ClearType in CanvasBGRA

[lainz]

ClearType is supported in CanvasBGRA?

See the attached shot, the top text is TBGRABitmap.CanvasBGRA.TextOut (with Font.Height := 0), the other is TBGRABitmap.Canvas.TextOut.

There is a way to 'enable' ClearType in CanvasBGRA TextOut / TextRect?

[circular]

I don't think there is an easy way to implement this, except by redirecting TextOut and TextRect calls to Canvas. But this would slow down the process. It may be needed to rebuild the TBitmap object for each call to TextOut. An other way would be to implement ClearType algorithm in BGRABitmap library.

[circular]

Hello Lainz, i've added cleartype support on subversion. Can you try it ?

[lainz]

Code: [Select]

  Bitmap.Fill(BGRAPixelTransparent);
  Bitmap.CanvasBGRA.Font.Quality := fqFineClearTypeRGB;
  Bitmap.CanvasBGRA.Font.Height := 30;
  Bitmap.CanvasBGRA.TextOut(100, 100, Caption);
  Bitmap.Draw(Canvas, 0, 0, False); 
ClearType is applied but I get some 'gray' in the borders.

[circular]

This has something to do with transparency. In fact drawing with ClearType does not make sense on a transparent canvas. But this should be handled and draw normal antialiasing instead in this case.

The rectangles you see are font overhang, i.e, where text may go out of its box, for example with italic style.

I've made some filters in LazPaint to simulate ClearType. It's on subversion. So you can take an image or a screenshot that does not have ClearType and apply it, or the contrary, take a screenshot and remove ClearType effect afterwards.

[lainz]

You can try the latest BGRAControls git. Open testbgracontrols, i'm trying to use the ClearType in the 'Windows 7 ToolBar example' the main problem is the normal state is transparent.

There is a way to avoid the grayed background, and using ClearType?

The drawing code is in the procedure 'DrawTextCanvas' in 'BGRAButton' unit.

[circular]

I think I found a way to compute cleartype on alpha pixels. It's on subversion.

Now ClearType just behaves like normal drawing when there are no pixels under.

[lainz]

Nice 

[circular]

I've improved font rendering in version 5.1. Here is what you get now :