unit fmask;
(* ***** BEGIN LICENSE BLOCK *****
 * Copyright (C) 2004 Durand Emmanuel
 * Copyright (C) 2004 Burgel Eric
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Contact :
 *   filters@edurand.com
 *   filters@burgel.com
 * Site :
 *   http://filters.sourceforge.net/
 *
 * ***** END LICENSE BLOCK ***** *)

{
 edurand (filters@edurand.com)
 eburgel (filters@burgel.com)
}

interface
uses
  image, windows;

type
  TMaskType = ( maskCustom, maskFilled, maskDisk, maskCross );

function createMask( const aWidth,aHeight:Integer; const aType : TMaskType ) : PBitmap32;


implementation
uses
  Math;

function createMask( const aWidth,aHeight:Integer; const aType : TMaskType ) : PBitmap32;
var
  mask : PBitmap32;
  r : TRect;
  center : TFPoint;
  radius : Single;
  w_3, h_3 : Integer;
  w_2d3, h_2d3 : Integer;
  row, col : Integer;
  t : TMaskType;
begin
  t := aType;
  if (t=maskDisk) and (aWidth=3) and (aHeight=3) then t:=maskCross; // a special case

  mask := image.createImage( aWidth, aHeight );
  center.x := aWidth / 2 -0.5;
  center.y := aHeight / 2 -0.5;
  radius := Min(aWidth,aHeight) / 2;

  case t of
    maskCustom :
    begin
    end;
    maskFilled :
    begin
      r.Left := 0;
      r.Top := 0;
      r.Right := aWidth-1;
      r.Bottom := aHeight-1;
      image.drawRectFilled( mask, r, clWhite32);
    end;
    maskDisk :
    begin
      image.drawDisk( mask, center.x, center.y, radius, clWhite32 );
    end;
    maskCross :
    begin
      w_3 := aWidth div 3;
      h_3 := aHeight div 3;
      w_2d3 := aWidth-1 - w_3;
      h_2d3 := aHeight-1 - h_3;
      for row:=0 to aHeight-1 do begin
        for col:=0 to aWidth-1 do begin
          if not ((row=0) and (col=aWidth-1)) and
             not ((row=aHeight-1) and (col=0)) and
             not ((row=aHeight-1) and (col=aWidth-1)) then begin
            if ((row>=h_3) and (row<=h_2d3)) or
               ((col>=w_3) and (col<=w_2d3)) then begin
              image.setPixel( mask, col, row, clWhite32 );
            end;
          end;
        end;
      end;
    end;
  end;
  Result := mask;
end;


end.