Slow CopyRect
lazarus / 39-Graphics

----------------------------------------------------------------------
BubikolRamios · 2013-02-17 17:55

Code: [Select]procedure TForm1.Image1MouseMove(Sender: TObject; Shift:
TShiftState; X,
  Y: Integer);
...
begin
    ...
    //These 2 lines works both the same, they copy part of image
(60x60 px) from source TBGRABitmap to destinaton TImage.canvas (60x60
px)

    ImageMagnifyGlass.Canvas.CopyRect(DestRect,cachedImageFromClipboar
d.Canvas,SrcRect);


    BitBlt(ImageMagnifyGlass.Canvas.Handle,0,0,60,60,cachedImageFromCl
ipboard.Canvas.Handle,SrcRect.Left,SrcRect.Top,SRCCOPY) ;
  
end; 

So, I move mouse acros sorce image and nothing happens, when I stop
moving , it draws copy of rect in about 0,5 sec. to destination.
I want it to work smooth(on each mouse move), is there a way todo that
? (CopyRect & BitBlt are both same slow)

----------------------------------------------------------------------
BubikolRamios · 2013-02-17 18:37

This works like a charm.

Code: [Select]magnified := cachedImageFromClipboard.GetPart(SrcRect)
as TBGRABitmap;
ImageMagnifyGlass.Picture.Bitmap.Assign(magnified);