unit MainUnit;

(* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1 or LGPL 2.1 with linking exception
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * Alternatively, the contents of this file may be used under the terms of the
 * Free Pascal modified version of the GNU Lesser General Public License
 * Version 2.1 (the "FPC modified LGPL License"), in which case the provisions
 * of this license are applicable instead of those above.
 * Please see the file LICENSE.txt for additional information concerning this
 * license.
 *
 * The Original Code is PixelCombine Example
 *
 * The Initial Developer of the Original Code is
 * Alex A. Denisov
 *
 * Portions created by the Initial Developer are Copyright (C) 2000-2005
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * ***** END LICENSE BLOCK ***** *)

interface

{$I GR32.inc}

uses
  {$IFNDEF FPC} Windows, {$ELSE} LCLIntf, LResources, {$ENDIF}
  SysUtils, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls,
  GR32, GR32_Image, GR32_Layers, GR32_Blend, GR32_RangeBars;

type
  TFormPixelCombine = class(TForm)
    ImgView: TImgView32;
    RadioGroup: TRadioGroup;
    procedure FormCreate(Sender: TObject);
    procedure RadioGroupClick(Sender: TObject);
  protected
    procedure PC_Add(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Sub(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Modulate(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Min(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Max(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Screen(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_ColorBurn(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_ColorDodge(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Difference(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Exclusion(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Pattern(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_Blend(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_BlendAdd(F: TColor32; var B: TColor32; M: TColor32);
    procedure PC_BlendModulate(F: TColor32; var B: TColor32; M: TColor32);
  public
    PatCount: Integer;
    L: TBitmapLayer;
  end;

var
  FormPixelCombine: TFormPixelCombine;

implementation

{$IFDEF FPC}
{$R *.lfm}
{$ELSE}
{$R *.dfm}
{$ENDIF}

uses
{$IFDEF Darwin}
  MacOSAll,
{$ENDIF}
{$IFNDEF FPC}
  JPEG;
{$ELSE}
  LazJPG;
{$ENDIF}

// TFormPixelCombine

procedure TFormPixelCombine.FormCreate(Sender: TObject);
var
  I, J: Integer;
  SinJ: Double;
  ResStream: TResourceStream;
  JPEG: TJPEGImage;
begin
  // Load background picture 'Runner'
  JPEG := TJPEGImage.Create;
  try
    ResStream := TResourceStream.Create(HInstance, 'Runner', RT_RCDATA);
    try
      JPEG.LoadFromStream(ResStream);
    finally
      ResStream.Free;
    end;
    ImgView.Bitmap.Assign(JPEG);
  finally
    JPEG.Free;
  end;

  // Create foreground bitmap layer
  L := TBitmapLayer.Create(ImgView.Layers);
  L.Bitmap.SetSize(200, 200);
  L.Bitmap.DrawMode := dmCustom;
  L.Location := FloatRect(20, 20, 220, 220);

  // Generate Bitmap
  for J := 0 to 199 do
  begin
    SinJ := Sin(J * 0.1);
    for I := 0 to 199 do
      L.Bitmap[I, J] := SetAlpha(
        Gray32(Round(((Sin(I * 0.1) + SinJ) * 0.25 + 0.5) * 255)),
        255 * J div 199  // alpha value
      );
  end;
  L.Bitmap.OnPixelCombine := nil; // none by default
end;

procedure TFormPixelCombine.PC_Add(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorAdd(F, B);
end;

procedure TFormPixelCombine.PC_Max(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorMax(F, B);
end;

procedure TFormPixelCombine.PC_Min(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorMin(F, B);
end;

procedure TFormPixelCombine.PC_Modulate(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorModulate(F, B);
end;

procedure TFormPixelCombine.PC_Pattern(F: TColor32; var B: TColor32; M: TColor32);
begin
  PatCount := 1 - PatCount;
  if PatCount = 0 then B := F;
end;

procedure TFormPixelCombine.PC_Sub(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorSub(F, B);
end;

procedure TFormPixelCombine.PC_Screen(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorScreen(F, B);
end;

procedure TFormPixelCombine.PC_ColorDodge(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorDodge(F, B);
end;

procedure TFormPixelCombine.PC_ColorBurn(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorBurn(F, B);
end;

procedure TFormPixelCombine.PC_Difference(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorDifference(F, B);
end;

procedure TFormPixelCombine.PC_Exclusion(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := ColorExclusion(F, B);
end;

procedure TFormPixelCombine.PC_Blend(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := BlendReg(F, B);
end;

procedure TFormPixelCombine.PC_BlendAdd(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := BlendColorAdd(F, B);
end;

procedure TFormPixelCombine.PC_BlendModulate(F: TColor32; var B: TColor32; M: TColor32);
begin
  B := BlendColorModulate(F, B);
end;

procedure TFormPixelCombine.RadioGroupClick(Sender: TObject);
begin
  case RadioGroup.ItemIndex of
    0:
      L.Bitmap.OnPixelCombine := nil;
    1:
      L.Bitmap.OnPixelCombine := PC_Add;
    2:
      L.Bitmap.OnPixelCombine := PC_Sub;
    3:
      L.Bitmap.OnPixelCombine := PC_Modulate;
    4:
      L.Bitmap.OnPixelCombine := PC_Min;
    5:
      L.Bitmap.OnPixelCombine := PC_Max;
    6:
      L.Bitmap.OnPixelCombine := PC_Screen;
    7:
      L.Bitmap.OnPixelCombine := PC_ColorDodge;
    8:
      L.Bitmap.OnPixelCombine := PC_ColorBurn;
    9:
      L.Bitmap.OnPixelCombine := PC_Difference;
    10:
      L.Bitmap.OnPixelCombine := PC_Exclusion;
    11:
      L.Bitmap.OnPixelCombine := PC_Pattern;
    12:
      L.Bitmap.OnPixelCombine := PC_Blend;
    13:
      L.Bitmap.OnPixelCombine := PC_BlendAdd;
    14:
      L.Bitmap.OnPixelCombine := PC_BlendModulate;
  end;
  L.Bitmap.Changed;
end;

end.