Class TGopBitBltAlphaChannel

class TGopBitBltAlphaChannel : public TGraphicsOperation;

Description

An accelerated graphics operation that copies a rectangular region of one bitmap into another, using alpha blending.

The alpha value is part of each pixel in the source bitmap. For instance, a 32 bits per pixel bitmap may have 8 bits for each of the alpha, red, green and blue values.

Supported bitmap formats with an alpha-channel are given in by TGraphicsAcceleratorCaps::iAlphaChannel.

The data members are all initialised on construction. Objects of this class can be passed to a graphics accelerator's Operation() function either individually, or in a buffer.

Derivation

• TGraphicsOperation - Abstract base class for all graphics operations.

• TGopBitBltAlphaChannel - An accelerated graphics operation that copies a rectangular region of one bitmap...

Members

Defined in TGopBitBltAlphaChannel:

• TGopBitBltAlphaChannel(const TPoint &,TAcceleratedBitmapSpec,TRect &)Constructor with a position, a bitmap handle and a rectangle.
• iDestinationThe destination for the top left hand corner of the portion of the bitmap.
• iSourceBitmapA handle to the source bitmap, and other information needed to access it.
• iSourceRectA rectangle defining all or a part of the bitmap to be copied.

Inherited from TGraphicsOperation:

• Append(TInt,TAny *)
• EAlphaBlendOneBitmap
• EAlphaBlendTwoBitmaps
• EBitBlt
• EBitBltAlphaBitmap
• EBitBltAlphaChannel
• EBitBltMasked
• EBitBltTransparent
• EChunkTest
• EFadeRect
• EFilledPolygon
• EFilledPolygonWithPattern
• EFilledRect
• EFilledRectUsingDrawMode
• EFilledRectWithPattern
• EInvertRect
• EScaledBitBlt
• EScaledBitBltAlphaBitmap
• EScaledBitBltAlphaChannel
• EScaledBitBltMasked
• EScaledBitBltTransparent
• EVirtualAddressTest
• Function()const
• Next()const
• Size()const
• TGopFunction
• TGraphicsOperation(TGopFunction,TInt)
• iFunction
• iSize

See also:

• TGraphicsAcceleratorCaps::iAlphaChannelSpecifies the capabilities relating to operations that use an alpha channel. Use...

inline TGopBitBltAlphaChannel(const TPoint &aDestination, TAcceleratedBitmapSpec aSourceBitmap, TRect &aSourceRect);

Description

Constructor with a position, a bitmap handle and a rectangle.

Parameters

const TPoint &aDestination The destination for the top left hand corner of the portion of the source bitmap. TAcceleratedBitmapSpec aSourceBitmap A handle to the source bitmap, and other information needed to draw it. TRect &aSourceRect A rectangle within the source bitmap. Its coordinates are relative to the top left of the source bitmap. Defines the part of the source bitmap to be copied.

TPoint iDestination;

Description

The destination for the top left hand corner of the portion of the bitmap.

TAcceleratedBitmapSpec iSourceBitmap;

Description

A handle to the source bitmap, and other information needed to access it.

TRect iSourceRect;

Description

A rectangle defining all or a part of the bitmap to be copied.