TIEBitmap.RenderToTBitmapEx

Declaration

procedure RenderToTBitmapEx(Dest: TBitmap; xDst, yDst, dxDst, dyDst: integer; xSrc, ySrc, dxSrc, dySrc: integer; Transparency: integer = 255; Filter: TResampleFilter = rfNone; RenderOperation: TIERenderOperation = ielNormal; Opacity: double = 1.0);

Description

Draws the rectangle from xSrc, ySrc and size dxSrc, dySrc inside the TBitmap destination rectangle at xDst, yDst and size: dxDst, dyDst of Dest.
The PixelFormat of Dest must be pf24bit. The source image can be any PixelFormat.
Transparency specifies the transparency value (0=Fully Transparent to 255=Fully Opaque).
Filter specifies the resampling filter.
RenderOperation specifies the rendering operation.
Opacity specifies the opacity (0=Fully Transparent to 1.0=Fully Opaque).

Note: Rendering will support the AlphaChannel if available, i.e. painting will not occur for areas of Alpha < 255

Opacity vs Transparency

Both the Opacity and Transparency parameters provide the same functionality. Transparency is the traditional ImageEn value, whereas Opacity provides easier PSD compatibility.
While they can be used in combination, generally only one will be used, i.e. leave Opacity=1 and make use of transparency, or alternatively, leave Transparency=255 and make use of Opacity. For example, for 50% opacity: Transparency = 255 and Opacity = 0.5, or Transparency = 128 and Opacity = 1.0

Example

// Render an image in a TImageEnView to a TBitmap at half-size
bmp.Width  := ImageEnView1.IEBitmap.Width div 2;
bmp.Height :=  ImageEnView1.IEBitmap.Height div 2;
ImageEnView1.IEBitmap.RenderToTIEBitmapEx( bmp,
                                           0, 0, bmp.Width, bmp.Height,
                                           0, 0, ImageEnView1.IEBitmap.Width, ImageEnView1.IEBitmap.Height,
                                           255, rfLanczos3 );

TIEBitmap Assignment and Drawing Methods

TBitmap Methods

TCanvas Methods

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