meta.h File Reference

Meta addon. More...

#include "meta_c.h"

Include dependency graph for meta.h:

Go to the source code of this file.

Classes
struct	EcsType
	Component that is automatically added to every type with the right kind. More...
struct	EcsPrimitive
	Component added to primitive types. More...
struct	EcsMember
	Component added to member entities. More...
struct	ecs_member_value_range_t
	Type expressing a range for a member value. More...
struct	EcsMemberRanges
	Component added to member entities to express valid value ranges. More...
struct	ecs_member_t
	Element type of members vector in EcsStruct. More...
struct	EcsStruct
	Component added to struct type entities. More...
struct	ecs_enum_constant_t
	Type that describes an enum constant. More...
struct	EcsEnum
	Component added to enum type entities. More...
struct	ecs_bitmask_constant_t
	Type that describes a bitmask constant. More...
struct	EcsBitmask
	Component added to bitmask type entities. More...
struct	EcsConstants
	Component with data structures for looking up enum or bitmask constants. More...
struct	EcsArray
	Component added to array type entities. More...
struct	EcsVector
	Component added to vector type entities. More...
struct	ecs_serializer_t
	Serializer interface. More...
struct	EcsOpaque
	Opaque type reflection data. More...
struct	ecs_unit_translation_t
	Helper type to describe translation between two units. More...
struct	EcsUnit
	Component that stores unit data. More...
struct	EcsUnitPrefix
	Component that stores unit prefix data. More...
struct	ecs_meta_op_t
	Meta type serializer instruction data. More...
struct	EcsTypeSerializer
	Component that stores the type serializer. More...
struct	ecs_meta_scope_t
	Type with information about the currently iterated scope. More...
struct	ecs_meta_cursor_t
	Type that enables iterating and populating a value using reflection data. More...
struct	ecs_primitive_desc_t
	Used with ecs_primitive_init(). More...
struct	ecs_enum_desc_t
	Used with ecs_enum_init(). More...
struct	ecs_bitmask_desc_t
	Used with ecs_bitmask_init(). More...
struct	ecs_array_desc_t
	Used with ecs_array_init(). More...
struct	ecs_vector_desc_t
	Used with ecs_vector_init(). More...
struct	ecs_struct_desc_t
	Used with ecs_struct_init(). More...
struct	ecs_opaque_desc_t
	Used with ecs_opaque_init(). More...
struct	ecs_unit_desc_t
	Used with ecs_unit_init(). More...
struct	ecs_unit_prefix_desc_t
	Used with ecs_unit_prefix_init(). More...

Macros
#define	FLECS_META_H
#define	ECS_MEMBER_DESC_CACHE_SIZE   (32)
	Max number of constants and members that can be specified in desc structs.
#define	ECS_META_MAX_SCOPE_DEPTH   (32)
	Maximum level of type nesting.
#define	ecs_primitive(world, ...)    ecs_primitive_init(world, &(ecs_primitive_desc_t) __VA_ARGS__ )
	Create a primitive type.
#define	ecs_enum(world, ...)    ecs_enum_init(world, &(ecs_enum_desc_t) __VA_ARGS__ )
	Create an enum type.
#define	ecs_bitmask(world, ...)    ecs_bitmask_init(world, &(ecs_bitmask_desc_t) __VA_ARGS__ )
	Create a bitmask type.
#define	ecs_array(world, ...)    ecs_array_init(world, &(ecs_array_desc_t) __VA_ARGS__ )
	Create an array type.
#define	ecs_vector(world, ...)    ecs_vector_init(world, &(ecs_vector_desc_t) __VA_ARGS__ )
	Create a vector type.
#define	ecs_opaque(world, ...)    ecs_opaque_init(world, &(ecs_opaque_desc_t) __VA_ARGS__ )
	Create an opaque type.
#define	ecs_struct(world, ...)    ecs_struct_init(world, &(ecs_struct_desc_t) __VA_ARGS__ )
	Create a struct type.
#define	ecs_unit(world, ...)    ecs_unit_init(world, &(ecs_unit_desc_t) __VA_ARGS__ )
	Create a unit.
#define	ecs_unit_prefix(world, ...)    ecs_unit_prefix_init(world, &(ecs_unit_prefix_desc_t) __VA_ARGS__ )
	Create a unit prefix.
#define	ecs_quantity(world, ...)    ecs_quantity_init(world, &(ecs_entity_desc_t) __VA_ARGS__ )
	Create a unit quantity.

Typedefs
typedef bool	ecs_bool_t
	Primitive type definitions.
typedef char	ecs_char_t
	Built-in char type.
typedef unsigned char	ecs_byte_t
	Built-in ecs_byte type.
typedef uint8_t	ecs_u8_t
	Built-in u8 type.
typedef uint16_t	ecs_u16_t
	Built-in u16 type.
typedef uint32_t	ecs_u32_t
	Built-in u32 type.
typedef uint64_t	ecs_u64_t
	Built-in u64 type.
typedef uintptr_t	ecs_uptr_t
	Built-in uptr type.
typedef int8_t	ecs_i8_t
	Built-in i8 type.
typedef int16_t	ecs_i16_t
	Built-in i16 type.
typedef int32_t	ecs_i32_t
	Built-in i32 type.
typedef int64_t	ecs_i64_t
	Built-in i64 type.
typedef intptr_t	ecs_iptr_t
	Built-in iptr type.
typedef float	ecs_f32_t
	Built-in f32 type.
typedef double	ecs_f64_t
	Built-in f64 type.
typedef char *	ecs_string_t
	Built-in string type.
typedef enum ecs_type_kind_t	ecs_type_kind_t
	Type kinds supported by meta addon.
typedef struct EcsType	EcsType
	Component that is automatically added to every type with the right kind.
typedef enum ecs_primitive_kind_t	ecs_primitive_kind_t
	Primitive type kinds supported by meta addon.
typedef struct EcsPrimitive	EcsPrimitive
	Component added to primitive types.
typedef struct EcsMember	EcsMember
	Component added to member entities.
typedef struct ecs_member_value_range_t	ecs_member_value_range_t
	Type expressing a range for a member value.
typedef struct EcsMemberRanges	EcsMemberRanges
	Component added to member entities to express valid value ranges.
typedef struct ecs_member_t	ecs_member_t
	Element type of members vector in EcsStruct.
typedef struct EcsStruct	EcsStruct
	Component added to struct type entities.
typedef struct ecs_enum_constant_t	ecs_enum_constant_t
	Type that describes an enum constant.
typedef struct EcsEnum	EcsEnum
	Component added to enum type entities.
typedef struct ecs_bitmask_constant_t	ecs_bitmask_constant_t
	Type that describes a bitmask constant.
typedef struct EcsBitmask	EcsBitmask
	Component added to bitmask type entities.
typedef struct EcsConstants	EcsConstants
	Component with data structures for looking up enum or bitmask constants.
typedef struct EcsArray	EcsArray
	Component added to array type entities.
typedef struct EcsVector	EcsVector
	Component added to vector type entities.
typedef struct ecs_serializer_t	ecs_serializer_t
	Serializer interface.
typedef int(*	ecs_meta_serialize_t) (const ecs_serializer_t *ser, const void *src)
	Callback invoked serializing an opaque type.
typedef int(*	ecs_meta_serialize_member_t) (const ecs_serializer_t *ser, const void *src, const char *name)
	Callback invoked to serialize an opaque struct member.
typedef int(*	ecs_meta_serialize_element_t) (const ecs_serializer_t *ser, const void *src, size_t elem)
	Callback invoked to serialize an opaque vector or array element.
typedef struct EcsOpaque	EcsOpaque
	Opaque type reflection data.
typedef struct ecs_unit_translation_t	ecs_unit_translation_t
	Helper type to describe translation between two units.
typedef struct EcsUnit	EcsUnit
	Component that stores unit data.
typedef struct EcsUnitPrefix	EcsUnitPrefix
	Component that stores unit prefix data.
typedef enum ecs_meta_op_kind_t	ecs_meta_op_kind_t
	Serializer instruction opcodes.
typedef struct ecs_meta_op_t	ecs_meta_op_t
	Meta type serializer instruction data.
typedef struct EcsTypeSerializer	EcsTypeSerializer
	Component that stores the type serializer.
typedef struct ecs_meta_scope_t	ecs_meta_scope_t
	Type with information about the currently iterated scope.
typedef struct ecs_meta_cursor_t	ecs_meta_cursor_t
	Type that enables iterating and populating a value using reflection data.
typedef struct ecs_primitive_desc_t	ecs_primitive_desc_t
	Used with ecs_primitive_init().
typedef struct ecs_enum_desc_t	ecs_enum_desc_t
	Used with ecs_enum_init().
typedef struct ecs_bitmask_desc_t	ecs_bitmask_desc_t
	Used with ecs_bitmask_init().
typedef struct ecs_array_desc_t	ecs_array_desc_t
	Used with ecs_array_init().
typedef struct ecs_vector_desc_t	ecs_vector_desc_t
	Used with ecs_vector_init().
typedef struct ecs_struct_desc_t	ecs_struct_desc_t
	Used with ecs_struct_init().
typedef struct ecs_opaque_desc_t	ecs_opaque_desc_t
	Used with ecs_opaque_init().
typedef struct ecs_unit_desc_t	ecs_unit_desc_t
	Used with ecs_unit_init().
typedef struct ecs_unit_prefix_desc_t	ecs_unit_prefix_desc_t
	Used with ecs_unit_prefix_init().

Enumerations
enum	ecs_type_kind_t {   EcsPrimitiveType , EcsBitmaskType , EcsEnumType , EcsStructType ,   EcsArrayType , EcsVectorType , EcsOpaqueType , EcsTypeKindLast = EcsOpaqueType }
	Type kinds supported by meta addon. More...
enum	ecs_primitive_kind_t {   EcsBool = 1 , EcsChar , EcsByte , EcsU8 ,   EcsU16 , EcsU32 , EcsU64 , EcsI8 ,   EcsI16 , EcsI32 , EcsI64 , EcsF32 ,   EcsF64 , EcsUPtr , EcsIPtr , EcsString ,   EcsEntity , EcsId , EcsPrimitiveKindLast = EcsId }
	Primitive type kinds supported by meta addon. More...
enum	ecs_meta_op_kind_t {   EcsOpPushStruct , EcsOpPushArray , EcsOpPushVector , EcsOpPop ,   EcsOpOpaqueStruct , EcsOpOpaqueArray , EcsOpOpaqueVector , EcsOpForward ,   EcsOpScope , EcsOpOpaqueValue , EcsOpEnum , EcsOpBitmask ,   EcsOpPrimitive , EcsOpBool , EcsOpChar , EcsOpByte ,   EcsOpU8 , EcsOpU16 , EcsOpU32 , EcsOpU64 ,   EcsOpI8 , EcsOpI16 , EcsOpI32 , EcsOpI64 ,   EcsOpF32 , EcsOpF64 , EcsOpUPtr , EcsOpIPtr ,   EcsOpString , EcsOpEntity , EcsOpId , EcsMetaTypeOpKindLast = EcsOpId }
	Serializer instruction opcodes. More...

Functions
FLECS_API const ecs_entity_t	ecs_id (EcsType)
	ID for component added to all types with reflection data.
FLECS_API const ecs_entity_t	ecs_id (EcsTypeSerializer)
	ID for component that stores a type-specific serializer.
FLECS_API const ecs_entity_t	ecs_id (EcsPrimitive)
	ID for component that stores reflection data for a primitive type.
FLECS_API const ecs_entity_t	ecs_id (EcsEnum)
	ID for component that stores reflection data for an enum type.
FLECS_API const ecs_entity_t	ecs_id (EcsBitmask)
	ID for component that stores reflection data for a bitmask type.
FLECS_API const ecs_entity_t	ecs_id (EcsConstants)
	ID for component that stores reflection data for constants.
FLECS_API const ecs_entity_t	ecs_id (EcsMember)
	ID for component that stores reflection data for struct members.
FLECS_API const ecs_entity_t	ecs_id (EcsMemberRanges)
	ID for component that stores min and max ranges for member values.
FLECS_API const ecs_entity_t	ecs_id (EcsStruct)
	ID for component that stores reflection data for a struct type.
FLECS_API const ecs_entity_t	ecs_id (EcsArray)
	ID for component that stores reflection data for an array type.
FLECS_API const ecs_entity_t	ecs_id (EcsVector)
	ID for component that stores reflection data for a vector type.
FLECS_API const ecs_entity_t	ecs_id (EcsOpaque)
	ID for component that stores reflection data for an opaque type.
FLECS_API const ecs_entity_t	ecs_id (EcsUnit)
	ID for component that stores unit data.
FLECS_API const ecs_entity_t	ecs_id (EcsUnitPrefix)
	ID for component that stores unit prefix data.
FLECS_API const ecs_entity_t	ecs_id (ecs_bool_t)
	Built-in boolean type.
FLECS_API const ecs_entity_t	ecs_id (ecs_char_t)
	Built-in char type.
FLECS_API const ecs_entity_t	ecs_id (ecs_byte_t)
	Built-in byte type.
FLECS_API const ecs_entity_t	ecs_id (ecs_u8_t)
	Built-in 8-bit unsigned int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_u16_t)
	Built-in 16-bit unsigned int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_u32_t)
	Built-in 32-bit unsigned int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_u64_t)
	Built-in 64-bit unsigned int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_uptr_t)
	Built-in pointer-sized unsigned int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_i8_t)
	Built-in 8-bit signed int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_i16_t)
	Built-in 16-bit signed int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_i32_t)
	Built-in 32-bit signed int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_i64_t)
	Built-in 64-bit signed int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_iptr_t)
	Built-in pointer-sized signed int type.
FLECS_API const ecs_entity_t	ecs_id (ecs_f32_t)
	Built-in 32-bit floating-point type.
FLECS_API const ecs_entity_t	ecs_id (ecs_f64_t)
	Built-in 64-bit floating-point type.
FLECS_API const ecs_entity_t	ecs_id (ecs_string_t)
	Built-in string type.
FLECS_API char *	ecs_meta_serializer_to_str (ecs_world_t *world, ecs_entity_t type)
	Convert serializer to string.
FLECS_API ecs_meta_cursor_t	ecs_meta_cursor (const ecs_world_t *world, ecs_entity_t type, void *ptr)
	Create meta cursor.
FLECS_API void *	ecs_meta_get_ptr (ecs_meta_cursor_t *cursor)
	Get pointer to current field.
FLECS_API int	ecs_meta_next (ecs_meta_cursor_t *cursor)
	Move cursor to next field.
FLECS_API int	ecs_meta_elem (ecs_meta_cursor_t *cursor, int32_t elem)
	Move cursor to a field.
FLECS_API int	ecs_meta_member (ecs_meta_cursor_t *cursor, const char *name)
	Move cursor to member.
FLECS_API int	ecs_meta_try_member (ecs_meta_cursor_t *cursor, const char *name)
	Same as ecs_meta_member(), but doesn't throw an error.
FLECS_API int	ecs_meta_dotmember (ecs_meta_cursor_t *cursor, const char *name)
	Move cursor to member.
FLECS_API int	ecs_meta_try_dotmember (ecs_meta_cursor_t *cursor, const char *name)
	Same as ecs_meta_dotmember(), but doesn't throw an error.
FLECS_API int	ecs_meta_push (ecs_meta_cursor_t *cursor)
	Push a scope (required and only valid for structs and collections).
FLECS_API int	ecs_meta_pop (ecs_meta_cursor_t *cursor)
	Pop a struct or collection scope (must follow a push).
FLECS_API bool	ecs_meta_is_collection (const ecs_meta_cursor_t *cursor)
	Is the current scope a collection?
FLECS_API ecs_entity_t	ecs_meta_get_type (const ecs_meta_cursor_t *cursor)
	Get type of current field.
FLECS_API ecs_entity_t	ecs_meta_get_unit (const ecs_meta_cursor_t *cursor)
	Get unit of current field.
FLECS_API const char *	ecs_meta_get_member (const ecs_meta_cursor_t *cursor)
	Get member name of current field.
FLECS_API ecs_entity_t	ecs_meta_get_member_id (const ecs_meta_cursor_t *cursor)
	Get member entity of current field.
FLECS_API int	ecs_meta_set_bool (ecs_meta_cursor_t *cursor, bool value)
	Set field with boolean value.
FLECS_API int	ecs_meta_set_char (ecs_meta_cursor_t *cursor, char value)
	Set field with char value.
FLECS_API int	ecs_meta_set_int (ecs_meta_cursor_t *cursor, int64_t value)
	Set field with int value.
FLECS_API int	ecs_meta_set_uint (ecs_meta_cursor_t *cursor, uint64_t value)
	Set field with uint value.
FLECS_API int	ecs_meta_set_float (ecs_meta_cursor_t *cursor, double value)
	Set field with float value.
FLECS_API int	ecs_meta_set_string (ecs_meta_cursor_t *cursor, const char *value)
	Set field with string value.
FLECS_API int	ecs_meta_set_string_literal (ecs_meta_cursor_t *cursor, const char *value)
	Set field with string literal value (has enclosing "").
FLECS_API int	ecs_meta_set_entity (ecs_meta_cursor_t *cursor, ecs_entity_t value)
	Set field with entity value.
FLECS_API int	ecs_meta_set_id (ecs_meta_cursor_t *cursor, ecs_id_t value)
	Set field with (component) ID value.
FLECS_API int	ecs_meta_set_null (ecs_meta_cursor_t *cursor)
	Set field with null value.
FLECS_API int	ecs_meta_set_value (ecs_meta_cursor_t *cursor, const ecs_value_t *value)
	Set field with dynamic value.
FLECS_API bool	ecs_meta_get_bool (const ecs_meta_cursor_t *cursor)
	Get field value as boolean.
FLECS_API char	ecs_meta_get_char (const ecs_meta_cursor_t *cursor)
	Get field value as char.
FLECS_API int64_t	ecs_meta_get_int (const ecs_meta_cursor_t *cursor)
	Get field value as signed integer.
FLECS_API uint64_t	ecs_meta_get_uint (const ecs_meta_cursor_t *cursor)
	Get field value as unsigned integer.
FLECS_API double	ecs_meta_get_float (const ecs_meta_cursor_t *cursor)
	Get field value as float.
FLECS_API const char *	ecs_meta_get_string (const ecs_meta_cursor_t *cursor)
	Get field value as string.
FLECS_API ecs_entity_t	ecs_meta_get_entity (const ecs_meta_cursor_t *cursor)
	Get field value as entity.
FLECS_API ecs_id_t	ecs_meta_get_id (const ecs_meta_cursor_t *cursor)
	Get field value as (component) ID.
FLECS_API double	ecs_meta_ptr_to_float (ecs_primitive_kind_t type_kind, const void *ptr)
	Convert pointer of primitive kind to float.
FLECS_API ecs_size_t	ecs_meta_op_get_elem_count (const ecs_meta_op_t *op, const void *ptr)
	Get element count for array or vector operations.
FLECS_API ecs_entity_t	ecs_primitive_init (ecs_world_t *world, const ecs_primitive_desc_t *desc)
	Create a new primitive type.
FLECS_API ecs_entity_t	ecs_enum_init (ecs_world_t *world, const ecs_enum_desc_t *desc)
	Create a new enum type.
FLECS_API ecs_entity_t	ecs_bitmask_init (ecs_world_t *world, const ecs_bitmask_desc_t *desc)
	Create a new bitmask type.
FLECS_API ecs_entity_t	ecs_array_init (ecs_world_t *world, const ecs_array_desc_t *desc)
	Create a new array type.
FLECS_API ecs_entity_t	ecs_vector_init (ecs_world_t *world, const ecs_vector_desc_t *desc)
	Create a new vector type.
FLECS_API ecs_entity_t	ecs_struct_init (ecs_world_t *world, const ecs_struct_desc_t *desc)
	Create a new struct type.
FLECS_API int	ecs_struct_add_member (ecs_world_t *world, ecs_entity_t type, const ecs_member_t *member)
	Add member to struct.
FLECS_API ecs_member_t *	ecs_struct_get_member (ecs_world_t *world, ecs_entity_t type, const char *name)
	Get member by name from struct.
FLECS_API ecs_member_t *	ecs_struct_get_nth_member (ecs_world_t *world, ecs_entity_t type, int32_t i)
	Get member by index from struct.
FLECS_API ecs_entity_t	ecs_opaque_init (ecs_world_t *world, const ecs_opaque_desc_t *desc)
	Create a new opaque type.
FLECS_API ecs_entity_t	ecs_unit_init (ecs_world_t *world, const ecs_unit_desc_t *desc)
	Create a new unit.
FLECS_API ecs_entity_t	ecs_unit_prefix_init (ecs_world_t *world, const ecs_unit_prefix_desc_t *desc)
	Create a new unit prefix.
FLECS_API ecs_entity_t	ecs_quantity_init (ecs_world_t *world, const ecs_entity_desc_t *desc)
	Create a new quantity.
FLECS_API void	FlecsMetaImport (ecs_world_t *world)
	Meta module import function.

Variables
FLECS_API const ecs_entity_t	EcsQuantity
	Tag added to unit quantities.

Detailed Description

Meta addon.

The meta addon enables reflecting on component data. Types are stored as entities, with components that store the reflection data. A type has at least two components:

• EcsComponent: core component, contains size and alignment
• EcsType: component that indicates what kind of type the entity is

Additionally, the type may have an additional component that contains the reflection data for the type. For example, structs have these components:

• EcsComponent
• EcsType
• EcsStruct

Structs can be populated by adding child entities with the EcsMember component. Adding a child with a Member component to an entity will automatically add the EcsStruct component to the parent.

Enums and bitmasks can be populated by adding child entities with the Constant tag. By default, constants are automatically assigned values when they are added to the enum or bitmask. The parent entity must have the EcsEnum or EcsBitmask component before adding the constants.

To create enum constants with a manual value, set (Constant, i32) to the desired value. To create bitmask constants with a manual value, set (Constant, u32) to the desired value. Constants with manual values should not conflict with other constants.

The _init APIs are convenience wrappers around creating the entities and components for the types.

When a type is created, it automatically receives the EcsComponent and EcsType components. The former means that the resulting type can be used as a regular component:

// Create Position type
ecs_entity_t pos = ecs_struct_init(world, &(ecs_struct_desc_t){
 .entity.name = "Position",
 .members = {
      {"x", ecs_id(ecs_f32_t)},
      {"y", ecs_id(ecs_f32_t)}
  }
});
 
// Create entity with Position component
ecs_entity_t e = ecs_new_w_id(world, pos);

Type entities do not have to be named.

Definition in file meta.h.