owned; /**< Is filter object owned by filter */
bool terms_owned; /**< Is terms array owned by filter */
ecs_flags32_t flags; /**< Filter flags */
char *variable_names[1]; /**< Placeholder variable names array */
int32_t *sizes; /**< Field size (same for each result) */
/* Mixins */
ecs_entity_t entity; /**< Entity associated with filter (optional) */
ecs_iterable_t iterable; /**< Iterable mixin */
ecs_poly_dtor_t dtor; /**< Dtor mixin */
ecs_world_t *world; /**< World mixin */
};
/* An observer reacts to events matching a filter */
struct ecs_observer_t {
ecs_header_t hdr;
ecs_filter_t filter; /**< Query for observer */
/* Observer events */
ecs_entity_t events[FLECS_EVENT_DESC_MAX];
int32_t event_count;
ecs_iter_action_t callback; /**< See ecs_observer_desc_t::callback */
ecs_run_action_t run; /**< See ecs_observer_desc_t::run */
void *ctx; /**< Callback context */
void *binding_ctx; /**< Binding context (for language bindings) */
ecs_ctx_free_t ctx_free; /**< Callback to free ctx */
ecs_ctx_free_t binding_ctx_free; /**< Callback to free binding_ctx */
ecs_observable_t *observable; /**< Observable for observer */
int32_t *last_event_id; /**< Last handled event id */
int32_t last_event_id_storage;
ecs_id_t register_id; /**< Id observer is registered with (single term observers only) */
int32_t term_index; /**< Index of the term in parent observer (single term observers only) */
bool is_monitor; /**< If true, the observer only triggers when the
* filter did not match with the entity before
* the event happened. */
bool is_multi; /**< If true, the observer triggers on more than one term */
/* Mixins */
ecs_poly_dtor_t dtor;
};
/** @} */
/** Type that contains component lifecycle callbacks.
*
* \ingroup components
*/
struct ecs_type_hooks_t {
ecs_xtor_t ctor; /**< ctor */
ecs_xtor_t dtor; /**< dtor */
ecs_copy_t copy; /**< copy assignment */
ecs_move_t move; /**< move assignment */
/** Ctor + copy */
ecs_copy_t copy_ctor;
/** Ctor + move */
ecs_move_t move_ctor;
/** Ctor + move + dtor (or move_ctor + dtor).
* This combination is typically used when a component is moved from one
* location to a new location, like when it is moved to a new table. If
* not set explicitly it will be derived from other callbacks. */
ecs_move_t ctor_move_dtor;
/** Move + dtor.
* This combination is typically used when a component is moved from one
* location to an existing location, like what happens during a remove. If
* not set explicitly it will be derived from other callbacks. */
ecs_move_t move_dtor;
/** Callback that is invoked when an instance of a component is added. This
* callback is invoked before triggers are invoked. */
ecs_iter_action_t on_add;
/** Callback that is invoked when an instance of the component is set. This
* callback is invoked before triggers are invoked, and enable the component
* to respond to changes on itself before others can. */
ecs_iter_action_t on_set;
/** Callback that is invoked when an instance of the component is removed.
* This callback is invoked after the triggers are invoked, and before the
* destructor is invoked. */
ecs_iter_action_t on_remove;
void *ctx; /**< User defined context */
void *binding_ctx; /**< Language binding context */
ecs_ctx_free_t ctx_free; /**< Callback to free ctx */
ecs_ctx_free_t binding_ctx_free; /**< Callback to free binding_ctx */
};
/** Type that contains component information (passed to ctors/dtors/...)
*
* \ingroup components
*/
struct ecs_type_info_t {
ecs_size_t size; /**< Size of type */
ecs_size_t alignment; /**< Alignment of type */
ecs_type_hooks_t hooks; /**< Type hooks */
ecs_entity_t component; /**< Handle to component (do not set) */
const char *name; /**< Type name. */
};
#include "flecs/private/api_types.h" /* Supporting API types */
#include "flecs/private/api_support.h" /* Supporting API functions */
#include "flecs/private/vec.h" /* Vector */
#include "flecs/private/hashmap.h" /* Hashmap */
/** Used with ecs_entity_init
*
* \ingroup entities
*/
typedef struct ecs_entity_desc_t {
int32_t _canary;
ecs_entity_t id; /**< Set to modify existing entity (optional) */
const char *name; /**< Name of the entity. If no entity is provided, an
* entity with this name will be looked up first. When
* an entity is provided, the name will be verified
* with the existing entity. */
const char *sep; /**< Optional custom separator for hierarchical names.
* Leave to NULL for default ('.') separator. Set to
* an empty string to prevent tokenization of name. */
const char *root_sep; /**< Optional, used for identifiers relative to root */
const char *symbol; /**< Optional entity symbol. A symbol is an unscoped
* identifier that can be used to lookup an entity. The
* primary use case for this is to associate the entity
* with a language identifier, such as a type or
* function name, where these identifiers differ from
* the name they are registered with in flecs. For
* example, C type "EcsPosition" might be registered
* as "flecs.components.transform.Position", with the
* symbol set to "EcsPosition". */
bool use_low_id; /**< When set to true, a low id (typically reserved for
* components) will be used to create the entity, if
* no id is specified. */
/** Array of ids to add to the new or existing entity. */
ecs_id_t add[FLECS_ID_DESC_MAX];
/** String expression with components to add */
const char *add_expr;
} ecs_entity_desc_t;
/** Used with ecs_bulk_init
*
* \ingroup entities
*/
typedef struct ecs_bulk_desc_t {
int32_t _canary;
ecs_entity_t *entities; /**< Entities to bulk insert. Entity ids provided by
* the application must be empty (cannot
* have components). If no entity ids are provided, the
* operation will create 'count' new entities. */
int32_t count; /**< Number of entities to create/populate */
ecs_id_t ids[FLECS_ID_DESC_MAX]; /**< Ids to create the entities with */
void **data; /**< Array with component data to insert. Each element in
* the array must correspond with an element in the ids
* array. If an element in the ids array is a tag, the
* data array must contain a NULL. An element may be
* set to NULL for a component, in which case the
* component will not be set by the operation. */
ecs_table_t *table; /**< Table to insert the entities into. Should not be set
* at the same time as ids. When 'table' is set at the
* same time as 'data', the elements in the data array
* must correspond with the ids in the table's type. */
} ecs_bulk_desc_t;
/** Used with ecs_component_init.
*
* \ingroup components
*/
typedef struct ecs_component_desc_t {
int32_t _canary;
/** Existing entity to associate with observer (optional) */
ecs_entity_t entity;
/** Parameters for type (size, hooks, ...) */
ecs_type_info_t type;
} ecs_component_desc_t;
/** Used with ecs_filter_init.
*
* \ingroup filters
*/
typedef struct ecs_filter_desc_t {
int32_t _canary;
/** Terms of the filter. If a filter has more terms than
* FLECS_TERM_DESC_MAX use terms_buffer */
ecs_term_t terms[FLECS_TERM_DESC_MAX];
/** For filters with lots of terms an outside array can be provided. */
ecs_term_t *terms_buffer;
/** Number of terms in array provided in terms_buffer. */
int32_t terms_buffer_count;
/** External storage to prevent allocation of the filter object */
ecs_filter_t *storage;
/** When true, terms returned by an iterator may either contain 1 or N
* elements, where terms with N elements are owned, and terms with 1 element
* are shared, for example from a parent or base entity. When false, the
* iterator will at most return 1 element when the result contains both
* owned and shared terms. */
bool instanced;
/** Flags for advanced usage */
ecs_flags32_t flags;
/** Filter expression. Should not be set at the same time as terms array */
const char *expr;
/** Entity associated with query (optional) */
ecs_entity_t entity;
} ecs_filter_desc_t;
/** Used with ecs_query_init.
*
* \ingroup queries
*/
typedef struct ecs_query_desc_t {
int32_t _canary;
/** Filter for the query */
ecs_filter_desc_t filter;
/** Component to be used by order_by */
ecs_entity_t order_by_component;
/** Callback used for ordering query results. If order_by_id is 0, the
* pointer provided to the callback will be NULL. If the callback is not
* set, results will not be ordered. */
ecs_order_by_action_t order_by;
/** Callback used for ordering query results. Same as order_by,
* but more efficient. */
ecs_sort_table_action_t sort_table;
/** Id to be used by group_by. This id is passed to the group_by function and
* can be used identify the part of an entity type that should be used for
* grouping. */
ecs_id_t group_by_id;
/** Callback used for grouping results. If the callback is not set, results
* will not be grouped. When set, this callback will be used to calculate a
* "rank" for each entity (table) based on its components. This rank is then
* used to sort entities (tables), so that entities (tables) of the same
* rank are "grouped" together when iterated. */
ecs_group_by_action_t group_by;
/** Callback that is invoked when a new group is created. The return value of
* the callback is stored as context for a group. */
ecs_group_create_action_t on_group_create;
/** Callback that is invoked when an existing group is deleted. The return
* value of the on_group_create callback is passed as context parameter. */
ecs_group_delete_action_t on_group_delete;
/** Context to pass to group_by */
void *group_by_ctx;
/** Function to free group_by_ctx */
ecs_ctx_free_t group_by_ctx_free;
/** If set, the query will be created as a subquery. A subquery matches at
* most a subset of its parent query. Subqueries do not directly receive
* (table) notifications from the world. Instead parent queries forward
* results to subqueries. This can improve matching performance, as fewer
* queries need to be matched with new tables.
* Subqueries can be nested. */
ecs_query_t *parent;
/** User context to pass to callback */
void *ctx;
/** Context to be used for language bindings */
void *binding_ctx;
/** Callback to free ctx */
ecs_ctx_free_t ctx_free;
/** Callback to free binding_ctx */
ecs_ctx_free_t binding_ctx_free;
} ecs_query_desc_t;
/** Used with ecs_observer_init.
*
* \ingroup observers
*/
typedef struct ecs_observer_desc_t {
int32_t _canary;
/** Existing entity to associate with observer (optional) */
ecs_entity_t entity;
/** Filter for observer */
ecs_filter_desc_t filter;
/** Events to observe (OnAdd, OnRemove, OnSet, UnSet) */
ecs_entity_t events[FLECS_EVENT_DESC_MAX];
/** When observer is created, generate events from existing data. For example,
* EcsOnAdd Position would match all existing instances of Position.
* This is only supported for events that are iterable (see EcsIterable) */
bool yield_existing;
/** Callback to invoke on an event, invoked when the observer matches. */
ecs_iter_action_t callback;
/** Callback invoked on an event. When left to NULL the default runner
* is used which matches the event with the observer's filter, and calls
* 'callback' when it matches.
* A reason to override the run function is to improve performance, if there
* are more efficient way to test whether an event matches the observer than
* the general purpose query matcher. */
ecs_run_action_t run;
/** User context to pass to callback */
void *ctx;
/** Context to be used for language bindings */
void *binding_ctx;
/** Callback to free ctx */
ecs_ctx_free_t ctx_free;
/** Callback to free binding_ctx */
ecs_ctx_free_t binding_ctx_free;
/** Observable with which to register the observer */
ecs_poly_t *observable;
/** Optional shared last event id for multiple observers. Ensures only one
* of the observers with the shared id gets triggered for an event */
int32_t *last_event_id;
/** Used for internal purposes */
int32_t term_index;
} ecs_observer_desc_t;
/** Used with ecs_emit.
*
* \ingroup observers
*/
typedef struct ecs_event_desc_t {
/** The event id. Only triggers for the specified event will be notified */
ecs_entity_t event;
/** Component ids. Only triggers with a matching component id will be
* notified. Observers are guaranteed to get notified once, even if they
* match more than one id. */
const ecs_type_t *ids;
/** The table for which to notify. */
ecs_table_t *table;
/** Optional 2nd table to notify. This can be used to communicate the
* previous or next table, in case an entity is moved between tables. */
ecs_table_t *other_table;
/** Limit notified entities to ones starting from offset (row) in table */
int32_t offset;
/** Limit number of notified entities to count. offset+count must be less
* than the total number of entities in the table. If left to 0, it will be
* automatically determined by doing ecs_table_count(table) - offset. */
int32_t count;
/** Single-entity alternative to setting table / offset / count */
ecs_entity_t entity;
/** Optional context. Assigned to iter param member */
const void *param;
/** Observable (usually the world) */
ecs_poly_t *observable;
/** Event flags */
ecs_flags32_t flags;
} ecs_event_desc_t;
/**
* @defgroup misc_types Miscellaneous types
* @brief Types used to create entities, observers, queries and more.
* @{
*/
/* Utility to hold a value of a dynamic type */
typedef struct ecs_value_t {
ecs_entity_t type;
void *ptr;
} ecs_value_t;
/** Type that contains information about the world. */
typedef struct ecs_world_info_t {
ecs_entity_t last_component_id; /**< Last issued component entity id */
ecs_entity_t min_id; /**< First allowed entity id */
ecs_entity_t max_id; /**< Last allowed entity id */
ecs_ftime_t delta_time_raw; /**< Raw delta time (no time scaling) */
ecs_ftime_t delta_time; /**< Time passed to or computed by ecs_progress */
ecs_ftime_t time_scale; /**< Time scale applied to delta_time */
ecs_ftime_t target_fps; /**< Target fps */
ecs_ftime_t frame_time_total; /**< Total time spent processing a frame */
ecs_ftime_t system_time_total; /**< Total time spent in systems */
ecs_ftime_t emit_time_total; /**< Total time spent notifying observers */
ecs_ftime_t merge_time_total; /**< Total time spent in merges */
ecs_ftime_t world_time_total; /**< Time elapsed in simulation */
ecs_ftime_t world_time_total_raw; /**< Time elapsed in simulation (no scaling) */
ecs_ftime_t rematch_time_total; /**< Time spent on query rematching */
int64_t frame_count_total; /**< Total number of frames */
int64_t merge_count_total; /**< Total number of merges */
int64_t rematch_count_total; /**< Total number of rematches */
int64_t id_create_total; /**< Total number of times a new id was created */
int64_t id_delete_total; /**< Total number of times an id was deleted */
int64_t table_create_total; /**< Total number of times a table was created */
int64_t table_delete_total; /**< Total number of times a table was deleted */
int64_t pipeline_build_count_total; /**< Total number of pipeline builds */
int64_t systems_ran_frame; /**< Total number of systems ran in last frame */
int64_t observers_ran_frame; /**< Total number of times observer was invoked */
int32_t id_count; /**< Number of ids in the world (excluding wildcards) */
int32_t tag_id_count; /**< Number of tag (no data) ids in the world */
int32_t component_id_count; /**< Number of component (data) ids in the world */
int32_t pair_id_count; /**< Number of pair ids in the world */
int32_t wildcard_id_count; /**< Number of wildcard ids */
int32_t table_count; /**< Number of tables */
int32_t tag_table_count; /**< Number of tag-only tables */
int32_t trivial_table_count; /**< Number of tables with trivial components (no lifecycle callbacks) */
int32_t empty_table_count; /**< Number of tables without entities */
int32_t table_record_count; /**< Total number of table records (entries in table caches) */
int32_t table_storage_count; /**< Total number of table storages */
/* -- Command counts -- */
struct {
int64_t add_count; /**< add commands processed */
int64_t remove_count; /**< remove commands processed */
int64_t delete_count; /**< delete commands processed */
int64_t clear_count; /**< clear commands processed */
int64_t set_count; /**< set commands processed */
int64_t get_mut_count; /**< get_mut/emplace commands processed */
int64_t modified_count; /**< modified commands processed */
int64_t other_count; /**< other commands processed */
int64_t discard_count; /**< commands discarded, happens when entity is no longer alive when running the command */
int64_t batched_entity_count; /**< entities for which commands were batched */
int64_t batched_command_count; /**< commands batched */
} cmd;
const char *name_prefix; /**< Value set by ecs_set_name_prefix. Used
* to remove library prefixes of symbol
* names (such as Ecs, ecs_) when
* registering them as names. */
} ecs_world_info_t;
/** Type that contains information about a query group. */
typedef struct ecs_query_group_info_t {
int32_t match_count; /**< How often tables have been matched/unmatched */
int32_t table_count; /**< Number of tables in group */
void *ctx; /**< Group context, returned by on_group_create */
} ecs_query_group_info_t;
/** @} */
/**
* @defgroup builtin_components Builtin component types.
* @brief Types that represent builtin components.
* @{
*/
/** A (string) identifier. Used as pair with EcsName and EcsSymbol tags */
typedef struct EcsIdentifier {
char *value; /**< Identifier string */
ecs_size_t length; /**< Length of identifier */
uint64_t hash; /**< Hash of current value */
uint64_t index_hash; /**< Hash of existing record in current index */
ecs_hashmap_t *index; /**< Current index */
} EcsIdentifier;
/** Component information. */
typedef struct EcsComponent {
ecs_size_t size; /**< Component size */
ecs_size_t alignment; /**< Component alignment */
} EcsComponent;
/** Component for storing a poly object */
typedef struct EcsPoly {
ecs_poly_t *poly; /**< Pointer to poly object */
} EcsPoly;
/** Target data for flattened relationships. */
typedef struct EcsTarget {
int32_t count;
ecs_record_t *target;
} EcsTarget;
/** Component for iterable entities */
typedef ecs_iterable_t EcsIterable;
/** @} */
/** @} */
/* Only include deprecated definitions if deprecated addon is required */
#ifdef FLECS_DEPRECATED
#include "flecs/addons/deprecated.h"
#endif
/**
* @defgroup api_constants API Constants
* @brief Public API constants.
* @{
*/
/**
* @defgroup id_flags Component id flags.
* @brief Id flags are bits that can be set on an id (ecs_id_t).
* @{
*/
/** Indicates that the id is a pair. */
FLECS_API extern const ecs_id_t ECS_PAIR;
/** Automatically override component when it is inherited */
FLECS_API extern const ecs_id_t ECS_OVERRIDE;
/** Adds bitset to storage which allows component to be enabled/disabled */
FLECS_API extern const ecs_id_t ECS_TOGGLE;
/** Include all components from entity to which AND is applied */
FLECS_API extern const ecs_id_t ECS_AND;
/** @} */
/**
* @defgroup builtin_tags Builtin component ids.
* @{
*/
/* Builtin component ids */
FLECS_API extern const ecs_entity_t ecs_id(EcsComponent);
FLECS_API extern const ecs_entity_t ecs_id(EcsIdentifier);
FLECS_API extern const ecs_entity_t ecs_id(EcsIterable);
FLECS_API extern const ecs_entity_t ecs_id(EcsPoly);
FLECS_API extern const ecs_entity_t EcsQuery;
FLECS_API extern const ecs_entity_t EcsObserver;
/* System module component ids */
FLECS_API extern const ecs_entity_t EcsSystem;
FLECS_API extern const ecs_entity_t ecs_id(EcsTickSource);
/* Pipeline module component ids */
FLECS_API extern const ecs_entity_t ecs_id(EcsPipelineQuery);
/* Timer module component ids */
FLECS_API extern const ecs_entity_t ecs_id(EcsTimer);
FLECS_API extern const ecs_entity_t ecs_id(EcsRateFilter);
/** Root scope for builtin flecs entities */
FLECS_API extern const ecs_entity_t EcsFlecs;
/** Core module scope */
FLECS_API extern const ecs_entity_t EcsFlecsCore;
/** Entity associated with world (used for "attaching" components to world) */
FLECS_API extern const ecs_entity_t EcsWorld;
/** Wildcard entity ("*"). Matches any id, returns all matches. */
FLECS_API extern const ecs_entity_t EcsWildcard;
/** Any entity ("_"). Matches any id, returns only the first. */
FLECS_API extern const ecs_entity_t EcsAny;
/** This entity. Default source for queries. */
FLECS_API extern const ecs_entity_t EcsThis;
/** Variable entity ("$"). Used in expressions to prefix variable names */
FLECS_API extern const ecs_entity_t EcsVariable;
/** Marks a relationship as transitive.
* Behavior:
* if R(X, Y) and R(Y, Z) then R(X, Z)
*/
FLECS_API extern const ecs_entity_t EcsTransitive;
/** Marks a relatoinship as reflexive.
* Behavior:
* R(X, X) == true
*/
FLECS_API extern const ecs_entity_t EcsReflexive;
/** Ensures that entity/component cannot be used as target in IsA relationship.
* Final can improve the performance of rule-based queries, as they will not
* attempt to substitute a final component with its subsets.
*
* Behavior:
* if IsA(X, Y) and Final(Y) throw error
*/
FLECS_API extern const ecs_entity_t EcsFinal;
/** Ensures that component is never inherited from an IsA target.
*
* Behavior:
* if DontInherit(X) and X(B) and IsA(A, B) then X(A) is false.
*/
FLECS_API extern const ecs_entity_t EcsDontInherit;
/** Ensures a component is always overridden.
*
* Behavior:
* As if the component is added together with OVERRIDE | T
*/
FLECS_API extern const ecs_entity_t EcsAlwaysOverride;
/** Marks relationship as commutative.
* Behavior:
* if R(X, Y) then R(Y, X)
*/
FLECS_API extern const ecs_entity_t EcsSymmetric;
/** Can be added to relationship to indicate that the relationship can only occur
* once on an entity. Adding a 2nd instance will replace the 1st.
*
* Behavior:
* R(X, Y) + R(X, Z) = R(X, Z)
*/
FLECS_API extern const ecs_entity_t EcsExclusive;
/** Marks a relationship as acyclic. Acyclic relationships may not form cycles. */
FLECS_API extern const ecs_entity_t EcsAcyclic;
/** Marks a relationship as traversable. Traversable relationships may be
* traversed with "up" queries. Traversable relationships are acyclic. */
FLECS_API extern const ecs_entity_t EcsTraversable;
/** Ensure that a component always is added together with another component.
*
* Behavior:
* If With(R, O) and R(X) then O(X)
* If With(R, O) and R(X, Y) then O(X, Y)
*/
FLECS_API extern const ecs_entity_t EcsWith;
/** Ensure that relationship target is child of specified entity.
*
* Behavior:
* If OneOf(R, O) and R(X, Y), Y must be a child of O
* If OneOf(R) and R(X, Y), Y must be a child of R
*/
FLECS_API extern const ecs_entity_t EcsOneOf;
/** Can be added to relationship to indicate that it should never hold data,
* even when it or the relationship target is a component. */
FLECS_API extern const ecs_entity_t EcsTag;
/** Tag to indicate that relationship is stored as union. Union relationships
* enable changing the target of a union without switching tables. Union
* relationships are also marked as exclusive. */
FLECS_API extern const ecs_entity_t EcsUnion;
/** Tag to indicate name identifier */
FLECS_API extern const ecs_entity_t EcsName;
/** Tag to indicate symbol identifier */
FLECS_API extern const ecs_entity_t EcsSymbol;
/** Tag to indicate alias identifier */
FLECS_API extern const ecs_entity_t EcsAlias;
/** Used to express parent-child relationships. */
FLECS_API extern const ecs_entity_t EcsChildOf;
/** Used to express inheritance relationships. */
FLECS_API extern const ecs_entity_t EcsIsA;
/** Used to express dependency relationships */
FLECS_API extern const ecs_entity_t EcsDependsOn;
/** Used to express a slot (used with prefab inheritance) */
FLECS_API extern const ecs_entity_t EcsSlotOf;
/** Tag added to module entities */
FLECS_API extern const ecs_entity_t EcsModule;
/** Tag to indicate an entity/component/system is private to a module */
FLECS_API extern const ecs_entity_t EcsPrivate;
/** Tag added to prefab entities. Any entity with this tag is automatically
* ignored by queries, unless EcsPrefab is explicitly queried for. */
FLECS_API extern const ecs_entity_t EcsPrefab;
/** When this tag is added to an entity it is skipped by queries, unless
* EcsDisabled is explicitly queried for. */
FLECS_API extern const ecs_entity_t EcsDisabled;
/** Event that triggers when an id is added to an entity */
FLECS_API extern const ecs_entity_t EcsOnAdd;
/** Event that triggers when an id is removed from an entity */
FLECS_API extern const ecs_entity_t EcsOnRemove;
/** Event that triggers when a component is set for an entity */
FLECS_API extern const ecs_entity_t EcsOnSet;
/** Event that triggers when a component is unset for an entity */
FLECS_API extern const ecs_entity_t EcsUnSet;
/** Event that triggers observer when an entity starts/stops matching a query */
FLECS_API extern const ecs_entity_t EcsMonitor;
/** Event that triggers when a table is created. */
FLECS_API extern const ecs_entity_t EcsOnTableCreate;
/** Event that triggers when a table is deleted. */
FLECS_API extern const ecs_entity_t EcsOnTableDelete;
/** Event that triggers when a table becomes empty (doesn't emit on creation). */
FLECS_API extern const ecs_entity_t EcsOnTableEmpty;
/** Event that triggers when a table becomes non-empty. */
FLECS_API extern const ecs_entity_t EcsOnTableFill;
/** Relationship used for specifying cleanup behavior. */
FLECS_API extern const ecs_entity_t EcsOnDelete;
/** Relationship used to define what should happen when a target entity (second
* element of a pair) is deleted. */
FLECS_API extern const ecs_entity_t EcsOnDeleteTarget;
/** Remove cleanup policy. Must be used as target in pair with EcsOnDelete or
* EcsOnDeleteTarget. */
FLECS_API extern const ecs_entity_t EcsRemove;
/** Delete cleanup policy. Must be used as target in pair with EcsOnDelete or
* EcsOnDeleteTarget. */
FLECS_API extern const ecs_entity_t EcsDelete;
/** Panic cleanup policy. Must be used as target in pair with EcsOnDelete or
* EcsOnDeleteTarget. */
FLECS_API extern const ecs_entity_t EcsPanic;
/** Component that stores data for flattened relationships */
FLECS_API extern const ecs_entity_t ecs_id(EcsTarget);
/** Tag added to root entity to indicate its subtree should be flattened. Used
* together with assemblies. */
FLECS_API extern const ecs_entity_t EcsFlatten;
/** Used like (EcsDefaultChildComponent, Component). When added to an entity,
* this informs serialization formats which component to use when a value is
* assigned to an entity without specifying the component. This is intended as
* a hint, serialization formats are not required to use it. Adding this
* component does not change the behavior of core ECS operations. */
FLECS_API extern const ecs_entity_t EcsDefaultChildComponent;
/* Builtin predicates for comparing entity ids in queries. Only supported by rules */
FLECS_API extern const ecs_entity_t EcsPredEq;
FLECS_API extern const ecs_entity_t EcsPredMatch;
FLECS_API extern const ecs_entity_t EcsPredLookup;
/* Builtin marker entities for opening/closing query scopes */
FLECS_API extern const ecs_entity_t EcsScopeOpen;
FLECS_API extern const ecs_entity_t EcsScopeClose;
/** Tag used to indicate query is empty */
FLECS_API extern const ecs_entity_t EcsEmpty;
/* Pipeline module tags */
FLECS_API extern const ecs_entity_t ecs_id(EcsPipeline);
FLECS_API extern const ecs_entity_t EcsOnStart;
FLECS_API extern const ecs_entity_t EcsPreFrame;
FLECS_API extern const ecs_entity_t EcsOnLoad;
FLECS_API extern const ecs_entity_t EcsPostLoad;
FLECS_API extern const ecs_entity_t EcsPreUpdate;
FLECS_API extern const ecs_entity_t EcsOnUpdate;
FLECS_API extern const ecs_entity_t EcsOnValidate;
FLECS_API extern const ecs_entity_t EcsPostUpdate;
FLECS_API extern const ecs_entity_t EcsPreStore;
FLECS_API extern const ecs_entity_t EcsOnStore;
FLECS_API extern const ecs_entity_t EcsPostFrame;
FLECS_API extern const ecs_entity_t EcsPhase;
/** Value used to quickly check if component is builtin. This is used to quickly
* filter out tables with builtin components (for example for ecs_delete) */
#define EcsLastInternalComponentId (ecs_id(EcsPoly))
/** The first user-defined component starts from this id. Ids up to this number
* are reserved for builtin components */
#define EcsFirstUserComponentId (8)
/** The first user-defined entity starts from this id. Ids up to this number
* are reserved for builtin entities */
#define EcsFirstUserEntityId (FLECS_HI_COMPONENT_ID + 128)
/* When visualized the reserved id ranges look like this:
* [1..8]: Builtin components
* [9..FLECS_HI_COMPONENT_ID]: Low ids reserved for application components
* [FLECS_HI_COMPONENT_ID + 1..EcsFirstUserEntityId]: Builtin entities
*/
/** @} */
/** @} */
/**
* @defgroup world_api World
* @brief Functions for working with `ecs_world_t`.
* @{
*/
/**
* @defgroup world_creation_deletion Creation & Deletion
* @{
*/
/** Create a new world.
* This operation automatically imports modules from addons Flecs has been built
* with, except when the module specifies otherwise.
*
* @return A new world
*/
FLECS_API
ecs_world_t* ecs_init(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.
*
* @return A new tiny world
*/
FLECS_API
ecs_world_t* ecs_mini(void);
/** 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]
*
* @return A new world
*/
FLECS_API
ecs_world_t* ecs_init_w_args(
int argc,
char *argv[]);
/** Delete a world.
* This operation deletes the world, and everything it contains.
*
* @param world The world to delete.
* @return Zero if successful, non-zero if failed.
*/
FLECS_API
int ecs_fini(
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.
*
* @param world The world.
* @return True if being deleted, false if not.
*/
FLECS_API
bool ecs_is_fini(
const ecs_world_t *world);
/** 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.
*
* @param world The world.
* @param action The function to execute.
* @param ctx Userdata to pass to the function */
FLECS_API
void ecs_atfini(
ecs_world_t *world,
ecs_fini_action_t action,
void *ctx);
/** @} */
/**
* @defgroup world_frame Frame functions
* @{
*/
/** Begin frame.
* When an application does not use ecs_progress to control the main loop, it
* can still use Flecs features such as FPS limiting and time measurements. This
* operation needs to be invoked whenever a new frame is about to get processed.
*
* Calls to ecs_frame_begin must always be followed by ecs_frame_end.
*
* The function accepts a delta_time parameter, which will get passed to
* systems. This value is also used to compute the amount of time the function
* needs to sleep to ensure it does not exceed the target_fps, when it is set.
* When 0 is provided for delta_time, the time will be measured.
*
* This function should only be ran from the main thread.
*
* @param world The world.
* @param delta_time Time elapsed since the last frame.
* @return The provided delta_time, or measured time if 0 was provided.
*/
FLECS_API
ecs_ftime_t ecs_frame_begin(
ecs_world_t *world,
ecs_ftime_t delta_time);
/** End frame.
* This operation must be called at the end of the frame, and always after
* ecs_frame_begin.
*
* @param world The world.
*/
FLECS_API
void ecs_frame_end(
ecs_world_t *world);
/** Register action to be executed once after frame.
* Post frame actions are typically used for calling operations that cannot be
* invoked during iteration, such as changing the number of threads.
*
* @param world The world.
* @param action The function to execute.
* @param ctx Userdata to pass to the function */
FLECS_API
void ecs_run_post_frame(
ecs_world_t *world,
ecs_fini_action_t action,
void *ctx);
/** Signal exit
* This operation signals that the application should quit. It will cause
* ecs_progress to return false.
*
* @param world The world to quit.
*/
FLECS_API
void ecs_quit(
ecs_world_t *world);
/** Return whether a quit has been signaled.
*
* @param world The world.
*/
FLECS_API
bool ecs_should_quit(
const ecs_world_t *world);
/** Measure frame time.
* Frame time measurements measure the total time passed in a single frame, and
* how much of that time was spent on systems and on merging.
*
* Frame time measurements add a small constant-time overhead to an application.
* When an application sets a target FPS, frame time measurements are enabled by
* default.
*
* @param world The world.
* @param enable Whether to enable or disable frame time measuring.
*/
FLECS_API void ecs_measure_frame_time(
ecs_world_t *world,
bool enable);
/** Measure system time.
* System time measurements measure the time spent in each system.
*
* System time measurements add overhead to every system invocation and
* therefore have a small but measurable impact on application performance.
* System time measurements must be enabled before obtaining system statistics.
*
* @param world The world.
* @param enable Whether to enable or disable system time measuring.
*/
FLECS_API void ecs_measure_system_time(
ecs_world_t *world,
bool enable);
/** Set target frames per second (FPS) for application.
* Setting the target FPS ensures that ecs_progress is not invoked faster than
* the specified FPS. When enabled, ecs_progress tracks the time passed since
* the last invocation, and sleeps the remaining time of the frame (if any).
*
* This feature ensures systems are ran at a consistent interval, as well as
* conserving CPU time by not running systems more often than required.
*
* Note that ecs_progress only sleeps if there is time left in the frame. Both
* time spent in flecs as time spent outside of flecs are taken into
* account.
*
* @param world The world.
* @param fps The target FPS.
*/
FLECS_API
void ecs_set_target_fps(
ecs_world_t *world,
ecs_ftime_t fps);
/** @} */
/**
* @defgroup commands Commands
* @{
*/
/** Begin readonly mode.
* Readonly mode guarantees that no mutations will occur on the world, which
* makes the world safe to access from multiple threads. While the world is in
* readonly mode, operations are deferred.
*
* Note that while similar to ecs_defer_begin, deferring only does not guarantee
* the world is not mutated. Operations that are not deferred (like creating a
* query) update data structures on the world and are allowed when deferring is
* enabled, but not when the world is in readonly mode.
*
* A call to ecs_readonly_begin must be followed up with ecs_readonly_end.
*
* The ecs_progress() function automatically enables readonly mode while systems
* are executed.
*
* When a world has more than one stage, the specific stage must be provided to
* mutating ECS operations. Failing to do so will throw a readonly assert. A
* world typically has more than one stage when using threads. An example:
*
* ecs_set_stage_count(world, 2);
* ecs_stage_t *stage = ecs_get_stage(world, 1);
*
* ecs_readonly_begin(world);
* ecs_add(world, e, Tag); // readonly assert
* ecs_add(stage, e, Tag); // OK
*
* @param world The world
* @return Whether world is in readonly mode.
*/
FLECS_API
bool ecs_readonly_begin(
ecs_world_t *world);
/** End readonly mode.
* This operation ends readonly mode, and must be called after
* ecs_readonly_begin. Operations that were deferred while the world was in
* readonly mode will be flushed.
*
* @param world The world
*/
FLECS_API
void ecs_readonly_end(
ecs_world_t *world);
/** Merge world or stage.
* When automatic merging is disabled, an application can call this
* operation on either an individual stage, or on the world which will merge
* all stages. This operation may only be called when staging is not enabled
* (either after progress() or after readonly_end()).
*
* This operation may be called on an already merged stage or world.
*
* @param world The world.
*/
FLECS_API
void ecs_merge(
ecs_world_t *world);
/** Defer operations until end of frame.
* When this operation is invoked while iterating, operations inbetween the
* defer_begin and defer_end operations are executed at the end of the frame.
*
* This operation is thread safe.
*
* @param world The world.
* @return true if world changed from non-deferred mode to deferred mode.
*/
FLECS_API
bool ecs_defer_begin(
ecs_world_t *world);
/** Test if deferring is enabled for current stage.
*
* @param world The world.
* @return True if deferred, false if not.
*/
FLECS_API
bool ecs_is_deferred(
const ecs_world_t *world);
/** End block of operations to defer.
* See defer_begin.
*
* This operation is thread safe.
*
* @param world The world.
* @return true if world changed from deferred mode to non-deferred mode.
*/
FLECS_API
bool ecs_defer_end(
ecs_world_t *world);
/** Suspend deferring but do not flush queue.
* This operation can be used to do an undeferred operation while not flushing
* the operations in the queue.
*
* An application should invoke ecs_defer_resume before ecs_defer_end is called.
* The operation may only be called when deferring is enabled.
*
* @param world The world.
*/
FLECS_API
void ecs_defer_suspend(
ecs_world_t *world);
/** Resume deferring.
* See ecs_defer_suspend.
*
* @param world The world.
*/
FLECS_API
void ecs_defer_resume(
ecs_world_t *world);
/** Enable/disable automerging for world or stage.
* When automerging is enabled, staged data will automatically be merged with
* the world when staging ends. This happens at the end of progress(), at a
* sync point or when readonly_end() is called.
*
* Applications can exercise more control over when data from a stage is merged
* by disabling automerging. This requires an application to explicitly call
* merge() on the stage.
*
* When this function is invoked on the world, it sets all current stages to
* the provided value and sets the default for new stages. When this function is
* invoked on a stage, automerging is only set for that specific stage.
*
* @param world The world.
* @param automerge Whether to enable or disable automerging.
*/
FLECS_API
void ecs_set_automerge(
ecs_world_t *world,
bool automerge);
/** Configure world to have N stages.
* This initializes N stages, which allows applications to defer operations to
* multiple isolated defer queues. This is typically used for applications with
* multiple threads, where each thread gets its own queue, and commands are
* merged when threads are synchronized.
*
* Note that the ecs_set_threads function already creates the appropriate
* number of stages. The set_stage_count() operation is useful for applications that
* want to manage their own stages and/or threads.
*
* @param world The world.
* @param stages The number of stages.
*/
FLECS_API
void ecs_set_stage_count(
ecs_world_t *world,
int32_t stages);
/** Get number of configured stages.
* Return number of stages set by ecs_set_stage_count.
*
* @param world The world.
* @return The number of stages used for threading.
*/
FLECS_API
int32_t ecs_get_stage_count(
const ecs_world_t *world);
/** Get current stage id.
* The stage id can be used by an application to learn about which stage it is
* using, which typically corresponds with the worker thread id.
*
* @param world The world.
* @return The stage id.
*/
FLECS_API
int32_t ecs_get_stage_id(
const ecs_world_t *world);
/** Get stage-specific world pointer.
* Flecs threads can safely invoke the API as long as they have a private
* context to write to, also referred to as the stage. This function returns a
* pointer to a stage, disguised as a world pointer.
*
* Note that this function does not(!) create a new world. It simply wraps the
* existing world in a thread-specific context, which the API knows how to
* unwrap. The reason the stage is returned as an ecs_world_t is so that it
* can be passed transparently to the existing API functions, vs. having to
* create a dediated API for threading.
*
* @param world The world.
* @param stage_id The index of the stage to retrieve.
* @return A thread-specific pointer to the world.
*/
FLECS_API
ecs_world_t* ecs_get_stage(
const ecs_world_t *world,
int32_t stage_id);
/** Test whether the current world is readonly.
* This function allows the code to test whether the currently used world
* is readonly or whether it allows for writing.
*
* @param world A pointer to a stage or the world.
* @return True if the world or stage is readonly.
*/
FLECS_API
bool ecs_stage_is_readonly(
const ecs_world_t *world);
/** Create asynchronous stage.
* An asynchronous stage can be used to asynchronously queue operations for
* later merging with the world. An asynchronous stage is similar to a regular
* stage, except that it does not allow reading from the world.
*
* Asynchronous stages are never merged automatically, and must therefore be
* manually merged with the ecs_merge function. It is not necessary to call
* defer_begin or defer_end before and after enqueuing commands, as an
* asynchronous stage unconditionally defers operations.
*
* The application must ensure that no commands are added to the stage while the
* stage is being merged.
*
* An asynchronous stage must be cleaned up by ecs_async_stage_free.
*
* @param world The world.
* @return The stage.
*/
FLECS_API
ecs_world_t* ecs_async_stage_new(
ecs_world_t *world);
/** Free asynchronous stage.
* The provided stage must be an asynchronous stage. If a non-asynchronous stage
* is provided, the operation will fail.
*
* @param stage The stage to free.
*/
FLECS_API
void ecs_async_stage_free(
ecs_world_t *stage);
/** Test whether provided stage is asynchronous.
*
* @param stage The stage.
* @return True when the stage is asynchronous, false for a regular stage or
* world.
*/
FLECS_API
bool ecs_stage_is_async(
ecs_world_t *stage);
/** @} */
/**
* @defgroup world_misc Misc
* @{
*/
/** Set a world context.
* This operation allows an application to register custom data with a world
* that can be accessed anywhere where the application has the world.
*
* @param world The world.
* @param ctx A pointer to a user defined structure.
* @param ctx_free A function that is invoked with ctx when the world is freed.
*/
FLECS_API
void ecs_set_ctx(
ecs_world_t *world,
void *ctx,
ecs_ctx_free_t ctx_free);
/** Set a world binding context.
* Same as ecs_set_ctx but for binding context. A binding context is intended
* specifically for language bindings to store binding specific data.
*
* @param world The world.
* @param ctx A pointer to a user defined structure.
* @param ctx_free A function that is invoked with ctx when the world is freed.
*/
FLECS_API
void ecs_set_binding_ctx(
ecs_world_t *world,
void *ctx,
ecs_ctx_free_t ctx_free);
/** Get the world context.
* This operation retrieves a previously set world context.
*
* @param world The world.
* @return The context set with ecs_set_ctx. If no context was set, the
* function returns NULL.
*/
FLECS_API
void* ecs_get_ctx(
const ecs_world_t *world);
/** Get the world binding context.
* This operation retrieves a previously set world binding context.
*
* @param world The world.
* @return The context set with ecs_set_binding_ctx. If no context was set, the
* function returns NULL.
*/
FLECS_API
void* ecs_get_binding_ctx(
const ecs_world_t *world);
/** Get world info.
*
* @param world The world.
* @return Pointer to the world info. Valid for as long as the world exists.
*/
FLECS_API
const ecs_world_info_t* ecs_get_world_info(
const ecs_world_t *world);
/** Dimension the world for a specified number of entities.
* This operation will preallocate memory in the world for the specified number
* of entities. Specifying a number lower than the current number of entities in
* the world will have no effect.
*
* @param world The world.
* @param entity_count The number of entities to preallocate.
*/
FLECS_API
void ecs_dim(
ecs_world_t *world,
int32_t entity_count);
/** Set a range for issueing new entity ids.
* This function constrains the entity identifiers returned by ecs_new to the
* specified range. This operation can be used to ensure that multiple processes
* can run in the same simulation without requiring a central service that
* coordinates issueing identifiers.
*
* If id_end is set to 0, the range is infinite. If id_end is set to a non-zero
* value, it has to be larger than id_start. If id_end is set and ecs_new is
* invoked after an id is issued that is equal to id_end, the application will
* abort.
*
* @param world The world.
* @param id_start The start of the range.
* @param id_end The end of the range.
*/
FLECS_API
void ecs_set_entity_range(
ecs_world_t *world,
ecs_entity_t id_start,
ecs_entity_t id_end);
/** Enable/disable range limits.
* When an application is both a receiver of range-limited entities and a
* producer of range-limited entities, range checking needs to be temporarily
* disabled when inserting received entities. Range checking is disabled on a
* stage, so setting this value is thread safe.
*
* @param world The world.
* @param enable True if range checking should be enabled, false to disable.
* @return The previous value.
*/
FLECS_API
bool ecs_enable_range_check(
ecs_world_t *world,
bool enable);
/** Get the largest issued entity id (not counting generation).
*
* @param world The world.
*/
FLECS_API
ecs_entity_t ecs_get_max_id(
const ecs_world_t *world);
/** Force aperiodic actions.
* The world may delay certain operations until they are necessary for the
* application to function correctly. This may cause observable side effects
* such as delayed triggering of events, which can be inconvenient when for
* example running a test suite.
*
* The flags parameter specifies which aperiodic actions to run. Specify 0 to
* run all actions. Supported flags start with 'EcsAperiodic'. Flags identify
* internal mechanisms and may change unannounced.
*
* @param world The world.
* @param flags The flags specifying which actions to run.
*/
FLECS_API
void ecs_run_aperiodic(
ecs_world_t *world,
ecs_flags32_t flags);
/** Cleanup empty tables.
* This operation cleans up empty tables that meet certain conditions. Having
* large amounts of empty tables does not negatively impact performance of the
* ECS, but can take up considerable amounts of memory, especially in
* applications with many components, and many components per entity.
*
* The generation specifies the minimum number of times this operation has
* to be called before an empty table is cleaned up. If a table becomes non
* empty, the generation is reset.
*
* The operation allows for both a "clear" generation and a "delete"
* generation. When the clear generation is reached, the table's
* resources are freed (like component arrays) but the table itself is not
* deleted. When the delete generation is reached, the empty table is deleted.
*
* By specifying a non-zero id the cleanup logic can be limited to tables with
* a specific (component) id. The operation will only increase the generation
* count of matching tables.
*
* The min_id_count specifies a lower bound for the number of components a table
* should have. Often the more components a table has, the more specific it is
* and therefore less likely to be reused.
*
* The time budget specifies how long the operation should take at most.
*
* @param world The world.
* @param id Optional component filter for the tables to evaluate.
* @param clear_generation Free table data when generation > clear_generation.
* @param delete_generation Delete table when generation > delete_generation.
* @param min_id_count Minimum number of component ids the table should have.
* @param time_budget_seconds Amount of time operation is allowed to spend.
* @return Number of deleted tables.
*/
FLECS_API
int32_t ecs_delete_empty_tables(
ecs_world_t *world,
ecs_id_t id,
uint16_t clear_generation,
uint16_t delete_generation,
int32_t min_id_count,
double time_budget_seconds);
/** Get world from poly.
*
* @param poly A pointer to a poly object.
* @return The world.
*/
FLECS_API
const ecs_world_t* ecs_get_world(
const ecs_poly_t *poly);
/** Get entity from poly.
*
* @param poly A pointer to a poly object.
* @return Entity associated with the poly object.
*/
FLECS_API
ecs_entity_t ecs_get_entity(
const ecs_poly_t *poly);
/** Test if pointer is of specified type.
* Usage:
* ecs_poly_is(ptr, ecs_world_t)
*
* This operation only works for poly types.
*
* @param object The object to test.
* @param type The id of the type.
* @return True if the pointer is of the specified type.
*/
FLECS_API
bool ecs_poly_is_(
const ecs_poly_t *object,
int32_t type);
#define ecs_poly_is(object, type)\
ecs_poly_is_(object, type##_magic)
/** Make a pair id.
* This function is equivalent to using the ecs_pair macro, and is added for
* convenience to make it easier for non C/C++ bindings to work with pairs.
*
* @param first The first element of the pair of the pair.
* @param second The target of the pair.
*/
FLECS_API
ecs_id_t ecs_make_pair(
ecs_entity_t first,
ecs_entity_t second);
/** @} */
/** @} */
/**
* @defgroup entities Entities
* @brief Functions for working with `ecs_entity_t`.
* @{
*/
/**
* @defgroup creating_entities Creating & Deleting
* @brief Functions for creating and deleting entities.
* @{
*/
/** Create new entity id.
* This operation returns an unused entity id. This operation is guaranteed to
* return an empty entity as it does not use values set by ecs_set_scope or
* ecs_set_with.
*
* @param world The world.
* @return The new entity id.
*/
FLECS_API
ecs_entity_t ecs_new_id(
ecs_world_t *world);
/** Create new low id.
* This operation returns a new low id. Entity ids start after the
* FLECS_HI_COMPONENT_ID constant. This reserves a range of low ids for things
* like components, and allows parts of the code to optimize operations.
*
* Note that FLECS_HI_COMPONENT_ID does not represent the maximum number of
* components that can be created, only the maximum number of components that
* can take advantage of these optimizations.
*
* This operation is guaranteed to return an empty entity as it does not use
* values set by ecs_set_scope or ecs_set_with.
*
* This operation does not recycle ids.
*
* @param world The world.
* @return The new component id.
*/
FLECS_API
ecs_entity_t ecs_new_low_id(
ecs_world_t *world);
/** Create new entity with (component) id.
* This operation creates a new entity with an optional (component) id. When 0
* is passed to the id paramter, no component is added to the new entity.
*
* @param world The world.
* @param id The component id to initialize the new entity with.
* @return The new entity.
*/
FLECS_API
ecs_entity_t ecs_new_w_id(
ecs_world_t *world,
ecs_id_t id);
/** Create new entity in table.
* This operation creates a new entity in the specified table.
*
* @param world The world.
* @param table The table to which to add the new entity.
* @return The new entity.
*/
FLECS_API
ecs_entity_t ecs_new_w_table(
ecs_world_t *world,
ecs_table_t *table);
/** Find or create an entity.
* This operation creates a new entity, or modifies an existing one. When a name
* is set in the ecs_entity_desc_t::name field and ecs_entity_desc_t::entity is
* not set, the operation will first attempt to find an existing entity by that
* name. If no entity with that name can be found, it will be created.
*
* If both a name and entity handle are provided, the operation will check if
* the entity name matches with the provided name. If the names do not match,
* the function will fail and return 0.
*
* If an id to a non-existing entity is provided, that entity id become alive.
*
* See the documentation of ecs_entity_desc_t for more details.
*
* @param world The world.
* @param desc Entity init parameters.
* @return A handle to the new or existing entity, or 0 if failed.
*/
FLECS_API
ecs_entity_t ecs_entity_init(
ecs_world_t *world,
const ecs_entity_desc_t *desc);
/** Bulk create/populate new entities.
* This operation bulk inserts a list of new or predefined entities into a
* single table.
*
* The operation does not take ownership of component arrays provided by the
* application. Components that are non-trivially copyable will be moved into
* the storage.
*
* The operation will emit OnAdd events for each added id, and OnSet events for
* each component that has been set.
*
* If no entity ids are provided by the application, the returned array of ids
* points to an internal datastructure which changes when new entities are
* created/deleted.
*
* If as a result of the operation triggers are invoked that deletes
* entities and no entity ids were provided by the application, the returned
* array of identifiers may be incorrect. To avoid this problem, an application
* can first call ecs_bulk_init to create empty entities, copy the array to one
* that is owned by the application, and then use this array to populate the
* entities.
*
* @param world The world.
* @param desc Bulk creation parameters.
* @return Array with the list of entity ids created/populated.
*/
FLECS_API
const ecs_entity_t* ecs_bulk_init(
ecs_world_t *world,
const ecs_bulk_desc_t *desc);
/** Create N new entities.
* This operation is the same as ecs_new_w_id, but creates N entities
* instead of one.
*
* @param world The world.
* @param id The component id to create the entities with.
* @param count The number of entities to create.
* @return The first entity id of the newly created entities.
*/
FLECS_API
const ecs_entity_t* ecs_bulk_new_w_id(
ecs_world_t *world,
ecs_id_t id,
int32_t count);
/** Clone an entity
* This operation clones the components of one entity into another entity. If
* no destination entity is provided, a new entity will be created. Component
* values are not copied unless copy_value is true.
*
* @param world The world.
* @param dst The entity to copy the components to.
* @param src The entity to copy the components from.
* @param copy_value If true, the value of components will be copied to dst.
* @return The destination entity.
*/
FLECS_API
ecs_entity_t ecs_clone(
ecs_world_t *world,
ecs_entity_t dst,
ecs_entity_t src,
bool copy_value);
/** Delete an entity.
* This operation will delete an entity and all of its components. The entity id
* will be made available for recycling. If the entity passed to ecs_delete is
* not alive, the operation will have no side effects.
*
* @param world The world.
* @param entity The entity.
*/
FLECS_API
void ecs_delete(
ecs_world_t *world,
ecs_entity_t entity);
/** Delete all entities with the specified id.
* This will delete all entities (tables) that have the specified id. The id
* may be a wildcard and/or a pair.
*
* @param world The world.
* @param id The id.
*/
FLECS_API
void ecs_delete_with(
ecs_world_t *world,
ecs_id_t id);
/** @} */
/**
* @defgroup adding_removing Adding & Removing
* @brief Functions for adding and removing components.
* @{
*/
/** Add a (component) id to an entity.
* This operation adds a single (component) id to an entity. If the entity
* already has the id, this operation will have no side effects.
*
* @param world The world.
* @param entity The entity.
* @param id The id to add.
*/
FLECS_API
void ecs_add_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Remove a (component) id from an entity.
* This operation removes a single (component) id to an entity. If the entity
* does not have the id, this operation will have no side effects.
*
* @param world The world.
* @param entity The entity.
* @param id The id to remove.
*/
FLECS_API
void ecs_remove_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Add override for (component) id.
* Adding an override to an entity ensures that when the entity is instantiated
* (by adding an IsA relationship to it) the component with the override is
* copied to a component that is private to the instance. By default components
* reachable through an IsA relationship are shared.
*
* Adding an override does not add the component. If an override is added to an
* entity that does not have the component, it will still be added to the
* instance, but with an uninitialized value (unless the component has a ctor).
* When the entity does have the entity, the component of the instance will be
* initialized with the value of the component on the entity.
*
* This is the same as what happens when calling ecs_add_id for an id that is
* inherited (reachable through an IsA relationship).
*
* This operation is equivalent to doing:
* ecs_add_id(world, entity, ECS_OVERRIDE | id);
*
* @param world The world.
* @param entity The entity.
* @param id The id to override.
*/
FLECS_API
void ecs_override_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Clear all components.
* This operation will remove all components from an entity.
*
* @param world The world.
* @param entity The entity.
*/
FLECS_API
void ecs_clear(
ecs_world_t *world,
ecs_entity_t entity);
/** Remove all instances of the specified (component) id.
* This will remove the specified id from all entities (tables). The id may be
* a wildcard and/or a pair.
*
* @param world The world.
* @param id The id.
*/
FLECS_API
void ecs_remove_all(
ecs_world_t *world,
ecs_id_t id);
/** Set current with id.
* New entities are automatically created with the specified id.
*
* @param world The world.
* @param id The id.
* @return The previous id.
*/
FLECS_API
ecs_entity_t ecs_set_with(
ecs_world_t *world,
ecs_id_t id);
/** Get current with id.
* Get the id set with ecs_set_with.
*
* @param world The world.
* @return The last id provided to ecs_set_with.
*/
FLECS_API
ecs_id_t ecs_get_with(
const ecs_world_t *world);
/** @} */
/**
* @defgroup enabling_disabling Enabling & Disabling
* @brief Functions for enabling/disabling entities and components.
* @{
*/
/** Enable or disable entity.
* This operation enables or disables an entity by adding or removing the
* EcsDisabled tag. A disabled entity will not be matched with any systems,
* unless the system explicitly specifies the EcsDisabled tag.
*
* @param world The world.
* @param entity The entity to enable or disable.
* @param enabled true to enable the entity, false to disable.
*/
FLECS_API
void ecs_enable(
ecs_world_t *world,
ecs_entity_t entity,
bool enabled);
/** Enable or disable component.
* Enabling or disabling a component does not add or remove a component from an
* entity, but prevents it from being matched with queries. This operation can
* be useful when a component must be temporarily disabled without destroying
* its value. It is also a more performant operation for when an application
* needs to add/remove components at high frequency, as enabling/disabling is
* cheaper than a regular add or remove.
*
* @param world The world.
* @param entity The entity.
* @param id The component.
* @param enable True to enable the component, false to disable.
*/
FLECS_API
void ecs_enable_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id,
bool enable);
/** Test if component is enabled.
* Test whether a component is currently enabled or disabled. This operation
* will return true when the entity has the component and if it has not been
* disabled by ecs_enable_component.
*
* @param world The world.
* @param entity The entity.
* @param id The component.
* @return True if the component is enabled, otherwise false.
*/
FLECS_API
bool ecs_is_enabled_id(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** @} */
/**
* @defgroup getting Getting & Setting
* @brief Functions for getting/setting components.
* @{
*/
/** Get an immutable pointer to a component.
* This operation obtains a const pointer to the requested component. The
* operation accepts the component entity id.
*
* @param world The world.
* @param entity The entity.
* @param id The id of the component to get.
* @return The component pointer, NULL if the entity does not have the component.
*/
FLECS_API
const void* ecs_get_id(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Create a component ref.
* A ref is a handle to an entity + component which caches a small amount of
* data to reduce overhead of repeatedly accessing the component. Use
* ecs_ref_get to get the component data.
*
* @param world The world.
* @param entity The entity.
* @param id The id of the component.
* @return The reference.
*/
FLECS_API
ecs_ref_t ecs_ref_init_id(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Get component from ref.
* Get component pointer from ref. The ref must be created with ecs_ref_init.
*
* @param world The world.
* @param ref The ref.
* @param id The component id.
* @return The component pointer, NULL if the entity does not have the component.
*/
FLECS_API
void* ecs_ref_get_id(
const ecs_world_t *world,
ecs_ref_t *ref,
ecs_id_t id);
/** Update ref.
* Ensures contents of ref are up to date. Same as ecs_ref_get_id, but does not
* return pointer to component id.
*
* @param world The world.
* @param ref The ref.
*/
FLECS_API
void ecs_ref_update(
const ecs_world_t *world,
ecs_ref_t *ref);
/** Get a mutable pointer to a component.
* This operation returns a mutable pointer to a component. If the component did
* not yet exist, it will be added.
*
* If get_mut is called when the world is in deferred/readonly mode, the
* function will:
* - return a pointer to a temp storage if the component does not yet exist, or
* - return a pointer to the existing component if it exists
*
* @param world The world.
* @param entity The entity.
* @param id The entity id of the component to obtain.
* @return The component pointer.
*/
FLECS_API
void* ecs_get_mut_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Combines get_mut + modifed in single operation.
* This operation is a more efficient alternative to calling ecs_get_mut_id and
* ecs_modified_id separately. This operation is only valid when the world is in
* deferred mode, which ensures that the Modified event is not emitted before
* the modification takes place.
*
* @param world The world.
* @param entity The entity.
* @param id The id of the component to obtain.
* @return The component pointer.
*/
FLECS_API
void* ecs_get_mut_modified_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Begin exclusive write access to entity.
* This operation provides safe exclusive access to the components of an entity
* without the overhead of deferring operations.
*
* When this operation is called simultaneously for the same entity more than
* once it will throw an assert. Note that for this to happen, asserts must be
* enabled. It is up to the application to ensure that access is exclusive, for
* example by using a read-write mutex.
*
* Exclusive access is enforced at the table level, so only one entity can be
* exclusively accessed per table. The exclusive access check is thread safe.
*
* This operation must be followed up with ecs_write_end.
*
* @param world The world.
* @param entity The entity.
* @return A record to the entity.
*/
FLECS_API
ecs_record_t* ecs_write_begin(
ecs_world_t *world,
ecs_entity_t entity);
/** End exclusive write access to entity.
* This operation ends exclusive access, and must be called after
* ecs_write_begin.
*
* @param record Record to the entity.
*/
FLECS_API
void ecs_write_end(
ecs_record_t *record);
/** Begin read access to entity.
* This operation provides safe read access to the components of an entity.
* Multiple simultaneous reads are allowed per entity.
*
* This operation ensures that code attempting to mutate the entity's table will
* throw an assert. Note that for this to happen, asserts must be enabled. It is
* up to the application to ensure that this does not happen, for example by
* using a read-write mutex.
*
* This operation does *not* provide the same guarantees as a read-write mutex,
* as it is possible to call ecs_read_begin after calling ecs_write_begin. It is
* up to application has to ensure that this does not happen.
*
* This operation must be followed up with ecs_read_end.
*
* @param world The world.
* @param entity The entity.
* @return A record to the entity.
*/
FLECS_API
const ecs_record_t* ecs_read_begin(
ecs_world_t *world,
ecs_entity_t entity);
/** End read access to entity.
* This operation ends read access, and must be called after ecs_read_begin.
*
* @param record Record to the entity.
*/
FLECS_API
void ecs_read_end(
const ecs_record_t *record);
/** Get entity corresponding with record.
* This operation only works for entities that are not empty.
*
* @param record The record for which to obtain the entity id.
*/
FLECS_API
ecs_entity_t ecs_record_get_entity(
const ecs_record_t *record);
/** Get component from entity record.
* This operation returns a pointer to a component for the entity
* associated with the provided record. For safe access to the component, obtain
* the record with ecs_read_begin or ecs_write_begin.
*
* Obtaining a component from a record is faster than obtaining it from the
* entity handle, as it reduces the number of lookups required.
*
* @param world The world.
* @param record Record to the entity.
* @param id The (component) id.
* @return Pointer to component, or NULL if entity does not have the component.
*/
FLECS_API
const void* ecs_record_get_id(
ecs_world_t *world,
const ecs_record_t *record,
ecs_id_t id);
/** Same as ecs_record_get_id, but returns a mutable pointer.
* For safe access to the component, obtain the record with ecs_write_begin.
*
* @param world The world.
* @param record Record to the entity.
* @param id The (component) id.
* @return Pointer to component, or NULL if entity does not have the component.
*/
FLECS_API
void* ecs_record_get_mut_id(
ecs_world_t *world,
ecs_record_t *record,
ecs_id_t id);
/** Test if entity for record has component.
*
* @param world The world.
* @param record Record to the entity.
* @param id The (component) id.
*/
FLECS_API
bool ecs_record_has_id(
ecs_world_t *world,
const ecs_record_t *record,
ecs_id_t id);
/** Emplace a component.
* Emplace is similar to get_mut except that the component constructor is not
* invoked for the returned pointer, allowing the component to be "constructed"
* directly in the storage.
*
* Emplace can only be used if the entity does not yet have the component. If
* the entity has the component, the operation will fail.
*
* @param world The world.
* @param entity The entity.
* @param id The component to obtain.
* @return The (uninitialized) component pointer.
*/
FLECS_API
void* ecs_emplace_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Signal that a component has been modified.
* This operation is usually used after modifying a component value obtained by
* ecs_get_mut_id. The operation will mark the component as dirty, and invoke
* OnSet observers and hooks.
*
* @param world The world.
* @param entity The entity.
* @param id The id of the component that was modified.
*/
FLECS_API
void ecs_modified_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** 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_get_mut_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.
*
* @param world The world.
* @param entity The entity.
* @param id The id of the component to set.
* @param size The size of the pointed-to value.
* @param ptr The pointer to the value.
* @return The entity. A new entity if no entity was provided.
*/
FLECS_API
ecs_entity_t ecs_set_id(
ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id,
size_t size,
const void *ptr);
/** @} */
/**
* @defgroup liveliness Entity Liveliness
* @brief Functions for testing and modifying entity liveliness.
* @{
*/
/** Test whether an entity is valid.
* Entities that are valid can be used with API functions. Using invalid
* entities with API operations will cause the function to panic.
*
* An entity is valid if it is not 0 and if it is alive.
*
* is_valid will return true for ids that don't exist (alive or not alive). This
* allows for using ids that have never been created by ecs_new or similar. In
* this the function differs from ecs_is_alive, which will return false for
* entities that do not yet exist.
*
* The operation will return false for an id that exists and is not alive, as
* using this id with an API operation would cause it to assert.
*
* @param world The world.
* @param e The entity.
* @return True if the entity is valid, false if the entity is not valid.
*/
FLECS_API
bool ecs_is_valid(
const ecs_world_t *world,
ecs_entity_t e);
/** Test whether an entity is alive.
* Entities are alive after they are created, and become not alive when they are
* deleted. Operations that return alive ids are (amongst others) ecs_new_id,
* ecs_new_low_id and ecs_entity_init. Ids can be made alive with the ecs_ensure
* function.
*
* After an id is deleted it can be recycled. Recycled ids are different from
* the original id in that they have a different generation count. This makes it
* possible for the API to distinguish between the two. An example:
*
* ecs_entity_t e1 = ecs_new_id(world);
* ecs_is_alive(world, e1); // true
* ecs_delete(world, e1);
* ecs_is_alive(world, e1); // false
*
* ecs_entity_t e2 = ecs_new_id(world); // recycles e1
* ecs_is_alive(world, e2); // true
* ecs_is_alive(world, e1); // false
*
* @param world The world.
* @param e The entity.
* @return True if the entity is alive, false if the entity is not alive.
*/
FLECS_API
bool ecs_is_alive(
const ecs_world_t *world,
ecs_entity_t e);
/** Remove generation from entity id.
*
* @param e The entity id.
* @return The entity id without the generation count.
*/
FLECS_API
ecs_id_t ecs_strip_generation(
ecs_entity_t e);
/** Override the generation of an entity.
* The generation count of an entity is increased each time an entity is deleted
* and is used to test whether an entity id is alive.
*
* This operation overrides the current generation of an entity with the
* specified generation, which can be useful if an entity is externally managed,
* like for external pools, savefiles or netcode.
*
* @param world The world.
* @param entity Entity for which to set the generation with the new generation.
*/
FLECS_API
void ecs_set_entity_generation(
ecs_world_t *world,
ecs_entity_t entity);
/** Get alive identifier.
* In some cases an application may need to work with identifiers from which
* the generation has been stripped. A typical scenario in which this happens is
* when iterating relationships in an entity type.
*
* For example, when obtaining the parent id from a ChildOf relationship, the parent
* (second element of the pair) will have been stored in a 32 bit value, which
* cannot store the entity generation. This function can retrieve the identifier
* with the current generation for that id.
*
* If the provided identifier is not alive, the function will return 0.
*
* @param world The world.
* @param e The for which to obtain the current alive entity id.
* @return The alive entity id if there is one, or 0 if the id is not alive.
*/
FLECS_API
ecs_entity_t ecs_get_alive(
const ecs_world_t *world,
ecs_entity_t e);
/** Ensure id is alive.
* This operation ensures that the provided id is alive. This is useful in
* scenarios where an application has an existing id that has not been created
* with ecs_new (such as a global constant or an id from a remote application).
*
* When this operation is successful it guarantees that the provided id exists,
* is valid and is alive.
*
* Before this operation the id must either not be alive or have a generation
* that is equal to the passed in entity.
*
* If the provided id has a non-zero generation count and the id does not exist
* in the world, the id will be created with the specified generation.
*
* If the provided id is alive and has a generation count that does not match
* the provided id, the operation will fail.
*
* @param world The world.
* @param entity The entity id to make alive.
*/
FLECS_API
void ecs_ensure(
ecs_world_t *world,
ecs_entity_t entity);
/** Same as ecs_ensure, but for (component) ids.
* An id can be an entity or pair, and can contain id flags. This operation
* ensures that the entity (or entities, for a pair) are alive.
*
* When this operation is successful it guarantees that the provided id can be
* used in operations that accept an id.
*
* Since entities in a pair do not encode their generation ids, this operation
* will not fail when an entity with non-zero generation count already exists in
* the world.
*
* This is different from ecs_ensure, which will fail if attempted with an id
* that has generation 0 and an entity with a non-zero generation is currently
* alive.
*
* @param world The world.
* @param id The id to make alive.
*/
FLECS_API
void ecs_ensure_id(
ecs_world_t *world,
ecs_id_t id);
/** Test whether an entity exists.
* Similar as ecs_is_alive, but ignores entity generation count.
*
* @param world The world.
* @param entity The entity.
* @return True if the entity exists, false if the entity does not exist.
*/
FLECS_API
bool ecs_exists(
const ecs_world_t *world,
ecs_entity_t entity);
/** @} */
/**
* @defgroup entity_info Entity Information.
* @brief Get information from entity.
* @{
*/
/** Get the type of an entity.
*
* @param world The world.
* @param entity The entity.
* @return The type of the entity, NULL if the entity has no components.
*/
FLECS_API
const ecs_type_t* ecs_get_type(
const ecs_world_t *world,
ecs_entity_t entity);
/** Get the table of an entity.
*
* @param world The world.
* @param entity The entity.
* @return The table of the entity, NULL if the entity has no components/tags.
*/
FLECS_API
ecs_table_t* ecs_get_table(
const ecs_world_t *world,
ecs_entity_t entity);
/** Convert type to string.
* The result of this operation must be freed with ecs_os_free.
*
* @param world The world.
* @param type The type.
* @return The stringified type.
*/
FLECS_API
char* ecs_type_str(
const ecs_world_t *world,
const ecs_type_t* type);
/** Convert table to string.
* Same as ecs_type_str(world, ecs_table_get_type(table)). The result of this
* operation must be freed with ecs_os_free.
*
* @param world The world.
* @param table The table.
* @return The stringified table type.
*/
FLECS_API
char* ecs_table_str(
const ecs_world_t *world,
const ecs_table_t *table);
/** Convert entity to string.
* Same as combining:
* - ecs_get_fullpath(world, entity)
* - ecs_type_str(world, ecs_get_type(world, entity))
*
* The result of this operation must be freed with ecs_os_free.
*
* @param world The world.
* @param entity The entity.
* @return The entity path with stringified type.
*/
FLECS_API
char* ecs_entity_str(
const ecs_world_t *world,
ecs_entity_t entity);
/** Test if an entity has an id.
* This operation returns true if the entity has or inherits the specified id.
*
* @param world The world.
* @param entity The entity.
* @param id The id to test for.
* @return True if the entity has the id, false if not.
*/
FLECS_API
bool ecs_has_id(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Test if an entity owns an id.
* This operation returns true if the entity has the specified id. The operation
* behaves the same as ecs_has_id, except that it will return false for
* components that are inherited through an IsA relationship.
*
* @param world The world.
* @param entity The entity.
* @param id The id to test for.
* @return True if the entity has the id, false if not.
*/
FLECS_API
bool ecs_owns_id(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_id_t id);
/** Get the target of a relationship.
* This will return a target (second element of a pair) of the entity for the
* specified relationship. The index allows for iterating through the targets,
* if a single entity has multiple targets for the same relationship.
*
* If the index is larger than the total number of instances the entity has for
* the relationship, the operation will return 0.
*
* @param world The world.
* @param entity The entity.
* @param rel The relationship between the entity and the target.
* @param index The index of the relationship instance.
* @return The target for the relationship at the specified index.
*/
FLECS_API
ecs_entity_t ecs_get_target(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_entity_t rel,
int32_t index);
/** Get parent (target of ChildOf relationship) for entity.
* This operation is the same as calling:
* ecs_get_target(world, entity, EcsChildOf, 0);
*
* @param world The world.
* @param entity The entity.
* @return The parent of the entity, 0 if the entity has no parent.
*/
FLECS_API
ecs_entity_t ecs_get_parent(
const ecs_world_t *world,
ecs_entity_t entity);
/** Get the target of a relationship for a given id.
* This operation returns the first entity that has the provided id by following
* the specified relationship. If the entity itself has the id then entity will
* be returned. If the id cannot be found on the entity or by following the
* relationship, the operation will return 0.
*
* This operation can be used to lookup, for example, which prefab is providing
* a component by specifying the IsA relationship:
*
* // Is Position provided by the entity or one of its base entities?
* ecs_get_target_for_id(world, entity, EcsIsA, ecs_id(Position))
*
* @param world The world.
* @param entity The entity.
* @param rel The relationship to follow.
* @param id The id to lookup.
* @return The entity for which the target has been found.
*/
FLECS_API
ecs_entity_t ecs_get_target_for_id(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_entity_t rel,
ecs_id_t id);
/** Return depth for entity in tree for the specified relationship.
* Depth is determined by counting the number of targets encountered while
* traversing up the relationship tree for rel. Only acyclic relationships are
* supported.
*
* @param world The world.
* @param entity The entity.
* @param rel The relationship.
* @return The depth of the entity in the tree.
*/
FLECS_API
int32_t ecs_get_depth(
const ecs_world_t *world,
ecs_entity_t entity,
ecs_entity_t rel);
typedef struct ecs_flatten_desc_t {
/* When true, the flatten operation will not remove names from entities in
* the flattened tree. This may fail if entities from different subtrees
* have the same name. */
bool keep_names;
/* When true, the flattened tree won't contain information about the
* original depth of the entities. This can reduce fragmentation, but may
* cause existing code, such as cascade queries, to no longer work. */
bool lose_depth;
} ecs_flatten_desc_t;
/** Recursively flatten relationship for target entity (experimental).
* This operation combines entities in the subtree of the specified pair from
* different parents in the same table. This can reduce memory fragmentation
* and reduces the number of tables in the storage, which improves RAM
* utilization and various other operations, such as entity cleanup.
*
* The lifecycle of entities in a fixed subtree are bound to the specified
* parent. Entities in a fixed subtree cannot be deleted individually. Entities
* can also not change the target of the fixed relationship, which includes
* removing the relationship.
*
* Entities in a fixed subtree are still fragmented on subtree depth. This
* ensures that entities can still be iterated in breadth-first order with the
* cascade query modifier.
*
* The current implementation is limited to exclusive acyclic relationships, and
* does not allow for adding/removing to entities in flattened tables. An entity
* may only be flattened for a single relationship. Future iterations of the
* feature may remove these limitations.
*
* @param world The world.
* @param pair The relationship pair from which to start flattening.
* @param desc Options for flattening the tree.
*/
FLECS_API
void ecs_flatten(
ecs_world_t *world,
ecs_id_t pair,
const ecs_flatten_desc_t *desc);
/** Count entities that have the specified id.
* Returns the number of entities that have the specified id.
*
* @param world The world.
* @param entity The id to search for.
* @return The number of entities that have the id.
*/
FLECS_API
int32_t ecs_count_id(
const ecs_world_t *world,
ecs_id_t entity);
/** @} */
/**
* @defgroup paths Entity Names
* @brief Functions for working with entity names and paths.
* @{
*/
/** Get the name of an entity.
* This will return the name stored in (EcsIdentifier, EcsName).
*
* @param world The world.
* @param entity The entity.
* @return The type of the entity, NULL if the entity has no name.
*/
FLECS_API
const char* ecs_get_name(
const ecs_world_t *world,
ecs_entity_t entity);
/** Get the symbol of an entity.
* This will return the symbol stored in (EcsIdentifier, EcsSymbol).
*
* @param world The world.
* @param entity The entity.
* @return The type of the entity, NULL if the entity has no name.
*/
FLECS_API
const char* ecs_get_symbol(
const ecs_world_t *world,
ecs_entity_t entity);
/** Set the name of an entity.
* This will set or overwrite the name of an entity. If no entity is provided,
* a new entity will be created.
*
* The name is stored in (EcsIdentifier, EcsName).
*
* @param world The world.
* @param entity The entity.
* @param name The name.
* @return The provided entity, or a new entity if 0 was provided.
*/
FLECS_API
ecs_entity_t ecs_set_name(
ecs_world_t *world,
ecs_entity_t entity,
const char *name);
/** Set the symbol of an entity.
* This will set or overwrite the symbol of an entity. If no entity is provided,
* a new entity will be created.
*
* The symbol is stored in (EcsIdentifier, EcsSymbol).
*
* @param world The world.
* @param entity The entity.
* @param symbol The symbol.
* @return The provided entity, or a new entity if 0 was provided.
*/
FLECS_API
ecs_entity_t ecs_set_symbol(
ecs_world_t *world,
ecs_entity_t entity,
const char *symbol);
/** Set alias for entity.
* An entity can be looked up using its alias from the root scope without
* providing the fully qualified name if its parent. An entity can only have
* a single alias.
*
* The symbol is stored in (EcsIdentifier, EcsAlias).
*
* @param world The world.
* @param entity The entity.
* @param alias The alias.
*/
FLECS_API
void ecs_set_alias(
ecs_world_t *world,
ecs_entity_t entity,
const char *alias);
/** Lookup an entity by name.
* Returns an entity that matches the specified name. Only looks for entities in
* the current scope (root if no scope is provided).
*
* @param world The world.
* @param name The entity name.
* @return The entity with the specified name, or 0 if no entity was found.
*/
FLECS_API
ecs_entity_t ecs_lookup(
const ecs_world_t *world,
const char *name);
/** Lookup a child entity by name.
* Returns an entity that matches the specified name. Only looks for entities in
* the provided parent. If no parent is provided, look in the current scope (
* root if no scope is provided).
*
* @param world The world.
* @param name The entity name.
* @return The entity with the specified name, or 0 if no entity was found.
*/
FLECS_API
ecs_entity_t ecs_lookup_child(
const ecs_world_t *world,
ecs_entity_t parent,
const char *name);
/** Lookup an entity from a path.
* Lookup an entity from a provided path, relative to the provided parent. The
* operation will use the provided separator to tokenize the path expression. If
* the provided path contains the prefix, the search will start from the root.
*
* If the entity is not found in the provided parent, the operation will
* continue to search in the parent of the parent, until the root is reached. If
* the entity is still not found, the lookup will search in the flecs.core
* scope. If the entity is not found there either, the function returns 0.
*
* @param world The world.
* @param parent The entity from which to resolve the path.
* @param path The path to resolve.
* @param sep The path separator.
* @param prefix The path prefix.
* @param recursive Recursively traverse up the tree until entity is found.
* @return The entity if found, else 0.
*/
FLECS_API
ecs_entity_t ecs_lookup_path_w_sep(
const ecs_world_t *world,
ecs_entity_t parent,
const char *path,
const char *sep,
const char *prefix,
bool recursive);
/** Lookup an entity by its symbol name.
* This looks up an entity by symbol stored in (EcsIdentifier, EcsSymbol). The
* operation does not take into account hierarchies.
*
* This operation can be useful to resolve, for example, a type by its C
* identifier, which does not include the Flecs namespacing.
*
* @param world The world.
* @param symbol The symbol.
* @param lookup_as_path If not found as a symbol, lookup as path.
* @param recursive If looking up as path, recursively traverse up the tree.
* @return The entity if found, else 0.
*/
FLECS_API
ecs_entity_t ecs_lookup_symbol(
const ecs_world_t *world,
const char *symbol,
bool lookup_as_path,
bool recursive);
/** Get a path identifier for an entity.
* This operation creates a path that contains the names of the entities from
* the specified parent to the provided entity, separated by the provided
* separator. If no parent is provided the path will be relative to the root. If
* a prefix is provided, the path will be prefixed by the prefix.
*
* If the parent is equal to the provided child, the operation will return an
* empty string. If a nonzero component is provided, the path will be created by
* looking for parents with that component.
*
* The returned path should be freed by the application.
*
* @param world The world.
* @param parent The entity from which to create the path.
* @param child The entity to which to create the path.
* @param sep The separator to use between path elements.
* @param prefix The initial character to use for root elements.
* @return The relative entity path.
*/
FLECS_API
char* ecs_get_path_w_sep(
const ecs_world_t *world,
ecs_entity_t parent,
ecs_entity_t child,
const char *sep,
const char *prefix);
/** Write path identifier to buffer.
* Same as ecs_get_path_w_sep, but writes result to an ecs_strbuf_t.
*
* @param world The world.
* @param parent The entity from which to create the path.
* @param child The entity to which to create the path.
* @param sep The separator to use between path elements.
* @param prefix The initial character to use for root elements.
* @param buf The buffer to write to.
*/
void ecs_get_path_w_sep_buf(
const ecs_world_t *world,
ecs_entity_t parent,
ecs_entity_t child,
const char *sep,
const char *prefix,
ecs_strbuf_t *buf);
/** Find or create entity from path.
* This operation will find or create an entity from a path, and will create any
* intermediate entities if required. If the entity already exists, no entities
* will be created.
*
* If the path starts with the prefix, then the entity will be created from the
* root scope.
*
* @param world The world.
* @param parent The entity relative to which the entity should be created.
* @param path The path to create the entity for.
* @param sep The separator used in the path.
* @param prefix The prefix used in the path.
* @return The entity.
*/
FLECS_API
ecs_entity_t ecs_new_from_path_w_sep(
ecs_world_t *world,
ecs_entity_t parent,
const char *path,
const char *sep,
const char *prefix);
/** Add specified path to entity.
* This operation is similar to ecs_new_from_path, but will instead add the path
* to an existing entity.
*
* If an entity already exists for the path, it will be returned instead.
*
* @param world The world.
* @param entity The entity to which to add the path.
* @param parent The entity relative to which the entity should be created.
* @param path The path to create the entity for.
* @param sep The separator used in the path.
* @param prefix The prefix used in the path.
* @return The entity.
*/
FLECS_API
ecs_entity_t ecs_add_path_w_sep(
ecs_world_t *world,
ecs_entity_t entity,
ecs_entity_t parent,
const char *path,
const char *sep,
const char *prefix);
/** Set the current scope.
* This operation sets the scope of the current stage to the provided entity.
* As a result new entities will be created in this scope, and lookups will be
* relative to the provided scope.
*
* It is considered good practice to restore the scope to the old value.
*
* @param world The world.
* @param scope The entity to use as scope.
* @return The previous scope.
*/
FLECS_API
ecs_entity_t ecs_set_scope(
ecs_world_t *world,
ecs_entity_t scope);
/** Get the current scope.
* Get the scope set by ecs_set_scope. If no scope is set, this operation will
* return 0.
*
* @param world The world.
* @return The current scope.
*/
FLECS_API
ecs_entity_t ecs_get_scope(
const ecs_world_t *world);
/** Set a name prefix for newly created entities.
* This is a utility that lets C modules use prefixed names for C types and
* C functions, while using names for the entity names that do not have the
* prefix. The name prefix is currently only used by ECS_COMPONENT.
*
* @param world The world.
* @param prefix The name prefix to use.
* @return The previous prefix.
*/
FLECS_API
const char* ecs_set_name_prefix(
ecs_world_t *world,
const char *prefix);
/** Set search path for lookup operations.
* This operation accepts an array of entity ids that will be used as search
* scopes by lookup operations. The operation returns the current search path.
* It is good practice to restore the old search path.
*
* The search path will be evaluated starting from the last element.
*
* The default search path includes flecs.core. When a custom search path is
* provided it overwrites the existing search path. Operations that rely on
* looking up names from flecs.core without providing the namespace may fail if
* the custom search path does not include flecs.core (EcsFlecsCore).
*
* The search path array is not copied into managed memory. The application must
* ensure that the provided array is valid for as long as it is used as the
* search path.
*
* The provided array must be terminated with a 0 element. This enables an
* application to push/pop elements to an existing array without invoking the
* ecs_set_lookup_path operation again.
*
* @param world The world.
* @param lookup_path 0-terminated array with entity ids for the lookup path.
* @return Current lookup path array.
*/
FLECS_API
ecs_entity_t* ecs_set_lookup_path(
ecs_world_t *world,
const ecs_entity_t *lookup_path);
/** Get current lookup path.
* Returns value set by ecs_set_lookup_path.
*
* @param world The world.
* @return The current lookup path.
*/
FLECS_API
ecs_entity_t* ecs_get_lookup_path(
const ecs_world_t *world);
/** @} */
/** @} */
/**
* @defgroup components Components
* @brief Functions for registering and working with components.
* @{
*/
/** Find or create a component.
* This operation creates a new component, or finds an existing one. The find or
* create behavior is the same as ecs_entity_init.
*
* When an existing component is found, the size and alignment are verified with
* the provided values. If the values do not match, the operation will fail.
*
* See the documentation of ecs_component_desc_t for more details.
*
* @param world The world.
* @param desc Component init parameters.
* @return A handle to the new or existing component, or 0 if failed.
*/
FLECS_API
ecs_entity_t ecs_component_init(
ecs_world_t *world,
const ecs_component_desc_t *desc);
/** Get the type for an id.
* This function returnsthe type information for an id. The specified id can be
* any valid id. For the rules on how type information is determined based on
* id, see ecs_get_typeid.
*
* @param world The world.
* @param id The id.
* @return The type information of the id.
*/
FLECS_API
const ecs_type_info_t* ecs_get_type_info(
const ecs_world_t *world,
ecs_id_t id);
/** Register hooks for component.
* Hooks allow for the execution of user code when components are constructed,
* copied, moved, destructed, added, removed or set. Hooks can be assigned as
* as long as a component has not yet been used (added to an entity).
*
* The hooks that are currently set can be accessed with ecs_get_type_info.
*
* @param world The world.
* @param id The component id for which to register the actions
* @param hooks Type that contains the component actions.
*/
FLECS_API
void ecs_set_hooks_id(
ecs_world_t *world,
ecs_entity_t id,
const ecs_type_hooks_t *hooks);
/** Get hooks for component.
*
* @param world The world.
* @param id The component id for which to retrieve the hooks.
* @return The hooks for the component, or NULL if not registered.
*/
FLECS_API
const ecs_type_hooks_t* ecs_get_hooks_id(
ecs_world_t *world,
ecs_entity_t id);
/** @} */
/**
* @defgroup ids Ids
* @brief Functions for working with `ecs_id_t`.
* @{
*/
/** Returns whether specified id a tag.
* This operation returns whether the specified type is a tag (a component
* without data/size).
*
* An id is a tag when:
* - it is an entity without the EcsComponent component
* - it has an EcsComponent with size member set to 0
* - it is a pair where both elements are a tag
* - it is a pair where the first element has the EcsTag tag
*
* @param world The world.
* @param id The id.
* @return Whether the provided id is a tag.
*/
FLECS_API
bool ecs_id_is_tag(
const ecs_world_t *world,
ecs_id_t id);
/** Return whether represents a union.
* This operation returns whether the specified type represents a union. Only
* pair ids can be unions.
*
* An id represents a union when:
* - The first element of the pair is EcsUnion/flecs::Union
* - The first element of the pair has EcsUnion/flecs::Union
*
* @param world The world.
* @param id The id.
* @return Whether the provided id represents a union.
*/
FLECS_API
bool ecs_id_is_union(
const ecs_world_t *world,
ecs_id_t id);
/** Returns whether specified id is in use.
* This operation returns whether an id is in use in the world. An id is in use
* if it has been added to one or more tables.
*
* @param world The world.
* @param id The id.
* @return Whether the id is in use.
*/
FLECS_API
bool ecs_id_in_use(
const ecs_world_t *world,
ecs_id_t id);
/** Get the type for an id.
* This operation returns the component id for an id, if the id is associated
* with a type. For a regular component with a non-zero size (an entity with the
* EcsComponent component) the operation will return the entity itself.
*
* For an entity that does not have the EcsComponent component, or with an
* EcsComponent value with size 0, the operation will return 0.
*
* For a pair id the operation will return the type associated with the pair, by
* applying the following rules in order:
* - The first pair element is returned if it is a component
* - 0 is returned if the relationship entity has the Tag property
* - The second pair element is returned if it is a component
* - 0 is returned.
*
* @param world The world.
* @param id The id.
* @return The type id of the id.
*/
FLECS_API
ecs_entity_t ecs_get_typeid(
const ecs_world_t *world,
ecs_id_t id);
/** Utility to match an id with a pattern.
* This operation returns true if the provided pattern matches the provided
* id. The pattern may contain a wildcard (or wildcards, when a pair).
*
* @param id The id.
* @param pattern The pattern to compare with.
*/
FLECS_API
bool ecs_id_match(
ecs_id_t id,
ecs_id_t pattern);
/** Utility to check if id is a pair.
*
* @param id The id.
* @return True if id is a pair.
*/
FLECS_API
bool ecs_id_is_pair(
ecs_id_t id);
/** Utility to check if id is a wildcard.
*
* @param id The id.
* @return True if id is a wildcard or a pair containing a wildcard.
*/
FLECS_API
bool ecs_id_is_wildcard(
ecs_id_t id);
/** Utility to check if id is valid.
* A valid id is an id that can be added to an entity. Invalid ids are:
* - ids that contain wildcards
* - ids that contain invalid entities
* - ids that are 0 or contain 0 entities
*
* Note that the same rules apply to removing from an entity, with the exception
* of wildcards.
*
* @param world The world.
* @param id The id.
* @return True if the id is valid.
*/
FLECS_API
bool ecs_id_is_valid(
const ecs_world_t *world,
ecs_id_t id);
/** Get flags associated with id.
* This operation returns the internal flags (see api_flags.h) that are
* associated with the provided id.
*
* @param world The world.
* @param id The id.
* @return Flags associated with the id, or 0 if the id is not in use.
*/
FLECS_API
ecs_flags32_t ecs_id_get_flags(
const ecs_world_t *world,
ecs_id_t id);
/** Convert id flag to string.
* This operation converts a id flag to a string.
*
* @param id_flags The id flag.
* @return The id flag string, or NULL if no valid id is provided.
*/
FLECS_API
const char* ecs_id_flag_str(
ecs_id_t id_flags);
/** Convert id to string.
* This operation interprets the structure of an id and converts it to a string.
*
* @param world The world.
* @param id The id to convert to a string.
* @return The id converted to a string.
*/
FLECS_API
char* ecs_id_str(
const ecs_world_t *world,
ecs_id_t id);
/** Write id string to buffer.
* Same as ecs_id_str but writes result to ecs_strbuf_t.
*
* @param world The world.
* @param id The id to convert to a string.
* @param buf The buffer to write to.
*/
FLECS_API
void ecs_id_str_buf(
const ecs_world_t *world,
ecs_id_t id,
ecs_strbuf_t *buf);
/** @} */
/**
* @defgroup filters Filters
* @brief Functions for working with `ecs_term_t` and `ecs_filter_t`.
* @{
*/
/** Iterator for a single (component) id.
* A term iterator returns all entities (tables) that match a single (component)
* id. The search for the matching set of entities (tables) is performed in
* constant time.
*
* @param world The world.
* @param term The term.
* @return The iterator.
*/
FLECS_API
ecs_iter_t ecs_term_iter(
const ecs_world_t *world,
ecs_term_t *term);
/** Return a chained term iterator.
* A chained iterator applies a filter to the results of the input iterator. The
* resulting iterator must be iterated with ecs_term_next.
*
* @param it The input iterator
* @param term The term filter to apply to the iterator.
* @return The chained iterator.
*/
FLECS_API
ecs_iter_t ecs_term_chain_iter(
const ecs_iter_t *it,
ecs_term_t *term);
/** Progress a term iterator.
* This operation progresses the term iterator to the next table. The
* iterator must have been initialized with `ecs_term_iter`. This operation
* must be invoked at least once before interpreting the contents of the
* iterator.
*
* @param it The iterator.
* @returns True if more data is available, false if not.
*/
FLECS_API
bool ecs_term_next(
ecs_iter_t *it);
/** Iterator for a parent's children.
* This operation is equivalent to a term iterator for (ChildOf, parent).
* Iterate the result with ecs_children_next.
*
* @param world The world.
* @param parent The parent for which to iterate the children.
* @return The iterator.
*/
FLECS_API
ecs_iter_t ecs_children(
const ecs_world_t *world,
ecs_entity_t parent);
/** Progress a children iterator.
* Equivalent to ecs_term_next.
*
* @param it The iterator.
* @returns True if more data is available, false if not.
*/
FLECS_API
bool ecs_children_next(
ecs_iter_t *it);
/** Test whether term id is set.
*
* @param id The term id.
* @return True when set, false when not set.
*/
FLECS_API
bool ecs_term_id_is_set(
const ecs_term_id_t *id);
/** Test whether a term is set.
* This operation can be used to test whether a term has been initialized with
* values or whether it is empty.
*
* An application generally does not need to invoke this operation. It is useful
* when initializing a 0-initialized array of terms (like in ecs_term_desc_t) as
* this operation can be used to find the last initialized element.
*
* @param term The term.
* @return True when set, false when not set.
*/
FLECS_API
bool ecs_term_is_initialized(
const ecs_term_t *term);
/** Is term matched on $this variable.
* This operation checks whether a term is matched on the $this variable, which
* is the default source for queries.
*
* A term has a $this source when:
* - ecs_term_t::src::id is EcsThis
* - ecs_term_t::src::flags is EcsIsVariable
*
* If ecs_term_t::src is not populated, it will be automatically initialized to
* the $this source for the created query.
*
* @param term The term.
* @return True if term matches $this, false if not.
*/
FLECS_API
bool ecs_term_match_this(
const ecs_term_t *term);
/** Is term matched on 0 source.
* This operation checks whether a term is matched on a 0 source. A 0 source is
* a term that isn't matched against anything, and can be used just to pass
* (component) ids to a query iterator.
*
* A term has a 0 source when:
* - ecs_term_t::src::id is 0
* - ecs_term_t::src::flags has EcsIsEntity set
*
* @param term The term.
* @return True if term has 0 source, false if not.
*/
FLECS_API
bool ecs_term_match_0(
const ecs_term_t *term);
/** Finalize term.
* Ensure that all fields of a term are consistent and filled out. This
* operation should be invoked before using and after assigning members to, or
* parsing a term. When a term contains unresolved identifiers, this operation
* will resolve and assign the identifiers. If the term contains any identifiers
* that cannot be resolved, the operation will fail.
*
* An application generally does not need to invoke this operation as the APIs
* that use terms (such as filters, queries and triggers) will finalize terms
* when they are created.
*
* The name and expr parameters are optional, and only used for giving more
* descriptive error messages.
*
* @param world The world.
* @param term The term to finalize.
* @return Zero if success, nonzero if an error occurred.
*/
FLECS_API
int ecs_term_finalize(
const ecs_world_t *world,
ecs_term_t *term);
/** Copy resources of a term to another term.
* This operation copies one term to another term. If the source term contains
* allocated resources (such as identifiers), they will be duplicated so that
* no memory is shared between the terms.
*
* @param src The term to copy from.
* @return The destination term.
*/
FLECS_API
ecs_term_t ecs_term_copy(
const ecs_term_t *src);
/** Move resources of a term to another term.
* Same as copy, but moves resources from src, if src->move is set to true. If
* src->move is not set to true, this operation will do a copy.
*
* The conditional move reduces redundant allocations in scenarios where a list
* of terms is partially created with allocated resources.
*
* @param src The term to move from.
* @return The destination term.
*/
FLECS_API
ecs_term_t ecs_term_move(
ecs_term_t *src);
/** Free resources of term.
* This operation frees all resources (such as identifiers) of a term. The term
* itself is not freed.
*
* @param term The term to free.
*/
FLECS_API
void ecs_term_fini(
ecs_term_t *term);
/** Initialize filter
* A filter is a lightweight object that can be used to query for entities in
* a world. Filters, as opposed to queries, do not cache results. They are
* therefore slower to iterate, but are faster to create.
*
* When a filter is copied by value, make sure to use "ecs_filter_move" to
* ensure that the terms pointer still points to the inline array:
*
* ecs_filter_move(&dst_filter, &src_filter)
*
* Alternatively, the ecs_filter_move function can be called with both arguments
* set to the same filter, to ensure the pointer is valid:
*
* ecs_filter_move(&f, &f)
*
* It is possible to create a filter without allocating any memory, by setting
* the .storage member in ecs_filter_desc_t. See the documentation for the
* member for more details.
*
* @param world The world.
* @param desc Properties for the filter to create.
* @return The filter if successful, NULL if not successful.
*/
FLECS_API
ecs_filter_t * ecs_filter_init(
ecs_world_t *world,
const ecs_filter_desc_t *desc);
/** Deinitialize filter.
* Free resources associated with filter.
*
* @param filter The filter to deinitialize.
*/
FLECS_API
void ecs_filter_fini(
ecs_filter_t *filter);
/** Finalize filter.
* When manually assigning an array of terms to the filter struct (so not when
* using ecs_filter_init), this operation should be used to ensure that all
* terms are assigned properly and all (derived) fields have been set.
*
* When ecs_filter_init is used to create the filter, this function should not
* be called. The purpose of this operation is to support creation of filters
* without allocating memory.
*
* @param filter The filter to finalize.
* @return Zero if filter is valid, non-zero if it contains errors.
* @
*/
FLECS_API
int ecs_filter_finalize(
const ecs_world_t *world,
ecs_filter_t *filter);
/** Find index for $this variable.
* This operation looks up the index of the $this variable. This index can
* be used in operations like ecs_iter_set_var and ecs_iter_get_var.
*
* The operation will return -1 if the variable was not found. This happens when
* a filter only has terms that are not matched on the $this variable, like a
* filter that exclusively matches singleton components.
*
* @param filter The rule.
* @return The index of the $this variable.
*/
FLECS_API
int32_t ecs_filter_find_this_var(
const ecs_filter_t *filter);
/** Convert term to string expression.
* Convert term to a string expression. The resulting expression is equivalent
* to the same term, with the exception of And & Or operators.
*
* @param world The world.
* @param term The term.
* @return The term converted to a string.
*/
FLECS_API
char* ecs_term_str(
const ecs_world_t *world,
const ecs_term_t *term);
/** Convert filter to string expression.
* Convert filter terms to a string expression. The resulting expression can be
* parsed to create the same filter.
*
* @param world The world.
* @param filter The filter.
* @return The filter converted to a string.
*/
FLECS_API
char* ecs_filter_str(
const ecs_world_t *world,
const ecs_filter_t *filter);
/** Return a filter iterator.
* A filter iterator lets an application iterate over entities that match the
* specified filter.
*
* @param world The world.
* @param filter The filter.
* @return An iterator that can be used with ecs_filter_next.
*/
FLECS_API
ecs_iter_t ecs_filter_iter(
const ecs_world_t *world,
const ecs_filter_t *filter);
/** Return a chained filter iterator.
* A chained iterator applies a filter to the results of the input iterator. The
* resulting iterator must be iterated with ecs_filter_next.
*
* @param it The input iterator
* @param filter The filter to apply to the iterator.
* @return The chained iterator.
*/
FLECS_API
ecs_iter_t ecs_filter_chain_iter(
const ecs_iter_t *it,
const ecs_filter_t *filter);
/** Get pivot term for filter.
* The pivot term is the term that matches the smallest set of tables, and is
* a good default starting point for a search.
*
* The following conditions must be met for a term to be considered as pivot:
* - It must have a This subject
* - It must have the And operator
*
* When a filter does not have any terms that match those conditions, it will
* return -1.
*
* If one or more terms in the filter have no matching tables the filter won't
* yield any results. In this case the operation will return -2 which gives a
* search function the option to early out.
*
* @param world The world.
* @param filter The filter.
* @return Index of the pivot term (use with filter->terms)
*/
FLECS_API
int32_t ecs_filter_pivot_term(
const ecs_world_t *world,
const ecs_filter_t *filter);
/** Iterate tables matched by filter.
* This operation progresses the filter iterator to the next table. The
* iterator must have been initialized with `ecs_filter_iter`. This operation
* must be invoked at least once before interpreting the contents of the
* iterator.
*
* @param it The iterator
* @return True if more data is available, false if not.
*/
FLECS_API
bool ecs_filter_next(
ecs_iter_t *it);
/** Same as ecs_filter_next, but always instanced.
* See instanced property of ecs_filter_desc_t.
*
* @param it The iterator
* @return True if more data is available, false if not.
*/
FLECS_API
bool ecs_filter_next_instanced(
ecs_iter_t *it);
/** Move resources of one filter to another.
*
* @param dst The destination filter.
* @param src The source filter.
*/
FLECS_API
void ecs_filter_move(
ecs_filter_t *dst,
ecs_filter_t *src);
/** Copy resources of one filter to another.
*
* @param dst The destination filter.
* @param src The source filter.
*/
FLECS_API
void ecs_filter_copy(
ecs_filter_t *dst,
const ecs_filter_t *src);
/** @} */
/**
* @defgroup queries Queries
* @brief Functions for working with `ecs_query_t`.
* @{
*/
/** Create a query.
* This operation creates a query. Queries are used to iterate over entities
* that match a filter and are the fastest way to find and iterate over entities
* and their components.
*
* Queries should be created once, and reused multiple times. While iterating a
* query is a cheap operation, creating and deleting a query is expensive. The
* reason for this is that queries are "prematched", which means that a query
* stores state about which entities (or rather, tables) match with the query.
* Building up this state happens during query creation.
*
* Once a query is created, matching only happens when new tables are created.
* In most applications this is an infrequent process, since it only occurs when
* a new combination of components is introduced. While matching is expensive,
* it is importent to note that matching does not happen on a per-entity basis,
* but on a per-table basis. This means that the average time spent on matching
* per frame should rapidly approach zero over the lifetime of an application.
*
* A query provides direct access to the component arrays. When an application
* creates/deletes entities or adds/removes components, these arrays can shift
* component values around, or may grow in size. This can cause unexpected or
* undefined behavior to occur if these operations are performed while
* iterating. To prevent this from happening an application should either not
* perform these operations while iterating, or use deferred operations (see
* ecs_defer_begin and ecs_defer_end).
*
* Queries can be created and deleted dynamically. If a query was not deleted
* (using ecs_query_fini) before the world is deleted, it will be deleted
* automatically.
*
* @param world The world.
* @param desc A structure describing the query properties.
* @return The new query.
*/
FLECS_API
ecs_query_t* ecs_query_init(
ecs_world_t *world,
const ecs_query_desc_t *desc);
/** Destroy a query.
* This operation destroys a query and its resources. If the query is used as
* the parent of subqueries, those subqueries will be orphaned and must be
* deinitialized as well.
*
* @param query The query.
*/
FLECS_API
void ecs_query_fini(
ecs_query_t *query);
/** Get filter from a query.
* This operation obtains a pointer to the internally constructed filter
* of the query and can be used to introspect the query terms.
*
* @param query The query.
* @return The filter.
*/
FLECS_API
const ecs_filter_t* ecs_query_get_filter(
const ecs_query_t *query);
/** Return a query iterator.
* A query iterator lets an application iterate over entities that match the
* specified query. If a sorting function is specified, the query will check
* whether a resort is required upon creating the iterator.
*
* Creating a query iterator is a cheap operation that does not allocate any
* resources. An application does not need to deinitialize or free a query
* iterator before it goes out of scope.
*
* To iterate the iterator, an application should use ecs_query_next to progress
* the iterator and test if it has data.
*
* Query iteration requires an outer and an inner loop. The outer loop uses
* ecs_query_next to test if new tables are available. The inner loop iterates
* the entities in the table, and is usually a for loop that uses iter.count to
* loop through the entities and component arrays.
*
* The two loops are necessary because of how data is stored internally.
* Entities are grouped by the components they have, in tables. A single query
* can (and often does) match with multiple tables. Because each table has its
* own set of arrays, an application has to reobtain pointers to those arrays
* for each matching table.
*
* @param world The world or stage, when iterating in readonly mode.
* @param query The query to iterate.
* @return The query iterator.
*/
FLECS_API
ecs_iter_t ecs_query_iter(
const ecs_world_t *world,
ecs_query_t *query);
/** Progress the query iterator.
* This operation progresses the query iterator to the next table. The
* iterator must have been initialized with `ecs_query_iter`. This operation
* must be invoked at least once before interpreting the contents of the
* iterator.
*
* @param iter The iterator.
* @returns True if more data is available, false if not.
*/
FLECS_API
bool ecs_query_next(
ecs_iter_t *iter);
/** Same as ecs_query_next, but always instanced.
* See "instanced" property of ecs_filter_desc_t.
*
* @param iter The iterator.
* @returns True if more data is available, false if not.
*/
FLECS_API
bool ecs_query_next_instanced(
ecs_iter_t *iter);
/** Fast alternative to ecs_query_next that only returns matched tables.
* This operation only populates the ecs_iter_t::table field. To access the
* matched components, call ecs_query_populate.
*
* If this operation is used with a query that has inout/out terms, those terms
* will not be marked dirty unless ecs_query_populate is called.
*
* @param iter The iterator.
* @returns True if more data is available, false if not.
*/
FLECS_API
bool ecs_query_next_table(
ecs_iter_t *iter);
/** Populate iterator fields.
* This operation can be combined with ecs_query_next_table to populate the
* iterator fields for the current table.
*
* Populating fields conditionally can save time when a query uses change
* detection, and only needs iterator data when the table has changed. When this
* operation is called, inout/out terms will be marked dirty.
*
* In cases where inout/out terms are conditionally written and no changes
* were made after calling ecs_query_populate, the ecs_query_skip function can
* be called to prevent the matched table components from being marked dirty.
*
* This operation does should not be used with queries that match disabled
* components, union relationships, or with queries that use order_by.
*
* When the when_changed argument is set to true, the iterator data will only
* populate when the data has changed, using query change detection.
*
* @param iter The iterator.
* @param when_changed Only populate data when result has changed.
*/
FLECS_API
int ecs_query_populate(
ecs_iter_t *iter,
bool when_changed);
/** Returns whether the query data changed since the last iteration.
* The operation will return true after:
* - new entities have been matched with
* - new tables have been matched/unmatched with
* - matched entities were deleted
* - matched components were changed
*
* The operation will not return true after a write-only (EcsOut) or filter
* (EcsInOutNone) term has changed, when a term is not matched with the
* current table (This subject) or for tag terms.
*
* The changed state of a table is reset after it is iterated. If a iterator was
* not iterated until completion, tables may still be marked as changed.
*
* If no iterator is provided the operation will return the changed state of the
* all matched tables of the query.
*
* If an iterator is provided, the operation will return the changed state of
* the currently returned iterator result. The following preconditions must be
* met before using an iterator with change detection:
*
* - The iterator is a query iterator (created with ecs_query_iter)
* - The iterator must be valid (ecs_query_next must have returned true)
* - The iterator must be instanced
*
* @param query The query (optional if 'it' is provided).
* @param it The iterator result to test (optional if 'query' is provided).
* @return true if entities changed, otherwise false.
*/
FLECS_API
bool ecs_query_changed(
ecs_query_t *query,
const ecs_iter_t *it);
/** Skip a table while iterating.
* This operation lets the query iterator know that a table was skipped while
* iterating. A skipped table will not reset its changed state, and the query
* will not update the dirty flags of the table for its out columns.
*
* Only valid iterators must be provided (next has to be called at least once &
* return true) and the iterator must be a query iterator.
*
* @param it The iterator result to skip.
*/
FLECS_API
void ecs_query_skip(
ecs_iter_t *it);
/** Set group to iterate for query iterator.
* This operation limits the results returned by the query to only the selected
* group id. The query must have a group_by function, and the iterator must
* be a query iterator.
*
* Groups are sets of tables that are stored together in the query cache based
* on a group id, which is calculated per table by the group_by function. To
* iterate a group, an iterator only needs to know the first and last cache node
* for that group, which can both be found in a fast O(1) operation.
*
* As a result, group iteration is one of the most efficient mechanisms to
* filter out large numbers of entities, even if those entities are distributed
* across many tables. This makes it a good fit for things like dividing up
* a world into cells, and only iterating cells close to a player.
*
* The group to iterate must be set before the first call to ecs_query_next. No
* operations that can add/remove components should be invoked between calling
* ecs_query_set_group and ecs_query_next.
*
* @param it The query iterator.
* @param group_id The group to iterate.
*/
FLECS_API
void ecs_query_set_group(
ecs_iter_t *it,
uint64_t group_id);
/** Get context of query group.
* This operation returns the context of a query group as returned by the
* on_group_create callback.
*
* @param query The query.
* @param group_id The group for which to obtain the context.
* @return The group context, NULL if the group doesn't exist.
*/
FLECS_API
void* ecs_query_get_group_ctx(
const ecs_query_t *query,
uint64_t group_id);
/** Get information about query group.
* This operation returns information about a query group, including the group
* context returned by the on_group_create callback.
*
* @param query The query.
* @param group_id The group for which to obtain the group info.
* @return The group info, NULL if the group doesn't exist.
*/
FLECS_API
const ecs_query_group_info_t* ecs_query_get_group_info(
const ecs_query_t *query,
uint64_t group_id);
/** Returns whether query is orphaned.
* When the parent query of a subquery is deleted, it is left in an orphaned
* state. The only valid operation on an orphaned query is deleting it. Only
* subqueries can be orphaned.
*
* @param query The query.
* @return true if query is orphaned, otherwise false.
*/
FLECS_API
bool ecs_query_orphaned(
const ecs_query_t *query);
/** Convert query to string.
*
* @param query The query.
* @return The query string.
*/
FLECS_API
char* ecs_query_str(
const ecs_query_t *query);
/** Returns number of tables query matched with.
*
* @param query The query.
* @return The number of matched tables.
*/
FLECS_API
int32_t ecs_query_table_count(
const ecs_query_t *query);
/** Returns number of empty tables query matched with.
*
* @param query The query.
* @return The number of matched empty tables.
*/
FLECS_API
int32_t ecs_query_empty_table_count(
const ecs_query_t *query);
/** Returns number of entities query matched with.
* This operation iterates all non-empty tables in the query cache to find the
* total number of entities.
*
* @param query The query.
* @return The number of matched entities.
*/
FLECS_API
int32_t ecs_query_entity_count(
const ecs_query_t *query);
/** Get query ctx.
* Return the value set in ecs_query_desc_t::ctx.
*
* @param query The query.
* @return The context.
*/
FLECS_API
void* ecs_query_get_ctx(
const ecs_query_t *query);
/** Get query binding ctx.
* Return the value set in ecs_query_desc_t::binding_ctx.
*
* @param query The query.
* @return The context.
*/
FLECS_API
void* ecs_query_get_binding_ctx(
const ecs_query_t *query);
/** @} */
/**
* @defgroup observer Observers
* @brief Functions for working with events and observers.
* @{
*/
/** Send event.
* This sends an event to matching triggers & is the mechanism used by flecs
* itself to send OnAdd, OnRemove, etc events.
*
* Applications can use this function to send custom events, where a custom
* event can be any regular entity.
*
* Applications should not send builtin flecs events, as this may violate
* assumptions the code makes about the conditions under which those events are
* sent.
*
* Triggers are invoked synchronously. It is therefore safe to use stack-based
* data as event context, which can be set in the "param" member.
*
* @param world The world.
* @param desc Event parameters.
*/
FLECS_API
void ecs_emit(
ecs_world_t *world,
ecs_event_desc_t *desc);
/** Create observer.
* Observers are like triggers, but can subscribe for multiple terms. An
* observer only triggers when the source of the event meets all terms.
*
* See the documentation for ecs_observer_desc_t for more details.
*
* @param world The world.
* @param desc The observer creation parameters.
*/
FLECS_API
ecs_entity_t ecs_observer_init(
ecs_world_t *world,
const ecs_observer_desc_t *desc);
/** Default run action for observer.
* This function can be called from a custom observer run action (see
* ecs_observer_desc_t::run for more details). This function ensures that the
* observer's filter is applied to the iterator's table, filters out duplicate
* events and implements EcsMonitor logic.
*
* @param it The iterator.
* @return True if the observer was invoked.
*/
FLECS_API
bool ecs_observer_default_run_action(
ecs_iter_t *it);
/** Get observer ctx.
* Return the value set in ecs_observer_desc_t::ctx.
*
* @param world The world.
* @param observer The observer.
* @return The context.
*/
FLECS_API
void* ecs_observer_get_ctx(
const ecs_world_t *world,
ecs_entity_t observer);
/** Get observer binding ctx.
* Return the value set in ecs_observer_desc_t::binding_ctx.
*
* @param world The world.
* @param observer The observer.
* @return The context.
*/
FLECS_API
void* ecs_observer_get_binding_ctx(
const ecs_world_t *world,
ecs_entity_t observer);
/** @} */
/**
* @defgroup iterator Iterators
* @brief Functions for working with `ecs_iter_t`.
* @{
*/
/** Create iterator from poly object.
* The provided poly object must have the iterable mixin. If an object is
* provided that does not have the mixin, the function will assert.
*
* When a filter is provided, an array of two iterators must be passed to the
* function. This allows the mixin implementation to create a chained iterator
* when necessary, which requires two iterator objects.
*
* If a filter is provided, the first element in the array of two iterators is
* the one that should be iterated. The mixin implementation may or may not set
* the second element, depending on whether an iterator chain is required.
*
* Additionally, when a filter is provided the returned iterator will be for a
* single term with the provided filter id. If the iterator is chained, the
* previous iterator in the chain can be accessed through it->chain_it.
*
* @param world The world or stage for which to create the iterator.
* @param poly The poly object from which to create the iterator.
* @param iter The iterator (out, ecs_iter_t[2] when filter is set).
* @param filter Optional term used for filtering the results.
*/
FLECS_API
void ecs_iter_poly(
const ecs_world_t *world,
const ecs_poly_t *poly,
ecs_iter_t *iter,
ecs_term_t *filter);
/** Progress any iterator.
* This operation is useful in combination with iterators for which it is not
* known what created them. Example use cases are functions that should accept
* any kind of iterator (such as serializers) or iterators created from poly
* objects.
*
* This operation is slightly slower than using a type-specific iterator (e.g.
* ecs_filter_next, ecs_query_next) as it has to call a function pointer which
* introduces a level of indirection.
*
* @param it The iterator.
* @return True if iterator has more results, false if not.
*/
FLECS_API
bool ecs_iter_next(
ecs_iter_t *it);
/** Cleanup iterator resources.
* This operation cleans up any resources associated with the iterator.
*
* This operation should only be used when an iterator is not iterated until
* completion (next has not yet returned false). When an iterator is iterated
* until completion, resources are automatically freed.
*
* @param it The iterator.
*/
FLECS_API
void ecs_iter_fini(
ecs_iter_t *it);
/** Count number of matched entities in query.
* This operation returns the number of matched entities. If a query contains no
* matched entities but still yields results (e.g. it has no terms with This
* sources) the operation will return 0.
*
* To determine the number of matched entities, the operation iterates the
* iterator until it yields no more results.
*
* @param it The iterator.
* @return True if iterator has more results, false if not.
*/
FLECS_API
int32_t ecs_iter_count(
ecs_iter_t *it);
/** Test if iterator is true.
* This operation will return true if the iterator returns at least one result.
* This is especially useful in combination with fact-checking rules (see the
* rules addon).
*
* The operation requires a valid iterator. After the operation is invoked, the
* application should no longer invoke next on the iterator and should treat it
* as if the iterator is iterated until completion.
*
* @param it The iterator.
* @return true if the iterator returns at least one result.
*/
FLECS_API
bool ecs_iter_is_true(
ecs_iter_t *it);
/** Get first matching entity from iterator.
* After this operation the application should treat the iterator as if it has
* been iterated until completion.
*
* @param it The iterator.
* @return The first matching entity, or 0 if no entities were matched.
*/
FLECS_API
ecs_entity_t ecs_iter_first(
ecs_iter_t *it);
/** Set value for iterator variable.
* This constrains the iterator to return only results for which the variable
* equals the specified value. The default value for all variables is
* EcsWildcard, which means the variable can assume any value.
*
* Example:
*
* // Rule that matches (Eats, *)
* ecs_rule_t *r = ecs_rule_init(world, &(ecs_filter_desc_t){
* .terms = {
* { .first.id = Eats, .second.name = "$food" }
* }
* });
*
* int food_var = ecs_rule_find_var(r, "food");
*
* // Set Food to Apples, so we're only matching (Eats, Apples)
* ecs_iter_t it = ecs_rule_iter(world, r);
* ecs_iter_set_var(&it, food_var, Apples);
*
* while (ecs_rule_next(&it)) {
* for (int i = 0; i < it.count; i ++) {
* // iterate as usual
* }
* }
*
* The variable must be initialized after creating the iterator and before the
* first call to next.
*
* @param it The iterator.
* @param var_id The variable index.
* @param entity The entity variable value.
*/
FLECS_API
void ecs_iter_set_var(
ecs_iter_t *it,
int32_t var_id,
ecs_entity_t entity);
/** Same as ecs_iter_set_var, but for a table.
* This constrains the variable to all entities in a table.
*
* @param it The iterator.
* @param var_id The variable index.
* @param table The table variable value.
*/
FLECS_API
void ecs_iter_set_var_as_table(
ecs_iter_t *it,
int32_t var_id,
const ecs_table_t *table);
/** Same as ecs_iter_set_var, but for a range of entities
* This constrains the variable to a range of entities in a table.
*
* @param it The iterator.
* @param var_id The variable index.
* @param range The range variable value.
*/
FLECS_API
void ecs_iter_set_var_as_range(
ecs_iter_t *it,
int32_t var_id,
const ecs_table_range_t *range);
/** Get value of iterator variable as entity.
* A variable can be interpreted as entity if it is set to an entity, or if it
* is set to a table range with count 1.
*
* This operation can only be invoked on valid iterators. The variable index
* must be smaller than the total number of variables provided by the iterator
* (as set in ecs_iter_t::variable_count).
*
* @param it The iterator.
* @param var_id The variable index.
* @return The variable value.
*/
FLECS_API
ecs_entity_t ecs_iter_get_var(
ecs_iter_t *it,
int32_t var_id);
/** Get value of iterator variable as table.
* A variable can be interpreted as table if it is set as table range with
* both offset and count set to 0, or if offset is 0 and count matches the
* number of elements in the table.
*
* This operation can only be invoked on valid iterators. The variable index
* must be smaller than the total number of variables provided by the iterator
* (as set in ecs_iter_t::variable_count).
*
* @param it The iterator.
* @param var_id The variable index.
* @return The variable value.
*/
FLECS_API
ecs_table_t* ecs_iter_get_var_as_table(
ecs_iter_t *it,
int32_t var_id);
/** Get value of iterator variable as table range.
* A value can be interpreted as table range if it is set as table range, or if
* it is set to an entity with a non-empty type (the entity must have at least
* one component, tag or relationship in its type).
*
* This operation can only be invoked on valid iterators. The variable index
* must be smaller than the total number of variables provided by the iterator
* (as set in ecs_iter_t::variable_count).
*
* @param it The iterator.
* @param var_id The variable index.
* @return The variable value.
*/
FLECS_API
ecs_table_range_t ecs_iter_get_var_as_range(
ecs_iter_t *it,
int32_t var_id);
/** Returns whether variable is constrained.
* This operation returns true for variables set by one of the ecs_iter_set_var*
* operations.
*
* A constrained variable is guaranteed not to change values while results are
* being iterated.
*
* @param it The iterator.
* @param var_id The variable index.
* @return Whether the variable is constrained to a specified value.
*/
FLECS_API
bool ecs_iter_var_is_constrained(
ecs_iter_t *it,
int32_t var_id);
/** Convert iterator to string.
* Prints the contents of an iterator to a string. Useful for debugging and/or
* testing the output of an iterator.
*
* The function only converts the currently iterated data to a string. To
* convert all data, the application has to manually call the next function and
* call ecs_iter_str on each result.
*
* @param it The iterator.
* @return A string representing the contents of the iterator.
*/
FLECS_API
char* ecs_iter_str(
const ecs_iter_t *it);
/** Create a paged iterator.
* Paged iterators limit the results to those starting from 'offset', and will
* return at most 'limit' results.
*
* The iterator must be iterated with ecs_page_next.
*
* A paged iterator acts as a passthrough for data exposed by the parent
* iterator, so that any data provided by the parent will also be provided by
* the paged iterator.
*
* @param it The source iterator.
* @param offset The number of entities to skip.
* @param limit The maximum number of entities to iterate.
* @return A page iterator.
*/
FLECS_API
ecs_iter_t ecs_page_iter(
const ecs_iter_t *it,
int32_t offset,
int32_t limit);
/** Progress a paged iterator.
* Progresses an iterator created by ecs_page_iter.
*
* @param it The iterator.
* @return true if iterator has more results, false if not.
*/
FLECS_API
bool ecs_page_next(
ecs_iter_t *it);
/** Create a worker iterator.
* Worker iterators can be used to equally divide the number of matched entities
* across N resources (usually threads). Each resource will process the total
* number of matched entities divided by 'count'.
*
* Entities are distributed across resources such that the distribution is
* stable between queries. Two queries that match the same table are guaranteed
* to match the same entities in that table.
*
* The iterator must be iterated with ecs_worker_next.
*
* A worker iterator acts as a passthrough for data exposed by the parent
* iterator, so that any data provided by the parent will also be provided by
* the worker iterator.
*
* @param it The source iterator.
* @param index The index of the current resource.
* @param count The total number of resources to divide entities between.
* @return A worker iterator.
*/
FLECS_API
ecs_iter_t ecs_worker_iter(
const ecs_iter_t *it,
int32_t index,
int32_t count);
/** Progress a worker iterator.
* Progresses an iterator created by ecs_worker_iter.
*
* @param it The iterator.
* @return true if iterator has more results, false if not.
*/
FLECS_API
bool ecs_worker_next(
ecs_iter_t *it);
/** Obtain data for a query field.
* This operation retrieves a pointer to an array of data that belongs to the
* term in the query. The index refers to the location of the term in the query,
* and starts counting from one.
*
* For example, the query "Position, Velocity" will return the Position array
* for index 1, and the Velocity array for index 2.
*
* When the specified field is not owned by the entity this function returns a
* pointer instead of an array. This happens when the source of a field is not
* the entity being iterated, such as a shared component (from a prefab), a
* component from a parent, or another entity. The ecs_field_is_self operation
* can be used to test dynamically if a field is owned.
*
* The provided size must be either 0 or must match the size of the datatype
* of the returned array. If the size does not match, the operation may assert.
* The size can be dynamically obtained with ecs_field_size.
*
* @param it The iterator.
* @param size The type size of the requested data.
* @param index The index of the field in the iterator.
* @return A pointer to the data of the field.
*/
FLECS_API
void* ecs_field_w_size(
const ecs_iter_t *it,
size_t size,
int32_t index);
/** Test whether the field is readonly.
* This operation returns whether the field is readonly. Readonly fields are
* annotated with [in], or are added as a const type in the C++ API.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return Whether the field is readonly.
*/
FLECS_API
bool ecs_field_is_readonly(
const ecs_iter_t *it,
int32_t index);
/** Test whether the field is writeonly.
* This operation returns whether this is a writeonly field. Writeonly terms are
* annotated with [out].
*
* Serializers are not required to serialize the values of a writeonly field.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return Whether the field is writeonly.
*/
FLECS_API
bool ecs_field_is_writeonly(
const ecs_iter_t *it,
int32_t index);
/** Test whether field is set.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return Whether the field is set.
*/
FLECS_API
bool ecs_field_is_set(
const ecs_iter_t *it,
int32_t index);
/** Return id matched for field.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return The id matched for the field.
*/
FLECS_API
ecs_id_t ecs_field_id(
const ecs_iter_t *it,
int32_t index);
/** Return index of matched table column.
* This function only returns column indices for fields that have been matched
* on the $this variable. Fields matched on other tables will return -1.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return The index of the matched column, -1 if not matched.
*/
FLECS_API
int32_t ecs_field_column_index(
const ecs_iter_t *it,
int32_t index);
/** Return field source.
* The field source is the entity on which the field was matched.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return The source for the field.
*/
FLECS_API
ecs_entity_t ecs_field_src(
const ecs_iter_t *it,
int32_t index);
/** Return field type size.
* Return type size of the field. Returns 0 if the field has no data.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return The type size for the field.
*/
FLECS_API
size_t ecs_field_size(
const ecs_iter_t *it,
int32_t index);
/** Test whether the field is matched on self.
* This operation returns whether the field is matched on the currently iterated
* entity. This function will return false when the field is owned by another
* entity, such as a parent or a prefab.
*
* When this operation returns false, the field must be accessed as a single
* value instead of an array. Fields for which this operation returns true
* return arrays with it->count values.
*
* @param it The iterator.
* @param index The index of the field in the iterator.
* @return Whether the field is matched on self.
*/
FLECS_API
bool ecs_field_is_self(
const ecs_iter_t *it,
int32_t index);
/** @} */
/**
* @defgroup tables Tables
* @brief Functions for working with `ecs_table_t`.
* @{
*/
/** Get type for table.
* The table type is a vector that contains all component, tag and pair ids.
*
* @param table The table.
* @return The type of the table.
*/
FLECS_API
const ecs_type_t* ecs_table_get_type(
const ecs_table_t *table);
/** Get type index for id.
* This operation returns the index for an id in the table's type.
*
* @param world The world.
* @param table The table.
* @param id The id.
* @return The index of the id in the table type, or -1 if not found.
*/
FLECS_API
int32_t ecs_table_get_type_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.
*
* @param world The world.
* @param table The table.
* @param id The component id.
* @return The column index of the id, or -1 if not found/not a component.
*/
FLECS_API
int32_t ecs_table_get_column_index(
const ecs_world_t *world,
const ecs_table_t *table,
ecs_id_t id);
/** 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.
*
* @param table The table.
* @return The number of columns in the table.
*/
FLECS_API
int32_t ecs_table_column_count(
const ecs_table_t *table);
/** 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.
*
* @param table The table.
* @param index The index in the table type.
* @return The index in the table column array.
*/
FLECS_API
int32_t ecs_table_type_to_column_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.
*
* @param table The table.
* @param index The column index.
* @return The index in the table type.
*/
FLECS_API
int32_t ecs_table_column_to_type_index(
const ecs_table_t *table,
int32_t index);
/** Get column from table by column index.
* This operation returns the component array for the provided index.
*
* @param table The table.
* @param index The column index.
* @param offset The index of the first row to return (0 for entire column).
* @return The component array, or NULL if the index is not a component.
*/
FLECS_API
void* ecs_table_get_column(
const ecs_table_t *table,
int32_t index,
int32_t offset);
/** Get column from table by component id.
* This operation returns the component array for the provided component id.
*
* @param table The table.
* @param id The component id for the column.
* @param offset The index of the first row to return (0 for entire column).
* @return The component array, or NULL if the index is not a component.
*/
FLECS_API
void* ecs_table_get_id(
const ecs_world_t *world,
const ecs_table_t *table,
ecs_id_t id,
int32_t offset);
/** Get column size from table.
* This operation returns the component size for the provided index.
*
* @param table The table.
* @param index The column index.
* @return The component size, or 0 if the index is not a component.
*/
FLECS_API
size_t ecs_table_get_column_size(
const ecs_table_t *table,
int32_t index);
/** Returns the number of records in the table.
* This operation returns the number of records that have been populated through
* the regular (entity) API as well as the number of records that have been
* inserted using the direct access API.
*
* @param table The table.
* @return The number of records in a table.
*/
FLECS_API
int32_t ecs_table_count(
const ecs_table_t *table);
/** Test if table has id.
* Same as ecs_table_get_type_index(world, table, id) != -1.
*
* @param world The world.
* @param table The table.
* @param id The id.
* @return True if the table has the id, false if the table doesn't.
*/
FLECS_API
bool ecs_table_has_id(
const ecs_world_t *world,
const ecs_table_t *table,
ecs_id_t id);
/** 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.
*
* @param world The world.
* @param table The table.
* @param rel The relationship.
* @return The depth of the table in the tree.
*/
FLECS_API
int32_t ecs_table_get_depth(
const ecs_world_t *world,
const ecs_table_t *table,
ecs_entity_t rel);
/** 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.
*
* @param world The world.
* @param table The table.
* @param id The id to add.
* @result The resulting table.
*/
FLECS_API
ecs_table_t* ecs_table_add_id(
ecs_world_t *world,
ecs_table_t *table,
ecs_id_t id);
/** 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.
*
* @param world The world.
* @param ids The id array.
* @param id_count The number of elements in the id array.
* @return The table with the specified (component) ids.
*/
FLECS_API
ecs_table_t* ecs_table_find(
ecs_world_t *world,
const ecs_id_t *ids,
int32_t id_count);
/** 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.
*
* @param world The world.
* @param table The table.
* @param id The id to remove.
* @result The resulting table.
*/
FLECS_API
ecs_table_t* ecs_table_remove_id(
ecs_world_t *world,
ecs_table_t *table,
ecs_id_t id);
/** Lock or unlock 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.
*
* @param world The world.
* @param table The table to lock.
*/
FLECS_API
void ecs_table_lock(
ecs_world_t *world,
ecs_table_t *table);
/** Unlock a table.
* Must be called after calling ecs_table_lock.
*
* @param world The world.
* @param table The table to unlock.
*/
FLECS_API
void ecs_table_unlock(
ecs_world_t *world,
ecs_table_t *table);
/** 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.
*
* @param table The table.
* @param flags The flags to test for.
* @return Whether the specified flags are set for the table.
*/
FLECS_API
bool ecs_table_has_flags(
ecs_table_t *table,
ecs_flags32_t flags);
/** Swaps two elements inside the table. This is useful for implementing custom
* table sorting algorithms.
* @param world The world
* @param table The table to swap elements in
* @param row_1 Table element to swap with row_2
* @param row_2 Table element to swap with row_1
*/
FLECS_API
void ecs_table_swap_rows(
ecs_world_t* world,
ecs_table_t* table,
int32_t row_1,
int32_t row_2);
/** 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 esc_table_remove_id. These arrays are
* required to properly execute OnAdd/OnRemove triggers.
*
* @param world The world.
* @param entity The entity to commit.
* @param record The entity's record (optional, providing it saves a lookup).
* @param table The table to commit the entity to.
* @return True if the entity got moved, false otherwise.
*/
FLECS_API
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);
/** Find record for entity. */
FLECS_API
ecs_record_t* ecs_record_find(
const ecs_world_t *world,
ecs_entity_t entity);
/** Get component pointer from column/record. */
FLECS_API
void* ecs_record_get_column(
const ecs_record_t *r,
int32_t column,
size_t c_size);
/** Search for component id in table type.
* This operation returns the index of first occurrance 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.
*
* @param world The world.
* @param table The table.
* @param id The id to search for.
* @param id_out If provided, it will be set to the found id (optional).
* @return The index of the id in the table type.
*/
FLECS_API
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 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.
*
* @param world The world.
* @param table The table.
* @param offset Offset from where to start searching.
* @param id The id to search for.
* @param id_out If provided, it will be set to the found id (optional).
* @return The index of the id in the table type.
*/
FLECS_API
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/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 betwen ecs_search, ecs_search_offset and ecs_search_relation,
* the simpler the function the better its performance.
*
* @param world The world.
* @param table The table.
* @param offset Offset from where to start searching.
* @param id The id to search for.
* @param rel The relationship to traverse (optional).
* @param flags Whether to search EcsSelf and/or EcsUp.
* @param subject_out If provided, it will be set to the matched entity.
* @param id_out If provided, it will be set to the found id (optional).
* @param tr_out Internal datatype.
* @return The index of the id in the table type.
*/
FLECS_API
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_flags32_t flags, /* EcsSelf and/or EcsUp */
ecs_entity_t *subject_out,
ecs_id_t *id_out,
struct ecs_table_record_t **tr_out);
/** @} */
/**
* @defgroup values Values
* @brief Construct, destruct, copy and move dynamically created values.
* @{
*/
/** Construct a value in existing storage
*
* @param world The world.
* @param type The type of the value to create.
* @param ptr Pointer to a value of type 'type'
* @return Zero if success, nonzero if failed.
*/
FLECS_API
int ecs_value_init(
const ecs_world_t *world,
ecs_entity_t type,
void *ptr);
/** Construct a value in existing storage
*
* @param world The world.
* @param ti The type info of the type to create.
* @param ptr Pointer to a value of type 'type'
* @return Zero if success, nonzero if failed.
*/
FLECS_API
int ecs_value_init_w_type_info(
const ecs_world_t *world,
const ecs_type_info_t *ti,
void *ptr);
/** Construct a value in new storage
*
* @param world The world.
* @param type The type of the value to create.
* @return Pointer to type if success, NULL if failed.
*/
FLECS_API
void* ecs_value_new(
ecs_world_t *world,
ecs_entity_t type);
/** Construct a value in new storage
*
* @param world The world.
* @param ti The type info of the type to create.
* @return Pointer to type if success, NULL if failed.
*/
void* ecs_value_new_w_type_info(
ecs_world_t *world,
const ecs_type_info_t *ti);
/** Destruct a value
*
* @param world The world.
* @param ti Type info of the value to destruct.
* @param ptr Pointer to constructed value of type 'type'.
* @return Zero if success, nonzero if failed.
*/
int ecs_value_fini_w_type_info(
const ecs_world_t *world,
const ecs_type_info_t *ti,
void *ptr);
/** Destruct a value
*
* @param world The world.
* @param type The type of the value to destruct.
* @param ptr Pointer to constructed value of type 'type'.
* @return Zero if success, nonzero if failed.
*/
FLECS_API
int ecs_value_fini(
const ecs_world_t *world,
ecs_entity_t type,
void* ptr);
/** Destruct a value, free storage
*
* @param world The world.
* @param type The type of the value to destruct.
* @return Zero if success, nonzero if failed.
*/
FLECS_API
int ecs_value_free(
ecs_world_t *world,
ecs_entity_t type,
void* ptr);
/** Copy value.
*
* @param world The world.
* @param ti Type info of the value to copy.
* @param dst Pointer to the storage to copy to.
* @param src Pointer to the value to copy.
* @return Zero if success, nonzero if failed.
*/
FLECS_API
int ecs_value_copy_w_type_info(
const ecs_world_t *world,
const ecs_type_info_t *ti,
void* dst,
const void *src);
/** Copy value.
*
* @param world The world.
* @param type The type of the value to copy.
* @param dst Pointer to the storage to copy to.
* @param src Pointer to the value to copy.
* @return Zero if success, nonzero if failed.
*/
FLECS_API
int ecs_value_copy(
const ecs_world_t *world,
ecs_entity_t type,
void* dst,
const void *src);
/** Move value.
*
* @param world The world.
* @param ti Type info of the value to move.
* @param dst Pointer to the storage to move to.
* @param src Pointer to the value to move.
* @return Zero if success, nonzero if failed.
*/
int ecs_value_move_w_type_info(
const ecs_world_t *world,
const ecs_type_info_t *ti,
void* dst,
void *src);
/** Move value.
*
* @param world The world.
* @param type The type of the value to move.
* @param dst Pointer to the storage to move to.
* @param src Pointer to the value to move.
* @return Zero if success, nonzero if failed.
*/
int ecs_value_move(
const ecs_world_t *world,
ecs_entity_t type,
void* dst,
void *src);
/** Move construct value.
*
* @param world The world.
* @param ti Type info of the value to move.
* @param dst Pointer to the storage to move to.
* @param src Pointer to the value to move.
* @return Zero if success, nonzero if failed.
*/
int ecs_value_move_ctor_w_type_info(
const ecs_world_t *world,
const ecs_type_info_t *ti,
void* dst,
void *src);
/** Move construct value.
*
* @param world The world.
* @param type The type of the value to move.
* @param dst Pointer to the storage to move to.
* @param src Pointer to the value to move.
* @return Zero if success, nonzero if failed.
*/
int ecs_value_move_ctor(
const ecs_world_t *world,
ecs_entity_t type,
void* dst,
void *src);
/** @} */
/** @} */
/**
* @defgroup c_addons Addons
* @brief C APIs for addons.
*
* \ingroup c
*
* @{
* @}
*/
#include "flecs/addons/flecs_c.h"
#ifdef __cplusplus
}
#endif
#include "flecs/private/addons.h"
#endif