Object: Scalar

Detailed Description

Defines the Scalar Object interface.

Typedefs
typedef struct _vx_scalar *	vx_scalar
	An opaque reference to a scalar. More...

Enumerations
enum	vx_scalar_attribute_e { VX_SCALAR_ATTRIBUTE_TYPE = ((( VX_ID_KHRONOS ) << 20) | ( VX_TYPE_SCALAR << 8)) + 0x0 }
	The scalar attributes list. More...

Functions
vx_scalar VX_API_CALL	vxCreateScalar (vx_context context, vx_enum data_type, const void *ptr)
	Creates a reference to a scalar object. Also see Node Parameters. More...
vx_status VX_API_CALL	vxQueryScalar (vx_scalar scalar, vx_enum attribute, void *ptr, vx_size size)
	Queries attributes from a scalar. More...
vx_status VX_API_CALL	vxReadScalarValue (vx_scalar ref, void *ptr)
	Gets the scalar value out of a reference. More...
vx_status VX_API_CALL	vxReleaseScalar (vx_scalar *scalar)
	Releases a reference to a scalar object. The object may not be garbage collected until its total reference count is zero. More...
vx_status VX_API_CALL	vxWriteScalarValue (vx_scalar ref, const void *ptr)
	Sets the scalar value in a reference. More...

Typedef Documentation

typedef struct _vx_scalar* vx_scalar

An opaque reference to a scalar.

A scalar can be up to 64 bits wide.

See also

vxCreateScalar

Definition at line 159 of file vx_types.h.

Enumeration Type Documentation

enum vx_scalar_attribute_e

The scalar attributes list.

Enumerator
VX_SCALAR_ATTRIBUTE_TYPE	Queries the type of atomic that is contained in the scalar. Use a vx_enum parameter.

Definition at line 820 of file vx_types.h.

Function Documentation

vx_scalar VX_API_CALL vxCreateScalar	(	vx_context	context,
		vx_enum	data_type,
		const void *	ptr
	)

Creates a reference to a scalar object. Also see Node Parameters.

Parameters

[in]	context	The reference to the system context.
[in]	data_type	The vx_type_e of the scalar. Must be greater than VX_TYPE_INVALID and less than VX_TYPE_SCALAR_MAX.
[in]	ptr	The pointer to the initial value of the scalar.

Returns

A scaler reference vx_scalar. Any possible errors preventing a successful creation should be checked using vxGetStatus.

vx_status VX_API_CALL vxReleaseScalar

(

vx_scalar *

scalar

)

Releases a reference to a scalar object. The object may not be garbage collected until its total reference count is zero.

Parameters

[in]

scalar

The pointer to the scalar to release.

Postcondition

After returning from this function the reference is zeroed.

Returns

A vx_status_e enumeration.

Return values

VX_SUCCESS	No errors.
VX_ERROR_INVALID_REFERENCE	If scalar is not a vx_scalar.

vx_status VX_API_CALL vxQueryScalar	(	vx_scalar	scalar,
		vx_enum	attribute,
		void *	ptr,
		vx_size	size
	)

Queries attributes from a scalar.

Parameters

[in]	scalar	The scalar object.
[in]	attribute	The enumeration to query. Use a vx_scalar_attribute_e enumeration.
[out]	ptr	The location at which to store the resulting value.
[in]	size	The size of the container to which ptr points.

Returns

A vx_status_e enumeration.

vx_status VX_API_CALL vxReadScalarValue	(	vx_scalar	ref,
		void *	ptr
	)

Gets the scalar value out of a reference.

Note

Use this in conjunction with Query APIs that return references which should be converted into values.

Parameters

[in]	ref	The reference from which to get the scalar value.
[out]	ptr	An appropriate typed pointer that points to a location to which to copy the scalar value.

Returns

A vx_status_e enumeration.

Return values

VX_ERROR_INVALID_REFERENCE	If the ref is not a valid reference.
VX_ERROR_INVALID_PARAMETERS	If ptr is NULL.
VX_ERROR_INVALID_TYPE	If the type does not match the type in the reference or is a bad value.

vx_status VX_API_CALL vxWriteScalarValue	(	vx_scalar	ref,
		const void *	ptr
	)

Sets the scalar value in a reference.

Note

Use this in conjunction with Parameter APIs that return references to parameters that need to be altered.

Parameters

[in]	ref	The reference from which to get the scalar value.
[in]	ptr	An appropriately typed pointer that points to a location to which to copy the scalar value.

Returns

A vx_status_e enumeration.

Return values

VX_ERROR_INVALID_REFERENCE	If the ref is not a valid reference.
VX_ERROR_INVALID_PARAMETERS	If ptr is NULL.
VX_ERROR_INVALID_TYPE	If the type does not match the type in the reference or is a bad value.