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MArrayDataHandle Class Reference

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Detailed Description

Data block handle for array data.

An MArrayDataHandle is a smart pointer into a data block (MDataBlock) that handles access to array data. MArrayDataHandle supports attributes that can have an array of data.

The array indices do not have to be continuous. The array can be sparse. Thus, an array could have four elements with the indicies 1, 6, 8, and 10.

MArrayDataHandle methods cannot be assumed to be threadsafe. The jumpToElement() method sets an internal pointer so definitely cannot be called by multiple threads simultaneously.

Examples:

anisotropicShader.cpp, apiMeshShape.cpp, apiMeshShape.h, backfillShader.cpp, dynExprField.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, multiCurveNode.cpp, ownerEmitter.cpp, ownerEmitter.h, phongShader.cpp, shadowMatteShader.cpp, simpleEmitter.cpp, simpleEmitter.h, stringFormatNode.cpp, sweptEmitter.cpp, sweptEmitter.h, testNucleusNode.cpp, torusField.cpp, and weightListNode.cpp.

#include <MArrayDataHandle.h>

List of all members.

Public Member Functions

 MArrayDataHandle (const MDataHandle &in, MStatus *ReturnStatus=NULL)
 Copy constructor.
MDataHandle inputValue (MStatus *ReturnStatus=NULL)
 Gets a handle into this data block for the current array element.
MDataHandle outputValue (MStatus *ReturnStatus=NULL)
 Gets a handle into this data block for the current array element.
MArrayDataHandle inputArrayValue (MStatus *ReturnStatus=NULL)
 Gets a handle into this data block for the current array element.
MArrayDataHandle outputArrayValue (MStatus *ReturnStatus=NULL)
 Gets a handle into this data block for the current array element.
MStatus next ()
 Advance to the next element in the array.
unsigned int elementCount (MStatus *ReturnStatus=NULL)
 Returns the number of elements in the array.
unsigned int elementIndex (MStatus *ReturnStatus=NULL)
 Returns the index that we are currently at in the array.
MStatus jumpToElement (unsigned int index)
 Jump to a specific element in the array.
MStatus jumpToArrayElement (unsigned int position)
 Jump to a specific array element in the array.
MStatus setClean ()
 Marks the data that is represented by this handle as being clean.
MStatus setAllClean ()
 Marks every element of the array attribute represented by the handle as clean.
MArrayDataBuilder builder (MStatus *ReturnStatus=NULL)
 Returns a builder for this handle's array so that it can be expanded.
MStatus set (MArrayDataBuilder &builder)
 Sets the data for this array from the data in the builder object.
 MArrayDataHandle (const MArrayDataHandle &other)
 Copy constructor.
MArrayDataHandleoperator= (const MArrayDataHandle &other)
 Assignment operator.

Static Public Member Functions

static const char * className ()
 Returns the name of this class.

Friends

class MDataBlock
class MArrayDataBuilder

Constructor & Destructor Documentation

MArrayDataHandle ( const MDataHandle in,
MStatus ReturnStatus = NULL 
)

Copy constructor.

Creates an new array data handle from the specified data handle.

This method can be used to access an array attribute that is a child of a compound array. Example: weightList[].weights[]

This method will only work for data handles to attributes that are arrays.

Parameters:
[in]inHandle to the child array attribute.
[out]ReturnStatusreturn status
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter source handle is null or is not an array
MArrayDataHandle ( const MArrayDataHandle other) [inline]

Copy constructor.

Parameters:
[in]otherthe source object to copy from.

Member Function Documentation

MDataHandle inputValue ( MStatus ReturnStatus = NULL)

Gets a handle into this data block for the current array element.

The data represented by the handle will be valid. If the data is from an dirty connection, then the connection will be evaluated.

It is important to note that you can not call inputValue on an element that is greater than the elementCount in this arrayDataHandle. That is, calls to inputValue must be protected by a call to elementCount to ensure the element exists. If this is not done, the call to inputValue will fail with an invalidParameter error.

The data handle that this arrayDataHandle represents must come from a valid data block, such as one returned from one of the MDataBlock methods like MDataBlock::inputValue(). If a data handle created and returned from MPlug::getValue() or MPlug::asMDataHandle() is passed to this arrayDataHandle, then the use of this method will be invalid.

Parameters:
[out]ReturnStatusreturn status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the requested element is out of range
  • kFailure an object error has occurred
Examples:
anisotropicShader.cpp, backfillShader.cpp, dynExprField.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, ownerEmitter.h, phongShader.cpp, shadowMatteShader.cpp, simpleEmitter.h, stringFormatNode.cpp, sweptEmitter.h, testNucleusNode.cpp, torusField.cpp, and weightListNode.cpp.
MDataHandle outputValue ( MStatus ReturnStatus = NULL)

Gets a handle into this data block for the current array element.

The data is not guaranteed to be valid. Therefore, this handle should only be used for writing over the data.

This method can also be used to retrieve handles to individual elements of non-datablock array handles, such as those returned by MPlug::getValue() and MPlug::asMDataHandle().

Parameters:
[out]ReturnStatusreturn status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp.
MArrayDataHandle inputArrayValue ( MStatus ReturnStatus = NULL)

Gets a handle into this data block for the current array element.

This method should be used when the array elements are also arrays. The data represented by the handle will be valid. If the data is from an dirty connection, then the connection will be evailuated.

It is important to note that you can not call inputArrayValue on an element that is greater than the elementCount in this arrayDataHandle. That is, calls to inputValue must be protected by a call to elementCount to ensure the element exists. If this is not done, the the call to inputArrayValue will fail with an invalidParameter error.

The data handle that this arrayDataHandle represents must come from a valid data block, such as one returned from one of the MDataBlock methods like MDataBlock::inputValue(). If a data handle created and returned from MPlug::getValue() or MPlug::asMDataHandle() is passed to this arrayDataHandle, then the use of this method will be invalid.

Parameters:
[out]ReturnStatusreturn status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the current item is not an array or the requested element is out of range.
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp.
MArrayDataHandle outputArrayValue ( MStatus ReturnStatus = NULL)

Gets a handle into this data block for the current array element.

This method should be used when the array elements are also arrays. The data is not guaranteed to be valid. Therefore, this handle should only be used for writing over the data.

The data handle that this arrayDataHandle represents must come from a valid data block, such as one returned from one of the MDataBlock methods like MDataBlock::inputValue(). If a data handle created and returned from MPlug::getValue() or MPlug::asMDataHandle() is passed to this arrayDataHandle, then the use of this method will be invalid.

Parameters:
[out]ReturnStatusreturn status
Returns:
Data handle for the current element's data
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the current item is not an array
  • kFailure an object error has occurred
MStatus next ( )

Advance to the next element in the array.

These may be sparse arrays so the next consecutive element may not necessarily have a consecutive index.

Returns:
Examples:
anisotropicShader.cpp, apiMeshShape.cpp, backfillShader.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, phongShader.cpp, and shadowMatteShader.cpp.
unsigned int elementCount ( MStatus ReturnStatus = NULL)

Returns the number of elements in the array.

Parameters:
[out]ReturnStatusreturn status
Returns:
The number of elements
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred
Examples:
anisotropicShader.cpp, backfillShader.cpp, fullLoftNode.cpp, geometrySurfaceConstraint.cpp, lambertShader.cpp, phongShader.cpp, shadowMatteShader.cpp, and weightListNode.cpp.
unsigned int elementIndex ( MStatus ReturnStatus = NULL)

Returns the index that we are currently at in the array.

It is possible for the index to be invalid, in which case the return status will report an error. These may be sparse arrays so the element index returned will be a logical index.

Parameters:
[out]ReturnStatusreturn status
Returns:
The current element's logical index
Status Codes:
  • kSuccess operation successful
  • kFailure current element has an invalid index, or this function set has an invalid object
Examples:
apiMeshShape.cpp.
MStatus jumpToElement ( unsigned int  index)

Jump to a specific element in the array.

The array is sparse, so the indices may not be consecutive.

NOTE: The index is the logical element index, which may be sparse. Jumping to an element is done through a binary search.

Parameters:
[in]indexthe logical index to jump to
Returns:
Status code
Status Codes:
Examples:
dynExprField.cpp, fullLoftNode.cpp, ownerEmitter.h, simpleEmitter.h, stringFormatNode.cpp, sweptEmitter.h, testNucleusNode.cpp, torusField.cpp, and weightListNode.cpp.
MStatus jumpToArrayElement ( unsigned int  position)

Jump to a specific array element in the array.

This method can be used to iterate over the entire array.

NOTE: Jumping to an array element does not require a search, since the array indices are non-sparse. The MArrayDataHandle::elementIndex() method can be used to determine the logical index related to the current array index.

Parameters:
[in]positionthe array position to jump to
Returns:
Status code
Status Codes:
Examples:
weightListNode.cpp.
MStatus setClean ( )

Marks the data that is represented by this handle as being clean.

This should be done after recalculating the data from the inputs.

The data handle that this arrayDataHandle represents must come from a valid data block, such as one returned from one of the MDataBlock methods like MDataBlock::inputValue(). If a data handle created and returned from MPlug::getValue() or MPlug::asMDataHandle() is passed to this arrayDataHandle, then the use of this method will be invalid.

Returns:
Return status
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred
MStatus setAllClean ( )

Marks every element of the array attribute represented by the handle as clean.

This method should be used if a compute function is asked to compute a single element of a multi, but instead calculates all the elements. Calling setAllClean in this situation will prevent further calls to the node's compute method for the other elements of the multi.

The data handle that this arrayDataHandle represents must come from a valid data block, such as one returned from one of the MDataBlock methods like MDataBlock::inputValue(). If a data handle created and returned from MPlug::getValue() or MPlug::asMDataHandle() is passed to this arrayDataHandle, then the use of this method will be invalid.

Returns:
Return status
Status Codes:
  • kSuccess operation successful
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp, and multiCurveNode.cpp.
MArrayDataBuilder builder ( MStatus ReturnStatus = NULL)

Returns a builder for this handle's array so that it can be expanded.

This method will fail if the current array does not support array data builders. This can be changed in a node's initialize routine using the setUsesArrayDataBuilder method in MFnAttribute.

The data handle that this arrayDataHandle represents must come from a valid data block, such as one returned from one of the MDataBlock methods like MDataBlock::inputValue(). If a data handle created and returned from MPlug::getValue() or MPlug::asMDataHandle() is passed to this arrayDataHandle, then the use of this method will be invalid.

Parameters:
[out]ReturnStatusreturn status
Returns:
The builder object
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter This item does not support array data builders
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp, ownerEmitter.cpp, simpleEmitter.cpp, sweptEmitter.cpp, and torusField.cpp.
MStatus set ( MArrayDataBuilder builder)

Sets the data for this array from the data in the builder object.

The data handle that this arrayDataHandle represents must come from a valid data block, such as one returned from one of the MDataBlock methods like MDataBlock::inputValue(). If a data handle created and returned from MPlug::getValue() or MPlug::asMDataHandle() is passed to this arrayDataHandle, then the use of this method will be invalid.

Parameters:
[in]builderthe builder object
Returns:
Return status
Status Codes:
  • kSuccess operation successful
  • kInvalidParameter the builder passed is invalid
  • kFailure an object error has occurred
Examples:
apiMeshShape.cpp, and multiCurveNode.cpp.
MArrayDataHandle & operator= ( const MArrayDataHandle other) [inline]

Assignment operator.

Parameters:
[in]otherthe source object to copy from.
const char * className ( ) [static]

Returns the name of this class.

Returns:
Name of this class.

MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle
MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle MArrayDataHandle