Delphi 与 DirectX 之 DelphiX(11): TPictureCollectionItem.DrawAdd、DrawSub

本例效果图:

---

代码文件:

---

unit Unit1;



interface



uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, DXDraws, StdCtrls, DXClass;



type

  TForm1 = class(TForm)

    DXDraw1: TDXDraw;

    DXImageList1: TDXImageList;

    Button1: TButton;

    Button2: TButton;

    procedure FormCreate(Sender: TObject);

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



var

  pic1,pic2: TPictureCollectionItem;



procedure TForm1.FormCreate(Sender: TObject);

const

  ImgPath1 = 'C:\Temp\Back.jpg';

  ImgPath2 = 'C:\Temp\DelphiX.bmp';

begin

  DXImageList1.DXDraw := DXDraw1;

  pic1 := TPictureCollectionItem(DXImageList1.Items.Add);

  pic1.Picture.LoadFromFile(ImgPath1);

  pic2 := TPictureCollectionItem(DXImageList1.Items.Add);

  pic2.Picture.LoadFromFile(ImgPath2);

end;



procedure TForm1.Button1Click(Sender: TObject);

var

  r: TRect;

begin

  r := Bounds((DXDraw1.Width - pic2.Width) div 2,

              (DXDraw1.Height - pic2.Height),

               pic2.Width,

               pic2.Height);



  DXDraw1.Surface.Fill(0);

  pic1.StretchDraw(DXDraw1.Surface, DXDraw1.ClientRect, 0);

  pic2.DrawAdd(DXDraw1.Surface, r, 0);

  DXDraw1.Flip;

end;



procedure TForm1.Button2Click(Sender: TObject);

var

  r: TRect;

begin

  r := Bounds((DXDraw1.Width - pic2.Width) div 2,

              (DXDraw1.Height - pic2.Height),

               pic2.Width,

               pic2.Height);



  DXDraw1.Surface.Fill(0);

  pic1.StretchDraw(DXDraw1.Surface, DXDraw1.ClientRect, 0);

  pic2.DrawSub(DXDraw1.Surface, r, 0);

  DXDraw1.Flip;

end;



end.