From: "Steve Schafer (TeamB)" <pandeng@telepath.com>
Subject: Re: How to apply the Windows Shutdown Screen Effect to a bitmap ?
Date: 24 Mar 2000 00:00:00 GMT
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On Fri, 24 Mar 2000 12:58:16 -0800, "Monte Etherton"
<mether@attglobal.net> wrote:

>I am a novice in graphics, but I would like to apply this "screening" effect
>to a bitmap.  I have tried PatBlt, DrawState, and BitBlt, but I don't know
>what combination of params I need.
>
>I can affect the bitmap, but not the way I want.  If any one has some sample
>code, I would appreciate it.

1) Create an 8x8 bitmap, where the pixels alternate black and white
(as in a checkerboard).

2) Load that bitmap into the Brush.Bitmap property of whatever Canvas
it is that you're trying to modify.

3) Set the canvas's CopyMode to $00A000C9. (This ANDs the destination
with the pattern.)

4) Use CopyRect to draw the canvas onto itself.

Here's a simple example:

 var
   Bmp: TBitmap;
 begin
 Bmp := TBitmap.Create;
 Bmp.LoadFromFile('brush.bmp');
 with Image1.Picture.Bitmap do begin
   Canvas.Brush.Bitmap := Bmp;
   Canvas.CopyMode := $00A000C9;
   Canvas.CopyRect(Rect(0, 0, Width, Height), Canvas, Rect(0, 0, 0,
     0)) end;
 Bmp.Free end;

-Steve