Class: TGraySrcOverTransferMode

Declaration: GrayTransferModes.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

TTransferMode

Inherited By:

None.

Purpose:

TGraySrcOverTransferMode is a concrete class, derived from TTransferMode, for applying the source over compositing operation using a grayscale. (The source and destination colors need not be grayscale, but the resulting color is always a gray.) Source over places the source image on top of the destination. If the source color is completely opaque (that is, if its alpha value is 1.0),.this transfer mode copies the grayscale equivalent of the source color to the destination. If the source color is completely transparent (alpha =0.0), the destination is unchanged. If the source's alpha value is between 0 and 1, the resultant gray value and transparency are computed by taking into account both the source and the destination.

Instantiation:

Allocate on the heap or the stack.

Deriving Classes:

None.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Member Function: TGraySrcOverTransferMode::TGraySrcOverTransferMode

TGraySrcOverTransferMode ()
TGraySrcOverTransferMode (const TGraySrcOverTransferMode &)

Interface Category:

API.

Purpose:

Default constructor.
Copy constructor.

Calling Context:

Called by the stream-in operators and as the default constructor.
Called to copy an object.

Parameters:

Takes no parameters.
const TGraySrcOverTransferMode & -The object to be copied.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TGraySrcOverTransferMode::~TGraySrcOverTransferMode

virtual ~ TGraySrcOverTransferMode ()

Interface Category:

API.

Purpose:

Destructor.

Calling Context:

Called to destroy an object.

Parameters:

Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TGraySrcOverTransferMode::GetResultingColor

virtual void GetResultingColor (const TColor & sourceColor, const TColor & destColor, TColor & resultingColor) const

Interface Category:

API.

Purpose:

If the source color is completely opaque (that is, if its alpha value is 1.0), copies the grayscale equivalent of the source color to the destination. If the source color is completely transparent (alpha =0.0), the destination is unchanged. The source color has an alpha component between 0.0 and 1.0, the resulting color is a composite gray color of the source and destination, returned in a TColor object.

Calling Context:

Call this function directly.

Parameters:

const TColor & sourceColor -The source color (its grayscale is used).
const TColor & destColor -The destination color to be modified.
TColor & resultingColor -The resulting color (after modification) returned in a TColor.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TGraySrcOverTransferMode::GetSrcOverResult

void GetSrcOverResult (const TGrayColor & sourceColor, const TGrayColor & destColor, TGrayColor & resultingColor) const

Interface Category:

API.

Purpose:

Calling Context:

Call this function directly.

Parameters:

const TColor & sourceColor -The source color (its grayscale is used).
const TColor & destColor -The destination color to be modified.
TGrayColor & resultingColor -The resulting color (after modification) returned in a TGrayColor.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TGraySrcOverTransferMode::operator=

TGraySrcOverTransferMode & operator =(const TGraySrcOverTransferMode & source)

Interface Category:

API.

Purpose:

Assignment operator.

Calling Context:

Call this function by using the operator in an assignment statement.

Parameters:

const TGraySrcOverTransferMode & source -The object to be copied.

Return Value:

A non-const reference to the left-hand side object.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TGraySrcOverTransferMode::operator>>=

virtual TStream & operator >>=(TStream & towhere) const

Interface Category:

API.

Purpose:

Stream-out operator.

Calling Context:

Called to stream out data.

Parameters:

TStream & towhere -The stream that the object streams itself out to.

Return Value:

Returns a reference to the stream the object streams itself out to.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TGraySrcOverTransferMode::operator<<=

virtual TStream & operator <<= (TStream & fromwhere)

Interface Category:

API.

Purpose:

Stream-in operator.

Calling Context:

Called to stream in data.

Parameters:

TStream & fromwhere -The stream that the object streams itself in from.

Return Value:

Returns a reference to the stream the object streams itself in from.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TGraySrcOverTransferMode::TemporaryTypeID

virtual ETransferModeClassID TemporaryTypeID () const

Interface Category:

API.

Purpose:

Returns the type of transfer mode this class represents.

Calling Context:

Call this function directly.

Parameters:

Takes no parameters.

Return Value:

Returns an ETransferModeClassID with value kGraySrcOverTransferMode.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

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