gr32_filters.pas

skin components for design of your applicastions

unit GR32_Filters;

(* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1
 *
 * 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.
 *
 * The Original Code is Graphics32
 *
 * The Initial Developer of the Original Code is
 * Alex A. Denisov
 *
 * Portions created by the Initial Developer are Copyright (C) 2000-2006
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * ***** END LICENSE BLOCK ***** *)

interface

{$I GR32.inc}

uses
  {$IFDEF CLX}
  Qt, Types, {$IFDEF LINUX}Libc, {$ENDIF}
  {$ELSE}
  Windows,
  {$ENDIF}
  Classes, SysUtils, GR32, GR32_Blend;

{ Basic processing }
type
  TLUT8 = array [Byte] of Byte;

procedure AlphaToGrayscale(Dst, Src: TBitmap32);
procedure IntensityToAlpha(Dst, Src: TBitmap32);
procedure Invert(Dst, Src: TBitmap32);
procedure InvertRGB(Dst, Src: TBitmap32);
procedure ColorToGrayscale(Dst, Src: TBitmap32; PreserveAlpha: Boolean = False);
procedure ApplyLUT(Dst, Src: TBitmap32; const LUT: TLUT8; PreserveAlpha: Boolean = False);
procedure CromaKey(ABitmap: TBitmap32; TrColor: TColor32);

procedure CheckParams(Dst, Src: TBitmap32);

implementation

const
  SEmptySource = 'The source is nil';
  SEmptyDestination = 'Destination is nil';
  SNoInPlace = 'In-place operation is unsupported';

procedure CheckParams(Dst, Src: TBitmap32);
begin
  if Src = nil then raise Exception.Create(SEmptySource);
  if Dst = nil then raise Exception.Create(SEmptyDestination);
  Dst.SetSize(Src.Width, Src.Height);
end;

{rocedure CheckParamsNoInPlace(Dst, Src: TBitmap32);
begin
  if (Src = nil) then
    raise Exception.Create(SEmptySource);
  if Dst = nil then
    raise Exception.Create(SEmptyDestination);
  if Dst = Src then
    raise Exception.Create(SNoInPlace);
  Dst.SetSize(Src);
end;       }

procedure AlphaToGrayscale(Dst, Src: TBitmap32);
var
  I: Integer;
  D, S: PColor32;
begin
  CheckParams(Dst, Src);
  Dst.SetSize(Src.Width, Src.Height);
  D := @Dst.Bits[0];
  S := @Src.Bits[0];
  for I := 0 to Src.Width * Src.Height - 1 do
  begin
    D^ := Gray32(AlphaComponent(S^));
    Inc(S); Inc(D);
  end;
  Dst.Changed;
end;

procedure IntensityToAlpha(Dst, Src: TBitmap32);
var
  I: Integer;
  D, S: PColor32;
begin
  CheckParams(Dst, Src);
  Dst.SetSize(Src.Width, Src.Height);
  D := @Dst.Bits[0];
  S := @Src.Bits[0];
  for I := 0 to Src.Width * Src.Height - 1 do
  begin
    D^ := SetAlpha(D^, Intensity(S^));
    Inc(S); Inc(D);
  end;
  Dst.Changed;
end;

procedure Invert(Dst, Src: TBitmap32);
var
  I: Integer;
  D, S: PColor32;
begin
  CheckParams(Dst, Src);
  Dst.SetSize(Src.Width, Src.Height);
  D := @Dst.Bits[0];
  S := @Src.Bits[0];
  for I := 0 to Src.Width * Src.Height - 1 do
  begin
    D^ := S^ xor $FFFFFFFF;
    Inc(S); Inc(D);
  end;
  Dst.Changed;
end;

procedure InvertRGB(Dst, Src: TBitmap32);
var
  I: Integer;
  D, S: PColor32;
begin
  CheckParams(Dst, Src);
  Dst.SetSize(Src.Width, Src.Height);
  D := @Dst.Bits[0];
  S := @Src.Bits[0];
  for I := 0 to Src.Width * Src.Height - 1 do
  begin
    D^ := S^ xor $00FFFFFF;
    Inc(S); Inc(D);
  end;
  Dst.Changed;
end;

procedure ColorToGrayscale(Dst, Src: TBitmap32; PreserveAlpha: Boolean = False);
var
  I: Integer;
  D, S: PColor32;
begin
  CheckParams(Dst, Src);
  Dst.SetSize(Src.Width, Src.Height);
  D := @Dst.Bits[0];
  S := @Src.Bits[0];
  
  if PreserveAlpha then
    for I := 0 to Src.Width * Src.Height - 1 do
    begin
      D^ := Gray32(Intensity(S^), AlphaComponent(S^));
      Inc(S); Inc(D);
    end
  else
    for I := 0 to Src.Width * Src.Height - 1 do
    begin
      D^ := Gray32(Intensity(S^));
      Inc(S); Inc(D);
    end;
    
  Dst.Changed;
end;

procedure ApplyLUT(Dst, Src: TBitmap32; const LUT: TLUT8; PreserveAlpha: Boolean = False);
var
  I: Integer;
  D, S: PColor32;
  a, r, g, b: TColor32;
  C: TColor32;
begin
  CheckParams(Dst, Src);
  Dst.SetSize(Src.Width, Src.Height);
  D := @Dst.Bits[0];
  S := @Src.Bits[0];

  if PreserveAlpha then
    for I := 0 to Src.Width * Src.Height - 1 do
    begin
      C := S^;
      a := C and $FF000000;
      r := C and $00FF0000;
      g := C and $0000FF00;
      a := a shr 24;
      r := r shr 16;
      b := C and $000000FF;
      g := g shr 8;
      r := LUT[r];
      g := LUT[g];
      b := LUT[b];
      D^ := a shl 24 or r shl 16 or g shl 8 or b;
      Inc(S);
      Inc(D);
    end
  else
    for I := 0 to Src.Width * Src.Height - 1 do
    begin
      C := S^;
      r := C and $00FF0000;
      g := C and $0000FF00;
      r := r shr 16;
      b := C and $000000FF;
      g := g shr 8;
      r := LUT[r];
      g := LUT[g];
      b := LUT[b];
      D^ := $FF000000 or r shl 16 or g shl 8 or b;
      Inc(S);
      Inc(D);
    end;
    
  Dst.Changed;
end;

procedure CromaKey(ABitmap: TBitmap32; TrColor: TColor32);
var
  P: PColor32;
  C: TColor32;
  I: Integer;
begin
  TrColor := TrColor and $00FFFFFF;
  with ABitmap do
  begin
    P := PixelPtr[0, 0];
    for I := 0 to Width * Height - 1 do
    begin
      C := P^ and $00FFFFFF;
      if C = TrColor then P^ := C;
      Inc(P)
    end;
  end;
end;

end.