unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls;

type
  TForm2 = class(TForm)
    PaintBox1: TPaintBox;
    Timer1: TTimer;
    Label1: TLabel;
    Label2: TLabel;
    Label3: TLabel;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure PaintBox1Paint(Sender: TObject);
  private
    { Private declarations }
    BitmapRect:TRect;
    PositiveMasks:array of TBrush;  //正畫刷
    NegativeMasks:array of TBrush;  //負畫刷
    SolidBlackBrush:TBrush;
    FadeBitmap:TBitmap;
    WorkSpaceBitmap:TBitmap;
    Progress:integer;
    Procedure ProcessFadeFromBlackStep; //淡出

  public
    { Public declarations }
  end;

var
  Form2: TForm2;
const
  BRUSHCOUNT:integer=11;
implementation

{$R *.DFM}

procedure TForm2.FormCreate(Sender: TObject);
var
i,j:integer;
BrushRect:TRect;
begin
  BrushRect.left := 0;
  BrushRect.top := 0;
  BrushRect.right := 8;
  BrushRect.bottom := 8;
  setLength(PositiveMasks,BRUSHCOUNT);
  setLength(NegativeMasks,BRUSHCOUNT);
  for j:=0 to BRUSHCOUNT-1 do
  begin
    PositiveMasks[j] := TBrush.Create;
    NegativeMasks[j] := TBrush.Create;
    PositiveMasks[j].Bitmap := TBitmap.Create;
    NegativeMasks[j].Bitmap := TBitmap.Create;
    PositiveMasks[j].Bitmap.Width := 8;
    PositiveMasks[j].Bitmap.Height:= 8;
    Randomize();
    for i:=0 to 8*j-1 do
    begin
       PositiveMasks[j].Bitmap.Canvas.
              Pixels[random(8),random(8)]:=clBlack;
       NegativeMasks[j].Bitmap.Assign(PositiveMasks[j].Bitmap);
       NegativeMasks[j].Bitmap.Canvas.CopyMode:=cmNotSrcCopy;
       NegativeMasks[j].Bitmap.Canvas.Draw(0,0,PositiveMasks[j].Bitmap);
//       InvertRect(NegativeMasks[j].Bitmap.Canvas.Handle, BrushRect);
    end;
    SolidBlackBrush := TBrush.Create;
    SolidBlackBrush.Style := bsSolid;
    SolidBlackBrush.Color := clBlack;
    FadeBitmap      := TBitmap.Create;
    WorkSpaceBitmap := TBitmap.Create;

    Progress := 0;
    FadeBitmap.LoadFromFile('huarongdao.bmp');
    WorkSpaceBitmap.Width  := FadeBitmap.Width;
    WorkSpaceBitmap.Height := FadeBitmap.Height;
    WorkSpaceBitmap.Canvas.Draw(0,0,FadeBitmap);

    BitmapRect := Rect(0,0,FadeBitmap.Width,FadeBitmap.Height);
  end;
end;

procedure TForm2.FormDestroy(Sender: TObject);
var
j:integer;
begin
   for j:=0 to BRUSHCOUNT-1 do
   begin
      PositiveMasks[j].Bitmap.Free;
      NegativeMasks[j].Bitmap.Free;
      PositiveMasks[j].Free;
      NegativeMasks[j].Free;
   end;
   SolidBlackBrush.Free;
   FadeBitmap.Free;
   WorkSpaceBitmap.Free;

end;

procedure TForm2.Timer1Timer(Sender: TObject);
begin
   ProcessFadeFromBlackStep;
end;

procedure TForm2.Button1Click(Sender: TObject);
begin
   Close; //關閉Form2,進入Form1
end;

Procedure TForm2.ProcessFadeFromBlackStep;
begin
   if (Progress = BRUSHCOUNT) then
   begin
      Progress := 0;
      Timer1.Enabled := false;
      WorkSpaceBitmap.Canvas.CopyMode:=cmSrcCopy;
      WorkSpaceBitmap.Canvas.Draw(0,0,FadeBitmap);
   end
   else
   begin
      WorkSpaceBitmap.Canvas.Brush := NegativeMasks[Progress];
      WorkSpaceBitmap.Canvas.CopyMode:=cmMergeCopy;
      WorkSpaceBitmap.Canvas.Draw(0,0,FadeBitmap);
      Progress:=Progress+1;
   end;
   PaintBox1.Canvas.Draw(0,0,WorkSpaceBitmap);

end;
procedure TForm2.PaintBox1Paint(Sender: TObject);
begin
   PaintBox1.Canvas.Draw(0,0,WorkSpaceBitmap);
end;

end.