Object: Scalar

Detailed Description

Defines the Scalar Object interface.

Modules
	The Scalar Attributes Constants
	The scalar attributes list.

Typedefs
typedef struct _vx_scalar *	vx_scalar
	An opaque reference to a scalar [R01409]. More...

Functions
vx_status VX_API_CALL	vxCopyScalar (vx_scalar scalar, void *user_ptr, vx_enum usage, vx_enum user_mem_type)
	Allows the application to copy from/into a scalar object [R00843]. More...
vx_scalar VX_API_CALL	vxCreateScalar (vx_context context, vx_enum data_type, const void *ptr)
	Creates a reference to a scalar object [R00828]. 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 [R00837]. More...
vx_status VX_API_CALL	vxReleaseScalar (vx_scalar *scalar)
	Releases a reference to a scalar object [R00833]. The object may not be garbage collected until its total reference count is zero. More...

Typedef Documentation

vx_scalar

typedef struct _vx_scalar* vx_scalar

An opaque reference to a scalar [R01409].

A scalar can be up to 64 bits wide [R01410].

See also

vxCreateScalar

Definition at line 183 of file vx_types.h.

Function Documentation

vxCreateScalar()

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

Creates a reference to a scalar object [R00828]. Also see Node Parameters.

Parameters

[in]	context	The reference to the system context [R00829].
[in]	data_type	The type of the scalar. Must be greater than VX_TYPE_INVALID and less than VX_TYPE_SCALAR_MAX [R00830].
[in]	ptr	The pointer to the initial value of the scalar [R00831].

Returns

A scalar reference vx_scalar [R00832]. Any possible errors preventing a successful creation should be checked using vxGetStatus.

vxReleaseScalar()

vx_status VX_API_CALL vxReleaseScalar

(

vx_scalar *

scalar

)

Releases a reference to a scalar object [R00833]. The object may not be garbage collected until its total reference count is zero.

Parameters

[in]

scalar

The pointer to the scalar to release [R00834].

Postcondition

After returning from this function the reference is zeroed [R00835].

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00836].
VX_ERROR_INVALID_REFERENCE	scalar is not a valid vx_scalar reference.

vxQueryScalar()

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

Queries attributes from a scalar [R00837].

Parameters

[in]	scalar	The scalar object [R00838].
[in]	attribute	The attribute to query, use a The Scalar Attributes Constants value. [R00839].
[out]	ptr	The location at which to store the resulting value [R00840].
[in]	size	The size of the container to which ptr points [R00841].

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00842].
VX_ERROR_INVALID_REFERENCE	scalar is not a valid vx_scalar reference.

vxCopyScalar()

vx_status VX_API_CALL vxCopyScalar	(	vx_scalar	scalar,
		void *	user_ptr,
		vx_enum	usage,
		vx_enum	user_mem_type
	)

Allows the application to copy from/into a scalar object [R00843].

Parameters

[in]	scalar	The reference to the scalar object that is the source or the destination of the copy [R00844].
[in]	user_ptr	The address of the memory location where to store the requested data if the copy was requested in read mode, or from where to get the data to store into the scalar object if the copy was requested in write mode [R00845]. In the user memory, the scalar is a variable of the type corresponding to VX_SCALAR_TYPE. The accessible memory must be large enough to contain this variable.
[in]	usage	This declares the effect of the copy with regard to the scalar object [R00846]. using the The memory accessor hint flags. value. Only VX_READ_ONLY and VX_WRITE_ONLY are supported [R00847]: VX_READ_ONLY means that data are copied from the scalar object into the user memory [R00848]. VX_WRITE_ONLY means that data are copied into the scalar object from the user memory [R00849].
[in]	user_mem_type	A Memory import type constants. value that specifies the memory type of the memory referenced by the user_addr [R00850].

Returns

A The vx_status Constants value.

Return values

VX_SUCCESS	No errors; any other value indicates failure [R00851].
VX_ERROR_INVALID_REFERENCE	scalar is not a valid vx_scalar reference.
VX_ERROR_INVALID_PARAMETERS	An other parameter is incorrect.