Delphi 与 DirectX 之 DelphiX(19): 绘图表面(TDirectDrawSurface)如何加载图片

上个例子中 TDirectDrawSurface 是从 TDXImageList 中获取的图片,
其实 TDirectDrawSurface 自己获取图片的方法有很多:

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TDirectDrawSurface.LoadFromFile();

TDirectDrawSurface.LoadFromStream();

TDirectDrawSurface.LoadFromGraphic();

TDirectDrawSurface.LoadFromGraphicRect();

TDirectDrawSurface.LoadFromDIB();

TDirectDrawSurface.LoadFromDIBRect();

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本例分别测试了它们, 运行效果图:

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代码文件:

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unit Unit1;



interface



uses

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

  Dialogs, DXDraws, StdCtrls, DIB;



type

  TForm1 = class(TForm)

    DXDraw1: TDXDraw;

    Button1: TButton;

    Button2: TButton;

    Button3: TButton;

    Button4: TButton;

    Button5: TButton;

    Button6: TButton;

    procedure Button1Click(Sender: TObject);

    procedure Button2Click(Sender: TObject);

    procedure Button3Click(Sender: TObject);

    procedure Button4Click(Sender: TObject);

    procedure Button5Click(Sender: TObject);

    procedure Button6Click(Sender: TObject);

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



const

  ImgPath1 = 'C:\Temp\DelphiX.bmp';



procedure TForm1.Button1Click(Sender: TObject);

var

  MySurface: TDirectDrawSurface;

begin

  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);



  MySurface.LoadFromFile(ImgPath1);



  DXDraw1.Surface.Fill($EEEEEE);

  DXDraw1.Surface.Draw(0, 0, MySurface);

  DXDraw1.Flip;

  FreeAndNil(MySurface);

end;



procedure TForm1.Button2Click(Sender: TObject);

var

  MySurface: TDirectDrawSurface;

  stream: TMemoryStream;

begin

  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);



  stream := TMemoryStream.Create;

  stream.LoadFromFile(ImgPath1);



  MySurface.LoadFromStream(stream);



  DXDraw1.Surface.Fill($CCCCCC);

  DXDraw1.Surface.Draw(0, 0, MySurface);

  DXDraw1.Flip;



  FreeAndNil(stream);

  FreeAndNil(MySurface);

end;



procedure TForm1.Button3Click(Sender: TObject);

var

  MySurface: TDirectDrawSurface;

  bit: TGraphic;

begin

  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);



  bit := TBitmap.Create;

  bit.LoadFromFile(ImgPath1);



  MySurface.LoadFromGraphic(bit);



  DXDraw1.Surface.Fill($999999);

  DXDraw1.Surface.Draw(0, 0, MySurface);

  DXDraw1.Flip;



  FreeAndNil(bit);

  FreeAndNil(MySurface);

end;



procedure TForm1.Button4Click(Sender: TObject);

var

  MySurface: TDirectDrawSurface;

  bit: TBitmap;

begin

  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);



  bit := TBitmap.Create;

  bit.LoadFromFile(ImgPath1);



  MySurface.LoadFromGraphicRect(bit,

                                bit.Width div 2, bit.Height div 2,

                                Rect(0, 0, bit.Width, bit.Height));



  DXDraw1.Surface.Fill($666666);

  DXDraw1.Surface.Draw(0, 0, MySurface);

  DXDraw1.Flip;



  FreeAndNil(bit);

  FreeAndNil(MySurface);

end;



{使用 TDIB 需要 uses DIB 单元}

procedure TForm1.Button5Click(Sender: TObject);

var

  MySurface: TDirectDrawSurface;

  dib: TDIB;

begin

  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);



  dib := TDIB.Create;

  dib.LoadFromFile(ImgPath1);



  MySurface.LoadFromDIB(dib);



  DXDraw1.Surface.Fill($333333);

  DXDraw1.Surface.Draw(0, 0, MySurface);

  DXDraw1.Flip;



  FreeAndNil(dib);

  FreeAndNil(MySurface);

end;



procedure TForm1.Button6Click(Sender: TObject);

var

  MySurface: TDirectDrawSurface;

  dib: TDIB;

begin

  MySurface := TDirectDrawSurface.Create(DXDraw1.DDraw);



  dib := TDIB.Create;

  dib.LoadFromFile(ImgPath1);



  MySurface.LoadFromDIBRect(dib,

                            DXDraw1.Width, DXDraw1.Height,

                            Rect(0, 0, dib.Width, dib.Height));



  DXDraw1.Surface.Fill(0);

  DXDraw1.Surface.Draw(0, 0, MySurface);

  DXDraw1.Flip;



  FreeAndNil(dib);

  FreeAndNil(MySurface);

end;



end.