unit filterArithmeticConstantAdd;
(* ***** 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
 *
 * ***** END LICENSE BLOCK ***** *)

{
 edurand (filters@edurand.com)
}

interface
uses
  filter, fparameters, image;

type
  TFilterArithmeticConstantAdd = class(TFilter)
  public
    constructor Create; override;
    procedure Run(); override;
  private
    parameterImageIn, parameterImageOut : TParameterImage;
    parameterConstant : TParameterInteger;
    parameterOverflowingMode : TParameterString;
    procedure saturation();
    procedure wrap_around_zero();
  end;

implementation

constructor TFilterArithmeticConstantAdd.Create;
begin
  inherited;
  parameterImageIn:=addParameterImage('inImage','explication...');
  parameterImageOut:=addParameterImage('outImage','explication...');
  parameterConstant:=addParameterInteger('constant','explication...',-255,255,0);
  parameterOverflowingMode:=addParameterString('overflowingMode','SATURATION or WRAP_AROUND_ZERO','SATURATION');
end;

procedure TFilterArithmeticConstantAdd.Run();
begin
  if (parameterImageIn.Image<>nil) and (parameterImageOut.Image<>nil) then begin
    if parameterOverflowingMode.Value = 'WRAP_AROUND_ZERO' then begin
      wrap_around_zero()
    end else begin
      saturation();
    end;
  end;
end;

procedure TFilterArithmeticConstantAdd.saturation();
var
  pSrc, PDest : PColor32Array;
  w,h :Integer;
  x, max : Cardinal ;
  constant : Integer;
  r,g,b : Integer;
  color : TColor32;
begin
  constant := parameterConstant.Value ;

  pSrc:=parameterImageIn.Image.Bits;
  pDest:=parameterImageOut.Image.Bits;
  h:=parameterImageIn.Image.Height ;
  w:=parameterImageIn.Image.Width  ;

  max := h*w-1 ;

  for x:= 0 to max do Begin
    color:=pSrc^[0];

    r:=RedComponent(color);
    inc(r,constant);
    if r>255 then r:=255
    else if r<0 then r:=0;

    g:=GreenComponent(color);
    inc(g,constant);
    if g>255 then g:=255
    else if g<0 then g:=0;

    b:=BlueComponent(color);
    inc(b,constant);
    if b>255 then b:=255
    else if b<0 then b:=0;

    pDest[0]:=Color32(r,g,b);

    inc(pSrc) ;
    inc(pDest) ;
  end ;

end;

procedure TFilterArithmeticConstantAdd.wrap_around_zero();
var
  pSrc, PDest : PColor32Array;
  w,h :Integer;
  x, max : Cardinal ;
  constant : Integer;
  r,g,b : Byte;
  color : TColor32;
begin
  constant := parameterConstant.Value ;

  pSrc:=parameterImageIn.Image.Bits;
  pDest:=parameterImageOut.Image.Bits;
  h:=parameterImageIn.Image.Height ;
  w:=parameterImageIn.Image.Width  ;

  max := h*w-1 ;

  for x:= 0 to max do Begin
    color:=pSrc^[0];

    r:=RedComponent(color);
    inc(r,constant);

    g:=GreenComponent(color);
    inc(g,constant);

    b:=BlueComponent(color);
    inc(b,constant);

    pDest[0]:=Color32(r,g,b);

    inc(pSrc) ;
    inc(pDest) ;
  end ;

end;

end.