unit EOTButton;

interface

uses
  ButtonBase,
  WinProcs, Classes, Graphics;

const
eotBlinkOff=-1; eotCancel=0; eotGray=1; eotBlinkOn=2; eotBackToNego=3;

type
  TEOTButton = class(TButtonBase)
    constructor Create(aOwner: TComponent); override;
    destructor Destroy; override;
    procedure SetButtonIndexFast(x: integer);
    procedure SetBack(ca: TCanvas; x,y: integer);
  private
    FTemplate: TBitmap;
    FIndex: integer;
    procedure SetIndex(x: integer);
  public
    property Template: TBitmap read FTemplate write FTemplate;
  published
    property Visible;
    property ButtonIndex: integer read FIndex write SetIndex;
    property OnClick;
  protected
    Buffer, Back: TBitmap;
    procedure Paint; override;
  end;

procedure Register;

implementation

procedure Register;
begin
RegisterComponents('Samples', [TEOTButton]);
end;

procedure ImageOp_CBC(Dst,Src: TBitmap; xDst,yDst,xSrc,ySrc,w,h,Color0,Color2: integer);
// Src is template
// B channel = Color0 amp
// G channel = background amp (old Dst content), 128=original brightness
// R channel = Color2 amp
type
TLine=array[0..9999,0..2] of Byte;
var
ix,iy,amp0,amp1,trans,Value: integer;
SrcLine,DstLine: ^TLine;
begin
for iy:=0 to h-1 do
  begin
  SrcLine:=Src.ScanLine[ySrc+iy];
  DstLine:=Dst.ScanLine[yDst+iy];
  for ix:=0 to w-1 do
    begin
    trans:=SrcLine[xSrc+ix,0]*2; // green channel = transparency
    amp0:=SrcLine[xSrc+ix,1]*2;
    amp1:=SrcLine[xSrc+ix,2]*2;
    if trans<>$FF then
      begin
      Value:=(DstLine[xDst+ix][0]*trans+(Color2 shr 16 and $FF)*amp1+(Color0 shr 16 and $FF)*amp0) div $FF;
      if Value<256 then
        DstLine[xDst+ix][0]:=Value
      else DstLine[xDst+ix][0]:=255;
      Value:=(DstLine[xDst+ix][1]*trans+(Color2 shr 8 and $FF)*amp1+(Color0 shr 8 and $FF)*amp0) div $FF;
      if Value<256 then
        DstLine[xDst+ix][1]:=Value
      else DstLine[xDst+ix][1]:=255;
      Value:=(DstLine[xDst+ix][2]*trans+(Color2 and $FF)*amp1+(Color0 and $FF)*amp0) div $FF;
      if Value<256 then
        DstLine[xDst+ix][2]:=Value
      else DstLine[xDst+ix][2]:=255;
      end
    end
  end;
end;

constructor TEOTButton.Create;
begin
inherited Create(aOwner);
Buffer:=TBitmap.Create;
Buffer.PixelFormat:=pf24bit;
Buffer.Width:=48;
Buffer.Height:=48;
Back:=TBitmap.Create;
Back.PixelFormat:=pf24bit;
Back.Width:=48;
Back.Height:=48;
ShowHint:=true;
SetBounds(0,0,48,48);
end;

destructor TEOTButton.Destroy;
begin
Buffer.Free;
Back.Free;
inherited Destroy;
end;

procedure TEOTButton.Paint;
begin
with Canvas do
  if FGraphic<>nil then
    begin
    BitBlt(Buffer.Canvas.Handle,0,0,48,48,Back.Canvas.Handle,0,0,SRCCOPY);
    ImageOp_CBC(Buffer, Template, 0, 0, 133, 149+48*byte(FDown), 48, 48, $000000, $FFFFFF);
    if FIndex>=0 then
      ImageOp_CBC(Buffer, Template, 8, 8, 1+32*byte(FIndex), 246, 32, 32, $000000, $FFFFFF);
    BitBlt(Canvas.Handle,0,0,48,48,Buffer.Canvas.Handle,0,0,SRCCOPY);
    end
  else begin Brush.Color:=$0000FF; FrameRect(Rect(0,0,48,48)) end
end;

procedure TEOTButton.SetIndex(x: integer);
begin
if x<>FIndex then
  begin
  FIndex:=x;
  Invalidate
  end
end;

procedure TEOTButton.SetButtonIndexFast(x: integer);
begin
if Visible and (x<>FIndex) then
  begin
  FIndex:=x;
  try
    Paint
  except
    end
  end
end;

procedure TEOTButton.SetBack(ca: TCanvas; x,y: integer);
begin
BitBlt(Back.Canvas.Handle,0,0,48,48,ca.Handle,x,y,SRCCOPY);
end;

end.