ImageEn, unit iexBitmaps




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);


Draws the rectangle xSrc, ySrc, dxSrc, dySrc inside the destination rectangle xDst, yDst, dxDst, dyDst of Dest TBitmap object.
DestPixelFormat must be pf24bit.
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).

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


// 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 );