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 into another, using alpha blending

Members

Defined in TGopBitBltAlphaChannel:
TGopBitBltAlphaChannel(), iDestination, iSourceBitmap, iSourceRect

Inherited from TGraphicsOperation:
Append(), EAlphaBlendOneBitmap, EAlphaBlendTwoBitmaps, EBitBlt, EBitBltAlphaBitmap, EBitBltAlphaChannel, EBitBltMasked, EBitBltTransparent, EFadeRect, EFilledPolygon, EFilledPolygonWithPattern, EFilledRect, EFilledRectUsingDrawMode, EFilledRectWithPattern, EInvertRect, EScaledBitBlt, EScaledBitBltAlphaBitmap, EScaledBitBltAlphaChannel, EScaledBitBltMasked, EScaledBitBltTransparent, Function(), Next(), Size(), TGopFunction, iFunction, iSize

See also:

• TGraphicsAcceleratorCaps::iAlphaChannel

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.